United States       Robert S. Kerr          EPA-600/2-89-011
            Environmental Protection  Environmental Research Laboratory
            Agency         Ada, OK 74820          March 1989

            Research and Development
$EPA     Treatability Potential for
            EPA Listed Hazardous
            Wastes in Soils

                                 ~-\ —.
                                • W £*5'?ff l/£p.

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                                                    PB89-166581

                                                    EPA/600/2-89/011
                                                    March 1989
  TREATABILITY  POTENTIAL FOR EPA  LISTED
         HAZARDOUS WASTES IN  SOIL
                        by
                  Raymond C. Loehr
           Environmental Engineering Program
             The University of Texas at Austin
                 Austin, Texas 78712
                Project  CR-812819
                    Project Officer

                   Scott G. Muling
        Extramural Activities and Assistance Division
      Robert S. Kerr Environmental Research Laboratory
                Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
       OFFICE OF RESEARCH AND DEVELOPMENT
       U.S. ENVIRONMENTAL PROTECTION AGENCY
               ADA, OKLAHOMA 74820
                                                   or THE

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                                  NOTICE
      The information in this document has been funded wholly or in part by the United
States Environmental Protection Agency under Cooperative Agreement CR-812819 to
The University of Texas at Austin.  It has been subjected to the Agency's peer and
administrative review, and  it has been approved for publication as an  EPA document.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.

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                                  FOREWORD

       EPA is charged by Congress to protect the Nation's land, air, and water systems.
 Under a mandate of national environmental laws focused on air and water quality, solid
 waste management and the control of toxic substances, pesticides, noise and radiation,
 the Agency strives to  formulate and implement actions which lead to a compatible
 balance between human activities and the  ability of natural  systems to support and
 nurture life.
       The Robert S. Kerr Environmental  Research Laboratory is the Agency's center
 of expertise for investigation of the soil and subsurface environment.  Personnel at the
 Laboratory are responsible for management of research programs to: (a) determine the
 fate, transport and transformation rates of pollutants in the soil, the  unsaturated and the
 saturated  zones of the subsurface environment; (b)  define the processes to be  used
 in characterizing the  soil  and subsurface  environment as a receptor of  pollutants; (c)
 develop techniques for predicting the effect of pollutants on groundwater, soil, and
 indigenous organisms;  and (d) define and demonstrate the applicability and limitations
 of using natural processes, indigenous to the soil and subsurface environment, for the
 protection of this resource.
      Soil treatment  systems that are designed and  managed based on a knowledge
of soil-waste interactions may represent a significant technology  for  simultaneous
treatment  and  ultimate disposal of selected hazardous  wastes in an  environmentally
 acceptable manner. Decisions pertaining to which wastes and chemicals are amenable
                                       in

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to this technology must take into account:  (1) the long-term  uncertainties associated
with the land disposal option; (2)  the goal of managing hazardous wastes  in an
appropriate  manner;  and (3)  the  persistence,  toxicity,  mobility,  and propensity to
bioaccumulate hazardous wastes and their hazardous constituents.  There is currently
a lack of scientifically derived fate and transport  information for  the wide range of
hazardous chemicals  for which such decisions can  be made.   This  report presents
information pertaining  to the quantitative evaluation of the treatment potential in soil of
specific  listed  hazardous  organic  chemicals  as identified  by the United  States
Environmental Protection Agency (EPA), and waste sludge from explosives production
and its related chemicals.
                                                 Clinton W. Hall
                                                 Director
                                                 Robert S. Kerr Environmental
                                                   Research Laboratory
                                        IV

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                             ABSTRACT

      This  study developed  comprehensive screening data on the
treatability  in  soil   of:   (a)  specific  listed'  hazardous  organic
chemicals,  and  (b) waste  sludge from  explosives production (KO44)
and  related  chemicals.    Laboratory  experiments  were  conducted
using  two soil  types,  an  acidic  soil  (Mississippi  soil)  with  less than
one percent  organic  matter,  and  a  slightly  basic  sandy  loam soil
(Texas soil)  containing 3.25% organic matter.   These experiments
evaluated  the:  (a) relative  toxicity of  the chemicals  and waste  using
the Microtox® bioassay method, (b) degradation of the chemicals and waste in
the soils, (c) adsorption characteristics of the chemicals in the two soils, and (d)
toxicity reduction that occurred during degradation.
      The major conclusions were:
   1. The chemical structure of the compounds evaluated affected their relative
      toxicity.   With  chlorophenols,  the  relative toxicity was related  to the
      position of the chlorine group on the phenol ring.  The order of relative
      toxicity was para>meta>ortho. The same order  appeared to occur for
      methylphenols and nitrophenols.   The  chemical substituted on the
      phenol ring appeared to have an  effect  on toxicity.  Nitro-substituted
      phenols appeared to be less toxic than the methyl- or chloro-substituted
      phenols. Mixing of the chemicals with the  soils did not affect the relative
      toxicity of the chemicals in the two soils.
   2. Data characterizing the chemical loss in the soil and in the water soluble
      fraction (WSF) extracted from the soil as well as the toxicity reduction in
      the WSF could be represented satisfactorily by either first or zero order

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   kinetics.   In most cases, the data were represented by either kinetic
   parameter with high correlation coefficients.
3. The rates of chemical loss were  higher in the Texas soil. Chlorophenols
   with chlorine substituted in the meta position had greater half-lives and
   lower loss rates. Chemicals with a nitro group substituted in the phenol
   ring appeared to have a lower loss rate.
4. The  Freundlich equation described the  adsorption  of most  of the
   chemicals with the two soils satisfactorily.  The values of the Freundlich
   constant (Kf) for the chemicals in the two soils were different.  For the acid
   extractables, the Kf values generally were greater in the  Mississippi soil.
   For the amines and alcohols, the Kf values were greater in the Texas soil.
5. The loss of the applied chemical in the soil and in the WSFas well as
   the reduction  of the  WSF  toxicity were  compared for nine  of the
   chemicals. The chemical loss in the WSF was about 1.5 times faster than
   the chemical loss in the  soil.  The WSF toxicity decreased at about the
   same  rate  as the WSF  chemical  concentration.   No  enhanced
   mobilization  of the applied chemical occurred during degradation.
                            VI

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                          CONTENTS

           SECTION                                      PAGE

 NOTICE	ii

 FOREWARD	iii

 ABSTRACT	 v

 FIGURES	x

 TABLES	xi

 ACKNOWLEDGEMENTS	xiv
 SECTION 1. INTRODUCTION	1
   Scope of Study	„	1
   Designated Chemicals and Waste	2

 SECTION 2. CONCLUSIONS	5
   A. Chemical Toxicity	5
   B. Degradation Studies	6
   C. Adsorption Studies	6
   D. Toxicity Reduction	7
   E. Munitions Chemicals and Wastes	8

 SECTION 3. GENERAL MATERIALS AND METHODS	8
   Chemicals	9
   Soil	9
   Instrumentation	11
      Gas Chromatography	11
      High Pressure Liquid Chromatography	13
   QA/QC Procedures	13
   Toxicity	13

SECTION 4. RELATIVE TOXICITY AND CHEMICAL LOADING	14
   Objectives	14
   Background	14
      Microtox	15
      EC5Q Evaluation	16
   Acceptable  Loadings	19
   Conclusions	27

SECTION 5. DEGRADATION STUDIES	29
   Introduction	29
   Materials and Methods	31
   Data Analysis	33
                          VII

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                     CONTENTS,  Continued

           SECTION                                         PAGE

   Results	37
      Recovery Efficiency	37
      Kinetic Parameters	37
   Conclusions	46

SECTION 6. ADSORPTION EXPERIMENTS	49
   Introduction	49
      Adsorption Equilibria	50
      Soil Organic Carbon	51
      Soil pH	52
   Materials and Methods	54
      Adsorption Method	54
      Stock Solutions	54
      Standard Solutions	54
      Soil Moisture	56
      Soil:Solution Ratio	;	56
      Solute Stability	58
      Other Factors	58
      Data Analysis	59
   Results	60
   Conclusions	67

SECTION 7. TOXICITY REDUCTION	69
   Approach	69
   Results	70
      Chemical Loss in Soil	70
      WSF Chemical Loss	72
      WSF Toxicity Reduction	76
      Comparison of Chemical Losses and Toxicity Reduction	76
   Conclusions	81

SECTION 8. MUNITONS WASTES AND CHEMICALS	82
   Relative Toxicity and Loading Evaluation	82
   Adsorption	83
      Methods	83
      Results	84
   Degradation Studies	87
   Munitions Wastewater Treatment Sludge	87
      Nitrogen  and COD	87
      Metals	91
      GC/MS Analysis	91
      Relative Toxicity	91
   Conclusions	95

SECTION 9. REFERENCES	97
                           VIII

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                   CONTENTS,  Continued

           SECTION                                       PAGE

APPENDIX A. THE MICROTOX© TOXICITY ASSAY USED
   IN THIS STUDY	101
   Introduction	101
   Evaluation of Chemical Loss Using Microcosms	101
   Water Extraction of Microcosms	101
   Toxicity Assay	102
   EC5Q Determination	102
   Assay Procedure	102
   Chemical Loading on Soil	103
   Microtox© Analysis	104

APPENDIX B. QUALITY CONTROL/QUALITY ASSURANCE
   PROCEDURES	107
   Toxicity	107
   Degradation Studies	107
   Adsorption Studies	109
   QA/QC For Analytical Instruments	111

APPENDIX C. VOLATILIZATION ESTIMATES	114

APPENDIX D. PUBLICATIONS	117
                          IX

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                              FIGURES
  NUMBER                                                       PAGE
 1.   Schematic of the Phenol Ring and Possible Substitution Positions	18
 2.   Loss of Phenol in Texas Soil at 20° C	42
 3.   Loss of Phenol in Mississippi Soil at 20° C	42
 4.   Loss of 2,6-Dichlorophenol in Texas Soil at 20° C	43
 5.   Loss of 2,6-Dichlorophenol in Mississippi Soil at 20° C	43
 6.   Adsorption of 2,3-Dichlorophenol and Toluenediamine in Texas
     Soil at 20° C	61
 7.   Adsorption of 2,3-Dichlorophenol and Toluenediamine in Mississippi
     Soil at 20° C	62
 8.   Loss of Chemical in Two Experiments When the Higher Loading Rates
     Were Used	74
 9.   Loss of Chemical in the WSF at Two Loading Rates	75
 10.  Toxicity Reduction in the WSF from the Soil Microcosms	78
 11.  Comparison of Chemical Loss in  the Soil and the WSF for Phenol and
     Eight Chlorophenols	79
 12.  Decrease of Soil and WSF Chemical Concentration and  of WSF
     Toxicity as a Function of Time-Degradation Study of
     2,4-Dichlorophenol	80
 13.  Comparison of the WSF Chemical Loss and the WSF Toxicity Reduction
     For Phenol and Eight Chlorophenols	80
 14.  Loss of 2,6-Dinitrotoluene in Texas and Mississippi soils at 20° C	89
 15.  Wastewater Treatment Process Flow Diagram for the Holston Army
     Ammunition Plant	90
B-1.  Representative Recovery Data for Phenol in Texas Soil	110
B-2.  Representative Recovery Data for o-Cresol in Texas Soil	110
B-3.  Representative Recovery Data for 2,4-Dichlorophenol in  Texas Soil	111

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                               TABLES
  NUMBER                                                        PAGE
 1.   Chemicals That Were Evaluated in This Study	3
 2.   The Hazardous Waste and Related Chemicals That Were Evaluated	4
 3.   Characteristics of Soils Used in This Study	10
 4.   Operating Conditions for the Gas Chromatographic Analysis
     of Compounds in Methylene Chloride	12
 5.   EC5Q for Chemicals Evaluated in This Study	17
 6.   Relative Toxicity of Chlorinated Phenols	20
 7.   Relative Toxicity of Non-Chlorinated Phenols	20
 8.   Comparative Relative toxicity of Chloro-, Methyl,
     and Nitrophenols	22
 9.   Method to Determine Acceptable Initial Chemical Loadings	22
 10.  Acceptable Non-Inhibitory Loading Rates -- Texas Soil	23
 11.  Acceptable Non-Inhibitory Loading Rates -- Mississippi Soil	24
 12.  Comparative Acceptable Loading Rates -- Chlorinated Phenols	25
 13.  Experimental Procedures Used in the Degradation Studies	33
 14.  Chemicals Whose Soil Concentration Was Evaluated
     Using Shake Extraction	34
 15.  Shake Extraction Procedure	34
16.  Recovery Efficiencies for Specific Chemicals (%)	38
17.  Acceptable and Actual Loading Rates Used in the Degradation
     Studies (mg/kg of Soil)	39
18.  Loss Rates, Correlation Coefficients and 95% Confidence
     Intervals for Specific Chemicals -- Texas Soil	40
19.  Loss Rates, Correlation Coefficients and 95%
     Confidence Intervals for Specific Chemicals
     --Mississippi Soil	41
                              XI

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                        TABLES,  Continued
  NUMBER                              .                          PAGE

 20.  Chemical Half-Lives in Texas and Mississippi Soils (days)	45
 21.  Effect of Substitution Position on Degradation Rates --
     Chlorinated Phenols	47
 22.  Effect of Substitution Position on Degradation Rates --
     Non-Chlorinated  Phenols	47
 23.  Comparative Degradation Rates of Chloro-, Methyl- and Nitrophenols....48
 24.  Procedure for Determining Solubility Limit of an Organic Compound
     In Water	55
 25.  List of Maximum Solubilities (20° C) in Water Determined as Part of the
     Adsorption Studies	55
 26.  Procedure for Measuring Soil Moisture Content.	56
 27.  Procedure for Determination of Optimum SoikSolution Ratio	57
 28.  Batch Sorption Isotherm Data - Texas Soil -- Freundlich Equation
     Parameters	63
 29.  Batch Sorption Isotherm Data -- Mississippi Soil -- Freundlich Equation
     Parameters	64
 30.  Chemical Concentration Range Evaluated During the Batch Adsorption
     Experiments -- Texas Soil	65
 31.  Chemical Concentration Range Evaluated During the Batch Adsorption
     Experiments -- Mississippi Soil	66
32.  Comparison of Freundlich Adsorption Coefficients (Kf) for the Texas and
     Mississippi Soils	68
33.  Chemical Loss in  Soil -- Kinetic Parameters	71
34.  Loss of Water Extractable Chemical -- Kinetic Parameters	73
35.  WSF Toxicity Reduction -- Kinetic Parameters	77
36.  ECso Data and Acceptable Loading Rates for Munitions Manufacturing
     Chemicals	83
                              XI I

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                        TABLES, Continued
  NUMBER                                                       PAGE

37.  Chemical Concentration Range Evaluated During the Batch
     Adsorption Experiments - Munitions Chemicals	85
38.  Freundlich Isotherm Data - Texas and Mississippi Soils -- 2,4- and
     2,6-Dinitrotoluene	85
39.  Adsorption Data for TNT, HMX and RDX in Texas Soil at 20° C	86
40.  Adsorption Data for TNT, HMX and RDX in Mississippi
     Soil at 20° C	86
41.  Loading Rate and Recovery Efficiency Data from the Munitions
     Chemical Degradation Studies	88
42.  Chemical  Loss Rate Data for 2,6-Dinitrotoluene and TNT in the
     Degradation Studies	88
43.  Nitrogen and COD Concentrations of Munitions Waste Sludge	91
44.  Metals in Munitions Sludge and Sludge Filtrate	92
45.  GC/MS Analysis of Munitions Sludge	93
46.  Munitions Waste Toxicity Data -- Undiluted Samples	95
B-1.  Accuracy Data:  Recovery Efficiencies (%) for Specific Chemicals
     As Determined From Day Zero Degradation Study Experiments	108
B-2.  Precision Analysis Data: Texas Soil Sorption Data	112
C-1.  Loss of Methanol and 1-Butanol in Volatilization Experiments	115
                            XIII

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                       ACKNOWLEDGEMENTS

This report represents the hard work and dedication of the undergraduate
students, graduate students, staff and faculty who assisted in this project. The
contribution of the following individuals deserves specific recognition and is
greatly appreciated:

      Barnes Bierck                       Michael McFarland
      Srinivasa Dasappa                  Joseph F. Malina, Jr.
      Carol English                       Wan Nam-Koong
      David Erickson                      Lynn Sanders
      Lisa Gilmour-Stallsworth             Karen Spaniel
      Nadine Gordon                      John Stephenson
      Frank Hulsey                        Eric White
      R. Krishnamoorthy                  Chun Yoon

      We also appreciate the assistance of the EPA-RSKERL project officers,
Mr. John E. Matthews and Mr. Scott G. Huling, who had responsibility for the
project throughout its duration.
                             XIV

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                                SECTION  1
                              INTRODUCTION

SCOPE  OF  STUDY
      This study  was designed to provide comprehensive  screening data on the
treatability in soil of: (a)  EPA listed hazardous organic chemicals, and (b) a specific
hazardous waste and related chemicals. The results of the study provide data that can
be used when permitting decisions are made related to: (a) management of spills, (b)
remediation of contaminated soils, and (c) the use of land as a waste management
alternative. The degradation and partitioning data can be used as input to predictive
models that estimate the movement of chemicals in the unsaturated zone of the soil.
Examples of such  models include RiTZ (Regulatory and Investigative Treatment Zone
Model)(1-2), VIP (Vadose Zone Interactive Processes Model)(3» 4),  and KOPT
(Kinematic Oily Pollutant Transport Model^).
      These models were developed to understand the treatment potential of organic
chemicals in soil.  The models integrate the processes that  affect chemicals in soil
(degradation and partitioning) so that an  assessment can be made of the extent to
which protection of human health and the environment occurs. The understanding
that results from the use of such models allows the identification of chemicals and
wastes that require control to reduce or eliminate  their hazard potential prior to
application to soil.
      Laboratory studies were  conducted to determine: (a) degradation kinetics, (b)
sorption,  (c) toxicity of the chemicals and waste, and (d) the reduction in toxicity that
occurs during degradation. The results of these studies are discussed in subsequent
sections.

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DESIGNATED  CHEMICALS  AND  WASTES
      The chemicals and specific waste that were part of this study are identified as
hazardous wastes under CFR Sections 261.32 and 261.33.  These chemicals can be
expected to be components of many industrial compounds and wastes that enter the
soil from spills and inadequately sealed impoundments (pits, ponds and lagoons) and
as part of wastes applied to operating land treatment units.
      The chemicals that were evaluated are identified in Table 1.  The specific
hazardous waste, and chemicals related to that waste, that were evaluated are noted
in Table  2.
      Samples of the explosives waste sludge (KO44) and the chemicals TNT, RDX,
and HMX were obtained with the help of the U.S. Army Toxic and Hazardous Materials
Agency (USATHAMA). A sample of wastewater treatment sludge resulting from the
manufacture and processing of explosives was  obtained from the Holston Army
Ammunition Plant with the assistance of USATHAMA.  This material was stored at  4° C
until required for analysis and use.

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        TABLE  1.   CHEMICALS THAT WERE EVALUATED IN THIS STUDY

                                                            EPA  Hazardous
Compound _ Formula _ Waste Number
Acid  Extrtctabl»»
Phenol [[[ CgHgO ........................................... U188
o-Cresol [[[ CyHgO ........................................... U052
p-Cresol [[[ 07830 ........................................... U052
m-Cresol [[[ C?H8O ........................................... U052
2-Chtorophenol ......................................... CgH5CIO .......................................... U048
3-Chkjrophenol ......................................... CgH5CIO ........................................... NOS
4-Chloroph«nol ......................................... CgHgCIO ........................................... NOS
2.3-Dichtorophenol .................................... CgH4CI2O .......................................... NOS
2,4-Dichtorophenol .................................... C6H4CI2O ......................................... U08.1
2.5-Dichloroph9nol .................................... CgH4CI2O .......................................... NOS
2,6-Dichtorophenol .................................... CgH4CI2O ......................................... U082
3.4-Dichlorophenol .................................... CgH4CI2O .......................................... NOS
2.4.5-Trtehlorophenol ................................. CgH3CI3O ......................................... U230
2,4.6-Trfchlorophenol ................................. CgH3CI3O ......................................... U231
Pentachlorophenol .................................... CgHCI5O .......................................... U242
2,4-Dimethylphenol ..................................... C8H10° .......................................... U101
2-Methyl-4-Chlorophenol ............................. C7H7CIO ........................................... NOS
3-Methyl-4-Chlorophenol ............................. C7H?CIO .......................................... U039
3-Methyl-6-Chlorophenol ............................. C7H7CIO ........................................... NOS
p-Nitroph«nol ............................................ Cgh^NO-j ......................................... U170
2.4-Dinitrophenol ...................................... CgH4N2O5 ........................................ P048
4,6-Dinrtro-o-Cresol .................................. Cr^W^S ........................................ Po48
Thtophenol ............................... , ................ -CgHgS ........................................... U014
Diphenylamina .......................................... C^H^N ......................................... X016
m-Phenyl«nediamine ................................... C6H8N2 .......................................... *017
Tolu«nBdiamin« ....................................... C         ....................................... U221
Brucin« ................................................ C23  26N2°4
Alcohols
Isobutyl alcohol ......................................... C4H10° .......................................... U14°
Allyl  alcohol ................................................ C3H6O ........................................... POOS
Propargyl alcohol ........................................ C3H4O ........................................... P102
1-Butanol .................................................. C4H10° .......................................... Uo31
2,3-Dichloropropanol ................................... ^HgC^ .......................................... X006
Methanol [[[ CH4O ............................................ U154
Othir

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          TABLE 2.  THE HAZARDOUS WASTE  AND  RELATED  CHEMICALS
                             THAT WERE EVALUATED
Specific Hazardous Waste
     KO44 -  Wastewater treatment sludge from the manufacturing and processing of explosives
Explosive and Munitions Manufacturing Chemicals
                                                   EPA Hazardous
Compound
2,4-Dinitrotoluene
2,6-Dinitrotoluene
TNT (2,4.6-Trinitrotoluene)
RDX+
HMX++
Formula
C7H6N204
C7H6N204
C7H5N306
C3H6N606
C4H8N808
Waste Number
U105
U106
-
-
—
+     RDX - Hexahydrotrinitrotriazine
++    HMX- Cyctotetramethylenetetranitramine

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                                 SECTION 2
                              CONCLUSIONS

      The  major  results  were  the following:
A. CHEMICAL  TOXICITY
   1. The Microtox® biological assay represents an appropriate method with which
      to evaluate the EC$Q  toxicity of a chemical or waste.
   2. Comparison  of the £650 data indicated that: (a) the alcohols were less toxic
      than the acid extractable compounds, and (b) within chemical categories, there
      were considerable differences in relative toxicity.
   3. The chemical structure of the compounds evaluated affected the relative toxicity
      of a compound.  With chlorophenols,  the relative toxicity was  related to the
      substitution position of the  chlorine  group on the  phenol ring.  The order of
      relative toxicity was para>meta>ortho. The £650 data suggested that the same
      order occurred for methylphenols and nitrophenols.
   4. The chemical that was substituted on the phenol ring appeared to have an
      effect on toxicity.  Nitro-substituted phenols, even when substituted in the para
      position, appeared to be less toxic than the methyl- or chloro-  substituted
      phenols.
   5. When the chemicals were mixed with two different soils, and the  EC50 value of
      the water soluble fraction (WSF) of the soil mixtures was measured, the values
      also indicated that chemicals with the chlorine  in the para position had the
      greater toxicity.  Mixing of the chemicals with the soils did  not affect the relative
      toxicity  of the chemicals in the two soils.
   6. In general,  the  acceptable non-inhibitory  chemical  loading  rates for the
      Mississippi soil  were lower than those for the Texas soil.  There was no
      consistent pattern for the  differences.

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B. DEGRADATION  STUDIES
   7. The  chemical  or  waste  loading  procedure  (Table  9,  Section  4)
      resulted in  chemical loadings  that did not inhibit  the  non-acclimated
      organisms  in the  laboratory  microcosms,  except  in  one  case (4,6-
      Dinitro-o-Cresol).   This  procedure  provided  a  good  estimate  of
      initial, acceptable chemical loadings that can be  used  in laboratory
      degradation  studies.
   8. Both zero and  first  order kinetics  provided adequate representation
      of  the  data.   For most  of the  chemicals,  the  data could be fit  to
      either kinetics  with  high correlation coefficients.
   9. The rates of chemical loss were higher in  the Texas soil than in the
      Mississippi  soil.   There did   not appear to be  any  pattern  to the
      differences  in rates in  the two soils.
  10. Chlorophenols with  the chlorine  substituted  in the meta position had
      greater  half-lives  and  therefore lower  chemical  loss  rates.  This
      was  particularly evident with the  mono-, di-,  and  trichlorophenols
      in the Texas soil.
  11. Chemicals  that  had a  nitro  group  substituted  on  the phenol  ring
      appeared to have a lower loss rate.
C. ADSORPTION STUDIES
  12. The Freundlich equation described the adsorption of the chemicals on
      the  two soils   satisfactorily,  with  high  correlative  coefficients,
      except for a few chemicals.
  13. The range of chemical  concentrations evaluated  ranged  from  the low
      mg/l  concentrations to  near or at saturation concentrations,  and for
      most chemicals  covered two to three orders of magnitude.  For these

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      concentration ranges, a  linear adsorption relationship, i.e.,  n •  1, did
      not occur.
  14. The values of the Freundlich constant (Kf) for the chemicals in the two soils
      were different. For the acid extractables, the Kf values generally were greater in
      the Texas soil which had the higher pH and the greater organic carbon content.
      For the amines and alcohols, the Kf values were greater in the Mississippi soil,
      which had the lower pH and the lower organic carbon content.
D.    TOXICITY  REDUCTION
  15. Two  loading rates,  the Texas  soil,  and nine chemicals (phenol and eight
      chlorinated phenols)  were used in this study.  Both first  and zero order Kinetics
      satisfactorily fit the water soluble fraction (WSF) chemical loss data and the
      toxicity reduction data.
  16. The higher chemical  loading rates resulted in higher chemical concentrations in
      the WSF and higher WSF toxicities at the beginning of the experiments.
  17. The higher chemical loading rates generally resulted in slower chemical  losses
      (higher half lives) and slower toxicity reduction.  However, at both loading rates
      for each chemical, the chemicals were degraded and the toxicity was reduced.
      No differences due to the loading  rates were apparent in zero order kinetics.
  18. The loss of the chemicals in the WSF was about 1.5 times faster than the  loss of
      the chemical in the soil.
  19. The WSF toxicity for each  chemical  decreased  as the  soil chemical and the
      WSF chemical concentrations decreased.
  20. The WSF toxicity decreased at  about  the same rate  as the WSF chemical
      concentration when the data for all nine chemicals were compared.
  21. No  enhanced mobilization of  the applied  chemicals  occurred as  the
      degradation and detoxification occurred.

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 22.  No water soluble toxic products appeared to be formed as the chemicals were
      degraded in the soil.
E. MUNITIONS CHEMICALS  AND  WASTES
 23.  The Freundlich equation described the sorption of 2,4- and 2,6-Dinitrotoluene in
      the two soils satisfactorily. It did not do so for TNT, RDX, or HMX.
 24.  No loss of 2,4-Dinitrotoluene occurred  over a 47-day study even though the
      loading  rate  used was determined to be  acceptable using  procedures
      discussed in  Section  4.   Degradation  loss rates were  obtained for 2,6-
      Dinitrotoluene and TNT.  First order kinetics were a better representation  for
      TNT than were zero order kinetics.
 25.  The half life of TNT in the Mississippi soil was shorter, and the loss faster, than
      in the Texas  soil.  No  difference in the  loss rates in the two soils for 2,6-
      Dinitrotoluene was apparent.
 26.  The sludge resulting from  the  manufacture and  processing  of explosives
      contained: (a) high concentrations of nitrogen and COD,  (b) concentrations
      generally less than 10 mg/l for heavy metals, and (c) no TNT, RDX or HMX.
 27.  The munitions sludge had  a high toxicity  as measured by the Microtox®
      procedure.  The constituents causing the relative toxicity were  in the soluble
      phase of the sludge.
                                  8

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                                 SECTION  3
                  GENERAL  MATERIALS  AND METHODS

CHEMICALS
      The chemicals evaluated in this study were identified in Section 1.  To the
extent possible, analytical grade chemicals were  used in the experiments  and as
spikes and controls  in the analytical procedures.  The chemicals were purchased
either from Aldrich Chemicals or Sigma Chemicals.  Specific explosive and munitions
manufacturing chemicals were obtained from sources identified in Section 8.
SOILS
      The intent of this study was to provide comprehensive screening data  on the
treatability of specific chemicals  and a hazardous waste in soil. The characteristics of
the soil will affect the degradation, sorption, and treatment potential and two soils with
different characteristics were used. One was an acid soil with a low organic  content
and the other was a basic soil with a higher organic content and cation exchange
capacity (CEC).
      The acid soil was obtained from an area near Wiggins, Mississippi, and was
supplied  by researchers at Mississippi State University.  This soil is referred to as
Mississippi soil in this report. The characteristics of  this soil are presented in Table 3.
The analyses were conducted by staff at Mississippi  State University using appropriate
methods(6).
      The basic soil was obtained from an area  near Austin, Texas, that, to the
knowledge of the personnel of this project,  had  not  been  exposed to  industrial
chemicals or wastes. This soil is referred to as Texas soil.  The characteristics of the
soil are presented in Table 3.  The analyses were conducted by staff at the soil testing
and characterization laboratory, Texas A&M University, College Station, Texas.

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      Because independent laboratories provided separate analyses of the soils, the
data in Table 3 are not always directly  comparable.  However, the data provide
pertinent information on the important characteristics of the two soils.
      Both soils had initial microorganism counts that were typical for an agricultural
soil with an active microbial population.

          TABLE 3.  CHARACTERISTICS OF SOILS USED  IN THIS STUDY
Characteristic
Texture
Classification
pH
CEC(meq/100g)
Organic Carbon
Sodium
Potassium
Calcium
Magnesium
Hydrogen
Carbonate (CO3)
Bicarbonate (HCO3)
Sulfate
Chloride
Particle Size Fraction (%)
Sand
Silt
Clay
Moisture Content by Weight (%)
1/3 atmosphere
15 atmosphere
Mississippi
Soil
sandy loam
Typic Paleudults
4.8
6.35
0.94%
0.02 meq/100 g
0.07 meq/1 00 g
0.29 meq/100 g
0.06 meq/100 g
5.9 meq/100 g
-
-
-
-

68.0
23.4
8.6

12.4
8.2
Texas
Soil
sandy silt loam
Mollisal, Cumulic
7.8
10.8
3.25%
0.3 meq/L+
3.6 meq/L
9.5 meq/L
1 .3 meq/L
-
0.0 meq/L
7.2 meq/L
1 .9 meq/L
2.8 meq/L

61.5
31.1
7.4

17.0
6.2
+ -- Saturated paste extract
                                  10

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      After the soils were  received at the Environmental and Water Resources
Engineering Laboratory at The University of Texas, they were air dried, sieved and
stored at 4° C in the dark. Prior to each experiment, soil samples were taken for use,
the moisture content increased to near saturation, and the  indigenous organisms
allowed to establish equilibrium concentrations.
INSTRUMENTATION
      The principal analytical instruments used were the Microtox© analyzer, the gas
chromatograph (GC),  and the  high pressure liquid chromatograph (HPLC).  The
Microtox© unit, which was used for chemical toxicity evaluation, is discussed in detail
in Section 4. The following describes the operational procedures employed for the QC
and HPLC analyses.
Gas Chromatoqraphv
      Two types  of  gas  chromatographs were  used  to  quantify chemical
concentrations. The choice of GC depended on the volatility of the compound and the
solvent used with the compound.
      Compounds extracted in Methylene Chloride  were analyzed  by  capillary
column gas chromatography. The analytical procedure followed is outlined in EPA-
SW 846 (Method 8040)(7).  The method consisted of injection of a 1 jiL sample into
the gas chromatograph (Hewlett Packard Model 5890A) which was equipped with an
electronic  integrator (Hewlett Packard  Model 3392A), a methyl silicone  capillary
column, and a  flame ionization detector.  The chromatographic system was calibrated
using an internal standard technique each day.
      The operating conditions of the capillary  column gas  chromatograph are
presented in Table 4.  The initial temperature and temperature progress rate were
selected based on the  retention time of the test compound and the internal  standard.
The integrator  options  were  set to minimize  the tailing of the chromatographic peaks,
which affected  the peak area calculations. The initial temperature was between 30° C
                                11

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and  100° C  depending on  the  retention  time  of the compound, the temperature
progress rate was between  15° C and 30° C/minute, and the final temperature was
180° C. A two-minute final time was utilized at the termination of each run in order to
ensure that the column was clean.

 TABLE  4.  OPERATING  CONDITIONS  FOR  THE GAS  CHROMATOGRAPHIC  ANALYSIS
                   OF COMPOUNDS  IN METHYLENE CHLORIDE
      Condition
                                   Description
   Capillary Column
   Temperature  Initial
   Detector
   Carrier Gas
               Final
               Injection Port
               Detector
Hydrogen Gas Rate
Air Rate

Helium Rate
                    methyl silicone (dimensions: 5m length x 0.53 mm I.D. x
                    2.65 urn film thickness)
30° C-100° C at 0 minutes with progress rate
of 15-30° C per minute.
180° C at 2 minutes
200° C
250° C

Flame lonization
30 mL/minute
400 mL/minute

20 mL/minute
      Compounds extracted in either water or Methanol (e.g.,  alcohols) were
quantified on a packed column gas chromatograph (Tracer 550) equipped with a six-
foot column packed with 5% Carbowax 1500, 80/100 Carbopack K-C (Supeico, Inc.).
The GC was operated isothermally at 130° C with a flame ionization detector.   The
electronic output signal was converted to concentration units by interfacing the GC
with  an integrator (Spectraphysics Model  4290).  The GC was calibrated by the
internal standard technique outlined in Method 8040 (EPA-SW846)(7).
                                 12

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High Pressure Liquid Chromatographv
      Phenolic compounds contained in filtered water (i.e., as part of the sorption
study, Section 6) and the compounds of low volatility (Brucine, Thiourea, RDX, HMX
and TNT) were analyzed by high pressure liquid chromatography (HPLC).
      The HPLC (Waters Associates Model 440) was operated at room temperature
and  utilized a C-18 reversed phase column.  Aqueous solutions  (50 (J.L) of various
samples were eluted with 50:50:0.1 of acetonitrile:deionized distilled wateracetic acid
solution.  The UV absorption detector wavelength was 254 nm.  The, flow  rate and
chart speed  were  maintained  at 3.0 ml/min and 0.1  inch/min respectively.  The
attenuation varied from 0.01 to 2.0 depending on the  relative compound absorption at
254 nm. Duplicate samples were analyzed to ensure instrument accuracy.
      Standard solutions for each compound were run prior to sample analysis  for
external standard calibration. The peak height  on the chart paper for each  standard
solution was measured and linear regression analysis (Lotus 1-2-3, IBM/PC) used to
determine the relationship between peak height (cm) and concentration (mg/L).
Comparison of peak heights of samples to peak heights determined  for  standard
solutions allowed estimation of sample chemical concentrations.
QA/QC PROCEDURES
      Care was taken to assure that sound, representative data were obtained. The
specific quality assurance  and quality control procedures that were followed and
information on precision and accuracy are presented in Appendix B.
TOXICITY
      The relative toxicity of the chemicals and the specific waste as well as of the
water soluble fraction of soil-chemical mixtures was  measured  by the Microtox®
system.  Details of the system and how it was used are presented in Section 4.
                                13

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                                 SECTION  4
              RELATIVE TOXICITY AND CHEMICAL  LOADING

OBJECTIVES
      A  major objective of this study was to obtain information on the degradation
kinetics of these chemicals and specific waste in soil.  To do so, it was important that
the chemicals be in the soil in concentrations that would not be toxic or inhibitory to the
soil microorganisms.  Therefore, it was necessary to determine: (a) the relative toxicity
of the chemicals and specific waste prior to adding them to the soils, and (b) the mass
loading rates of the chemicals that would not be  inhibitory.
      The  relative toxicity tests that were conducted were not intended to provide
information  on toxicity from a  human hearth  or  safety or from  an environmental
standpoint.  Rather,  these tests were used as a relative toxicity  screening  method.
Such tests also can be used to identify the relative toxicity reduction that occurs when
chemicals and waste are managed by the land treatment process.
BACKGROUND
      The usual procedures to quantify toxicity of a chemical are toxicity assays which
measure  the effect of the chemical on a test species under specified test conditions.
The toxicity of a chemical is  proportional to  the severity of the chemical on  the
monitored response of the test organism(s).  Toxicity  assays utilize test species that
include rats, fish, invertebrates, microbes  and seeds.  The assays may use single or
multiple species  of test organisms.  The need to unequivocally measure the  effect of
the toxicant on the monitored activity has favored the use of a single specie as the test
organism in a toxicity assay.
      Toxicity assays using bacteria as the test organism are gaining popularity due
to their rapidity, ease in  handling, cost effectiveness and  the  use of  a statistically
significant number of test organisms^. 9).  The Microtox® assay is a microbial assay
                                 14

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used for toxicity measurement, hazard assessment, and quantitative-structure activity
relationship (QSAR) studies of environmental pollutants^"11).
      Although no single bioassay procedure can provide a comprehensive toxicity
evaluation of a chemical, a valid toxicity screening test can provide information about
the relative  toxicity of a compound and can  help  predict non-inhibitory  chemical
application rates.  The Microtox® system is  a relatively simple, rapid and inexpensive
test and was used as the toxicity screening method in this project.  The use of the
Microtox© procedure to screen and predict the treat ability potential of waste in soil has
been evaluated and found to be satisfactory(12-13).
Microtox®
      The Microtox® system is a standardized toxicity  test system which  utilizes
marine luminescent bacteria (Photobacterium phosphoreum) as indicator organisms.
Bio luminescence of this test organism depends on a complex chain of biochemical
reactions  involving  the  luciferin-luciferase system.  Chemical inhibition any of the
involved biochemical reactions causes a reduction in bacterial luminescence.  The
Microtox® toxicity assessment considers the physiological effect of a toxicant, and not
just mortality.
      The system utilizes an instrumental approach in which the indicator organisms
are handled  as chemical reagents.  Suspensions of about one million bioluminescent
organisms are "challenged" by addition of serial dilutions  of an aqueous sample. A
temperature  controlled photometric  device  quantifies  the  light output in each
suspension  before  and after sample addition.  Reduction of light output reflects
physiological inhibition which indicates presence of toxic constituents in the sample.
The small  sample volume required (-10 ml_) is a positive aspect of the system.
      The instrument  used in this project was  the Beckman Microtox® Model 2055
Toxicity Analyzer System.  Except for slight modifications, procedures indicated in the
                                 15

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Microtox© System Operating ManuaK14) were followed.  A summary of the procedure
that was used is included in Appendix A.
EC«;n Evaluation
      The ECso  is  the  concentration of a chemical that causes a 50% decrease of
light produced by luminescent bacteria in the Microtox® test. The method provides for
simultaneous testing of a control and dilutions of a chemical.  The  percent  light
decrease after 5 minutes is plotted against sample concentration.  The concentration
that diminishes the  light output by  50% is designated the ECso under the defined
conditions of exposure  time and test temperature.  When calculating ECso data,
responses  for  all  concentrations  are normalized against  blank responses by
multiplying the initial  light output of each  concentration by the mean blank ratio for  time
f.  This normalization corrects for effects of light drift and offsets in light output due to
dilution.  An explanation of  the analytical and calculation methods used to obtain
EC5Q data is presented in Appendix A.
       ECso evaluations for  the specific chemicals are presented in Table 5.  Results
for the munitions chemicals  and sludge are presented in Section 8.  These ECso
values represent values for the chemicals and sludge as a solution of the chemical
and of the as-received sludge. The values are not comparable to the £650 values that
might occur in  a soil-chemical or soil-sludge mixture. These £650 values are useful
as: (a) a relative screening evaluation for the chemicals to estimate which chemicals
have a greater toxicity potential, and (b) input to decisions about concentrations that
can be applied to soil that will be non-inhibitory to the soil microorganisms.
      In Table  5, the 95% confidence values (95% Cl)  of the  EC5Q values also are
presented.  The 95% Cl was  calculated  in a standard statistical manner.   Specific
details about the  procedure  are presented in Section 5. The  95% Cl  identifies the
                                 16

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                       TABLE 5.  EC5Q DATA  FOR CHEMICALS EVALUATED IN THIS STUDY
Compound
                               <50-
                                    Values lma/l)
Value
95% Cl
Acid Extractables

Phenol	26.7	25.4-28.1
o-Cresol	22.4	21.8-23.0
p-Cresol	1.1	1.07-1.16
m-Cresol	5.8	5.6-6.1
2-Chtorophenol	16.1	15.1-17.1
3-Chlorophenol	3.8	3.4-4.3
4-Chlorophenol	1.0	0.9-1.0
2,3-Dichlorophenol	4.8	4.7-5.0
2,4-Dichlorophenol	2.8	2.7-2.9
2,5-Dichloropnenol	8.2	7.8-8.6
2.6-Dichlorophenol	15.9	14.8-17.1
3,4-Dichlorophenol	0.5	0.4-0.5
2,4.5-Trichtorophenol	0.9	0.8-1.0
2,4.6-Trichlorophenol	9.3	8.6-10.1
Pentachlorophenol	1.1	1.1-1.2
2.4-Dimethylphenol	3.8	3.4-4.3
2-Methyl-4-Chtorophenol	1.1	1.06-1.14
3-Methyl-4-Chtorophenol	0.3	0.2-0.3
3-Methyl-6-Chtorophenol	5.8	5.7-6.0
p-Nitrophenol	7.0	6.7-7.3
2,4-Dinitrophenol	13.5	11.0-16.6
4,6-Diritro-o-Cresol	10.5	9.1-12.1
Thiophenol	2.8	2.6-3.1
Compound
                                                               «50-
                                                                    Values fma/n
Value
95% Cl
                               Amines

                               Diphenylarrine	2	1.9-2.1
                               m-Phenylenediamine	112	99-122
                               Toluenediamine	44	41-47
                               Brucine	213	197-230

                               Alcohols

                               Isobutyl alcohol	1740	1590-1920
                               AByl alcohol	1120	960-1320
                               Propargyl alcohol	106	99-115
                               1-Butanol	2400	2180-2640
                               2,3-Dichloropropanol	120	104-140
                               Methanol	>84.500	-
                               Other

                               Carbon bisulfide	30...
                               2-NHropropane	49...
                               Thiourea	4530.
                                                             	27-32
                                                             	41-59
                                                             .4050-5080

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range of values within which the estimated true mean  EC$Q value should occur with
the probability of error being 0.05.  The  relatively narrow 95% Cl values indicate the
low scatter of the data obtained.
      Low ECso values indicate  a higher toxicity potential  and the higher £650
values indicate a low toxicity.  In Table 5, the EC$Q data indicate that phenol (£650 -
26.7) has a lower toxicity potential than p-Cresol (EC$Q  = 1.1).
      The comparison of the EC$Q data (Tab|e 5) indicates that: (a) the alcohols are
less toxic than the acid extractables, and (b) within particular categories, there are
considerable  differences in  relative toxicity.  It appeared that there was a relationship
between the  relative toxicity and the chemical structure of the chemical.  This was
explored using EC$Q values for several of the acid extractables.
      In discussing  these  relationships, an  understanding of the structure of the
phenol compound and where substitutions can occur is helpful.  Figure 1 indicates the
basic structure of phenol and  indicates that substitutions can occur at five locations
that can be  identified  by  number  or name.  Thus,  a 2-Chlorophenol indicates a
chlorine compound is substituted at the 2- or ortho position.  A p-nitrophenol indicates
that a nitro- (NC>2) group is located at the 4- or para position.
               6 (ORTHO)
                5 (META) 	
   •2 (ORTHO)
	3  (META)
                                 4 (PARA)
     Figure 1.  Schematic of the Phenol Ring and Possible Substitution Positions
                                18

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      Data for fourteen  chlorinated phenols were evaluated to identify whether a
 relationship between chemical structure and relative toxicity existed in this study. The
 EC5Q values for these compounds provide a reasonable data base to consider the
 effect of chemical  structure. When the £659 values were compared (Table 6), the
 relative toxicity of these compounds appeared related to the substitution position of the
 chlorine group on the phenol ring. The order of toxic potential was para>meta>ortho.
 The order was particularly evident with the mono- and  di-chlorophenols.
      This order also appeared  when the methylphenols were compared (Table  7).
 There were not enough data to infer that the same order occurred with nitrophenols,
 although it was suggested (Table  7).
      The chemical compound that is substituted on the phenol ring also appeared to
 have  an effect on toxicity (Table 8).  Nitro-substituted phenols, even when substituted
 in the para position, appear to be less toxic than  the methyl- or chloro-substituted
 phenols.
      While it  appears  that the chemical  structure of a compound, such as a
 substituted phenol, affects the relative toxicity of the  compound, this study was not
 designed  to determine such effects or the reason  differences occur. The effect of
 substitution position  and  chemical may be due to the influence of physicochemical,
 electronic and/or steric properties  of the chemical.
 ACCEPTABLE  LOADINGS
      Microbial  degradation is the  major organic  removal mechanism in the soil.
 Therefore, microbial  inhibition by a chemical or waste can be a limiting factor when
 chemicals are added to the soil. A chemical and waste loading determination protocol
 for land treatment  demonstrations to  estimate the non-inhibitory loading  has been
 proposed^12'13).  This protocol combines the leaching potential of the waste and the
toxicity of the leachate  to arrive at  a non-inhibitory loading.   In  this study,  the
 acceptable loading  rates were determined by following this protocol which is outlined
                               19

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            TABLE  6.   RELATIVE TOXICITY  OF CHLORINATED  PHENOLS


   Compound                   EC50 Value                 Substitution
                                  (mg/l)                      Position
        2-Chlorophenol	16.1	ortho
        3-Chlorophenol	3.8	meta
        4-Chlorophenol	1.0	para

        2,3-Dichlorophenol	4.8	ortho, meta
        2,4-Dichlorophenol	2.8	ortho, para
        2,5-Dichlorophenol	8.2	ortho, meta
        2,6-Dichlorophenol	15.9	ortho, ortho
        3,4-Dichlorophenol	0.5	meta, para

        2,4,5-Trichlorophenol	0.9	ortho, para, meta
        2,4,6-Trichlorophenol	9.3	ortho, para, ortho

        Pentachlorophenol	1.1	all

        2-Methyl-4-Chlorophenol	1.1	ortho, para
        3-Methyl-4-Chlorophenol	0.3	meta, para
        3-Methyl-6-Chlorophenol	5.8	meta, ortho
          TABLE 7.   RELATIVE TOXICtTY  OF  NON-CHLORINATED  PHENOLS
            Compound      ECso  Value             Substitution
                                (mg/l)                  Position
Methylphenols

o-Cresol (2-Methylphenol)	22.4	ortho
p-Cresol (4-Methylphenol)	1.1	para
m-Cresol (3-Methylphenol)	5.8	meta
2,4-Dimethylphenol	3.8	ortho, para

Nitrophenols

p-Nitrophenol	7.0	para
2,4-Dinitrophenol	13.5	ortho, para
                                   20

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in Table 9. The logic behind this procedure is that other studies^, 13) have shown
that the detoxification of water soluble organics in soil did not occur or proceeded very
slowly when the ECso value of the initial mixture was less than 20%.
      When  determining  an acceptable chemical loading, it  is assumed that any
toxicity that results is due to the added chemical and not the soil. This assumption was
evaluated and the toxicity of  the  WSF of the  Texas and  Mississippi soils was
determined using the Microtox© procedure. No toxicity of either soil was found.
      The acceptable  loading rates that resulted when  the specific chemicals were
mixed with two soils are noted in Tables 10 and 11.  These acceptable loading data
should be viewed  as initial screening data for degradation  and land treatment
demonstration  studies.  The protocol employs  only an acute toxicity testing.  The
soiksolution ratio used (1:4) is low and simulates only short-term leaching effects.  In
the degradation studies (Section 5), the actual  loading rates used were equal to or
less than those noted in Tables 10 and 11.
      The loading  limit of several of the alcohols  was not determined.  This was
because  the  large quantities of such soluble chemicals that were needed saturated
the soil and caused nonrepresentative land treatment conditions.
      The effect of chemical structure  on  the acceptable loading rate also was
evaluated. The chlorinated phenol data (Table 12) indicated that the chemicals with
chlorine in the para position generally required the lower non-inhibitory loading rates.
The mixing of the chemicals with the two different soils did not appear to affect the
relative toxicity order of the chemicals discussed earlier.
      In general, the acceptable loading rates for the Mississippi soil were lower than
those for the Texas soil. There was, however, no consistent pattern for the differences.
Some of the  rates  were  close  and some differed by  an order of magnitude.  The
experiments were not planned to investigate the reasons for differences with different
                               21

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          TABLE 8.  COMPARATIVE RELATIVE TOXICITY  OF  CHLORO-,
                          METHYL-  AND  NITROPHENOLS
             Compound                      EC50  Value
                                                (mg/l)
          3-Chlorophenol	3.8
          m-Cresol (3-Methylphenol)	5.8

          p-Nitrophenol	7.0
          p-Cresol (4-Methylphenol)	1.1
          4-Chlorophenol	1.0

          2,4-Dinitrophenol	13.5
          2,4-Dimethylphenol	3.8
          2,4-Dichlorophenol	2.8
                  TABLE 9.   METHOD  TO  DETERMINE  ACCEPTABLE INITIAL
                                     CHEMICAL  LOADINGS
     1.   Prepare several different ratios of a waste-soil mixture or a chemical-soil mixture. This results
          in different loading rates.

     2.   Obtain a water soluble fraction (WSF) for each mixture, i.e., loading rate.

     3.   Determine the EC50 for each WSF.

     4.   Determine relative toxicity units using the following equation: TU = 400/EC5Q.*

     5.   Prepare a log-log plot of TU values versus loading rate.

     6.   The interception point for 20 toxicity units (20TU) is the lower loading limit for the soil.  Since
          there can be a window of acceptable lower loading rates, a value of twice the tower limit is
          identified as the upper limit for this acceptable window.*

See Appendix A for discussion of these items.
                                 22

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                               TABLE 10.  ACCEPTABLE NON-INHIBITORY LOADING RATES --  TEXAS  SOIL
ro
oo
                Compound
                                   Loading Rate*
                                   (mg/kg of soil)
           Acid Extractabtes
Phenol	
o-Cresol	
p-Cresol	
m-Cresol	
2-Chlorophenol	
3-Chlorophenol	
4-Chlorophenol	
2,3-Dichlorophenol	
2,4-Dichlorophenol	
2,5-Dichlorophenol	
2,6-Dichlorophenol	
3,4-Dichlorophenol	
2,4,5-Trichlorophenol	
2,4,6-Trichlorophenol	
Pentachlorophenol	
2,4-Dimethylphenol	
2-Methyl-4-Chk>rophenol.
3-Methyl-4-Chk>rophenol.
3-Methyl-6-Chtorophenol.
p-Nitrophenol	
2,4-Dinitrophenol	
4,6-Dinitro-o-Cresol	
Thiophenol	
...720
...490
...100
...124
...380
...120
....88
...130
....90
...300
...630
	30
....40
...300
	30
	88
	48
	18
...150
....250
...1380
....350
....160
                          Compound
                                   Loading Rate*
                                   (mg/kg of soil)
Amines

Diphenylamine	230
m-Phenylenediamine	7900
Toluenediamine	1080
Brucine	3600

Alcohols

Isobutyl alcohol	++
Alfyl alcohol	++
Propargyl alcohol	8200
1-Butanol	++
2,3-Dichloropropanol	1050
Methanol	++

Other

Carbon disulfide	400
2-Nitropropane	1620
Thiourea	6580
            +   lower loading rate as determined using the procedure in Table 9
            ++  not determined, see text

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                            TABLE 11.  ACCEPTABLE NON-INHIBITORY LOADING RATES -  MISSISSIPPI  SOIL
ro
                Compound
                                   Loading Rate*
                                   (mg/kg of soil)
Acid Extractables

Phenol	320
o-Cresol	250
p-Cresol	50
m-Cresol	130
2-Chlorophenol	290
3-Chlorophenol	60
4-Chlorophenol	45
2,3-Dichlorophenol	60
2,4-Dichlorophenol	45
2,5-Dichlorophenol	30
2,6-Dichlorophenol	50
3,4-Dichlorophenol	23
2,4,5-Trichtorophenol	30
2,4,6-Trichlorophenol	215
Pentachtorophenol	55
2,4-Dimethylphenol	45
2-Methyl-4-Chtorophenol	38
3-Methyl-4-Chtorophenol	10
3-Methyl-6-Chtorophenol	140
p-Nitrophenol	45
2,4-Dinitrophenol	270
4,6-Dinitro-o-Cresol	26
Thiophenol	330
     Compound
Loading Rate*
(mg/kg of soil)
Amines

Diphenylamine	110
m-Phenylenediamine	*
Toluenediamine	1400
Brucine	3200

Alcohols

Isobutyl alcohol	++
Allyl alcohol	++
Propargyl alcohol	5100
1-Butanol	++
2,3-Dichtoropropanol	700
Methanol	++

Other
Carbon disulfide	1540
2-Nitropropane	1170
Thiourea	910
           +   lower loading rate as determined using the procedure in Table 9
           ++  not determined, see text
           *   chemical deterioration of this chemical in this soil prevented evaluation of mass loading data

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            TABLE 12.   COMPARATIVE ACCEPTABLE LOADING  RATES
                             CHLORINATED  PHENOLS
                             Loading  Rate (ma/ka)
Compound                   Texas      Mississippi      Substitution
                              Soil           Soil           Position


2-Chlorophenol	380	290	ortho
3-Chlorophenol	120	60	meta.
4-Chlorophenol	88	45	para

2,3-Dichlorophenol	130	60	ortho, meta
2,4-Dichlorophenol	90	45	ortho, para
2,5-Dichlorophenol	300	30	ortho, meta
2,6-Dichlorophenol	630	50	ortho, ortho
3,4-Dichlorophenol	30	23	meta, para

2,4,5-Trichlorophenol	40	30	ortho, para, meta
2,4,6-Trichlorophenol	300	215	ortho, para, meta

Pentachlorophenol	30	55	al

2-Methyl-4-Chlorophenol	48	38	ortho, para
3-Methyl-4-Chlorophenol	18	10	meta, para
3-Methyl-6-Chlorophenol	150	140	meta, ortho
soils.  Therefore, it was not possible to identify the fundamental factors causing the

observed differences.  However, there are several possibilities.

      The concept of determining  an  acceptable chemical loading for a soil is to

identify an application rate or range of rates that will ensure  degradation of waste

without inhibiting the microorganisms in the soil. The chemical loading determination

procedure  consists of two aspects: (i)  quantity of the chemical partitioning into the

water soluble fraction (WSF) under standard test conditions, and (ii) toxicity of WSF.

      The first aspect is a function of sorption characteristics of the chemical under the

test conditions. The second aspect depends on the relative toxicity of the chemical,

the impact of soil characteristics on the toxicity, and the method used to measure

toxicity.
                                25

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      The sorption of a chemical in soil depends on: (i) soil characteristics such as
pH, organic content,  particle size distribution, and presence  of other chemicals, (ii)
chemical characteristics such as solubility, partition coefficient, and pK value, and (iii)
test conditions such as soiksolution ratio, test temperature and agitation.
      The sorption data obtained in this study are presented in Section 6 and there
are differences in the sorption characteristics of the two soils.  Sorption increases the
persistence of a chemical in the soil  and reduces the migration potential of the
chemical. Therefore, a chemical that has greater sorption characteristics will be more
tightly bound to the soil and less likely to be in solution and therefore in the WSF. The
basis of the procedure to estimate the  acceptable chemical or waste loading rate
(Table 9) is  the assumption that  the  WSF of the chemical  or waste poses the
immediate and significant threat to soil microorganisms and to groundwater.
      The  results that were obtained were similar  to those obtained  by other
researchers.  Sims(1^) reported waste mass loading data for petroleum and wood-
preserving wastes with  clay loam and sandy loam soils. The same procedure (Table 9)
was used to  obtain the data.  In the clay loam soil, higher chemical loadings  were
possible than with the  sandy loam soil.  This was attributed to the higher adsorption
and hence lower leaching  of the wastes in clay  loam soil.  Pentachlorophenol (PCP)
waste  showed  a lower loading than  the other wastes  containing creosote and
polynuclear aromatic hydrocarbons (PAH's).  This may  have been due to the higher
toxicity of PCP using the Microtox® assay.
      The pH of the  Microtox®  method also  may have had an effect on speciation of
the chemicals that were available for sorption and the resultant relative toxicity. The
acceptable pH of the  sample in the Microtox® assay is the range of 6.0-8.0. The pH of
the samples analyzed  in this study was within this range.  The chemicals evaluated
have pKa values that  range widely.  As an  example, the pKa  of pentachlorophenol
(PCP) is about 5.0 while that of phenol is about 9.3. When a sample is adjusted to the
                               26

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Microtox© pH range (6.0-8.0), the speciation will vary.  For instance, at this pH range,
POP would be completely dissociated, whereas the dissociation of phenol would be
minimal.
      The method (Table 9) used to identify acceptable, non-inhibitory chemical and
waste loading rates is conservative in that acclimation of the organisms to the waste or
chemicals is not considered, in the field the actual non-inhibitory waste and chemical
loading  rates to the soil may be higher than those noted in this study since microbial
acclimation will occur with time.
      The higher the chemical or waste loading that can be successfully treated on
the land, the more economical will be the land treatment option.  Huddleston et al.(16)
reported increased soil respiration rates and waste removal rates with an increase in
oil waste application in land treatment investigations.  The microbial acclimation may
significantly  increase the degradation of a  waste at  high waste  application
concentrations^ 5> 17)  However, the method in Table 9 does  result  in an initial
chemical and waste loading that  will not  inhibit the soil  microorganisms.  Such
loadings will allow the soil treatability of chemicals and wastes to be determined.
CONCLUSIONS
   1. The Microtox©  biological assay represents an inexpensive and expedient
      method with which to evaluate the EC$Q toxicity of a chemical or waste.  This
      method was used to estimate the £650 values of specific chemicals and to
      estimate the non-inhibitory soil loadings of the chemicals and waste that were
      evaluated.
   2. The comparison of the EC$Q data indicated that: (a) the alcohols were less toxic
      than the acid  extractable compounds, and (b) within chemical categories, there
      were considerable differences in relative toxicity.
                               27

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3. The chemical structure of the compounds evaluated affected the relative toxicity
   of a compound.  With chlorophenols, the relative toxicity was  related to the
   substitution  position of the chlorine group on  the  phenol  ring.  The order of
   relative toxicity was para>meta>ortho.  The EC$Q data suggested that the same
   order occurred for methylphenols and nitrophenols.
4. The  chemical that was substituted on the phenol ring appeared to have an
   effect on toxicity.  Nitro-substituted phenols, even when substituted in the para
   position, appeared to be less toxic  than the methyl-  or chioro-substituted
   phenols.
5. When the chemicals were mixed with two different soils, and the £€50 value of
   the water soluble  fraction (WSF) of the soil mixtures was measured, the values
   indicated that chemicals with the chlorine in the para position had the greater
   toxicity. Mixing of the chemicals with the soils did not affect the relative toxicity
   of the chemicals in the two soils.
6. In general, the  acceptable  non-inhibitory chemical  loading  rates for  the
   Mississippi  soil were lower than  those for the Texas soil.  There was no
   consistent  pattern  for the  differences.  The  differences  were likely due to
   different sorption characteristics of the chemicals in the two soils.
                            28

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                                SECTION  5
                         DEGRADATION  STUDIES

INTRODUCTION
       These experiments were conducted to determine the removal kinetics of the
designated chemicals and wastes (Table 1) in soil. Several of the chemicals could not
be  evaluated because of chemical reactions in the  soils which made analytical
detection  impossible.   These were  Diphenylamine,  m-Phenylenediamine  and
Thiophenol.
      Biodegradation is believed to be the most important removal mechanism for
organic compounds in soil systems.  Biodegradation of organics is accomplished in a
series  of biochemical reactions through  which a parent compound  is changed or
transformed to organic and inorganic end products.  Complete degradation is the term
used to describe the  process whereby  constituents are mineralized to inorganic end
products, including carbon dioxide, water, and inorganic nitrogen, phosphorus, and
sulfur compounds.
      Aerobic soil bacteria possess the ability to biochemically catalyze the oxidation
of organic compounds.  For this reason, and because the zone of incorporation at land
treatment sites generally is aerobic, the protocol used  in this study allowed aerobic
conditions and aerobic biodegradation reactions to occur.
      In the  mixed  microbial population of  soil systems,  one metabolic group of
microorganisms may partially metabolize a compound and may  furnish  a suitable
growth substrate  for another group.   Organic compounds also may be  partially
degraded or transformed to organic intermediates that may be recalcitrant and/or toxic.
      The primary goal of biodegradation testing is to obtain an overall  estimate of the
rate at which a compound  will biodegrade  in a soil environment.   While few
compounds appear in the environment in pure form, a common approach for studying
                              29

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removal rates of organic compounds has been to  evaluate individual compounds.
Although this approach provides an understanding of the removal rates for specific
compounds, it is recognized that during actual land treatment chemicals normally are
applied as mixtures. Interactions between compounds in a mixture within the soil
matrix may promote or inhibit their removal from soil.
      In this study, the chemicals were evaluated as individual compounds and the
data should be understood in that context.
      Methods used to evaluate the biodegradation of organics in the environment
commonly use indirect measures such as oxygen consumption, CC>2 evolution, and
dissolved organic carbon (DOC) loss, to assess the persistence of compounds in test
environments, to determine chemical loss rates and to predict the relative importance
of biodegradation.
      While these procedures provide a qualitative  assessment of  biodegradation,
they do not determine quantitative rates of degradation for specific constituents.   Such
chemical specific  rates  are essential for the  assessment of compound fate  and
transport as well as  for risk analyses.  For quantitative assessment  of the rate of
biodegradation of an individual constituent in a soil system, it is necessary to measure
changes in parent compound concentration with time, and the loss of a chemical due
to methods other  than  biodegradation.  In  addition, the  immobilization potential
(partitioning into soils, liquid, and gaseous phases) provides  additional information for
assessing the soil treatment potential of hazardous constituents.
      In this study, no distinction was made between specific loss mechanisms.   Thus
removal  rates can be due  to  biodegradation, chemical degradation, hydrolysis,
photolysis and volatilization.    The chemicals that were evaluated did not have a high
volatilization  potential and volatilization was not considered an important removal
mechanism in these degradation  experiments.  The logic for this statement is
                               30

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presented in Appendix C.  Thus, the degradation rates presented in this section were
not corrected for volatilization.
MATERIALS  AND  METHODS
      In this  study, the  rate of degradation was  experimentally determined by
measuring the difference between the amount of compound initially added to a soil
and that which was recovered after specified time intervals.  The general protocol used
to determine these differences is presented in Table 13. The protocol notes that the
soils should be maintained at a moisture content which is about 80% of field capacity.
This will  provide adequate moisture for the biodegradative  reactions  but avoid
saturated conditions.  For the two soils that were used, the equivalent of 80% field
capacity was a moisture content of about 12% for the Mississippi soil and about 16%
for the Texas soil.
      Soil used in this experimental program: (a) had not had previous exposure to
industrial chemicals or wastes, and (b) did not receive any pretreatment such as soil
amendments or specially  acclimated biological cultures prior to these experiments.
Thus, the naturally  occurring soil  microbial consortium was responsible for the
bioremediated removal of the chemicals.
      Chemical mass  loadings were determined as part of the toxicity  screening
evaluations (Section 4).  These determinations ensured that the loadings at which the
chemicals were applied did not inhibit soil microbial activity. Soil pH was not adjusted
nor were  supplementary organic substrates used.  The control  beaker (blank)  was
carried  through the  experimental procedure  to ensure  quality control of the
instrumental analysis.
      Various techniques can be used to  apply test compounds to soil in laboratory-
scale studies. When the test compounds were not  highly  water soluble, the  test
compound was dissolved in a small  aliquot of solvent before application into a soil. In
                               31

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these experiments, the chemicals were added to the soil as a solution of water or of
Methylene Chloride depending on their solubility characteristics.
      To minimize the possible toxic effect of the Methylene Chloride, a small volume
(100 jiL) of the solvent, which contained an  appropriate amount  of chemical for  a
specific initial concentration, was applied to each soil sample and mixed thoroughly
immediately after application with glass stirrers. Each beaker contained a glass stirrer
to prevent  possible cross-contamination.  A  20 JJ.L microdispenser was utilized to
distribute the 100 JJ.L solvent/chemical at five different points on the surface of the soil
sample.  The Methylene Chloride also was added in the above volume  to the control
beakers.  Prior to applying the aluminum foil cover, a brief time was  allowed for
volatilization of the Methylene Chloride.
      As noted  in  Table  13,  at selected time intervals the concentration of the
remaining chemical in  a set of beakers was determined.  The time intervals were
based on estimates  of the half-life of the chemical and were chosen to provide at least
five data points to establish the removal rates. At these sampling  periods, a sample
set (four beakers  - one blank and three with chemical) was taken from the constant
temperature room and extracted for sixteen hours  with either Methylene Chloride for
phenolic compounds or Methanol for amines (including  Brucine and Thiourea) in  a
Soxhlet extraction apparatus (Method 3540)(7).
      The extract was concentrated in a Kuderna-Danish extraction unit attached to a
three-ball Snyder column (Method 3540)(7).  The concentration step was conducted in
a water bath maintained at 60° C for phenolic compounds and  at  78° C  for amines.
The concentrated extracts  were dried by passing them through disposable sodium
sulfate columns and then refrigerated  at 4° C until analysis by  gas chromatography
(GC) or high pressure liquid chromatography (HPLC).
      Several of the chemicals were extracted using water as a solvent and the shake
                               32

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  TABLE  13.   EXPERIMENTAL  PROCEDURES  USED IN THE  DEGRADATION  STUDIES
       Each experiment consisted of eight sample sets.  Each sample set contained four beakers
(triplicates for a sample and one blank). The experimental procedure for each chemical was as follows;

  (a)   Place 10 g of air-dried soil, which has been kept at 4° C, into each 150 ml beaker and adjust the
       soil moisture content to 80% of field capacity with distilled deionized water. Place a glass stirrer in
       each beaker.  Record all weights, including beaker, soil, water and glass stirrer.

  (b)   Mix soil and water thoroughly, cover the beakers with aluminum foil and place the beakers in the
       dark at 20° C. The cover minimizes water loss and the possible addition of contaminated dust.

  (c)   Wait for 10 days to allow soil microorganisms to equilibrate to experimental conditions.

  (d)   Prepare solutions of the test chemicals so that 100 uL of the solution gives the desired mass
       loading rate. The mass loadings are based on toxicity screening results.

       Add 100 uL of solution into  each sample beaker using a 20 u.L micropipet.  Do this five times to
       distribute the solution to five points on the soil surface and mix thoroughly. Return the beakers to
       the constant temperature room.

  (e)   Sample beakers should be  arranged so that the chemical solution is added to the day 0 beaker
       last.  For example, if samples are scheduled at day 0, 2, 4, 8,16, 24, 32, and 64, the order for
       adding a chemical to soil is sample sets for day 64,32,24,16,8,4,2 and day 0.

  (f)   The beakers are incubated in the dark to prevent photodegradation of the added chemicals.

  (g)   During the study, adjust the moisture content in each beaker weekly and maintain between 60%
       and 80% of field capacity.

  (h)   Sacrifice sample sets at the selected time intervals for test chemical analysis.

  (i)   When experimental data show that the  chemical remaining in the soil is below  GC or HPLC
       detection limits, the remaining sample beakers can be discarded.
extraction procedure.  The compounds extracted in this manner are noted in Table 14

and the extraction procedure is summarized in Table 15.

DATA  ANALYSIS

       Biodegradation information can be used to identify the rate of loss of an organic

chemical in a soil.  Such information  results  from treatability  studies such as those

conducted in  this study.   Biodegradation rates were determined experimentally by

applying the chemical of interest to a soil microcosm and monitoring concentration

over time.  A plot of the disappearance of  a constituent originally  present in the

chemical/soil  mixture  versus treatment time  provided the  following:   (a) the type of

reaction (generally zero or first order), (b) the reaction rate constants for the zero or first

order reactions, and (c) the half-life (l-\/2) time  of each constituent of concern.
                                   33

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  TABLE  14.   CHEMICALS  WHOSE  SOIL  CONCENTRATION WAS  EVALUATED  USING
                                   SHAKE  EXTRACTION
                      Compound                        Solvent Used

                      Methanol                                water
                      1 -Butanol                                water
                      Isobutyl Alcohol                          water
                      2,3-Dichloropropanol                Methylene Chloride
                      2-Nitropropane                           water
                      Allyl Alcohol                             water
                      Propargyl Alcohol                         water
                     TABLE  15.   SHAKE  EXTRACTION  PROCEDURE

        Each experiment consisted of eight sample sets.  Each sample set contained four beakers
 (triplicates for a sample and one blank). The experimental procedure for each chemical was as follows.
(a)  Place 40 g of air-dried soil, which has been kept at 4° C, into each of the 200 ml mason jars and adjust
    the soil moisture content to 80% of field capacity with distilled deionized water. Record all weights,
    including beaker, soil, water and glass stirrer.
(b)  Mix soil and water thoroughly then cap reactors with screw-on top and place in 20° C incubator.
(c)  Wait for 10 days to allow soil microorganisms to equilibrate to experimental conditions.
(d)  Prepare solutions of the test chemicals so that 100 u.L of the solution gives the desired mass loading
    rate. The mass loadings are based on toxicity screening results.
    Add 100 u.L of solution into each sample beaker using a 20 ul micropipet and mix thoroughly. Return
    the reactors to incubator.
(e)  On day of analysis,  four reactors are removed.  Each is filled with 200 milliliters of the appropriate
    extracting solvent. The reactors are sealed with the gas tight cap and placed on the shaker apparatus.
(f)  The shaker apparatus is operated at 250  rpm for one hour. After this period, the reactors are allowed
    to settle for 15 to 30  minutes.
(g)  The supernatant from the reactors is decanted and centrifuged at 5000 rpm for 30 minutes.
(h)  After centrifugation, the supernatant is filtered using a 0.45 ^m pore size filter and the filtrate stored at
    4° C until analysis on the gas chrornatograph.
                                      34

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       First and  zero order kinetic relationships were used to model data from the
degradation studies. The following describes both kinetic relationships.
      The expression for first order kinetics is:
                               -dC/dt =kC                                    (1)
where C is the chemical concentration (mg of compound/kg of soil), t  is time (days),
and k is the first order kinetic constant (day '1).  The integrated form of Equation 1 is:
                               C = C0 exp (-kt)                                (2)
where Co is the initial concentration of chemical.
      Taking the natural logarithm of Equation 2 results in:
                               In C = (In C0) -kt                               (3)
Using linear regression,  the  relationship between In C and t (time)  data allows
determination of the loss coefficient k (which is the slope of In C versus t curve).
      Half life  (t-|/2) is defined as the time  required for the amount  of chemical to
decrease to half  of its initial value. Half  life  values based on first  order kinetics are
obtained by rearranging Eqn. 3:
                               ti/2 = lrt2/k                                    (4)
      The common expression for zero order kinetics is:
                               -dC/dt m K                                     (5)
where K  is the zero order kinetic constant (mg/Kg/day).   The integrated form of
Equation 5 is:
                               C= (C0) -Kt
The zero order kinetic constant K may be estimated by analyzing C versus t data by
linear regression.
    Data obtained from  each sampling interval were used to calculate both first order
and zero order  kinetic parameters.  Half-life data were calculated based on first order
kinetics.   Total loss rate data (mg  chemical/kg dry soil/day) were  reported for zero
order kinetics.

                                35

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    The zero and first order kinetic parameters and the correlation coefficient were
obtained from a least squares fit of the data.  To estimate the 95% confidence interval
for the data, the standard deviation and the student t statistic were computed based on
the data and used as
                          t«s
      95% Cl = (k or K) ±
where: k or K = least squares calculated first or zero order kinetic parameter,
      t = student t statistic for the data and 95% confidence,
      s = sample standard deviation, and
      ssx = sum of squares for the data.
      Recovery efficiency data  for each chemical  were  acquired and used  to
determine the chemical concentration that actually remained in the soil. The day zero
extraction data identified the extraction efficiency of the chemical under the conditions
of that specific experiment.  It was assumed that the day zero extraction efficiency was
constant throughout the specific experiment. The recovery efficiencies were used to
calculate the  actual soil concentration prior to extraction as follows.  Assume that: (a)
the recovery efficiency was 50% as shown by the day zero data and (b) the extracted
soil concentration for the chemical at sampling time three was 100 mg/kg soil.  The
actual  recovery efficiency corrected chemical concentration at this sampling time was
calculated to  be 200 mg/kg (extraction concentration divided by extraction efficiency).
The recovery  efficiency corrected chemical  concentrations  were used in  all
calculations to determine the kinetic relationships and constants.
      Because of time constraints, the appropriate analytical protocol for measuring
Carbon Disulfide  (CS2) was not developed.  Thus, this chemical is not included  as
part of these experiments.
                               36

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RESULTS
Recovery Efficiency
      Recovery efficiency data for the selected chemicals are given in Table 16.
There were differences in recovery efficiencies  for the two soils but there were no
consistent patterns.   The  differences  may  be due  to the  different sorption
characteristics of the soils with specific chemicals.
Kinetic  Parameters
      The loading rates for the chemicals to the  soil were at or below the acceptable
loading  rates determined as described in Section 4 (Table  17).  In some cases, the
actual loading rates were  slightly above the lower acceptable loading rate but were
within the acceptable  loading  rate window.  In one case (4,6-Dinitro-o-Cresol in
Mississippi soil) (Table 17), the actual loading rate inadvertently was considerably
higher than the acceptable loading rate.  Except in the latter case, the loading rates
should not have been such to inhibit the microorganisms in the two  soils during the
degradation experiments.
      The first and zero  order rate constants, correlation-coefficients, and  95%
confidence intervals for the selected chemicals in Texas and Mississippi soils are
given in Tables 18 and 19  respectively.  Chemical loss curves illustrative of the type
obtained in this study are shown in Figures 2-5.
      In reviewing the kinetic parameters, it should be recalled that  a small half-life
and a large zero order constant indicate a faster degradation rate.  For example, in the
Texas soil, p-Cresol had a higher degradation rate and was  removed faster in the
microcosms than was phenol.
      In general, high correlation coefficients were obtained with the data.  Higher
correlation coefficients were obtained with the acid extractables in both soils.  Based
on the correlation coefficient data and a visual inspection of the chemical loss curves,
                               37

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       TABLE 16.    RECOVERY EFFICIENCIES* FOR SPECIFIC CHEMICALS  (%)


                                     Texas                         Mississippi
Compound                          Soil	Soil	

Acid  Extractable*

Phenol	88	78
o-Cresol	57	63
p-Cresol	78	97
m-Cresol	81	88
2-Chtorophenol	23	25
3-Chlorophenol	94	85
4-Chtorophenol	97	85
2,3-Dichlorophenol	115	104
2.4-Dichtorophenol	82	92
2,5-Dichtorophenol	88	84
2,6-Dichlorophenol	80	71
3,4-Dichtorophenol	115	104
2,4,5-Trichlorophenol	82	92
2,4,6-Trichlorophenol	88	84
Pentachlorophenol	115	106
2,4-Dimethylphenol	80	81
2-Methyl-4-Chlorophenol	91	101
3-Methyl-4-Chlorophenol	99	99
3-Methyl-6-Chlorophenol	100	100
p-Nitrophenol	110	110
2,4-Oinitrophenol	95	132
4,6-Dinrtro-o-Cresol	84	100

Amln»*

Toluenediamine	100	72
Brucine	65	100

Alcoholt

Isobutyl alcohol	92	94
Allyl alcohol	,119	110
Propargyl alcohol	95	97
1-Butanol	90	89
2,3-Dichloropropanol	100	86
Methanol	100	106

Other

2-Nitropropane	60	55
Thiourea	88	93


+   Average of results from triplicate samples
                                      38

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        TABLE  17.   ACCEPTABLE  AND ACTUAL  LOADING  RATES  USED  IN THE
                         DEGRADATION  STUDIES  (mg/kg of  SOIL)
                        	Texas  Soil	               Mississippi Soil

 Compound              Acceptable*     Actual          Acceptable*       Actual


 Add Extnctable*

 Phenol	720	700	320	350
 o-Cresol	490	500	250	250
 p-Cresol	100	100	50	45
 m-Cresol	124	120	130	130
 2-Chtorophenol	380	400	290	300
 3-Chtorophanol	120	120	60	55
 4-Chtorophenol	88	90	45	50
 2,3-Dichtoroph«nol	130	130	60	60
 2,4-Dichbroph«K>l	90	90	45	40
 2,5-Dichtoroph«nol	300	300	30	30
 2,6-Dfchlorophenol	630	630	50	48
 3,4-Dichk>rophenol	30	30	23	22
 2.4,5-Trichlorophenol	40	40	30	30
 2.4.6-Trichloroph«nol	300	300	215	220
 Pentachlorophenol	30	30	55	50
 2,4-Dimethylphenol	88	90	45	40
 2-Methyl-4-Chlorophenol	48	50	38	40
 3-Methyl-4-Chloroph«nol	18	20	10	10
 3-Methyl-6-Chloroph«nol	150	150	140	140
 p-Nitrophenol	250	250	45	50
 2,4-Dinitroph«nol	1380	140	270	330
 4.6-Dinitro-o-Cresol	350	300	26	105

 Amines

 Toluenediamine	1080	500	1400	680
 Brucine	3600	180	3200	150

 Alcohol*

 Isobutyl alcohol	++	925	++	940
 Allyl alcohol	++	750	++	700
 Propargyl alcohol	8200	980	5100	930
 1-Butanol	++	870	-H-	850
 2,3-Dichloropropanol	1050	1200	700	700
 Methanol	++	740	++	740

 Other
 2-Nitropropane	1620	640	1170	540
Thiourea	6580	660	910	100


+   As determined by the procedure described in Section 4, data from Table 10

 '   As determined by the procedure described in Section 4. data from Table 11

++  Sea text, Section 4: acceptable loading rate was considerably greater than 1000 mg/kg.
                                     39

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  TABLE  18.   LOSS  RATES, CORRELATION COEFFICIENTS  AND  95% CONFIDENCE
                    INTERVALS FOR SPECIFIC  CHEMICALS --
                                 TEXAS  SOIL
COMPOUND
KINETIC PARAMETERS
FIRST ORDER
HALF LIFE
(day)
Acid Extractables
Phenol 	
o-Cresol 	
p-Cresol 	
m-Cresol 	
2-Chlorophenol 	
3-Chterophenol 	
4-Chtorophenol 	
2,3-Dichlorophenol 	
2,4-Dichtorophenol 	
2,5-Dichlorophanol 	
2,6-Dichtorophenol 	
3,4-Dichbrophenol 	
2,4,5-Tr ichlorophenol 	
2,4,6-Trichlorophenol 	
Pentachlorophenol 	
2,4-Dimethylphenol 	
2-Methyl,4-Chlorophenol 	
3-Methyl-4-Chlorophenol 	
3-Methyl, 6-Chlorophanol....
p-Nitrophenol 	
2,4-Dinitrophenol 	
4,6-Dintro-o-Cresol 	
Amln»»
Toluanediamine 	
Brucine 	
Alcohol*
Isobutyl Alcohol 	
Allyl Alcohol 	
Propargyl Alcohol 	
1-Butanol 	
2,3-Dichloropropanol 	
Methanol 	
Othfr
2-Nitropropane 	
Thiourea 	

.4.1 	
.1.6 	
..(1) 	
.0.6 	
.1.7 	
.21.8.,..
.1.0 	
.8.3 	
.1.5 	
.16.6....
.2.4 	
.3.2 	
.14.6....
.5.3 	
.6.7 	
.0.7 	
.2.9 	
.1.4 	
.2.1 	
.10.2....
.4.6 	
. (2) ....

.11.9....
.23.1....

.2.4 	
,10.2....
.12.6....
.1.0 	
.23.1....
.1.0 	

.0.5 	
.12.8....
*
r

	 0.92.
	 0.83.
«,.
	 0.87.
	 0.98.
	 0.97.
	 0.91.
	 0.97.
	 0.94.
	 0.99.
	 0.91.
	 0.89.
	 0.95.
	 0.94.
	 0.92.
	 0.99.
	 0.90.
	 0.99.
	 0.98.
	 0.81.
	 0.92.
..

	 0.65.
	 0.86.

	 0.96.
	 0.95.
	 0.94.
	 0.75.
	 0.97.
	 0.75.

	 0.97.
	 0.86.
95% C.I,

	 3.1-6.1..
	 1.5-1.7..
„
	 0.4-1.4..
	 1.5-1.9..
	 19.6-24.6
	 0.7-1.3..
	 7.4-9.3..
	 1.1-1.9..
	 15.6-17.7
	 2.0-3.0..
	 2.3-4.9..
	 12.2-18.1
	 4.6-6.3..
	 5.5-8.5..
	 0.6-0.8..
	 2.7-3.0..
	 1.2-1.6..
	 1.9-2.4..
	 7.5-16.3.
	 2.9-11.7.
-M

	 7.5-28.5.
	 18.0-33.0

	 2.1-2.9..
	 8.8-12.2.
	 10.7-15.2
	 0.7-2.4..
	 20.9-26.0
	 0.68-2.4.

	 0.4-0.6..
	 9.9-18.0.
ZERO ORDER
mg/Kg/day r*

	 59.3...
	 62.2...
	 >100 (1)
	 28.2...
	 26.2...
	 2.3....
	 14.5...
	 3.6....
	 14.1...
	 6.1....
	 41.8...
	 2.7....
	 1.4....
	 10.4...
	 1.0... .
	 27.3...
	 3.7....
	 3.8....
	 11.2...
	 6.8....
	 12.9...
(2)

	 5.9....
	 3.1....

	 172...
	 30.0...
	 29.5...
	 184...
	 22.2...
	 184...

	 155...
	 2.1....

	 0.96.
	 0.95.
,.
	 0.96.
	 0.90.
	 0.95.
	 0.91.
	 0.98.
	 1.00.
	 0.96.
	 0.97.
	 0.95.
	 0.96.
	 0.94.
	 0.91.
	 0.90.
	 0.94.
	 0.93.
	 0.94.
	 0.92.
	 0.96.
__

	 0.47.
	 0.81.

	 0.96.
	 0.93.
	 0.97.
	 0.90.
	 0.94.
	 0.94.

	 0.77.
	 0.95.
95% C.I

	 46.9-71.4
	 48.5-75.9
„
	 20.5-36.9
	 20.4-32.0
	 2.0-2.6
	 9.7-19.2
	 3.2-3.9
	 13.0-15.2
	 5.4-6.8
	 36.7-46.9
	 2.1-3.3
	 1.2-1.6
	 8.8-12.1
	 0.8-1.2
	 18.1-36.5
	 3.0-4.4
	 2.1-5.4
	 9.2-13.1
	 5.3-8.3
	 7.5-18.3
,,

	 0.7-11.2
	 2.4-4.2

	 144-200
	 24.3-35.6
	 26.2-32.9
	 130-239
	 18.7-25.6
	 140-228

	 79-230
	 1.8-2.4
(1) No chemical was detected after one day.

(2) No loss during the 65-day experiment

'   Correlation coefficient
                               40

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  TABLE  19. LOSS RATES, CORRELATION  COEFFICIENTS  AND  95% CONFIDENCE
           INTERVALS  FOR SPECIFIC COMPOUNDS - MISSISSIPPI SOIL
COMPOUND
KINETIC
FIRST ORDER
HALF LIFE
(day)
Acid Extractables
Phenol 	
o-Crasol 	
p-Cresol 	
m-Cresol 	
2-Chlorophenol 	
3-Chtorophenol 	
4-Chlorophenol 	
2,3-Dichlorophanol 	
2,4-Dichloroph«nol 	
2,5-Dichk>roph«nol 	
2,6-Dichk>roph«nol 	
3,4-Dichtoroph«nol 	
2,4,5-Trichlorophenol 	
2,4,6-Trichlorophanol 	
Pentachlorophenol 	
2 4-Oirnathylphenol 	
2-Mathyl,4-Chlorophanol....
3-Mathyl-4-Chlorophanol....
3-Mathyl, 6-Chlorophenol...
p-Nitrophanol 	
2,4-Dinitrophenol 	
4 6-Dintro-o-Crasol
Amlnet
Toluenadiamina 	
Brucine 	
Alcohol*
Isobutyl Alcohol 	
Allyl Alcohol 	
Propargyl Alcohol 	
1-Butanol 	
2,3-Dichloropropanol 	
Methanol 	
Other
2-Nitropropane 	
Thiourea 	

..23.0 	
..5.1 	
..0.5 	
..11.3 	
..7.2 	
..15.1 	
..2.5 	
..18.3 	
..3.5 	
..18.5 	
..16.2 	
..18.3 	
..22.3 	
..6.3 	
..12.0 	
..1.4 	
..6.3 	
..4.2 	
..12.5 	
..2.5 	
..32.1 	
(1) 	

..6.5 	
..37.1 	 „

..11.3 	
..9.5 	
..13.0 	
..8.5 	
..55.3 	
..3.2 	

..0.66 	
..18.7 	
*
r

...0.95.
...0.88.
...0.93.
...0.97.
...0.95.
...0.97.
...0.96.
...0.84.
...0.95.
...0.94.
...0.94.
...0.90.
...0.95.
...0.93.
...0.94.
...0.99.
...0.94.
...0.92.
...0.93.
...0.81.
...0.96.
»

...0.85.
...0.66.

...0.66.
...0.93.
...0.89.
...0.60.
...0.92.
...0.73.

...0.95.
...0.45.
95% C.I.

	 19.6-27.8 	
	 4.0-6.7 	
	 0.4-0.8 	
	 9.7-13.4 	
	 6.3-8.7 	
	 13.6-17.1 	
	 2.1-3.1 	
	 13.9-26.8 	
	 2.9-4.6 	
	 16-22 	
	 13.9-19.5 	
	 15.0-23.4 	
	 19.1-26.9 	
	 5.3-7.8 	
	 10.2-14.6 	
	 1.2-1.6 	
	 5.2-7.7 	
	 3.2-5.9 	
	 10.6-15.3 	
	 1.4-5.8 	
	 25.9-42.1 	
„

	 :4.9-9.7 	
	 21.7-126.3 	

	 7.7-20.8 	
	 7.9-11.8 	
	 10.6-16.6 	
	 5.3-21.2 	
	 45.8-69.5 	
	 2.3-5.6 	

	 0.56-0.79 	
	 -8.3to+76.2 	
PARAMETERS
ZERO ORDER
mg/Kg/day

	 7.0 	
	 6.4 	
	 23.2 	
	 5.0 	 .-.
	 8.4 	
	 1.3 	
	 5.6 	
	 1.0 	
	 2.3 	
	 5.2 	
	 8.9 	
	 0.5 	
	 0.6 	
	 5.7 	
	 1.1 	
	 6.7 	
	 1.8 	
	 0.9 	
	 3.0 	
	 3.6 	
	 3.7 	
	 (1) 	

	 12.0 	
	 2.7 	

	 37.7 	
	 26.9 	
	 23.7 	
	 39.6 	
	 10.9 	
	 68 	

	 115 	
	 2.7 	
r*

.0.93..
.0.97..
.0.88..
.0.96..
.0.88..
.0.95..
.0.90..
.079..
.0.85..
.0.87..
.0.88..
.0.91..
.0.92..
.0.94..
.0.94..
.0.96..
.0.87..
.0.88..
.0.85..
.0.93..
.0.89..
„

.0.57..
.0.59..

.0.73..
.0.96..
.0.96..
.0.79..
.0.91..
.0.96..

.0.84..
.0.50..
95% C.I

	 5.6-8.4
	 5.7-7.1
	 11.8-34.5
	 4.1-5.9
	 6.2-10.6
	 1.1-1.5
	 3.6-7.5
	 0.6-1.3
	 1.3-3.3
	 3.9-6.5
	 6.5-10.6
	 0.4-0.6
	 0.5-0.7
	 4.7-6.7
	 0.9-1.3
	 4.9-8.5
	 1.2-2.3
	 0.5-1.2
	 2.1-3.9
	 1.9-5.3
	 1.5-5.5
	

	 2.7-21.2
	 0.4-4.9

	 23.1-52.3
	 23.0-30.8
	 20.6-26.7
	 25.9-53.3
	 8.5-13.4
	 59-76

	 76-154
....-0.22 to +5.6
(1)  No loss during the 65-day experiment
   Correlation coefficient
                               41

-------
                        Loss of Phenol from Texas Soil
 o
 OT
 *»
 o

 D>

 0»



 O

 4>

Q.
                                 First Order Half Life . 4.1 days
                                 Zero Order Total Loss Rate - 59.3 mg/Kg/day
 Figure  2.   Loss of Phenol In  Texas Soil at 20° C.
             Moisture content was maintained between 12 and 16%.
             The initial chemical loading was 700 mg/kg.
                     Loss of Phenol from Mississippi Soil
      400
(0

O
      300-
at
E
-     200-
  O
  O

  Q.

  "5

  u
,_    100-
O
o
 Figure  3.
                                   First Order Half Life . 23.0 days
                                   Zero Order Total Loss Rate » 7 mg/Kg/day
               Loss of Phenol In Mississippi Soil at 20° C.
               Moisture content was maintained between 12 and 16%.
               The initial chemical loading was 350 mg/kg.
                              42

-------
                Loss  of  2,6-Dlchlorophenol from Texas Soil
=    600
o
at
o
O)

o»
§

a
o
o

df

o

u
C
o
o
500


400
         Jl
300


200-


100-
           O
                               First Order Half Life -2.4 days
                               Zero Order Total Loss Rate -41.8 mg/Kg/day
                        a
                              i
                 10
                                     40
                                                  50
                         20     30

                            Days
Figure  4.   Loss of 2,6-Dlchlorophenol In Texas Soil  at  20°  C.
            Moisture content was maintained between 12 and 16%.
            The initial chemical loading was 630 mg/kg.
             Loss  of  2,6-Dlchlorophenol from Mississippi Soil
 o

 o
Q.
O
o
  v «  i  '  i
                          10  12  14  16  18 20
                         Days
       Loss of  2,6-Dlchlorophenol In  Mississippi Soil  at  20°  C.
       Moisture content was maintained between 12 and 16%.
       The initial  chemical loading was 48 mg/kg.
                               43

-------
it was not possible to discern whether zero or first order kinetics  were a better
representation of the data.
      Generally the rates of chemical loss were higher in the Texas soil than the
Mississippi soil (Table 20).  There were a few situations in which the chemical loss
rates were about the same or greater in the Mississippi  soil than those in the Texas
soil.  There did not appear to be any particular pattern to the differences of rates in the
two soils.  Because the study was not designed to determine the reasons that such
differences occur, it  was not  possible to identify the factors causing the differences.
However, there  are several possibilities.   These  include: (a) different sorption
characteristics and solubilities and therefore different availability of the chemical for
microbial degradation, and (b) the different pH in the soils and the effect of pH on
chemical dissociation and the form of the chemical available for degradation. Some
discussion of these possibilities was presented in Section 4.
      Care should  be taken in  extrapolating these chemical  loss rates to  field
conditions,  since such conditions can be different than those in the  laboratory
microcosms. For example, these loss rates were obtained at 20° C, with no nutrient
additions, with a reasonable but narrow range of moisture, without pH control, without
acclimated  microorganisms,  under quiescent conditions, and each  chemical was
evaluated separately. At field sites, moisture and temperature can  vary considerably
over the seasons, nutrients may be added to assure  microbial growth, and soils may
be limed. Typically, chemicals are added as mixtures and acclimated microorganisms
will exist at the site after repeated waste applications.  In addition higher chemical
loading rates can occur.  Thus,  in attempting  to utilize these loss rates to predict
chemical loss at specific sites, the differences between laboratory and field conditions
should be recognized and taken into account.
      In Section  4, the data  indicated that the substitution position of a chemical on
the phenol  ring and the type of chemical group that was substituted  affected the
                                  44

-------
    TABLE 20.  CHEMICAL HALF-LIVES  IN TEXAS  AND MISSISSIPPI SOILS  (days)
                                           Texas                 Mississippi
       Compound                          Soil                    Soil
Acid Extractables

     Phenol	4.1	23.0
     o-Cresol	1.6	5.1
     p-Cresol	(1)	0.5
     m-Cresol	0.6	11.3
     2-Chlorophenol	1.7	7.2
     3-Chlorophenol	21.8	15.1
     4-Chlorophenol	1.0	2.5
     2,3-Dichlorophenol	8.3	18.3
     2,4-Dichlorophenol	1.5	3.5
     2,5-Dichlorophenol	16.6	18
     2,6-Dichlorophenol	2.4	16.2
     3,4-Dichlorophenol	3.2	18.3
     2,4,5-Trichlorophenol	14.6	22.3
     2,4,6-Trichlorophenol	5.3	6.3
     Pentachlorophenol	6.7	12.0
     2,4-Dimethylphenol	0.7	1.4
     2-Methyl-4-Chlorophenol	2.9	6.3
     3-Methyl-4-Chlorophenol	1.4	4.2
     3-Methyl-6-Chlorophenol	2.1	12.5
     p-Nitrophenol	10.2	2.5
     2,4-Dinitrophenol	4.6	32.1

Amines
     Toluenediamine	11.9	6.5
     Brucine	23.1	37.1

Alcohols

     Isobutyl  alcohol	2.4	11.3
     Allyl alcohol	10.2	9.5
     Propargyl alcohol	12.6	13.0
     1-Butanol	1.0	8.5
     2,3-Dichloropropanol	?3.1	55.3
     Methanol	1.0	3.2

Other
     2-Nitropropane	0.5	0.66
     Thiourea	12.8	18.7
(1) No chemical was detected after one day.
                                      45

-------
relative toxicity and  the acceptable loading rate  data.  Each chemical group and
substitution position  also was evaluated to see their effect on the degradation rate
data.
      When the half-life data are compared for the fourteen chlorinated phenols with
chlorine in different  positions on the  phenol ring (Table 21), it appeared that the
compounds with the chlorine substituted in the meta position had the greater half-lives
and therefore the lowest loss rate.  This was particularly evident with the mono-, di-,
and trichlorophenols.  Using the data in Table 21, it was not possible to discern
whether there were any real differences when the chlorine was in the ortho and para
positions.  These results are somewhat different from those in Section 4 where relative
toxicity of these  compounds appeared related to the substitution  position of the
chlorine group with the order being para>meta>ortho.
      When the data from  non-chlorinated phenols were compared (Table 22), all of
the methylphenols were lost very rapidly in the Texas soil.  In the Mississippi soil, the
chemical loss rate was considerably slower when the methyl group was substituted in
the meta position.
      In Table  23, data for chemicals with different compounds substituted  on the
phenol ring were compared.  The data suggested that compounds that had  a nitro
compound substitution on the phenol ring had a lower loss rate. No other differences
in terms of type  of compound substitution were apparent.
CONCLUSIONS
   1. The chemical  or waste loading procedure (Table 9, Section  4)  resulted in
      chemical loadings  that did not inhibit  the  non-acclimated organisms in the
      laboratory microcosms, except in  one case (4,6-Dinitro-o-Cresol).  Thus, this
      procedure  provided a good estimate of initial, acceptable chemical loadings
      that can be used in laboratory degradation studies.
                                 46

-------
    TABLE 21.  EFFECT  OF  SUBSTITUTION  POSITION ON DEGRADATION  RATES
                              CHLORINATED  PHENOLS
    Compound               Chemical Half-Life (davs)          Substitution
                         Texas Soil     Mississippi Soil       Position
 2-Chlorophenol	1.7	7.2	ortho
 3-Chlorophenol	21.8	15.1	meta
 4-Chlorophenol	1.0	2.5	para

 2,3-Dichlorophenol	8.3	18.3	ortho, meta
 2,4-Dichlorophenol	1.5	3.5	ortho, para
 2,5-Dichlorophenol	16.6	18.5	ortho, meta
 2,6-Dichlorophenol	2.4	16.2	ortho, ortho
 3,4-Dichlorophenol	3.2	18.3	meta, para

 2,4,5-Trichlorophenol	14.6	22.3	ortho, para, meta
 2,4,6-Trichlorophenol	5.3	6.3	ortho, para, ortho

 Pentachlorophenol	6.7	12.0	al

 2-Methyl-4-Chlorophenol	2.9	6.3	ortho, para
 3-Methyl-4-Chlorophenol	1.4	4.2	meta, para
 3-Methyl-6-Chlorophenol	2.1	12.5	meta, ortho
   TABLE 22.   EFFECT  OF SUBSTITUTION  POSITION ON  DEGRADATION RATES
                           NON-CHLORINATED  PHENOLS
    Compound               Chemical Half-Life (days)         Substitution
	Texas Soli      Mississippi Soil	Position

 Methylphenols

 o-Cresol (2-Methylphenol)	1.6	5.1	ortho
 p-Cresol (4-Methylphenol)	(1)	0.5	para
 m-Cresol (3-Methylphenol)	0.6	11.3	meta
 2,4-Dimethylphenol	0.7	1.4	ortho, para

 Nltrophenols

 p-Nitrophenol	10.2	2.5	para
 2,4-Dinitrophenol	4.6	32.1	ortho, para

 (1)  No chemical was detected after one day.
                                     47

-------
     TABLE 23.  COMPARATIVE DEGRADATION  RATES OF  CHLORO-, METHYL-
                               AND  NITROPHENOLS
   Compound                   	Chemical Half-Life (davs)	
                                  Texas Soil                Mississippi Soil
3-Chlorophenol	21.8	15.1
m-Cresol (3-Methylphenol)	0.6	11.3
p-Nitrophenol	10.2	2.5
p-Cresol (4-Methylphenol)	(1)	0.5
4-Chlorophenol	1.0	2.5
2,4-Dinitrophenol	4.6	32.1
2,4-Dimethylphenol	0.7	1.4
2,4-Dichlorophenol	1.5	3.5
(1) No chemical was detected after one day.


   2. Based on the data, it was not possible to discern whether zero or first  order
      kinetics provided a better representation of data. For most of the chemicals the
      data could be fit to  either kinetics with high correlation coefficients.
   3. In general, the rates of chemical loss were higher in the Texas  soil than in the
      Mississippi soil.  There  did not appear to be any  pattern to the differences in
      rates in the two soils.
   4. Chlorophenols with chlorine substituted in the  meta position had greater half-
      lives and therefore lower chemical loss rates. This was particularly evident with
      the mono-, di- and  trichlorophenols in the Texas soils.
   5. Chemicals that  had a nitro group  substituted on the phenol ring appeared to
      have a lower loss rate.
                                   48

-------
                                 SECTION  6
                       ADSORPTION  EXPERIMENTS

INTRODUCTION
      The persistence of hazardous organic compounds in soils is related to reactions
that  affect the transport and fate  of such  chemicals.  One of the most important
reactions is adsorption.
      Adsorption is the process by which ions or molecules present in one phase tend
to concentrate at a surface or interface.  The process  can occur at an interface
between any two phases,  such as liquid-liquid, gas-liquid, or solid-liquid interfaces.
The adsorbed substance is the adsorbate  while the adsorption phase is referred to as
the adsorbent. The tendency of organic molecules to adsorb on soil is determined by
the physical and chemical characteristics of the chemical compound and the soil to
which it is added.  The two driving forces for adsorption are the lyophobic (solvent-
disliking) character of a solute relative to a particular solvent, and the affinity  of the
solute for the solid, such as electrical attraction or van der Waal's attraction/19).
      Adsorption is the major retention mechanism for most organic and  inorganic
compounds  in soils.  As a result, the leaching potential of a chemical in soil is, in
general, proportional to the magnitude of the adsorption (partitioning) coefficient of that
chemical in a soil.  The  adsorption  potential of  a  chemical is governed by the
properties of both the soil and the chemical.   Important properties of the chemical that
affect adsorption include: (a) chemical structure, (b) acidity or basicity of the molecule
(pKa or pKfc), (c) water solubility, (d) permanent charge, (e) polarity, and (f) molecule
size.
      To estimate the environmental  movement of  a  chemical, values  of the
adsorption coefficient and other sorption equation coefficients can be compared to the
                                 49

-------
value of other chemicals  whose  behavior in  soil and  sediment  systems is well
documented.
Adsorption  Equilibria
      At equilibrium, the solute  remaining in solution is in dynamic equilibrium with
that of the soil surface.  At  this point, there is a defined distribution of solute between
the liquid and solid phases.  The  preferred form for depicting this  distribution is to
express the quantity qe (amount of solute sorbed per unit weight of solid sorbent) as a
function  of the equilibrium solution concentration (Ce) at a fixed temperature.  An
expression of this type is an adsorption isotherm.
      One of the oldest adsorption equations that has been used  widely for solid-
liquid systems is the Freundlich equation:
                        qe = KfCe1/n                                        (6)
where qe is the equilibrium distribution coefficient (mg of chemical/gm of adsorbent),
Ce is the equilibrium chemical concentration (mg/liter of solvent),  and Kf and 1/n are
constants.  The constant, Kf, is related to the capacity or affinity of the adsorbent and
the exponential term, 1/n, is an  indicator of the intensity, or how  the capacity  of the
adsorbent varies with the equilibrium solute concentration. The Freundlich isotherm
has had success in describing sorption  behavior of organics^)  and the adsorption
data generated  in this study were compared to this empirical model.
      The Freundlich constants  may be determined statistically when the equation  is
expressed in  linear form by  a logarithmic transformation:
                        log qe =  log Kf + 1/n log Ce                           (7)
The constants,  Kf and 1/n,  can be obtained, respectively, from the  intercept and slope
of log-log plots of qe vs Ce.
      The  Freundlich equation that results from specific experiments should not be
extrapolated  beyond the experimental range of data used in its construction.  This is
                                  50

-------
because the Freundlich equation predicts infinite adsorption at infinite concentrations,
and that any soil or clay has an unlimited capacity to retain chemicals dissolved in
water.   Such  an infinite capacity  is not only thermodynamically inconsistent, but
experience has shown that the extent of adsorption ultimately is limited by the surface
area of the  adsorbent.  Thus, the  Freundlich equation cannot  be extrapolated with
confidence beyond the experimental range used in its construction and will not yield a
maximum  capacity term.  The latter term is a convenient single-valued number that
estimates  the maximum amount of adsorption beyond which the soil surfaces are
saturated and no further net adsorption can be expected.
Soil Organic  Carbon
      Sorption of nonionic organic compounds from  water  onto soil has been
shown(20) t0 occur primarily by partition onto the soil organic phase.  Adsorption by
soil minerals is  relatively  unimportant in wet soils, presumably  because of strong
dipole interaction between the soil minerals and water, which excludes neutral organic
solutes from this portion of soil. Therefore, the more organic matter in soil, the more
adsorption is expected.  Soil organic matter has been the single best predictor of the
adsorption isotherm parameter(21-23), and the use of the soil  organic  matter-water
partition coefficient, Kom, rather than the adsorption partition coefficient, Kp, has been
proposed  as more appropriate:
      K0m -  Qom/C                                                        (8)
where qom = mg adsorbed/g soil organic matter and C = liquid  phase concentration,
mg/L.
      Organic matter content can be obtained by measurement or by multiplying an
experimentally  determined  organic carbon concentration  by  an  appropriate
conversion factor.  Because various researchers used different conversion factors, the
soil organic carbon content  has  been proposed(20, 23) f0 normalize adsorption
partition coefficients. This parameter (Koc) is:
                                 51

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                   = (KD/%OO 100                                          (9)
where qoc = mg sorbed/g soil organic carbon, %OC = (mass of organic carbon/mass
of soil) 100, %OM m %OC (f), and f = conversion factor ranging from 1.7 to 2.0.
      Rao et al.(24) performed an exhaustive literature search, showed that coefficient
of variation (CV) values for Koc were much lower than those of KD or K (Freundlich
coefficient),  and suggested that Koc be  used as a universal  adsorption partition
coefficient. This relationship is valid when the organic carbon content of the soil is
more than 0.1%.
      With regard to inorganics, the sorptive  effect of the  inorganic  matrix was
indicated to be negligible at an organic content level of 1% and above(25). However,
for some sorbents,  chemical interaction with the inorganic  matrix may be important. In
the  absence of organic carbon, the specific surface area and the nature of the mineral
surface have a greater impact on the degree of sorptionC2^).
Soil pH
      The pH of a soil-water system  can affect the sorption of  organic solutes.
Because the extent of ionization of an acidic or basic compound affects its adsorption,
pH  affects adsorption in that it governs the degree of ionization(1^).  Except with ion
exchange adsorption, ions tend  to be  less readily adsorbed  than  neutral species.
Many organics form negative ions at high pH, positive ions at low pH, and neutral
species in intermediate pH ranges.  Generally adsorption is increased at pH ranges
where the species are  neutral in charge.  pH  also affects the charge  on the  soil
surface, altering its  ability to adsorb materials^27).
      In general,  adsorption of organic pollutants from water increases  with
decreasing pH.  In many cases, this may result from neutralization of  negative charges
at the  soil surface with increasing hydrogen ion concentration, thereby  reducing
hindrance to  diffusion and  making  more  available the active surface of  the
           .  Usually,  organic acids are more  adsorbable at low pH, whereas the
                                 52

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adsorption of organic bases  is favored by  high  pH.  The  optimum pH  for any
adsorption process must be determined by laboratory testing.
      Sorption of  the  non-dissociated chemical species and also of their anionic
species can occur^S). When the pKa of a species, such as pentachlorophenol, is
relatively low compared to a natural water system, anionic species adsorption can
occur.   For highly chlorinated  phenols, prediction of overall distribution ratios on
simple partitioning of the nondissociated species can be in error(28).
      Another soil adsorption characteristic which  is influenced by  soil pH is the
Cation Exchange Capacity (CEC).  At very low pH values, only a small portion of the
positive ions held by  the clays and organic colloids can be  replaced by cation
exchange.  As pH increases, the hydrogen held  by organic colloids and silicate clays
becomes ionized and can be exchanged by positively charged organic molecules.
      Ion exchange is hypothesized to dominate  the sorption process in acidic
soil(29). The higher sorption in the acidic soil, as compared to basic soil, reflects
stronger sorption of the protonated organic cations.  Competitive adsorption occurs
between compounds  in  an  acidic soil  where  the  protonated  compound  species
predominates in solution, in  contrast, competition is minimal in a basic soil when the
compounds are neutral.  Non-ionic organic compounds may sorb independently on
soil from a mixture^20).
      When the protonated and neutral species coexist, site-specific sorption of the
cation is preferred because of the  electrostatic attraction between the  base  and the
negatively  charged soil  surface^),  when anionic and neutral  species  coexist,
neutral species sorption occurs because  of the  electrostatic repulsive forces of the
anionic species^). Maximum adsorption is attained near the point where pH = pKa,
and sorption capacity drops rapidly at pH values above pKa.
                                 53

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MATERIALS  AND  METHODS
Adsorption Method
      The adsorption of the specific chemicals was investigated in batch adsorption
experiments.  A list of the chemicals investigated and a description of the soil types
used were presented earlier (Tables 1 and 3).  The batch adsorption technique^31)
consists of mixing an aqueous solution containing a solute of known composition and
concentration with a given mass of sorbent (soil)  for a period of time.  The solution is
then separated from  the sorbent and chemically analyzed to  determine changes in
solute concentration.  The amount of solute sorbed is assumed to be the difference
between  the initial concentration (before contact with the  sorbent) and the solute
concentration after mixing.
Stock  Solutions
      The solvent used was distilled deionized  water (DDW) obtained by passage
through a Barnstead Water Purification Cartridge #DO 809. The stock solution of each
organic compound contained the maximum soluble amount of the compound in DDW
at room temperature (25°C).  The procedure used to prepare the stock solutions and to
determine the solubility limit of specific chemicals is noted in Table 24.
      The solubility limits of chemicals determined as part of this study are included in
Table  25.  This  table contains only those chemicals whose maximum aqueous
solubilities were determined as part of this research. The solubilities of chemicals not
listed in Table 25 were obtained from the literature^).
Standard  Solution
      To prepare a calibration curve for a chemical, an accurately prepared standard
solution  is  required.  The following procedure  was used  to prepare the standard
solution of each  compound.  A  calculated amount of  the compound  and 100 ml of
DDW was added  to an oven-dried 100 ml volumetric flask. The solution was mixed
                                 54

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   TABLE  24.   PROCEDURE FOR  DETERMINING  SOLUBILITY  LIMIT OF AN  ORGANIC
                                 COMPOUND  IN  WATER


(a)  Put distilled deionized water into a teflon-capped bottle (4 L).
(b)  Add enough organic compound to the bottle to observe some nonsoluble (liquid) or paniculate (solid)
    organic compound in the water phase.

(c)  Stir the solution at room temperature (20° C) with magnetic stirrer.

(d)  Add enough compound to produce a saturated solution. This will be identified when there is residual
    insoluble compound remaining in the bottle after the mixing period.
(e)  Before the filtration, prewash a filter with about 100 ml_ of water, then rinse the prewashed filter with
    about 10 ml of the saturated solution.  The prewashing procedure can remove any so-called wetting
    agent from the filter.

(f)  Filter solution with 0.45u.m pore size membrane filter.

(f)  Determine the concentration of organic compound in the filtrate by HPLC.

(g)  The HPLC result is the solubility limit in water. The filtrate is transferred into a teflon-capped amber
    bottle and stored at 4° C room. This is the stock solution for adsorption test. Prior to use, this solution
    is mixed at 20° C.
  TABLE 25.  LIST OF MAXIMUM SOLUBILITIES (20° C)  IN WATER  DETERMINED AS
                         PART  OF  THE  ADSORPTION STUDIES
Compound
Concentration  (mg/L)
Acid Extractables

2-Chlorophenol	20,300
3-Chlorophenol	17,000
4-Chlorophenol	8,650
2,3-Dichlorophenol	3,900
2,4-Dichlorophenol	2,600
2,5-Dichtorophenol	3,600
2,6-Dichlorophenol	1,500
3,4-Dichlorophenol	520
2,4,5-Trichlorophenol	930
2,4,6-Trichlorophenol	415
Pentachlorophenol	13
2,4-Dimethylphenol	7,500
2-Methyl-4-Chlorophenol	2,500
3-Methyl-4-Chlorophenol	3,900
3-Methyl-6-Chlorophenol	1,400
p-Nitrophenol	5,300
2,4-Dinitrophenol	500
Compound
Concentration  (mg/L)
                               Amines

                               Diphenylamine	2.5
                               Toluenediamine	590
                               Brucine	310

                               Alcohols
                               Isobutyl alcohol	3,700
                               Allyl alcohol	4,300
                               Propargyl alcohol	4,900
                               1-Butanol	4,200
                               2,3-Dichloropropanol	7,600

                               Other

                               2-Nitropropane	2,800
                               Thiourea	5,000

                               Explosive Chemicals

                               2,4-Dinitrotoluene	160
                               2,4,6-Dinitrotoluene	610
                               RDX	42
                               HMX	3.8
                                      55

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well until no paniculate matter was visible.  This known concentration was diluted to
five concentrations ranging from 10 mg/L to 100 mg/L (usually 10, 30, 50, 70 and 100
mg/L) since five data points are needed to construct the calibration curve.  The five
standard solutions for each compound were stored at  4° C and used whenever soil
extracts containing the compound were analyzed by HPLC.
Soil Moisture
      The soil moisture content is needed to calculate the amount of chemical sorbed
per unit of dry soil.  The  standard ASTM procedure(33) for measuring  soil moisture
content was followed (Table 26).
SoihSolutlon Ratio
      A single soihsolution ratio may not be satisfactory for all organic compounds.
This is because a weakly  adsorbed compound  may not result in a measurable
concentration  change after contact with soil.  Conversely, a compound's affinity for soil
may be so strong that the final solution  concentration is below analytical detection
limits.
       TABLE 26.  PROCEDURE FOR MEASURING SOIL MOISTURE CONTENT
                           (Taken from ASTM D2216)<33>
  (a)   Place aluminum pans  in an 105° oven for 24 hours.  Transfer them to a dessicator at room
      temperature (20° C) for approximately 1 hour. Measure and  record the weight of an aluminum pan
      on the analytical balance (wt grams).  Precision of the fourth  decimal place is required.
  (b)   Weigh out approximately thirty grams of the sorted soil (w2 grams) into dried aluminum pans.
  (c)   Dry soil at 105° C for 48 hours.
  (d)   Measure and record the weight of the dried soil and the aluminum pan (W3 grams).
  (e)   Calculate soil moisture content, W (%) using the following equation:
              w =     weight of moisture      1QO _ W2 ' W3  x1QO
                   weight of oven-dried soil        w3 - w1

      To  determine an optimum soil:solution  ratio for each compound, batch sorption
tests  were performed using  several soil:solution ratios.  To  evaluate the optimum
                                      56

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soiksolution ratio, the adsorption characteristics  of the  compounds at two different
initial compound concentrations were evaluated. The maximum concentration used for
the adsorption  measurements was the solubility limit of the compound  in water. The
minimum concentration used was about one  order of magnitude  higher than the
lowest  detection limit  determined by high  pressure  liquid chromatography.   The
procedure for determining the optimum soil:solution ratio is outlined in Table 27.

             TABLE 27.  PROCEDURE FOR DETERMINATION OF OPTIMUM
                               SOILrSOLUTION   RATIO
(a)   Set soil-to-solution ratio at 1 :1 to 1 :X.  Required mass of the sorted soil, Ms (gram), and volume of
     solution, V (ml), are calculated by:
                                       Ms(1 -(
                                       V + MS.(W/100)*X
     where W - moisture content of the soil.
(b)   Weigh out the desired amount of sorted soil (Ms grams) into an amber bottle.
(c)   Add V ml of solution to the amber bottle. This is designated as a sample. Prepare another bottle
     which will not contain any soil. This is designated as the blank.
(d)   Place bottles in rotating tumbler in the 20° C room and tumble continuously for 24 hours at 30 rpm.
(e)   After tumbling, centrifuge the bottles for 30 minutes at 4,000 rpm.
(f)   After centrifugation, filter the supernatant with a glass fiber filter and then with a 0.45 u.m pore size
     membrane filter.
(g)   Analyze the concentrations of the filtrate by HPLC.
(h)   Calculate the percent absorption P(%):
                      f    f8
                      cfb
                              100
     where Cfb - final concentration of blank (mg/L), and
          Cfs - final concentration of sample (mg/L).
(j)    Use another soil-to-solution ratio, and repeat (a) through (h).
(k)   The optimum soil solution ratio is one that satisfies the condition that P(%) is between 20% and
      80%.
                                        57

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Solute  Stability
      In conducting batch adsorption  experiments, it  is important to consider the
stability of the solute in solution.   Processes such  as photolysis, hydrolysis, and
microbial degradation can cause a decrease in solute concentration leading to errors
in adsorption results.
      In this study, photolysis was minimized by using  amber bottles to  limit
transmission of light during solution/soil mixing.   By limiting contact time to one day
and  using   an unacclimated soil,  chemical losses due to chemical and microbial
degradation were minimal. Chemical losses due to hydrolysis were not quantified and
thus are included in adsorption calculations.
Other Factors
      Other factors which affect adsorption efficiency include temperature and ionic
strength. The sorption experiments were conducted at 20° C.  All experiments were
conducted at the pH of the soil:solution which was approximately that of the respective
soils. No pH adjustment of the soil solution was made.
      Adsorption is not instantaneous and mixing for  a specific amount of time is
necessary to assure equilibrium. The equilibration time should be the minimum time
beyond  which relatively insignificant changes in the solute concentration will occur.  In
this study,  a separate set of experiments  was conducted to determine the effect of
mixing time on the amount of  chemical  adsorbed.  The results indicated that the
amount  of adsorption, q (mg sorbed/g soil) slightly increased with  time.  However, the
q values did not  vary greatly with  time after 24 hours. The data representing the
amount  of chemical adsorbed after 24 hours were analyzed statistically.  The slope of
q with time was not-statistically  different from zero and q was shown not to vary with
time after 24 hours.  This implied that 24 hours of mixing was enough for equilibrium,
and thus mixing for one day was used in the batch adsorption studies.
                                     58

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Data Analysis
      At least four data points are needed to construct the Freundlich isotherms and to
determine the appropriate coefficients.  In this study, a minimum of four and frequently
as many as eight data points were used to develop the isotherms. The isotherm data
were fit to the Freundlich adsorption equation (Eqn. 6).  A log-log scale was used to
plot the Freundlich isotherm.  The abscissa was the equilibrium (final) concentration in
liquid phase and the ordinate was the amount adsorbed per unit of soil.
      The  data were analyzed by least-square linear regression methods with 95%
confidence interval (Cl)  determined as described in Section 4.  Routine statistical
methods were used(1®).  First, the linear relation between Xj (= log Cj) and Yj (= log qj)
was  determined by the Lotus 1-2-3 program:
      Y =  a + b X                                                           (7)
where a = intercept and b - slope of the line.
      Second, the variances of a and b, Sa2 and S^2 were calculated, respectively
by:
      Sa2 . Sy2 {1/n + Xavg2/(IXj - Xavg)2}                                 (8)
      SD2 = Sy2/(LXj - Xavg)2                                                (9)
where
                  - YUnt j)2/(n-2)}0-5
      Xj, YJ = individual data point of log Cj, log qj, respectively,
      Xavg m average of Xjt
      Y|jnj = estimated Yj value with respect to Xj from the linear relationship
            Y = a+bX,and
      n = number of samples.
      The 95% Cl for the estimates of a and b were determined by a-t Sa to a+t Sa
and b-t S^ to b+t SD, respectively, where the t value can be found in a typical statistical
text for a two-sided test  with a degree of freedom  = n-2, and alpha = 5% level of
significance.
                                     59

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RESULTS
      Following the procedures described above, the  adsorption  isotherms and
constants were determined.  Illustrative sorption patterns and isotherms are noted in
Figures 6 and 7.  The isotherm data are presented in Tables 28 and 29. Based on the
correlation coefficients calculated for the data, the Freundlich equation described the
adsorption satisfactorily for all but a few chemicals in both soils.
      As described  earlier,  the  pH  of  the solution   can affect the  sorption
characteristics.  In this study, no attempt was made to control the pH of the extracts to
any set  value.   Therefore, the  pH of the  extracts varied between  soil types and
between  samples of the same soil type (Tables 28 and 29). In the Texas soil, the pH
range varied from 7.5 to 8.0 while in the Mississippi soil it ranged from 4.5 to 7.0.  In
evaluating and using the sorption data, the different pH  ranges should be recognized.
      As noted earlier, the adsorption  coefficients represent the results obtained over
a specific chemical concentration range and the Freundlich equation that results for a
chemical should not be extrapolated beyond that range.  Tables 30 and 31  indicate
the chemical concentration ranges for which the data in  Tables 28 and 29 are valid.
      A  wide range of chemical concentrations was  evaluated, i.e., from  low mg/l
concentrations  to near or at  saturation  concentrations.   In  many cases, the  range
covered two to three orders of magnitude. Thus, the Freundlich adsorption coefficients
are appropriate for concentrations found  at  sites  with  low as  well as with high
concentrations of these chemicals.
      As discussed, the  adsorption potential  of a chemical  is  governed by
characteristics  of both the chemical and the soil to which it is  exposed.   The
characteristics include: (a) chemical structure, (b) solubility, (c) pH of the solution, (d)
ionization potential of the chemical, (e) polarity, and (f) molecular size. The complex
interaction of these  factors will affect  the  adsorption  that does occur.   These
                                     60

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     Adsorption  of  2,3-Dlchlorophenol in Texas  Soil  at  20°  C


            1.0-
     •8
     c«
     *


     i
     6
     ^»/
     cr

     if
 0.51



 0.0



-0.5-



-1.0-



-1.5-
           -2.0
               1
                                  = 0.99
                  2             3

               log Concentration (mg/1)
       Adsorption of Toluenedlamlne In Texas Soil at 20° C
      B
      N-W
      cr

      j?
-0.6



•0.8-



-1.0-



-1.2-



•1.4-



-1.6-



-1.8
                                 R-0.96
                          a
                             1             2

                          log Concentration (mg/1)
Figure &.   Adsorption  of 2,3-Dichlorophenol  and Toluenedlamlne
                      In Texas Soil at 20° C
                               61

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  Adsorption of 2,3-Dlchlorophenol In Mississippi Soil at  20° C
        0.0-
 j?    -1.5-
       -2.0
                     1          2         3
                      log Concentration (mg/1)
     Adsorption of Toluenedlamlne In Mississippi Soil at 20° C
  o
 I
  E
 s
•0.4-

-0.8

-1.2

-1.6-
       -2.0
                             R = 0.94
Q
                         1             2
                      log Concentration (mg/1)
Figure 7.   Adsorption  of  2,3-Dlchlorophenoi and Toluenediamlne
                   In Mississippi  Soil at 20° C.
                               62

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        TABLE 28.  BATCH SORPTION  ISOTHERM DATA -  TEXAS  SOIL
                    FREUNDLICH  EQUATION  PARAMETERS

COMPOUND	Kg	1_/n	T	PH**
Acid Extractables
Phenol	3.44x10'3	0.53	0.97	7.9
o-Cresol	2.65x10'3	0.58	0.97	7.9
p-Cresol	9.53x10'3	0.55	0.98	++
m-Cresol	3.19x10"6	0.59	0.97	7.9)
2-Chlorophenol	1.01x10'3	0.87	0.99	,	++
3-Chlorophenol	2.93x10'3	0.76	0.99	7.9
4-Chlorophenol	5.50x10'3	0.72	0.98	7.8
2,3-Dichlorophenol	1.71x10'3	0.91	0.99	,	7.8
2,4-Dichlorophenol	4.92x10'3	0.77	0.99	7.6
2,5-Dichlorophenol	2.71x10"3	0.82	0.99	8.0
2,6-Dichlorophenol	6.84x10'4	0.90	0.99	7.5
3.4-Dichlorophenol	7.16x10'3	0.75	0.99	8.0
2,4,5-Trichlorophenol	1.46x10"3	1.02	0,96	7.9
2,4,6-Trichlorophenol	1.76x10'3	0.73	0.99	8.1
Pentachlorophenol	5.94x10'3	0.68	0.99	8.1
2,4-Dimethylphenol	3.94x10"3	0.76	0.99	8.1
2-Methyl-4-Chlorophenol	4.97x10'3	0.75	0.99	7.4
3-Methyl-4-Chlorophenol	4.37x10"3	0.79	0.99	7.4
3-Methyl-6-Chlorophenol	1.56x10"3	0.88	0.99	7.4
p-Nitrophenol	3.20x10'3	0.99	0.96	7.4
2,4-Dinitrophenol	1.14x10'3	0.58	0.96	7.7
4,6-Dinitro-o-Cresol	2.30x10'3	0.57	0.96	8.1
Amines
Toluenediamine	1.74x10"2	0.44	0.96	7.7
Brucine	1.24	0.03	0.47	7.4
Alcohols
Isobutyl alcohol	I.46x10'3	0.59	0.94	8.0
Allyl alcohol	4.50x10'3	0.45	0.91	8.0
Propargyl alcohol	4.60x10'3	0.73	0.85	8.0
1-Butanol	6.20x10'3	0.42	0.81	8.0
2,3-Dichloropropanol	1.10	0.0004	0.78	++
Methanol	9.30	0.28	0.79	8.0
Other
2-Nitropropane	3.54x10"3	0.66	0.94	8.0
Thiourea	2.54x10*4	0.81	0.98	8.2
* -- correlation coefficient; ** - pH of adsorption extract, ++ -- not measured
                                          63

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     TABLE  29.   BATCH SORPTION  ISOTHERM DATA --  MISSISSIPPI SOIL
                    FREUNDLICH  EQUATION  PARAMETERS

COMPOUND	Kjj	-\_ljn	r	PH**
Acid Extractables
Phenol	1.30x10'3	0.71	0.98	5.8
o-Cresol	6.00x10'4	0.87	0.98	++
p-Cresol	1.21x10"2	0.47	0.99	++
m-Cresol	8.60x10'4	0.75	1.00	++
2-Chlorophenol	1.60x10'3	0.77	1.00	++
3-Chlorophenol	4.50x10"3	0.63	0.98	5.5
4-Chlorophenol	9.90x10"3	0.55	0.99	5.6
2,3-Dichlorophenol	8.5x10"3	0.65	1.00	6.9
2,4-Dichlorophenol	6.80x10'3	0.65	1.00	++
2,5-Dichlorophenol	6.90x10'3	0.80	0.99	++
2.6-Dichlorophenol	6.70x10"3	0.61	1.00	++
3.4-Dichlorophenol	4.70x10'3	0.78	0.96	5.6
2,4,5-Trichlorophenol	3.60x10"3	0.91	0.97	++
2,4,6-Trichlorophenol	9.80x10'3	0.57	1.00	++
Pentachlorophenol	1.6xlO'3	0.51	1.00	6.2
2,4-Dimethylphenol	5.10x10"5	1.28	0.92	5.1
2-Methyl-4-Chlorophenol	6.40x10'3	0.65	1.00	++
3-Methyl-4-Chlorophenol	7.30x10"3	0.68	0.99	7.0
3-Methyl-6-Chlorophenol	3.00x10'3	0.77	0.99	6.2
p-Nitrophenol	3.20x10'3	0.64	1.00	5.7
2,4-Dinitrophenol	1.10x10~3	0.78	0.95	++
4,6-Dinitro-o-Cresol	8.60x10"4	0.86	0.99	4.5
Amines
Toluenediamine	5.07x10'5	1.28	0.94	5.3
Brucine	6.18x10'2	0.48	0.97	++
Alcohols
Isobutyl alcohol	5.10x10'5	1.28	0.92	5.7
Allyl alcohol	3.30x10'4	0.72	0.96	5.7
Propargyl alcohol	6.30x10'4	0.61	0.89	5.8
1-Butanol	2.80x10"3	0.43	0.85	5.7
2,3-Dichloropropanol	S.OxlO"5	0.90	0.64	++
Methanol	1.40x10'3	0.66	0.82	5.9
Other
2-Nitropropane	3.54x10"2	0.66	0.94	5.7
Thiourea	1.50x10"4	0.92	0.98	5.1
* - correlation coefficient; " -- pH of adsorption extract, ++ - not measured
                                          64

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TABLE  30.   CHEMICAL CONCENTRATION RANGE EVALUATED DURING THE BATCH
                    ADSORPTION  EXPERIMENTS ••  TEXAS  SOIL
                  Compound                Concentration Range (mg/l)
            Acid Extractables

            Phenol	9-10,300
            o-Cresol	20-1,000
            p-Cresol	11-6,400
            m-Cresol	8-3,200
            2-Chlorophenol	26-20,300
            3-Chlorophenol	27-7,800
            4-Chlorophenol	18-8,600
            2,3-Dichlorophenol	40-3,900
            2,4-Dichlorophenol	19-2,300
            2,5-Dichlorophenol	16-3,600
            2,6-Dichlorophenol	26-1,500
            3,4-Dichlorophenol	21-520
            2,4,5-Trichlorophenol	19-910
            2,4,6-Trichlorophenol	20-410
            Pentachlorophenol	3-13
            2,4-Dimethylphenol	90-7,400
            2-Methyl-4-Chlorophenol	18-2,400
            3-Methyl-4-Chlorophenol	25-3,800
            3-Methyl-6-Chlorophenol	36-1,400
            p-Nitrophenol	10-5,200
            2,4-Dinitrophenol	10-500
            4,6-Dinitro-o-Cresol	18-130

            Amines

            Toluenediamine	27-550
            Brucine	15-300

            Alcohols

            Isobutyl alcohol	40-3,600
            Allyl alcohol	15-4,300
            Propargyl alcohol	45-4,900
            1-Butanof	67-3,800
            2,3-Dichloropropanol	78-7,600
            Methanol	49-4,200

            Other

            2-Nitropropane	58-2,800
            Thiourea	17-4,800
                                        65

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TABLE  31.   CHEMICAL  CONCENTRATION RANGE EVALUATED DURING THE  BATCH
                 ADSORPTION  EXPERIMENTS -- MISSISSIPPI  SOIL
                  Compound                Concentration Range (mg/l)
             Acid Extractables

             Phenol	9-10,300
             o-Cresol	20-1,000
             p-Cresol	12-6,400
             m-Cresol	100-13,000
             2-Chlorophenol	34-20,300
             3-Chlorophenol	25-8,800
             4-Chlorophenol	34-8,600
             2,3-Dichlorophenol	30-2,600
             2,4-Dichlorophenol	18-2,500
             2,5-Dichlorophenol	22-2,800
             2,6-Dichlorophenol	26-1,500
             3,4-Dichlorophenol	18-520
             2,4,5-Trichlorophenol	22-930
             2,4,6-Trichlorophenol	16-310
             Pentachlorophenol	7-13
             2,4-Dimethylphenol	18-6,300
             2-Methyl-4-Chlorophenol	15-2,500
             3-Methyl-4-Chlorophenol	43-3,900
             3-Methyl-6-Chlorophenol	12-1,400
             p-Nitrophenol	10-5,300
             2,4-Dinitrophenol	4-260
             4,6-Dinitro-o-Cresol	23-130

             Amines

             Toluenediamine	160-580
             Brucine	30-300

             Alcohols

             Isobutyl alcohol	40-3,700
             Allyl alcohol	15-4,300
             Propargyl alcohol	45-4,900
             1-Butanol	67-3,800
             2,3-Dichloropropanol	78-7,600
             Methanol	49-4,000

             Other

             2-Nitropropane	59-2,800
             Thiourea	21-5,000
                                         66

-------
experiments were  conducted  under reasonable  real world  conditions.   Soils  of
different characteristics  (pH, CEC and organic carbon) different chemicals, and
different chemical concentrations were used.   As a result it was not possible  to
determine the relative effect of such parameters.
      However, the data do allow overall effects to be identified. When the Freundlich
Kf values for the two soils, i.e., the capacity or  affinity of the  soils, were compared
(Table 32), in general, the Texas soil had the greater values and therefore the greater
sorption capacity for the  acid extractables.  However, the opposite was true for the
amines and alcohols for which the Mississippi soil had the greater Kf values, in  some
cases greater by a factor of 10 or 100.
CONCLUSIONS
1.    The Freundlich equation described the adsorption of the chemicals on the two
      soils  satisfactorily,  i.e., with high correlation  coefficients, except for a few
      chemicals.
2.    The range of chemical concentrations evaluated  ranged from the low mg/l
      concentrations to near or at saturation concentrations and for most chemicals
      covered  two  to  three  orders of magnitude.  Thus,  the adsorption data are
      appropriate for concentrations found at sites with  low as well  as high
      concentrations of these chemicals.
3.    For these concentration ranges, a linear adsorption  relationship, i.e., n =  1, did
      not occur.
4.    The Freundlich Kf values for chemicals in the two soils were different.  For the
      acid extractables, the Kf values generally  were greater in the Mississippi soil.
      For the amines and alcohols, the Kf values were greater in the Texas soil.
                                     67

-------
TABLE 32.  COMPARISON OF FREUNDLICH  ADSORPTION COEFFICIENTS   (Kf) FOR
                   THE TEXAS  AND MISSISSIPPI  SOILS
Tsxas Mississippi
Compound
Add Extractables
Phenol
o-Cresol
p-Cresol
m-Cresol
2-Chtorophenol
3-Chlorophenol
4-Chtorophenol
2,3-Dichlorophenol
2,4-Dichlorophenol
2,5-Dichtorophenol
2,6-Dichlorophenol
3,4-Dichtorophenol
2,4,5-Trichlorophanol
2,4,6-Trichlorophenol
Pentachlorophanol
2,4-Dimethylphenol
2-Methyl-4-Chforophenol
3-Methyl-4-Chk>rophenol
3-Methyl-6-Chtorophenol
p-Nitrophenol
2,4-Dinitrophanol
4,6-Dinrtrophenol
Soil

3.4x1 0'3
2.7x10'3
9.5x1 0'3
3.2x1 0'6
1.0x10'3
2.9x1 0'3
5.5x1 0'3
1.7x10"3
4.9x1 0'3
2.7x1 0'3
j
6.8x1 0'4
7.2x1 0'3
1.5x10"3
1.8x10'3
5.9x1 0'3
3.9x1 0'3
5.0x1 0'3
4.4x1 0'3
1.6x10'3
3.2x1 0"3
1.1x10'3
2.3x1 0'3
Soil

1.3x10"3
6.0x1 0"4
1.2x10"2
8.6x1 0'4
1.6x10'3
4.5x1 0'3
9.9x1 0'3
8.5x1 0"3
6.8x1 0'3
6.9x1 0"3
1%
6.7x1 0'3
4.7x1 0'3
3.6x1 0'3
9.8x1 0"3
1.6x10-3
5.1x1 0'5
6.4x1 0'3
7.3x1 0"3
3.0x1 0'3
3.2x1 0'3
1.1xiO'3
8.6x1 0'3
Compound
Amlnet
Toluenediamine
Brucina
Alcoholi
Isobutyl alcohol
Allyl alcohol
Propargyl alcohol
1 -Butanol
2,3-Oichloropropanol
Methanol
Othir

2-Nitropropane
Thiourea









Texas Mississippi
Soil

1.7x10'2
1.24

1.5x10"3
4.5x1 0"3
4.6x1 O*3
6.2x1 0'3
1.10
9.3


3.5x1 0"3
2.5x1 0'4









Soil

5.1x1 0"5
o
6.2x1 0'2

5.1x10'5
3.3x1 0'4
6.3x1 0'4
2.8x1 0"3
5.0x1 0'5
1.4x10"3


3.5x1 0'2
1.5x10'4









                                68

-------
                                SECTION  7
                           TOXICITY  REDUCTION

    A major objective of this study was to provide comprehensive screening data on
the treatability of specific organic chemicals in soil.  Hazardous constituents that enter
the soil are to be detoxified or immobilized.
    When a chemical is added to the soil, it is transformed into other products through
chemical  and biological  reactions with or without  complete detoxification and
immobilization. Measuring the loss of the parent compound, such as was presented in
Section 4, does  not assure that complete detoxification and  immobilization occurs.
Intermediate degradation products, which may be more mobile and/or toxic than the
parent compound, may be generated as the parent compound degrades.
    Additional information on the transformation and/or detoxification of a chemical is
necessary to establish that the loss of the parent compound leads to the complete
detoxification of the chemical or waste.  Such information can be obtained using either
chemical or bioassay analyses.
    Chemical  analysis  of detoxification  products may  yield information about
biochemical  degradation pathways, but it is time  consuming  and expensive.
Bioassays have been used successfully to demonstrate detoxification of the applied
waste in the soiK12> 13> 15) and are less expensive and time consuming.  Such
bioassays also have been used as  a screening tool to evaluate the soil  treatment
potential of a chemical or wasted ^« 34)
APPROACH
    In this study, the reduction of toxicity that occurred in selected degradation studies
was evaluated by determining the toxicity of the water soluble fraction  (WSF) of the
chemical/soil mixture at the same sampling intervals used to obtain the degradation
data.  The chemical compounds that can be  extracted with water represent the

                                69

-------
 potentially  leachable  fraction of  the  chemical  or any  intermediate  chemical
 detoxification  products.  The WSF of the chemical poses the  greatest threat  to
 groundwater contamination.   Hence, evaluating the loss of the potentially  leachable
 fraction of a chemical is important.
    In addition, the concentration of the parent chemical in the WSF  also  was
 determined. This concentration was expressed in terms of quantity of chemical that
 was water extractable per kg of the soil. The procedures for: (a) obtaining the WSF, (b)
 determining the toxicity of the WSF using the Microtox© method, and (c) determining
 the chemical concentration were the same as those described in the earlier sections.
    To put the toxicity reduction data in perspective, the WSF toxicity reductions, the
 WSF  chemical  concentration  reductions and  the  soil  chemical concentration
 reductions were compared.
 RESULTS
    This toxicity and chemical reduction comparison was done  for phenol  and eight
 different chloro- substituted phenols: phenol; 2-, 3- and  4-Chlorophenol; 2,3-, 2,4-, and
 2,6-Dichlorophenol; 2,4,6-Trichlorophenol;  and  Pentachlorophenol.  Texas soil  was
 used in each degradation study.
    Two loading rates were used.  One was the acceptable loading  rate identified  in
 Section 4  (Table 11)  and the other was  twice those loading  rates.  Based upon
 previous work(12- 13), loading rates twice the acceptable rates were not expected to
 completely inhibit degradation.  However,  the higher rates  could slow degradation
 rates and may  result in detoxification by-products if incomplete detoxification  occurred.
 Chemical  Loss In Soil
    The kinetic  parameters  for the loss  of chemical in  the  soil microcosms are
 presented in Table 33.  Data that represented concentrations that were zero or below
the detectable  limit were not included in the kinetic analyses because it was not clear

                                 70

-------
           TABLE  33.   CHEMICAL LOSS  IN  SOIL  - KINETIC  PARAMETERS
Initial Cone First Order Kinetics
Chemical mg/kg+
Phenol
2-Chlorophenol
3-Chlorophenol
4-Chlorophenol
2,3-Dichlorophenol
2,4-Dichlorophenol
2,6-Dichlorophenol
2,4,6-Trichlorophenol
Pentachlorophenol
1400
700
760
380
235
120
176
88
260
130
180
90
1260
630
600
300
60
30
Half Life
(days)
19.5
4.1
4.1
1.7
16.2
21.8
1.5
1.0
27.2
8.3
3.7
1.5
12.8
2.4
11.0
5.3
3.6a
6.7
r*
0.96
0.92
0.97
0.98
0.93
0.97
0.92
0.91
0.91
0.97
0.89
0.94
0.99
0.91
0.92
0.94
1.00
0.92
95%CI"
16.5-23.9
3.2-5.7
3.5-4.9
1.5-1.9
13.1-21.5
19.6-24.6
0.9-3.6
0.7-1.3
21.2-37.9
8.1-8.5
2.7-5.8
1.1-2.4
12.0-13.7
2.0-3.0
8.7-15.0
4.60-6.3
5.5-8.5
•*
?ero Order Kinetics
mg/kg-d
32.7
59.3
37.0
26.1
6.0
2.3
21.5
14.5
4.7
3.6
8.4
6.1
34.3
41.8
18.0
10.4
4.4a
0.99
r
0.95
0.96
.0.90
0.90
0.92
0.9,5
0.92
0.91
0.88
0.98
0.98
0.96
0.96
0.97
0.88
0.94
0.88
0.90
95% Cl
25.7-39.6
48.5-70.1
24.2-49.8
20.4-32.0
4.4-7.6
2.0-2.6
8.6-34.3
9.7-19.2
3.0-6.3
3.5-3.7
7.2-9.6
5.4-6.8
27.9-40.7
36.7-46.9
11.9-24.2
8.8-12.1
0.80-1.2
+    Initial concentration of chemical in soil at time zero, mg/chemical per kg of dry soil, lower concentration is the
     acceptable loading rate as discussed in Section 4 and as noted in Table 11.
*    Correlation coefficient
' *   95% confidence interval for the kinetic parameter
a    Data from initial lag phase (through day 21) were excluded in calculating these values; data points were too few
     to calculate 95% confidence intervals.
when the chemical actually disappeared.  The data fit both first and zero order kinetics
satisfactorily as indicated by the  high correlation coefficients.
    The data for the  lower loading rates were  the same as  that  obtained in the
degradation studies (Section 5, Table 18) since they were done at the same time as
                                      71

-------
the previous studies.  In most cases, the kinetic parameters at the higher loading rates
were larger than those at the lower loading rates.
    Example chemical loss patterns for 2,4-Dichlorophenol and Pentachlorophenol
(PCP) at the higher loading  rates are noted in Figure 8. The initial PCP concentration
of 60 mg/kg resulted in a lag phase  up to 21 days  after the chemical loading.
However, the microcosm extracted on day 29 indicated a  reduced concentration of
PCP and that acclimation had occurred.  Because there was a rapid chemical loss
after the lag period (Figure 8), kinetic parameters were obtained using data from days
21 and 29.  No lag periods occurred for the other chemicals at any of the loading rates.
WSF Chemical Loss
    The change of chemical concentration in  the WSF  also was analyzed and both
first  and zero order kinetic parameters were determined.   The  kinetic data  are
summarized in Table 34. First and zero order kinetics satisfactorily represented the
data.  Due to rapid loss of 4-Chlorophenol, data on the WSF reduction of this chemical
were limited. As with the soil data, PCP concentrations in the WSF exhibited a lag
phase at the higher loading and only zero order kinetics could be calculated from the
data obtained after the end of the lag phase.
    With respect  to the  higher loading rates, Table 34  indicates that:  (a)  higher
chemical concentrations  were in the WSF initially at the  higher loading rates, and (b)
for the first order kinetics, the WSF chemical concentrations decreased at a slower rate
(greater half life) when the chemicals were applied  at the higher  loading rate.  No
difference was apparent in zero order kinetics due to the difference in loading rates.
    Examples of WSF chemical loss patterns for two  chemicals  are presented in
Figure 9. The losses for both initial concentrations are indicated.
                                 72

-------
TABLE 34. LOSS OF WATER EXTRACTABLE CHEMICAL -- KINETIC PARAMETERS
Initial Cone
Chemical mg/kg+
Phenol

2-Chlorophenol
3-Chlorophenol
4-Chlorophenol
2,3-Dichlorophenol
2,4-Dichlorophenol
2,6-Dichlorophenol
2,4,6-Trichlorophenol
Pentachlorophenol
+ Milligram of chemical
replicates
' Correlation coefficient
1150
575
610
305
155
75
93
32
130
68
98
55
1080
580
570
310
25
11
First Order Kinetics
Half Life
(days)
10.9
3.7
4.0
2.2
14.6
9.5
1.6
1.6
17.0
7.9
3.3
0.93
9.5
8.3
11.5
6.5
— initial
3.9

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
r*
.80
.60
.98
.95
.98
.93
.99
.97
.89
.97
.91
.85
.92
.99
.92
.98
lag phase —
0.84
that was water soluble at



time zero

95%CI"
7.8-18.1
2.0-36.8
3.7-4.4
1.8-2.9
13.2-16.4
7.9-11.9
	 £ 	
	 £ 	
13.5-22.9
7.0-9.1
2.6-4.6
0.6-1.9
7.9-12.0
7.7-8.9
9.5-14.7
5.9-7.4
2.7-7.3
per kilogram

Zen
mg/kg-d
35.5
46.8
21.7
30.6
4.
2.
11
5.
3.
3.
4.
8.
32
27
17
16
2.
1.
of dry

4
9
.9
3
2
6
8
8
.4
.9
.0
.4
2
2
soil,

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
a Order Kinetics
r
.85
.87
.86
.95
.95
.91
.95
.74
.90
.95
.94
.97
.98
.97
.93
.98
.99
.88
average


95% Cl
23.5-47.5
27.9-65.7
15.3-28.2
23.6-37.6
3.6-5.1
2.3-3.6
:
-#~
_a_
ff
2.4-4.0
3.0-4.1
3.8-5.8
7.0-10.6
30.
24.
13.
14.
0-35.8
2-31.6
6-20.4
6-18.1
0.76-1.7
of two

or three

95% confidence interval for the kinetic parameter
* Insufficient data to calculate 95%
confidence intervals due to rapid loss of chemicals
                           73

-------
o
(A
••»
O

O»
J£
O>
—
"o
c
0
.c
Q.
O
£
£
O
O
<*
en


"5
«
"5
CT
01
§,
a
0




200-
i


150-
•
100-



50-


0.


Loss of 2,4-Dichlorophenol
a
a
Initial chemical concentration in soil = 1 80 mg/kg
a
D
D

a

m ^
i • i i • i • i
0 5 10 15 20 25

Time in Days
80-
60 <
•
40-


20-


-i
Loss of Pentachlorophenol
B
B Initial PCP concentration in soil = 60 mg/kg
a a a Q
a




B


0- 5 101520253035
                        Time  in Days
Figure 8.  Loss  of Chemical in Two Experiments When the Higher
                  Loading  Rates  Were Used
                        74

-------
 Loss of 2-Chlorophenol in the WSF of the Soil Microcosms






^^
~0
in
"5
CD
£
Q.
O
CM
"5
U.
(fi

800-
600 J

400-
i
200-
o-
C

I a = initial concentration = 760 mg/kg of soil
» = initial concentration = 380 mg/kg of soil

Q
a
D
B
9 • a m
*D « q g
) 5 10 15 20 25 30
Tim* in Days
Loss of 2,4,6-Trichlorophenol in the WSF of the Soil Microcosms
'o
o
0
O)
Q.
O
40
CM"
"5
u.
w






600-
500-
400-
300-
200-
100-
o-
0


g H = initial concentration - 600 mg/kg of soil
H « = /n/'f/a/ concentration = 300 mg//cg of so//
t Q
* • * B 5 i
• ° B
* a

10 20 30
Tim* In Day*
Figure 9.  Loss of Chemical  in The WSF at Two  Loading Rates
                      75

-------
WSF  Toxicltv Reduction
    The evaluation of loss of applied chemical in the soil microcosms and in WSF did
not address the existence of possible toxic transformation products.  A study of the
toxicity of the constituents in the WSF can indicate the presence and/or accumulation
of any potentially teachable toxic intermediate products.
    The toxicity of the WSF was measured by the Microtox® procedure and  was
expressed as soil toxicity units (Section 4).  The resulting  data was analyzed by  both
first and zero order kinetics to  provide  results  that were consistent with the soil
chemical loss and the WSF chemical loss. Data on these kinetic parameters, in terms
of toxicity reduction, are presented in Table 35.  Both first and zero order kinetics
appeared to represent the data satisfactorily.
    Examples  of the toxicity  reduction patterns that occurred are presented in Figure
10. The WSF toxicity reductions that were noted were the result of the detoxification
that occurred in the soil microcosms as they were incubated at 20° C for the indicated
time periods.
    With Pentachlorophenol, the WSF toxicity reduction indicated a slow reduction for
the first days of incubation, followed by a rapid decrease (Figure 10).  No other lag
periods in toxicity reduction were observed for the other chemicals.
    As had been  noticed with the WSF chemical loss and the soil chemical loss, the
soil chemical  loading rates did cause different results.  With respect to the toxicity
reduction data (Table 35), the higher loading rates: (a) resulted  in a higher initial WSF
toxicity, and (b) larger toxicity reduction  half-lives.  No difference in the zero  order
kinetics as a function of loading rate was apparent.
Comparison  of  Chemical  Losses and Toxicltv Reduction
    The loss of the chemical in the soil and in the WSF and the  WSF toxicity reduction
data were compared using the first order kinetic data (half-lives).  Figure 11 compares
the half-life of the soil and the WSF chemical loss for all of  the nine chemicals tested at
                                  76

-------
both low and high loadings.  The correlation shows that, in general, the soil chemical
half-life  was about  1.5 times greater than the WSF  chemical  half-life.  For these
chemicals, this indicates that the loss of the chemical in the WSF was about 1.5 times
faster than the loss of the chemical in the soil.  This correlation also indicated that no
enhanced mobilization  of  applied chemical  occurred as the degradation  and
detoxification took place.

         TABLE 35.   WSF TOXICITY REDUCTION --  KINETIC PARAMETERS
First Order Kinetics
Chemical Chemical
Initial Cone
rna/ko+

Phenol

2-Chlorophenol

3-Chlorophenof

4-Chlorophenol

2,3-Oichlorophenol

2,4-Dichlorophenol

2,6-Dichlorophenol


1400
700
760
380
235
120
176
88
260
130
180
90
1260
630
2,4,6-Trichlorophenol600

Pentachlorophenol

300
60
30
Initial
Toxicity

40
13
20
10
28
15
46
6
37
19
52
22
31
14
29
12
31
13
Half Life
(davsl r*

14.9
10.2
5.8
5.8
14.5
8.9
1.8
0.6
18.7
7.7
5.3
2.4
11.2
13.3
12.1
5.8
24.3
7.3

0.87
0.5
0.96
0.95
0.88
0.91
0.87
0.97
0.92
0.90
0.95
0.87
0.95
0.79
0.92
0.94
0.78
0.88
95%cr

11.6-20.6
Zero Order
Sol
JJJffl r


1.17
— 1.17
5.0-7.0
4.6-7.8
11.5-19.5
7.3-11.3
1.1-4.0
-@-
15.5-23.6
6.2-10.2
4.5-6.5
1.7-4.1
9.6-13.4
9.3-23.7
9.9-15.3
5.0-7.1
16.4-46.6
5.3-11.9
0.90
0.76
0.76
0.
6
4
0.
1
2
2
0.
0.
0.
0.
0.
0.
62
.0
.5
75
.1
.2
.9
95
49
79
64
65
90

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

.90
.81
.91
.95
.92
.95
.90
.88
.89
.89
.98
.93
.95
.81
.89
.94
.76
.88
Kinetics

95% Cl

0.89-1
0.65-1
0.69-1
0.57-0.
0.60-0.
0.52-0.
3.0-9.
2.3-6.
0.56-0.
0.8-1.
2.0-2.
2.1-3.
0.80-1
0.29-0.
0.59-0.
0.53-0.
0.31-1
0.55-1

.5
.7
.7
95
91
95
0
6
94
3
5
8
.1
70
99
76
.0
.3
+   Initial concentration of chemical in soil at time zero, mg/chemical per kg of dry soil, lower concentration is the
    acceptable loading rate as discussed in Section 4 and as noted in Table 11
++  Toxicity of the WSF at time zero in toxicity units (Section 4)
    Correlation coefficient
''   95% confidence interval for the kinetic parameter
a   Data from initial lag phase (through day 21) were excluded in calculating these values; data points were too few
    to calculate 95% confidence intervals.
                                     77

-------
50
40
S
&J 30
n 20
1 10
n.
2,3-Dichlorophenol
• * initial concentration
g • * initial concentration
t ™ 0 B
•t; • " g :

- 260 mg/kg of soil
m 130 mg/kg of soil


             10
20
30
40
                          Time In Days
Pentaohlorophenol
40 n
§ 30-
I 20-
>-
S 10-
o-
c
i
• _ • - initial concentration m 60 mg/kg of soil
m • - //?/f/a/ concentration m 30 mg/kg of soil
• S B
8

1 10 20 30
Time In Days
Figure 10.  Toxlclty Reduction In the WSF from the Soil Microcosms
                         78

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                to
                w
                o
"m <"   20
ra Q   *"
o°
E —
62
= 2   «1
               -1.39+ 1.47x
                                                          R-0.87
   10        21
  Half Life In Days
WSF Chemical  Loss
                                                   30
          Figure 11.  Comparison of Chemical Loss In the Soil and the WSF
                       for Phenol and Eight  Chlorophenols
      The toxicity reduction study was conducted to evaluate the possibility of toxic
intermediate chemicals and their effect, if any, on the treatment of the chemical applied
to the soil.   The WSF of the land applied hazardous constituents pose the immediate
threat to soil microbes and groundwater, and the identification of any  potentially
leachable toxic constituents is important to evaluate the performance of a HWLT.
      The toxicity of the WSF could be a result of: (a) the chemical added to the soil,
(b)  intermediate transformation products that are potentially teachable,  and (c)
background  toxicity  from the soil.  The analyses of blank samples (soil only) did not
show any background toxicity from the Texas soil used in this research. The toxicity of
the  WSF extracted on day zero was contributed only by the applied target chemical,
since degradation had not yet occurred. The subsequent reduction in toxicity  of the
WSF was a result of detoxification and immobilization reactions in the soil.
      The chemical loss in the soil and the WSF and the WSF toxicity reduction were
compared.   In each case, the WSF toxicity decreased as the soil chemical and the
                                 79

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 WSF chemical concentrations decreased.  Figure  12 provides an example of the
 decreases for 2,4-Dichlorophenol.

«^
o

o


w
0
0
o
E



250-

200


150

100
SO

0 .
•
I »


1
" '
<_« '
It


i
O
in
o
- WSF toxicity reduction r> » ui
- chemical toss in soil
-WSF chemical toss




-
n
• • *
L t
0
*
45
H

30 5
c
3
15 >,
*;
_u
• n K
                               10        20
                                  Time In Days
so
 Figure 12.  Decrease of Soil and WSF Chemical Concentration and of WSF Toxicity as a
              Function of Time-Degradation  Study  of  2,4-Dlchlorophenol

      Figure 13 compares the WSF chemical loss and the WSF toxicity reduction for
all nine tested chemicals at both low and  high loadings.  The correlation of 0.90
indicates that the WSF toxicity can be attributed to the target chemical concentration in
the WSF and that no water extractable toxic intermediate products were formed.  Thus,
these chemicals were detoxified in the soil.
              3 >»
                    10
              (0
                                             y-2.0 + 0.95x    R-0.90
                      0             10             20
                                 Half Life In Days
                               WSF Chemical Loss
   Figure 13.  Comparison of WSF Chemical  Loss and the WSF Toxicity Reduction for
                         Phenol and  Eight Chlorophenols
                                  80

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CONCLUSIONS
      The loss of chemical in the soil and in the WSF extracted from the soil and the
reduction of toxicity of the WSF were evaluated for nine chemicals that were part of this
study: phenol and eight chlorophenols. Two loading rates and one soil (Texas soil)
were used.  The results were:
  1.   Both first and zero order kinetics satisfactorily represented the chemical loss
      and toxicity reduction data.
  2.   The microcosms with  Pentachlorophenol resulted in a lag phase in  chemical
      loss and WSF toxicity  reduction, especially at the higher loading rate.  No lag
      periods were observed with any of the other chemicals at either loading rate.
  3.   The higher chemical loading rates resulted in higher chemical concentrations in
      the WSF and higher WSF toxicities at time zero.
  4.   The higher chemical loading rates generally resulted in slower chemical losses
      (higher half-lives) and toxicity reduction. However, at both loading rates for
      each chemical, the chemicals were  degraded and the toxicity was reduced.
  5.   No differences were apparent in zero order kinetics due to the loading  rates.
  6.   The loss of the chemicals in the WSF was about 1.5 times faster than the loss of
      the chemical in the soil.
  7.   The WSF  toxicity for  each chemical decreased as the  soil chemical and the
      WSF chemical concentrations decreased.
  8.   The WSF  toxicity decreased  at about the  same rate as the WSF  chemical
      concentration when the data for all the nine chemicals were compared.
  9.   No enhanced mobilization of the applied chemical  occurred as the degradation
      and detoxification occurred.
                                 81

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                               SECTION  8
                 MUNITIONS  WASTES  AND  CHEMICALS

    As part of this cooperative agreement, the soil treatablility potential of a hazardous
waste generated in the explosives industry and  several chemicals used  in that
industry were evaluated (Table 2).  The toxicity and  adsorption behavior of these
chemicals and the waste were determined using procedures outlined in Sections 3
and 4.  Because of limited quantities of ROX and HMX available, these compounds
were not evaluated as part of the degradation studies.  RDX and  HMX were obtained
from the United States Army Toxic and Hazardous Materials Agency (USATHAMA).
TNT was obtained commercially from Chem Services, Inc. in Pennsylvania. 2,4- and
2,6-Dinitrotoluene were purchased from Aldrich Chemicals, Milwaukee, Wisconsin.
    In  addition to  these   chemicals, wastewater  treatment  sludge  from  the
manufacturing of explosives at the Holston Army Ammunition Plant was evaluated for
its land treatability potential.  This sludge was obtained with the help of USATHAMA.
The following  sections summarize  the toxicity,  adsorption and  degradation
characteristics of the pure compounds  and the land treatability potential of munitions
waste treatment sludge.
RELATIVE TOXICITY AND LOADING  EVALUATION
      Results of the toxicity evaluation are summarized in Table 36.  As  part of the
adsorption experiments, the  maximum solubility of HMX was established as 3.8 mg/l.
This low  solubility made the toxicity evaluation difficult.  The toxicity of hydrophobic
compounds cannot be properly evaluated using the Microtox© system. Because of the
limited quantities of HMX and RDX that were obtained, neither chemical was able to
be evaluated for soil mass loading ranges.
                                82

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    TABLE 36.  EC5Q DATA AND ACCEPTABLE  LOADING RATES FOR MUNITIONS
                          MANUFACTURING CHEMICALS

                        ECgQ Value (mg/h         Loading Rates (mg/kg of soil)*
Compound	Value	95%  Cl    Texas  Soil    Mississippi Soil

2,4-Dinitrotoluene	31.2	29.7-32.8	500	165
2,6-Dinitrotoluene	4.4	4.3-4.5	86	74
TNT (2,4,6-Trinitrotoluene)	1.0	0.7-1.3	14	12
RDX	76.1	60.0-97.0	*	*
HMX	"	"	*	*
*   Loading rate data for RDX and HMX could not be evaluatod since sufficient quantities of
   material could not be obtained.
''  Due to its insolubility, EC5Q data for HMX could not be obtained.
+  Lower loading rate as determined using the procedure in Table 9
ADSORPTION
Methods
      The procedure followed for evaluation of the adsorption behavior of RDX, HMX,
and  TNT was a  modification of that outlined  in Section 3.  The  following section
describes the protocol used to evaluate the sorption behavior of these chemicals.
      RDX and HMX were received as aqueous solutions consisting of approximately
100 mg of chemical in  five milliliters of water. Prior to use, the compounds were dried
at 105° C. After drying, each chemical was used to prepare standard stock solutions
using a 50:50 mixture  of waterMethanol as the solvent.  This protocol improved the
accuracy of chemical detection.  The final concentrations of the RDX and HMX stock
solutions were 41.8  and 3.8  mg/l, respectively.  The  resulting concentration of HMX
was  very close to the detection limit of  this  compound  by  high pressure  liquid
chromatography (~1  mg/l).
                                  83

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      TNT was received as a solid consisting of 20% moisture.  The moisture content
was taken into account in  preparing a stock solution  of 700 mg/l TNT using a 50:50
mixture of watenmethanol as the solvent.
      External standard solutions were prepared from the stock solutions by a serial
dilution technique utilizing the 50:50 watermethanol solvent mixture.  These external
standards were used  to  evaluate  the concentration of aqueous  chemical stock
solutions used in adsorption  tests.  Chemical concentrations were determined using
the HPLC and a 50:50  watermethanol solution as the eluent for the RDX and HMX.
Methanol was used as the eluent for TNT.
Results
      The range of chemical concentrations evaluated is noted in Table 37.   The
adsorption results for 2,4- and  2,6-Dinitrotoluene are presented in Table 38.   The
Freundlich  equation  described  the sorption of these chemicals on the two  soils
satisfactorily, i.e., with high correlation coefficients. However, such was not the case
for the other munitions chemicals.
      The sorption data for TNT, RDX and HMX are  presented in Tables 39 and 40.
With TNT, for both soils, the value of qe  reached a maximum of about 0.045 mg
TNT/gm dry  soil at a solution  concentration of about 15 mg/l TNT and then decreased
at higher solution concentrations.   This  is not in agreement  with  the Freundlich
equation in which qe  should increase as the compound concentration approaches its
solubility limit(31).  Data for the other chemicals (RDX and HMX) also produced poor
correlation with the Freundlich equation. The correlation coefficients  ranged from 0.0
to 0.44.
      As discussed in Section 6, the adsorption of a chemical is affected by a number
of characteristics, none of  which were evaluated in these experiments.  For the two
chemicals for which the Freundlich equation did seem to fit the adsorption data (Table
38), the  Texas soil appeared to have a greater affinity (higher Kf value) for 2,4-
                                 84

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 TABLE 37.   CHEMICAL CONCENTRATION RANGE  EVALUATED DURING  THE BATCH
            ADSORPTION EXPERIMENTS •• MUNITIONS CHEMICALS
                               Concentration Range fma/ko)
Compound
2,4-Dinitrotoluene
2,6-Dinitrotoluene
(2,4,6-Trinitrotoluene) TNT
RDX
HMX
Texas Soil
32-160
37-600
0.1-60
8-30
0.9-3.6
Mississippi Soil
15-150
14-200
0.3-90
11-32
1.5-3.8
  TABLE 38.  FREUNDLICH ISOTHERM DATA - TEXAS AND MISSISSIPPI SOILS
                      2,4- AND 2,6-DINITROTOLUENE
Compound
'correlation coefficient
1/n
r*
PH
Texas Soil
2,4-Dinitrotoluene
2,6-Dinitrotoluene
Mississippi Soil
2,4-Dinitrotoluene
2,6-Dinitrotoluene

9.2x1 0'3
5.0x1 0'3

6.3x1 0"3
1.4x10"2

0.59
0.61

1.08
0.68

0.88
0.90

0.99
0.95

7.6
8.1

5.2
5.6
                              85

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          TABLE 39.  ADSORPTION DATA FOR TNT, HMX AND  RDX
                          IN TEXAS SOIL AT 20° C
2,4,6-Trlnltrotoluene  (TNT)   (pH=7.8)

      Concentration fmg/l)                         q£ (mg sorbed/ g dry soin
             0.1                                         0.0031
             6.5                                         0.0238
             13.2                                        0.0475
             60.8                                        0.0311

RDX (pH=8.0)

      Concentration (mg/l)                         q^ (mg sorbed/ g dry soil)
             8.6                                         0.0077
             10.7                                        0.0056
             11.7                                        0.0151
             13.7                                        0.0106
             26.6                                        0.0154

HMX (pH=7.9)

      Concentration (mg/l)                         q^ (mg sorbed/ g dry soil)
             0.9                                         0.00322
             1.6                                         0.00086
             2.3                                         0.00322
             3.6                                         0.00036
              TABLE 40.  ADSORPTION  DATA  FOR TNT, HMX AND RDX
                          IN MISSISSIPPI SOIL AT 20° C

2,4,6  Trinitrotoluene  (pH=5.8)

      Concentration (mg/h                        q^ (mg sorbed/ a dry soin
             0.4                                         0.00275
            10.6                                         0.0197
            17.9                                         0.0428
            90.7                                         0.0012

RDX (pH=5.8)

      Concentration (mg/h                        q^ (mg sorbed/ g dry sol!)
             11.3                                        0.00498
             11.9                                        0.00439
             12.7                                        0.0142
             19.2                                        0.00506
             32.3                                        0.00973

HMX (pH=5.9)

      Concentration (mg/n                        q^ (mg sorbed/ g dry soil)
             1.5  '                                       0.00092
             1.7                                         0.00069
             3.8                                         0.00022
                                   86

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Dinitrotoluene while the Mississippi soil appeared to have a greater affinity for the 2,6-
Dinitrotoluene.
DEGRADATION  STUDIES
      The experimental procedures for these degradation  studies were identical to
those described in Section 5.   The degradation of RDX and  HMX could not be
evaluated due to the limited quantities that were available.
      The recovery efficiencies and the loadings that were used in these degradation
studies are presented in Table 41. Even though the loading  rate for 2,4-Dinitrotoluene
was in the acceptable range, no  loss of this chemical occurred over a 47-day study.
However, losses of 2,6-Dinitrotoluene and 2,4,6-Trinitrotoluene (TNT) did occur.  The
loss pattern for 2,6-Dinitrotoluene in both soils is presented in Figure 14.  The loss
rates for the two chemicals are indicated in Table 42.
      The data indicate that first order kinetics were a better representation for TNT
than were zero order kinetics. The data also indicate that the first order half-life of TNT
in the  Mississippi  soil  was less, and the loss faster, than in the Texas soil.  No
differences in the loss rates for 2,6-Dinitrotoluene for the two soils were apparent.
MUNITIONS WASTEWATER  TREATMENT SLUDGE
      In addition to the compounds noted above, the land treatability potential of
wastewater sludge resulting from the manufacture and processing  explosives at  the
Holston Army Ammunition Plant (HAAP) was evaluated.  Figure 15 indicates  the
wastewater treatment process  flow diagram  at HAAP.  The sludge  evaluated was
obtained  from the Area  B raw wastewater settling basin.  Prior  to  use, the
characteristics of this sludge were determined.
    Nitrogen and  COD -- Nitrogen and  COD concentrations of the sludge (Table
43) were determined according to procedures described in Standard Methods(36).
                                 87

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     TABLE  41.   LOADING  RATE AND RECOVERY EFFICIENCY DATA FROM THE
                  MUNITIONS CHEMICAL DEGRADATION STUDIES
Compound
  Loading Rate (trig/kg of soil)
Acceptable*          Actual
Average Recovery
 Efficiency /%1++
Texas Soil
2,4-Dinitrotoluene	500	500	100
2,6-Dinitrotoluene	86	85	91
2,4,6-Trinitrotoluene	14	14	:...100

Mississippi Soil
2,4-Dinitrotoluene	165	150	92
2,6-Dinitrotoluene	74	70	85
2,4,6-Trinitrotoluene	12	12	101

+  data from Table 36
** average of three replicates	__
   TABLE 42.  CHEMICAL  LOSS  RATE  DATA  FOR  2,6-DINITROTOLUENE AND TNT
                         IN THE DEGRADATION STUDIES
KINETIC PARAMETERS
COMPOUND


Texas So//
2,6-Dinitrotoluene
2,4,6-Trinitrotoluene

HALF LIFE
(day)

72
7.7
FIRST
*
r


0.91
0.94
ORDER
95% C.I.


59-90
6.5-9.4
7ERO ORDER
mg/Kg/day


0.7
0.5
r*


0.91
0.81
95% C.I


0.6-0.9
0.3-0.6
Mississippi Soil
2,6-Dinitrotoluene
2,4,6-Trinitrotoluene

92
5.7

0.78
0.93

66-153
4.6-7.2

0.5
0.4

0.80
0.80

0.3-0.6
0.2-0.6
   correlation coefficient
                                   88

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                                   Concentration of  2 6-DNT
                                         (mg/Kg  of soil)
oo
to
                      c
                      o
                      c*
                      o
                      «•»
                      M
                      0>
                      6
o
o
c
                            2
s
en
fit
a
                      (0
                      (0
                      (0
                      (0
                     •o
                     •o

                      (A
                      O
                      O
                      o

                      O
                                                              Concentration  of  2,6-DNT
                                                                    (mg/Kg of soil)
                                                                                 en -
                                                     1
                                                     a
                                                     O
                                                                                 10
                                                                                 o
                                                           to
                                                           en
                                                                                 u
                                                                                 O
                                                                                 CO
                                                                                 en
                                                                                            NJi
                                                                                            5" 8s
                                                                                           0)
                                                                                           o
                                                                       I

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           AREA B
        RAW WASTE
           WATER
Nutrient  Additions
  and oH Control
        Stilling  Bttln
                         Denltriflcatlon  by
                        Submerged Anaerobic
                              Filters
AREA A
RAW WASTE
WATER




PH
/
\
         Equtllzttlan
            Buln
                              Control
                                                                          Nutrient
                                                                          Additions
                                                                           &  pH
                                                                          Control
                                                                 'Aerobic^
                                                               /Fixed  Fllm\
                                                                  Reactors
                                                               V (Trickling /
                                                               \Fllters)/
                                                             Aerobic Suspended
                                                              Growth  Reactors
                                                             (Activated Sludge)
Figure 15.  Wastewater Treatment Process Flow Diagram for the  Holston Army
                              Ammunition
                                  90

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TABLE 43.  NITROGEN AND COD  CONCENTRATIONS OF MUNITIONS WASTE SLUDGE

Total Kjeldahl Nitrogen	4820 mg/L
Ammonia Nitrogen	2300 mg/L
C.O.D	1.27 x 105 mg/L

    Metals -- The metals in the munitions sludge were analyzed at the USEPA Robert
S. Kerr Environmental Research Laboratory in Ada, Oklahoma. Results were obtained
using  procedures outlined in EPA SW 846   for both the total sludge and the liquid
fraction. The results are contained in Table 44.
    GC/MS Analysis --  One goal of this study was to determine if quantities of
hazardous  organics were present in the munitions waste sludge.  If significant
quantities were  present,  degradation experiments would be conducted to estimate
loss rates of these constituents.  The organics present in the sludge were determined
as follows.  The organics were extracted from  the sludge using  a shake  extraction
procedure and Methylene Chloride as the extracting solvent (EPA method 3450)^).
The extract was analyzed  on  a  Finnigan-MAT4000 gas  chromatograph/mass
spectrometer (GC/MS) located in  the Department of  Chemistry at The University of
Texas at Austin.  Results are summarized in Table 45.  The listed compounds
represent the fourteen most significant peaks of the chromatogram.  Many small peaks
were observed but they had a peak intensity of the same magnitude as instrument
noise.  None of the small peaks corresponded to TNT, HMX or RDX.  Because of the
absence of these compounds in the munitions waste sludge, degradation experiments
with the sludge were not conducted.
       Relative Toxlcltv -- The toxicity of the munitions sludge was evaluated using
the Microtox© procedure. It is possible that the chemicals contained as part of the
sludge solids could cause toxicity as  the solids decomposed. To determine if the

                                91

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TABLE 44.  METALS IN MUNITIONS SLUDGE AND SLUDGE FILTRATE
Element
Na
K
Ca
Mg
Fe
Mn
Co
Mo
Al
As
Se
Cd
Be
Cu
Cr
Ni
Zn
Ag
Tl
Pb
Li
Sn
V
Ba
B
Ti
mg/l
20.7
18.8
45.8
12.4
400
1.10
0.02
<.01
<.1
<.03
<.1
<.003
<.003
0.03
0.01
0.01
0.10
<.03
<.04
<.02
<.01
0.17
<.03
0.01
0.23
<.1
Filtrate
Std. Dev.
2.0
1.9
4.5
1.2
40
0.09
0.01
-
-
-
-
-
-
0.01
0.01
0.01
0.01
-
-
-
-
0.01
-
0.01
0.03
_
Total
mg/kg
wet wt.
92.8
202
711
196
3940
14.7
0.81
0.69
1740
5.8
<1
0.19
0.21
13.9
7.85
2.85
35.9
<.3
<.7
10.4
1.15
3.59
4.76
11.0
0.88
6.7
Sample
Std. Dev.
9.2
20
71
1.9
390
1.3
0.15
0.26
170
2.50
-
0.04
0.04
1.3
0.77
0.28
3.6
-
-
1.5
0.14
0.35
0.71
1.1
0.31
1.4
                      92

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                 TABLE  45.   GC/MS ANALYSIS OF MUNITIONS SLUDGE
COMPOUND MOLECULAR WT.
6-Methyl. 1-H Indole
CgHgN
Benzenemethanlmlne
C/H7N
1.3 Benzoxazlne
CfgHi7ON
8-Methyl. Decanolc Acid
C12H24O2
2.2-Dlmethylcvclohexanol
C8H16OCI
10-Undecenoyl Chlorlda
CiiHigOCI
8-Methvl Paeanolc Acid
C12H2402
1-Methyl. 4-Nltrosoplperazlne
C5HnON3
Sulfur
S8
Undecenal
7- Methyl. Nonanolc acid
Hexanedlolc Acid
C14H26O4
3-Nltro. 1.2-Benzana-
DIcarboxyHc Acid
CsHsOgN
Thlocyanlc Acid
C-| iH-jsONS
131
105
239
200
128
202
202
129
256
168
186
258
21 1
207
% FIT* PEAK INTENSITY**
93.8
89.1
73.1
79.0
83.8
84.3
87.3
70.2
84.8
82.7
85.4
84.1
85.7
81.4
268
81
.402
338
172
170
290
242
641
148
240
223
443
254
*   The % fit refers to how well the library fit matched the ion chromatograph generated from the sample.

* *  Peak intensity refers to the relative concentrations of the compounds in the extract. For example, sulfur (Sg)
    had the largest concentration of the fourteen compounds listed.
                                        93

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solids may have included chemicals that exhibited a toxic effect, one set of samples
was homogenized and the other was not before the toxicity was determined.  With the
Microtox© procedure, the soluble constituents exert the greatest effect.
       Preparation  of both  sets  of  samples consisted  of  taking  aliquots  of
homogenized and aliquots of  nonhomogenized sludge (100 ml each), diluting them
with  distilled deionized water to obtain different concentrations of the sludge
constituents and centrifuging them at 2000 rpm for 15 minutes.   Fifty milliliters of the
supernatant liquid  from each sample were discarded and replaced by fifty milliliters of
a 2% Sodium Chloride/distilled deionized water solution.  The addition of the salt
solution maintained  the proper environment for the marine bioluminescent bacteria
used in the toxicity test.  This  procedure was in accordance with standard Microtox©
operating methods (Section 4).  The samples  were then centrifuged at 2000 rpm for an
additional  15  minutes. Twenty five milliliters  of the supernatant were withdrawn from
each sample and filtered (0.45 |im pore size filter).  Within thirty minutes after filtering,
the samples went  from clear to a brownish red color suggesting the oxidation of some
metal species. Because of the color interference, a color absorbance correction was
necessary to  obtain toxicity  results.  The results of the toxicity evaluation  are
summarized in Table 46.
      As  noted above, the homogenized and nonhomogenized  sludge  samples
were diluted to  provide  varying  concentrations of  sludge  constituents  for
the toxicity  evaluation.   This resulted  in the toxicity  results  being known
in  terms  of  percent  of  the original sludge.   If the  sludge  were nontoxic,
the  ECso value would be around 100%.   These  evaluations  (Table  46)
indicated  that high dilutions were  needed  to obtain  £659 values and that,
therefore, the sludge was toxic to the  Microtox® organisms.
                                 94

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      Because these samples demonstrated significant toxicity,  a second set of
samples was processed in the same way and the relative toxicity determined to verify
the previous results.  The results from this second evaluation were comparable to
those presented in Table 46.

      TABLE 46.  MUNITIONS WASTE TOXICITY DATA  - UNDILUTED SAMPLES
Sample H&C(D*
EC50(5min., 15°C) 0.92%
95% confidence interval 0.52 -1 .65%
pH of the sample 5.6
H&C(2)*
1 .30%
1.25 -1.35%
5.7
cm
1.22%
1.16-1.28%
5.7
C(2)
1 .47%
1.37-1.57%
5.7
* H - homogenized, C - centrifuged; (1) and (2) are replicates.
      The relative toxicity results indicated that: (a) the munitions sludge exhibited
considerable  relative toxicity, and (b) there was  no  difference in relative toxicity
between the homogenized and the nonhomogenized samples.  The latter statement
indicates that the constituents causing the toxicity effect were in the soluble and not the
solid phase.  The low pH of the sludge (Table 46) may have contributed to the relative
toxicity.
CONCLUSIONS
   1. The Freundlich equation described the sorption of 2,4- and 2,6-Dinitrotoluene in
      the two soils satisfactorily.  However, it did not do so for TNT, RDX, or HMX.
   2. No loss of 2,4-Dinitrotoluene occurred over  a 47-day  study, even though the
      loading rate used  was  determined  to  be acceptable  using procedures
      discussed in Section 4.
   3. Because of the  small  amounts  of RDX  and HMX that were received, no
      degradation studies could  be conducted.
                                 95

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4. Degradation loss rates could be obtained for 2,6-Dinitrotoluene and TNT.  First
   order kinetics were a  better representation for TNT than were  zero order
   kinetics.
5. The half-life of TNT in the Mississippi soil was shorter, and the loss  faster, than
   in  the Texas soil.  No differences in the loss rates in the two soils for 2,6-
   Dinitrotoluene were apparent.
6. The  sludge resulting  from the manufacture and  processing of  explosives
   contained:  (a) high concentrations of nitrogen and COD, (b) concentrations
   generally less than 10 mg/l for the heavy metals, and (c) no amounts of TNT,
   RDX, or HMX.
7. The  munitions  sludge had a  high toxicity as measured by the  Microtox©
   procedure.  The constituents causing the relative toxicity were in  the soluble
   and not the solid phase of the sludge.
                               96

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                               SECTION  9

                              REFERENCES
1.   Short, Thomas E. "Modeling of Processes in the Unsaturated Zone".  In: B.C.
    Loehr and J.F. Malina, Jr., Editors, Land Treatment:  A Hazardous Waste
    Management Alternative.  Water Resources Symposium 13,  Center  for
    Research in Water Resources, The University of Texas at Austin, Austin, Texas
    78712, 1986,  pp. 211-240.

2.   Nofziger, D.L, Williams, J.R. and T.E. Short. "Interactive Simulation of the Fate of
    Hazardous Chemicals  During Land Treatment of Oily Wastes: RITZ  Users'
    Guide".  Robert S. Kerr Environmental Research Laboratory, U.S. Environmental
    Protection Agency, Ada, Oklahoma, 1988, 59 pages.

3.   Caupp,  C.L.,  Grenney, W.J.,  and P.J.  Ludvigsen.  "VIP --  A Model for the
    Evaluation of Hazardous Substances  in Soil  --  Version  2".  Civil and
    Environmental Engineering Department,  Utah State University,  Logan, Utah,
    1988, 25 pages.

4.   Grenney, W.J., Caupp, C.L, Sims, R.C. and T.E. Short. "A Mathematical Model
    for the Fate of  Hazardous  Substances  in Soil:  Model   Description and
    Experimental Results".  Haz. Waste and Haz. Materials 4:223-240,1987.

5.   Charbeneau,  R.J., Weaver, J.W. and V.J. Smith.  "Kinematic Modelling  of
    Multiphase Solute Transport in the Vadose Zone".  Final Report, Cooperative
    Agreement CR-813080, Robert S. Kerr Environmental Research Laboratory, U.S.
    Environmental Protection Agency, Ada, Oklahoma, 1989,108 pages.

6.   McGinnis,  G.D., Borazjani, H., McFarland, L.K., Pope, D.F. and  D.A. Strobel.
    "Characterization  and  Laboratory Soil Treatability  Studies for Creosote and
    Pentachlorophenol Sludges and  Contaminated  Soil".  Final Project Report,
    Robert  S.  Kerr  Environmental Research Laboratory,  U.S. Environmental
    Research Laboratory, U.S. Environmental Protection Agency, Ada,  Oklahoma,
    1988, 138 pages.

7.   U.S. Environmental Protection Agency.  Test Methods for Evaluating Solid
    Waste SW-846, Volumes 1-4 (Third Edition). National Technical Information
    Service, Springfield, Virginia, 1986.

8.   Dutka, B.J. and G. Bitton. Toxicity  Testing  Using Microorganisms. Boca
    Raton, Florida, CRC Press, Inc., 1986, 395 pages.

9.   Liu, D. and B.J.  Dutka (Editors). Toxicity  Screening  Procedures  Using
    Bacterial Systems.  Marcel Dekker, Inc., New York, 1984, 470 pages.
                                97

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10.  Hermans, J., Busser, F., Leeuwangh, P. and A. Musch. "QSAR's and Mixture
    Toxicity of Organic Chemicals in Photobacterium Phosphoreum: The Microtox©
    Test".  Ecotox. Environ. Safety 9:17-25,1985.

11.  Kamlet, M.J., Doherty, R.M., Veith, G.D., Taft, R.W., and M.H. Abraham. "Solubility
    Properties  in Polymers  and  Biological Media 7.   An Analysis of Toxicant
    Properties  That  Influence Inhibition  of  Bioluminescence  in Photobacterium
    Phosphorium (The Microtox Test)". Environ. Sci. Tech.: 690-695, 1986.

12.  Matthews, J.E. and A.A. Bulich. "A Toxicity Reduction Test System to Assist in
    Predicting Land Treatability of Hazardous Organic Wastes".  In: J.K. Petros, Jr. et
    al., Editors, Hazardous  and Industrial Solid Waste  Testing:   Fourth
    Symposium. Philadelphia, ASTM/STP 886,  1984.

13.  Matthews,  J.E.  and L Hastings.  "Evaluation of Toxicity  Test Procedure for
    Screening Treatability Potential of Waste in Soil". Toxicity Assessment 2. 265-
    281,1987.
14.  Beckman Instruments, Inc..  Microtox® System  Operating Manual. Beckman
    Instruments, Inc., Carlsbad, California, 1982, 52 pages.

15.  Sims, R.C.  "Loading Rates and Frequencies for Land Treatment Systems in Land
    Treatment". In:  R.C. Loehr and J.F. Malina,  Jr., Editors, Land Treatment:  A
    Hazardous Waste Management Alternative.  Water Resources Symposium
    13, Center  for Research in Water Resources, The University of Texas at Austin,
    Austin, Texas 78712, 1986, 370 pages.

16.  Huddleston, R.L, Bleckmann,  C.A. and J.R. Wolfe.  "Land  Treatment Biological
    Degradation Processes".   In: R.C. Loehr and J.F.  Malina, Jr., Editors,  Land
    Treatment:   A Hazardous Waste  Management Alternative.   Water
    Resources Symposium 13,  Center for Research  in Water Resources, The
    University of Texas at Austin, Austin, Texas 78712,1986, 370 pages.

17.  Edgehill, R.V.  and R.K.  Finn.   "Microbial Treatment  of Soil to Remove
    Pentachlorophenol".  Appl. Environ. Microbiol.  45:1122-1125, 1983.

18.  Kennedy, J.B. and A.M.  Neville.  Basic Statistical Methods for Engineers
    and Scientists  (Third Edition).   Harper and Row, Inc., New York, 1986, 495
    pages.

19.  Weber, W.J., Jr.  Physicochemical  Process for  Water Quality Control.
    John Wiley and Sons, Inc., New York, 1972, 640 pages.

20.  Chiou, C.T., Porter, P.E. and D.W.  Schmedding.  "Partition Equilibrium of
    Nonionic Organic Compounds Between Soil Organic Matter and Water".  Environ.
    Sci. Technol 17:227-231, 1983.

21.  Sheets, T.J., Crafts, A.S. and  H.R. Drever. "Influence of Soil Properties  on the
    Phytotoxicity of s-triazines". J. Agric. Food Chem. 70:458-462,1962.
                                98

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22.  Savage,  K.E.  and R.D. Wauchope.   "Fluometuron Adsorption-Desorption
    Equlibria in Soils".  Weed Sci. 21-A 06-110, 1974.

23.  Hamaker, J.W. and J.M. Thompson.  "Adsorption".  In: Goring and Hamaker,
    Editors, Organic Chemicals in the Environment.  Marcel Dekker, Inc., New
    York, 1972.

24.  Rao, P.S.C. and  J.M.  Davidson.   "Estimation of Pesticide Retention  and
    Transportation  Parameters Required in  Nonpoint  Source Pollution  Models".
    Environmental Impact of Nonpoint Source Pollution, Ann Arbor Science
    Publications, Ann Arbor,  Michigan, 1980, pages 23-67.

25.  McCarty, P.L, Reinhard,  M. and B.E. Rittmann. "Trace Organics in Groundwater".
    Environ. Sci. Technol.  75:40-51, 1981.

26.  Schwarzenbach,  R.P.  and J. Westell.   "Transport  of Nonpolar Organic
    Compounds from  Surface  Water to  Groundwater".  Environ. Sci.  Technol.
    75:1360-1367,  1981.

27.  Sawyer,  C.N.  and and P.L.  McCarty.   Chemistry  for   Environmental
    Engineers  (Third  Edition).  McGraw-Hill,  Inc., New  York, New York, 1978, 370
    pages.

28.  Schellenberg,  K.,  Leuenberger,  C. and  R.P.  Schwarzenbach.  "Sorption  of
    Chlorinated  Phenols by Natural  Sediments and Aquifer Materials".  Environ. Sci.
    Technol. 18:652-657, 1984.

29.  Zachara, J.M.,  Alnsworth, C.C., Cowan, C.E. and B.L  Thomas.  "Sorption  of
    Binary  Mixtures of Aromatic Nitrogen Heterocyclic Compounds on  Subsurface
    Materials". Environ. Sci. Technol. 21:397-402, 1987.

30.  Murin,  C.J.  and V.L Snoeyink.  "Competitive Adsorption of 2,4-Dichlorophenol
    and 2,4,6-Trichlorophenol in the Nanomolar to Micromolar Concentration Range".
    Environ. Sci. Technol.  73:305-311, 1979.

31.  U.S. Environmental Protection Agency. "Batch Type Adsorption Procedures for
    Estimating  Soil Attenuation of Chemicals".  Technical Resource Document
    (EPA/530-SW-87-006),  Office of Solid  Waste and Emergency  Response,
    Washington, D.C. , 1986, 183 pages.

32.  Verschueren,  K.   Handbook  of  Environmental   Data  on  Organic
    Chemicals, Second  Edition.  Van  Nostrand  Reinhold Company, Inc., New
    York , 1983,  1310 pages.

33.  American Society  for  Testing Materials.  Annual Book of ASTM Standards,
    Part 19.  Soil and  Rock, Building Stone.   Philadelphia,  Pennsylvania,
    ASTM D2216, 1982, pp.  338-339.
                               99

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34.  U.S. Environmental  Protection  Agency, Office of Solid  Waste.  Permit
    Guidance  Manual   on   Hazardous  Waste   Land   Treatment
    Demonstrations  - Final Version.  National Technical Information Service,
    Springfield, Virginia , 1986, 98 pages.

35.  Burrows, R.D. Letter to R.C. Loehr, December 1986.

36.  American  Public Health  Association.   Standard  Methods  for  the
    Examination  of  Water and Wastewater,  16th Edition.   American Public
    Health Association, Washington, DC, 1985, 1268 pages.
37.  Qureshi, A.A., Coleman, R.N., and J.H. Paran. "Evaluation and Refinement of the
    Microtox® Test".  In:  D. Liu and B.J. Dutka, Editors, Toxlcity  Screening
    Procedures  Using  Bacterial Systems.  New York,  Marcel Dekker,  Inc.,
    1984, pages 1-22.
                              100

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                              APPENDIX  A
                  THE  MICROTOX® TOXICITY  ASSAY
                         USED  IN THIS STUDY
INTRODUCTION
      The Microtox® toxicity assay was used for toxicity screening due to its simplicity,
rapidity, cost effectiveness, and because the assay procedure  had undergone
evaluation and standardization for this purpose^ 2- 13).  The test organism is a
marine bioluminescent bacteria  (Photobacterium  phosphoreum Strain NRRL B-
11177).  The Microtox® Model  2055  Toxicity Analyzer System and Microtox®
accessories used  in this research were obtained from Beckman Instruments, Inc., and
Microbics, Inc., Carlsbad, California.
EVALUATION OF  CHEMICAL LOSS  USING MICROCOSMS
      The batch type microcosms used to  simulate aerobic soil conditions were 150
ml_ glass beakers.  The  chemicals were  extracted from the soil microcosms with
Methylene  Chloride  using  a  Soxhlet  extraction  apparatus.   The  extract was
concentrated using a Kuderna-Danish apparatus. The final extract was analyzed with
a Model 5890 (Hewlett Packard) Gas Chromatographic System.
 WATER EXTRACTION OF  MICROCOSMS
      For the Microtox®  analyses, a water soluble fraction (WSF)  is  needed. The
contents of a microcosm were transferred into an amber glass bottle having a Teflon-
lined cap and 40 mL (1:4 by soil weight:water volume) of distilled deionized water was
added. The soil-water mixture was extracted in a rotary extractor for about 24 hours at
30 rpm at room  temperature.   Immediately after the extraction, the sample was
centrifuged at about 2000 rpm  for 15 minutes to separate the WSF. The WSF was
vacuum filtered through a 0.45 ^im membrane filter.  Ten milliliters  of the filtered
sample were adjusted to 2%  NaCI  using reagent  grade dry NaCI and tested for
toxicity.  In addition,  the  pH of the composite sample of triplicates  of a chemical
                              101

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loading at a sampling time was measured.  The remaining portion of the WSF was
stored in a sample vial with minimum head space. The vial was frozen to < -20° C to
maintain  the integrity of the chemical composition of the sample until further analysis
by HPLC.
TOXICITY ASSAY
      The toxicity  assay was used to: (a) determine the Effective Concentration
(EC50) of a chemical solution or of a waste, (b) determine the EC50 of the WSF to
determine the safe initial chemical loading on soil, and (c) study the toxicity reduction
of the WSF.
EC50    DETERMINATION
      The EC5Q of a sample is defined as the concentration of the sample required to
reduce the initial luminescence of the bacterial suspension by 50% under standard
test conditions.  To determine the EC50 of the chemicals that were evaluated, a
solution of a known concentration of a chemical was prepared in distilled deionized
water (DDW). The DDW used in the sample preparation did not exhibit any toxicity as
determined by the Microtox® assay. The solution was mixed using a magnetic stirrer
for 24 hours or until the chemical was completely dissolved.  To the extent possible,
the  solubility of the chemical was estimated from the literature, before attempting
sample preparation.  The chemical solution was adjusted to 2% Sodium Chloride
(NaCI) using either reagent grade dry NaCI or Microtox© Osmotic Adjusting Solution
(MOAS -- 22% NaCI solution).
      The sample  preparation for EC$Q values that were  part of the  acceptable
loading determination and toxicity reduction studies followed the same procedure.
ASSAY  PROCEDURE
      This section.briefly describes the standard Microtox® toxicity assay procedure.
A detailed description of the assay  can be found elsewhere (14> 37).
                               102

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      The   lyophilized  Microtox©  bacteria  are reconstituted  with  1.0 ml of
reconstitution solution  (ultra-pure water) maintained at 2-4° C in a glass cuvette.
Aliquots of 10jiL of the reconstituted bacterial suspension are equilibrated for about 15
minutes at 15° C in 0.5 mL of Microtox© diluent (2% NaCI solution) in glass cuvettes.
At the end of the equilibration period, the initial luminescence intensity is measured as
light units using the Microtox© System. 0.5 ml of the sample and three serial dilutions
of the sample are added to the respective cuvettes.  The final  luminescence readings
are taken at the end of the desired exposure time intervals: 5 minutes, 15 minutes, 30
minutes or longer.
      The test sample and  its dilutions were tested in duplicate.  Blank cuvettes
containing just the diluent also are read to correct for any shift in the luminescence that
may be caused by the  bacteria or the machine.  From the observed results a dose-
response curve is obtained and the EC50  value calculated.
CHEMICAL LOADING ON SOIL
      The chemical concentration applied to the soil should be within the assimilative
capacity of the soil to avoid toxic effects that may limit the microbial degradation of the
chemical.  The safe chemical  loading determination is based on the water soluble
fraction (WSF) of the chemical and the toxicity of WSF using the Microtox© assay.
      One  hundred  grams of air-dried soil were weighed into glass jars and mixed
with 400 mL ( 1:4 by soil weight : water volume) of DDW.  Immediately,  the organic
chemical (solution prepared in ethanol)  was added to  the  soil-water  mixture, at
concentrations  of 2x,  5x, 10x  and 20x where  x is the £650 of the chemical.  All
chemical loadings were prepared in  duplicate. The  maximum  concentration of the
ethanol in the water was limited by the required chemical loading and the ease with
which the chemical dissolved in ethanol.  The maximum concentration of ethanol in
water was 2500 to 5000 ppm. The £€59 value of ethanol using  the Microtox© assay
is 30,000-35,000 ppm.   Hence,  the  concentrations  of  ethanol used  in  these
                                103

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 experiments did not have a significant influence on the toxicity of WSF. The chemical
 was extracted with DDW for about 24 hours in a tumbler shaker rotating at 30 rpm at
 room temperature (usually 21-25° C).
      After the extraction, the soil-water mixture was allowed to settle for about 20
 minutes.  About 50 ml_  of the supernatant was transferred into small glass bottles
 which were centrifuged at about 2000 rpm for 15 minutes to separate the WSF from
 the soil particles. The WSF was filtered through a 0.45 p.m filter using a vacuum.  The
 filtered sample  was osmotically adjusted to 2%  NaCI with  dry NaCI and analyzed
 using the Microtox© system.  These results were used to indicate  the  safe lower
 chemical loading on the soil.  The upper limit was set as two times the lower chemical
 loading.
 MICROTOX©  ANALYSIS
      The sample analysis  using the Microtox©  system  was done as described
 above.  The  luminescence readings are converted into toxicity measurements as
 indicated in the system operating manuaK14):

 where
 Ij = Initial luminescence reading
 If = Final luminescence reading and,
 X = Blank Ratio = If + Ij from the blank cuvette luminescence reading
 G = Relative toxicity measurement
      The concentration  of the sample, as ppm or % of the sample solution, is plotted
 against the toxicity measurements, G, on a log-log scale.  The concentration of the
 sample corresponding to a toxicity  measurement  of 1.0 is termed the EC§Q of the
 sample, as shown below.
      In the chemical loading determination and toxicity reduction study, the EC$Q of
the water extract  was converted to soil toxicity  units (soil  TU) in the following
                               104

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manner^13- 37); TU = 400 + £€50- The chemical loading and the corresponding soil
TU were plotted on a log-log graph.
                       An Example Plot of EC50 Determination
                         Chemical: Pentachlorophenol
                         Chemical concentration in ppm
      As has been described(13), the point at which the loading rate intercepted the
value of 20 toxicity units (TU), i.e.,  £650  = 20, was used as the lower limit, or toxic
floor, of the initial loading rate window.  The available logic and data(13) indicated that
chemicals or waste that exhibited an £650  less than 20 were  likely to cause inhibition
of the microorganisms in the soil and result in no detoxification.  An example plot is
shown below.
                                105

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  10
              An Example Plot of Chemical Loading Determination

                         Chemical: 3-chlorophenol
     3 _
:f
I10
            20 soil TU
                                       Low loading ~ 12mg/1 OOg soil

                                     (calculated value-11.9mg/1 OOg soil)
10°                 101
         Chemical Loading in mg/100g of soil
                                                 10
                            106

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                               APPENDIX  B
       QUALITY  CONTROL/QUALITY  ASSURANCE PROCEDURES

      The objective of this study was to evaluate the  relative toxicity, degradation
kinetics and sorption of specific EPA  listed hazardous chemicals  and a specific
hazardous waste and related chemicals. The data generated consisted of physical
and chemical analyses performed by the project  personnel.  All data and observations
were recorded in permanent laboratory notebooks.  Replicates and standards were
part of the analytical protocol.  The following sections describe measures used to
determine the accuracy and precision of the  measurements.
TOXICITY
      Toxicity screening and relative toxicity evaluations were performed  using the
Microtox© system to establish ECso values for each chemical. Procedures for the
Microtox© system outlined in the operation manual were followed^4). ECso values
were determined  graphically by  evaluating duplicate  samples at each  chemical
concentration. To  evaluate  randomness  in toxicity data,  ECso data and 95%
confidence intervals were reported.
      Water soluble fraction (WSF) samples were obtained following  procedures
outlined  in  EPA SW-846(7).   Duplicate samples of WSF at  each  chemical
concentration were  used to graphically determine the  chemical loading rate  as
outlined in Section 3.
DEGRADATION  STUDIES
      Accuracy and precision of  degradation data were monitored  routinely. The
procedures and analytical techniques included replicate analyses and determination
of recovery efficiencies as part of the overall  quality control effort. Replicate analysis of
three samples at each sampling  time avoided basing degradation kinetic results on
one data point which could be an outlier.
                               107

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      Illustrative recovery efficiency data are presented in Table B-1.  The analytical
data were reviewed frequently to discover possible anomalies or omissions.  If suspect
data were discovered, the raw data used to calculate the results were reviewed and
the experiment in question was repeated if necessary. To determine the conformity of
the degradation data to zero and first order kinetic models, 95% confidence intervals
were determined for all chemicals.
    TABLE B-1.   ACCURACY  DATA: RECOVERY  EFFICIENCIES (%) FOR SPECIFIC
       CHEMICALS AS DETERMINED  FROM DAY ZERO DEGRADATION STUDY
                                EXPERIMENTS
Compound
#2
#3
Average  Std.  Dev.    C.v.
Texas Soil
Phenol
m-Cresol
2-Chlorophenol
2,4,5-Trichlorophenol
Pentachlorophenol
2,4-Dimethylphenol
3-Methyl-4-Chlorophenol
p-Nitrophenol
Mississippi Soil
Phenol
m-Cresol
2-Chlorophenol
2,4.5-Trichlorophenol
Pentachlorophenol
2,4-Dimethylphenol
3-Methyl-4-Chlorophenol
p-Nitrophenol

97
78
73
99
118
84
89
122

80
93
27
110
108
83
99
100

84
85
71
95
117
80
105
101

75
86
23
107
105
80
101
116

83
81
76
98
110
76
104
108

80
84
24
107
106
80
98
114

88
81.3
73.3
97.3
115
80
99.3
110.3

78.3
87.7
24.7
108
106.3
81
99.3
110

7.8
3.5
2.5
2.1
4.4
4.0
9.0
10.7

2.9
4.7
2.1
1.7
1.5
1.7
1.5
8.7

8.9
4.3
3.4
2.1
3.8
5.0
9.0
9.7

3.7
5.4
8.4
1.6
1.4
2.1
1.5.
7.9
+   standard deviation
++  coefficient deviation (%)
                                108

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      Degradation study procedures, extraction and analytical methods, and data
analysis procedures were described in Section 5.  The day zero percent recovery
value for each chemical was assumed to remain unchanged for extractions at later
sampling periods.
      To understand the typical variation that could occur with the day zero recovery
data  (chemical  recovery efficiencies),  multiple extractions of  three chemicals
representative of those used in this study  were conducted.  The chemicals  were:
Phenol, o-Cresol, and 2,4-Dichlorophenol.  In each case, each chemical was added to
the Texas soil  and immediately  extracted and analyzed  using  the procedures
presented in Sections 3 and  5.  From eighteen to thirty-one extractions and analyses
were conducted with these chemicals.
      The results that were obtained are shown in Figures B-1, B-2 and B-3. Data in
the figures include the average percent recovery, two standard deviations of the data
as upper and lower warning limits, and three standard  deviations as the upper and
lower control limits.  Ideally, the data should fall within two standard deviations  of the
mean.  Based on the  data  in these figures, the recovery efficiencies used  in the
degradation study calculations  (Table 16) fall  within satisfactory limits.  Since the
recoveries for these three chemicals were within satisfactory limits, it was assumed
that the  recoveries for  the other chemicals  (Table 16) also were within satisfactory
limits.
ADSORPTION  STUDIES
      Procedures used to obtain the adsorption data were described  in Section 6.
Isotherms were  determined using soil-chemical  mixtures with  different  initial
concentrations of chemical.  Replicate  samples of the low and  high concentrations
were run.   Precision was monitored  using replicate data points.  These replicate
results were averaged and standard deviations and corresponding  coefficients of
                                109

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     110
     too J
     90-
     80 i
     70-
     60-
                                   Uppw Control Limit
                                  Upper Warning Umit
                            . LOMT Warning Umtt
                                  Lo««r Control Umtt
     80 H	1	1	P
                  -1	1	1	1	1	1	1—
                   8       12       16       20
—I	1	«	«—
 24       28      32
    Figure B-1.  Representative Recovery Data  for  Phenol In Texas Soil
      110
i
100-


 90-


 60-


 70-


 60-


 SO
       40
       30
                              Upp*r Control Umlt
                                   Warning Umtt
                                    WG.
                              LMMT Warning LMk
                                   Control Unit
           •T	1	1	1	1	1	1	«   "!"
            3        S       7       9       11
                                                        13      13       17
    Figure  B.2.  Representative Recovery Data  for  o-Cresol In Texas  Soil
                                 110

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                                                          10
                         7    »
                             Sompto !
   Figure B-3.   Representative Recovery Data for 2,4-Dlchlorophenol  In Texas Soil

variation (CV) for each sample pair were calculated.  Illustrative data are presented in
Table B-2 for Texas soil.  The results indicated close agreement among duplicates.
QA/QC FOR  ANALYTICAL INSTRUMENTS
      Daily Logs  of  Instrument Usage
      Individual  logs were  maintained for each major analytical  instrument (gas
chromatograph, high pressure liquid chromatography, Microtox®. The  log contained
information  pertaining  to instrument conditions and analyses performed.  Unusual
events or circumstances were  noted  and reported if instrument performance was
affected.
      Calibration  Procedures
      Prior to  each day's  analysis the  instruments were  calibrated  using known
standards.   Both  internal and external  standards were used  depending upon
application.  Instrument responses of greater than 10% of that expected for standard
                               111

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                                 TABLE  B-2
         PRECISION  ANALYSIS DATA+:  TEXAS SOIL SORPTION DATA
CHEMICAL SAMPLE A
(mg/l)
3-Chtorophenol
4-Chtorophenol
2,4-Dichtarophenol
2,5-Dichtorophenol
2,6-Dichlorophenol
3,4-Dichlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Pentachlorophenol
2,4-Dimethylphenol
2-Methyl,4-Chlorophenol
3--Methyl,4-Chlorophenol
3-Methyl,6-Chlorophenol
p-Nitrophenol
2,4-Din'rtrophenol
4,6-DinJtro-o-Cresol
Thiourea
9.7
5540
2.7
5810
3.9
1180
4.4
1980
16.3
1380
4.3
659
24.7
508
21.8
298
0.8
4.5
33.4
4770
7.2
1730
5.8
1930
72.6
2570
6.3
3520
5.6
445
49.4
112
42.4
4380
SAMPLE B
(mg/l)
10.0
5550
2.7
6250
3.9
1260
5.2
2040
16.8
1480
5.3
659
24.9
508
22.1
298
0.8
4.6
34.0
4950
7.8
1780
5.8
1950
67.8
2680
6.5
3720
6.0
463
52.0
120
43.5
4700
MEAN
(rng/l)
9.9
5545
2.7
6030
3.9
1220
4.8
2010
16.6
1430
4.8
659
24.8
508
22.0
298
0.8
4.6
33.7
4860
7.5
1760
5.8
1940
70.2
2630
6.4
3620
5.8
454
50.7
116
43.0
4540
STANDARD
DEVIATION
(ma/I)
0.21
6.2
0.00
313
0.00
56
0.57
42
0.35
65
0.71
0.00
0.14
0.00
0.21
0.00
0.00
0.07
0.42
133
0.42
37
0.00
11
3.4
75
0.14
144
0.28
12.3
1.84
5.8
0.78
225
COEFF. OF
VARIATION
(%)
2.15
0.11
0.00
5.19
0.00
4.59
11.8
2.14
2.15
4.58
14.7
0.00
0.57
0.00
0.97
0.00
0.00
1.55
1.26
2.75
5.66
2.11
0.00
0.59
4.83
2.85
2.21
3.99
4.88
2.71
3.63
4.97
1.81
4.96
The two values for each chemical represent tow and high concentrations used in the sorption studies.
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solutions  required  setting new chemical  standards  and/or making appropriate
adjustments to the instrument.  This action was the responsibility of the project analyst.
      All  reagents for chemical analysis were prepared using analytical reagent
grade (AR) chemicals.  For all analyses requiring reagent water, organic free DDW
was used.
      Data calculation, manipulaitons and analysis were performed using calculators
and computers.   Computer programs used for data reduciton and analysis were
validated before use.
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                               APPENDIX C
                       VOLATILIZATION  ESTIMATES

      The  results of  the  degradation  studies  (Section 5) represent the overall
chemical loss that occurred in the soil microcosms. While the main loss mechanism
was expected to be microbial degradation, it was possible that chemical degradation,
hydrolysis  and volatilization  could  have contributed  to the  removals that were
observed. Most of the chemicals evaluated had low vapor pressures and volatilization
losses were assumed to be negligible.
      However, several chemicals such as Methanol and 1-Butanol had higher vapor
pressures,  and it was possible that appreciable  volatilization losses could have
occurred during the degradation studies.  To evaluate this possibility, a series of
simple experiments was conducted to estimate the amount of volatilization that might
occur.
      These experiments consisted of adding the chemicals to two soil microcosms,
one of which  had a constant air sweep to remove  any  volatilized chemical, and the
other of which did not  have any air sweep.  The experiments were conducted for two
and twenty-four hours. These times were used because the greatest volatilization
potential occurred when the chemical concentration in the soil was the highest, i.e., at
the beginning  of a study.  Twenty-four hours was the longest period that could be used
since  degradation also would  be occurring during the experiments, thus decreasing
the chemical concentration.
      Texas soil was used for these  experiments. The  chemicals were added to the
soil to achieve a concentration of about 1000 mg/kg which  was close to but higher
than the concentrations of  Methanol  and  1-Butanol used in the degradation studies.
The air sweep was held constant at 100 ml/minute during the experiments. The results
are presented in Table C-1.

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                TABLE C-1.  LOSS OF  METHANOL AND 1-BUTANOL
                        IN VOLATILIZATION EXPERIMENTS
Condition                 Time Period        Chemical             Chemical
                          (hours)         Added (mg)+ +       Remaining (mg)
Methanol
   no air sweep	2	40	25.0
   continuous air sweep"1"	2	40	23.5
1-Butanol
   no air sweep	2	40	34.2
   continuous air sweep"1"	2	40	34.8
   no air sweep	24	40	35.2
   continuous air sweep"1"	24	40	14.2
*  A constant air flow of 100 ml/min was maintained over the surface of the microcosms
   throughout the noted time period.
** This amount of chemical was added to 40 grams of soil resulting in an initial soil concentration of 1000 mg/kg.
      The data indicate that there was little change due to the  air sweep and little
enhanced volatile loss during a two-hour time period. However, over a twenty-four
hour period the continuous air sweep did increase the loss of 1-Butanol.
      The driving force for volatilization is related to the concentration gradient at the
boundary layer (soil surface)  established by the  concentration  in the  soil  and the
concentration in  the air layer  immediately above the soil.  With an air sweep,  any
volatile constituents in the air layer above  the soil are continuously removed, the
concentration gradient will be maximum, and the volatilization potential will be the
greatest.  In the degradation experiments, quiescent conditions were maintained  and
no air sweep was used. Under quiescent conditions, if any volatilization occurs, the
concentration above the  soil  builds up, the concentration gradient  is less,  the
volatilization potential is the least, and the volatile flux from the soil is suppressed.
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      For this reason, even for chemicals in this study with a high vapor pressure, little
volatilization  was expected under the conditions  used for the  degradation
experiments.
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                              APPENDIX D
                             PUBLICATIONS
      In addition to this report, a technical report and several technical articles, two
M.S. theses, one Ph.D. dissertation and several presentations have resulted from this
research. These are:
TECHNICAL  REPORT
      One of the objectives of this research effort was an assessment of the terrestrial
and aquatic bioaccumulation that could result by the chemicals evaluated in this study.
The  following draft report was  submitted to the EPA project officer,  Mr. John  E.
Matthews:
Loehr, R.C. and R.  Krishnamoorthy, "Bioaccumulation Potential of Designated
      Hazardous Organic Chemicals", July 1987.
The  report  was reviewed  and accepted  by the project officer and therefore is not
included in this final report.
TECHNICAL   ARTICLES
Loehr, R.C. and R. Krishnamoorthy, "Terrestrial Bioaccumulation Potential of Phenolic
      Compounds", Hazardous Waste and Hazardous Materials 5:109-120 (1988).
Nam-Koong, W., Loehr, R.C. and J.F. Malina, Jr., "Kinetics of Phenolic Compounds in
      Soil", Hazardous Waste and Hazardous Materials 4:321-328 (1988).
M.S. THESES
  •
Yoon, C.G., "Multisolute Adsorption of Toxic Organic Compounds Onto Soil", The
      University of Texas at Austin, May 1988.
Dasappa, S.M., "Detoxification  and Immobilization of Chlorophenols in  Soil", The
      University of Texas at Austin, September 1988.
PH.D. DISSERTATION
Nam-Koong, W., "Removal of Phenolic Compounds in Soil", The University of Texas at
      Austin, May 1988.
PRESENTATIONS
Nam-Koong, W., Loehr, R.C. and J.F. Malina, Jr., "Removal of Phenolic Compounds in
      Soils", Texas Water Pollution Control Association Conference, Corpus  Christi,
      Texas, June 1987.
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Dasappa, S.M. and R.C. Loehr, "Detoxification and Immobilization of Chlorophenols in
      Soil", Texas Water Pollution Control Association Conference, Houston, Texas,
      June 1988.

Nam-Koong, W., Loehr, R.C., and J.F. Malina, Jr., "Removal of Phenolic Compounds in
      Soil",  Joint CSCE-ASCE National Conference on Environmental Engineering,
      Vancouver, BC, Canada, July 1988.

Dasappa, S.M. and R.C. Loehr, "Detoxification and Immobilization of Chlorophenols in
      Soil", 61st Annual Conference, Water  Pollution Control Federation, Dallas,
      Texas, October 1988.

Nam-Koong, W., Loehr, R.C. and J.F. Malina, Jr., "Effects of Mixture and Acclimatio'  n
      Removal Rate of Phenolic Compounds in Soil", 61st Annual Conference, v   sr
      Pollution Control Federation, Dallas, Texas, October 1988.
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