EPA-600/3-76-001
January 1976
Ecological Research Series
                               DYNAMIC BEHAVIOR  OF
       VINYL  CHLORIDE  IN  AQUATIC ECOSYSTEMS
                                       Environmental Research Laboratory
                                       Office of Research and Development
                                      U.S. Environmental Protection Agency
                                              Athens, Georgia 30601

-------
                 RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection  Agency, have  been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology.  Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.     Environmental Health Effects Research
     2,     Environmental Protection Technology
     3.     Ecological Research
     4.     Environmental Monitoring
     5.     Socioeconomic Environmental Studies

This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects  of pollution on humans, plant and animal
species, and materials.  Problems are assessed for their long- and short-term
influences. Investigations include formation, transport, and pathway studies to
determine the fate of pollutants and their effects. This work provides the technical
basis for setting standards to  minimize undesirable changes in living organisms
in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

-------
                                        EPA-600/3-76-001
                                        January 1976
   DYNAMIC BEHAVIOR OF VINYL CHLORIDE

         IN AQUATIC ECOSYSTEMS
                 by

   James Hill IV, Heinz P. Kollig,
    Doris P. Paris, N. Lee Wolfe,
       and Richard G. Zepp

  Environmental Research Laboratory
U.S. Environmental Protection Agency
        Athens, Georgia  30601
 U.S.  ENVIRONMENTAL PROTECTION AGENCY
  OFFICE OF RESEARCH AND DEVELOPMENT
   ENVIRONMENTAL RESEARCH LABORATORY
        ATHENS,  GEORGIA  30601

-------
                        DISCLAIMER
     This report has been reviewed by the Environmental
Research Laboratory, U.S. Environmental Protection Agency,
and approved for publication.   Mention of trade names or
commercial products does not constitute endorsement or
recommendation for use.
                            11

-------
                           ABSTRACT
    To evaluate  the behavior of vinyl  chloride   in   aquatic
ecosystems,  best estimate and worst case Models  of  lake and
stream  ecosystems  were  analyzed  through   the   use    of
mathematical   simulation*    The   characteristics   of   the
chemical, biological,  and physical transformations of vinyl
chloride    indicated   in  the  models  were  determined  by
laboratory  experimentation  and  extrapolation  of   reaction
data  for similar compounds*  These transformations  included
oxidation,  substitution, elimination, hydrolysis,  and  free
radical   reactions;   complexation;   direct  and   indirect
photochemical  reactions; microbial degradation and toxicity;
bacterial,  algal, and fungal sorption;  and  volatilization*
Loss  of  vinyl   chloride  from  the  aquatic environment by
volatilization appeared to be the most  significant   process
in its distribution*

    This  report was submitted in fulfillment of  ROAP 04AEM,
Tasks 005   and  009,  and  ROAP  03ACQ,  Task  009,   at   the
Environmental  Research  Laboratory!  Athens, Georgia*   Work
was completed  as of September 1975*
                              ill

-------
                           CONTENTS
I      Conclusions  and Recommendations                 1

II     Introduction                                    3

III    System Analysis                                 7

          Assumptions                                   9
          Results and  Discussion                      16

IV     Chemical  Interactions                          33

          Materials and Methods                       34
          Results and  Discussion                      36

             pH  Studies                               36
             Oxidation Studies                        36
             Natural Waters                            38
             Complexation                              38

V      Photochemical Interactions                     41

          Materials and Methods                       43
          Results and  Discussion                      44

             Direct Photolysis                        44
             Indirect  Photolysis                      45

VI     Microbiological Interactions                   48

          Materials and Methods                       48
          Results and  Discussion                      51

             Sorption  to Microorganisms               51
             Bacterial Degradation                    52
             Toxicity  to Bacteria                     53

VII    Physical  Interactions                          54

          Materials and Methods                       55
          Results and  Discussion                      55

VIII   References                                      50

-------
                           FIGURES
1      Composite  representation of the analysis            4
       procedures

2      Initial conceptual model of vinyl chloride          5
       interactions  in an aquatic environment

3      Working conceptual model of vinyl chloride          8
       interactions  in an aquatic system

4      Best estimate model of vinyl chloride in the       10
       aquatic environment

5      System model  with worst case chemical and          11
       biological transformation reaction rates

6      System model  of vinyl chloride in stratified       12
       lake with  a simple idealized food web

7      Lake simulation with best estimate model           17

8      Stream simulation with best estimate model         18

9      Lake simulation of the model of Figure 5           19

10     Stream simulation of the model of Figure 5         20

11-14  Stratified lake simulation of the model in         21-24
       Figure 6

15-18  Stratified lake model's response to pulse          26-29
       input of vinyl chloride to epilimnion water

19-21  Stratified lake model's response to pulse          30-32
       input of vinyl chloride to sediments

22     Vinyl chloride reaction vessel                     35

23     Pathways for  light induced decomposition of        42
       vinyl chloride

24     Decomposition of vinyl chloride in water by        47
                             VI

-------
       attack of free radicals generated by photolysis
       (300 am) of hydrogen peroxide

25     Apparatus for vinyl chloride degradation and      49
       toxicity studies

26     KVCM versus Kn  a* *our mixing levels             58
                             VII

-------
                           TABLES



Mm.

1      Worst case model parameters                        15

2      Order of magnitude estimates  for  half-lives       37
       for vinyl chloride reactions

3      Equilibrium constants for some  compounds          40
       structurally related to  vinyl chloride

4      Rate coefficients for oxygen  and  vinyl chloride   57
       gas exchange at four mixing levels
                            Vlll

-------
                      ACKNOWLEDGEMENTS
    The authors gratefully acknowledge the  contributions  of
their  colleagues* John T. Barnettf David !.•  Lewis*  and Bill
ifaca*  Helpful and constructive content  vas   received  fron
Say R« Lassiter* James W. Falcot and George L.  Baughnan*

    The  efforts  of Shirley H. Hercules in editing  and Anne
L* Warner and  Carlyn  B«  Haley  in  typing   are  sincerely
apprec iat ed»
                              IX

-------
                          SECTION I

              CONCLUSIONS AND RECOMMENDATIONS
    A worst case  system analysis of vinyl chloride   behavior
in aquatic systems  suggests that unrealistically  high levels
of  vinyl  chloride  inputs  would  be necessary  to  maintain
significant concentrations in these systems.  However*  given
extreme environmental conditions*  aquatic  sediments  could
exhibit long-term storage of low levels of vinyl  chloride*

    Chemical   degradation  of  vinyl  chloride  under  pH*s*
reactant concentrations*  and  temperatures  common   to  the
environment    should  not  be  significant*   Neither  auto-
oxidation nor  degradation by free radicals is  important   in
most  natural   waters  at low vinyl chloride concentrations*
Increased persistence of vinyl chloride due to  complexation
with  Ag* and  Cu* should be minimal*  Data are not available
for consideration of other metal species*

    Experiments with distilled water* water from  the  efflu-
ent  of  a  PVC  plant* and two natural waters indicate that
photolysis of  vinyl chloride  is  probably  a  slow   process
under environmental conditions*

    Vinyl   chloride   does  not  appear  to  be  sorbed   by
microorganisms* as  indicated by laboratory experiments  with
five   mixed    bacterial  populations*  three  mixed  fungal
populations* two  axenic bacterial cultures*  and  one  alga*
The  five  mixed  bacterial  populations did not  degrade  the
vinyl chloride to any detectable  extent*   Also*  at  vinyl
chloride  concentrations  up to 900 mg l~l» no toxic effects
on the bacterial  cultures could be detected*

    The rate of bulk exchange of gaseous vinyl chloride bet-
ween atmosphere and water is about  twice  that   of   oxygen*
Loss  of  vinyl  chloride  by  volatilization  from  water is
therefore probably   the  most  significant  process   in  its
distribution*

    The assumptions and consequently the conclusions of this
analysis  may   be  invalid  when vinyl chloride enters  a  re-
ceiving water  as  a  component of a  tar  or  sludge   or when
large  concentrations  of  surface active agents  are present
with the vinyl chloride in water*  Further study  is  neces-
sary for specific situations where these conditions  exist*

-------
    The  reactions of vinyl chloride with  chlorine and hypo-
chlorous acid should be studied under conditions  that  pre-
vail in the chlorination processes of municipal water treat-
ment  plants*  Alsot the reactions o± organics that may form
vinyl chloride under these conditions should be studied*

-------
                          SECTION  II

                         INTRODUCTION
    Vinyl chloride (CH2 = CHCl)f  a  colorless,  highly  flam-
mable gas,  is  used primarily in -the production of the resin,
polyvlnylchloride  (PVC)*  The PVC  is  then used in the manu-
facture of   many  synthetic  plastics   and  rubbers*   Vinyl
chloride    monomer   (VCM)  is  therefore  present  in  many
manufacturing  operations and, because  water  is  used  as   a
medium in the  polymerization reaction,  it is also a possible
contaminant of waste water discharged  from these plants*

    In  recent studies, chronic exposure to VCM has resulted
in liver injury to laboratory rats  and rabbits*  Also,  some
workers  in PVC  plants have contracted angiosarcoma of the
liver (1)*   Because  of  its  possible  harmful  effects   on
humans  and other living organisms  and the ubiquitous nature
of vinyl chloride in the manufacturing industry, the  behav-
ior  of  VCM  in  aquatic ecosystems has come under critical
study*
  /
    The present study was undertaken to investigate the  be-
havior of vinyl chloride in aquatic systems under conditions
simulating  large inputs of VCM from industrial sources*  The
study  involved  the  use  of  a  conceptual  model of vinyl
chloride   interactions   in   aquatic    systems;   physical,
chemical,   and  biological  experiments with vinyl chloride;
mathematical models; and system analysis*  The relationships
among the various facets of the study  are represented in the
diagram in  Figure 1*

    The physical, chemical, and biological  interactions   of
vinyl chloride with the components  of  aquatic systems deter-
mine  the   behavior  of  vinyl  chloride in the system*  The
individual  interactions can be characterized  quantitatively
by laboratory  experimentation and the  behavior of VCM within
an  aquatic system  can  be approximated by simulation of a
system  model*   An  initial   conceptual   model   of   the
interactions  of  vinyl  chloride in an aquatic environment,
developed  as described by Gillett et al* (2) is  represented
by  the compartment diagram in Figure  2*  In the diagram the
boxes represent storage of vinyl  chloride  or  its  reaction
products     and    the   arrows   represent   transport    or
transformation processes*

-------
                            Conceptual Models of
                         Vinyl Chloride Interactions
                           in Aquatic Ecosystems
           Model Structure
Mathematical Models of
Vinyl Chloride Behavior
        I
Simulation
  System Analysis of
 Mathematical Models
                                        Quantitative
                                        Interactions
                      Qualitative
                      Interactions
                  Model Parameters
         Chemical, Biological, and
          Physical Experiments
Mechanistic Behavior
                   Holistic Behavior
                                           Results and Conclusions
    Figure !•   Composite  representation  of  the  analysis
                              procedures*

-------
Elimination Reaction
     Products
 Hydrolysis Reaction
     Products
                        INPUT
    Free Radical
 Reaction Products
                                     Vinyl Chloride in Atmosphere
                                        Vinyl Chloride in Water
   Vinyl Chloride
Sorbed on Participates

   Vinyl Chloride
    in Sediments
                             OUTPUT
                                         Direct Photochemical
                                           Reaction Products
                                                                                 Indirect Photochemical
                                                                                   Reaction Products
                                                                                 Microbial Degradation
                                                                                      Products
                                                                                Vinyl Chloride in Food
                                                                                   Web Organisms
               Figure 2.   Initial  conceptual  model  of  vinyl  chloride
                        interactions in  an  a
-------
    A system analysis based upon the  conceptual   model  was
used  to  estimate the behavior of vinyl  chloride  In aquatic
systems under both typical  ("best  estimate")  and  extreme
("worst   case")  conditions*   The  rates   of  the  various
possible  transport  and   transformation   processes   were
determined in the laboratory*

-------
                         SECTION III

                      SYSTEM ANALYSIS
    For  the  purposes   of  the present study the behavior of
vinyl chloride  in  an  aquatic system may be assumed to  be  a
function of four aspects of the system:

    •  the components of the system with which  vinyl  chlo-
       ride  may associate  or react (£.*&•* water, organisms)
       other chemical species);
    •  the interactions  or   coupling  pathways  among  these
       components;
    •  the characteristics  of the interactions (£,*£*, magni-
       tude* rate,  saturation); and
    •  the rates of vinyl chloride inputs to the system*

    The conceptual  model of Figure 2 was  used  to  organize
the. facts and  assumptions  into an initial system hypothesis
as described by Gillett  et  al* (2).  This  model  represents
the  components and  interaction  pathways considered to be
important in a  study  of  vinyl chloride in an aquatic system*
This  initial   conceptual  model  was  transformed  to   the
conceptual  model   of Figure 3 through consideration of pre-
liminary studies of vinyl chloride (3),  available  data  on
vinyl  chloride and  analogous compounds, and constraints on
the scope of the investigation,as defined by the  nature  of
the problem*

    The  working   conceptual  model (Figure 3) indicated the
need for quantitative characterization of the chemical, bio-
logical, and physical interactions between  the  components*
The  transport  process  dynamics have been evaluated in pub-
lished descriptions of the  behavior of the  transport  media
(£•£*,   particle,    fluid,   and  trophic  dynamics)*   The
transformation  process dynamics were evaluated by  chemical,
biological, and physical experimentation*

    The  qualitative  conceptual  model  (Figure  3) and the
associated  quantitative interaction  descriptions  can  be
logically  reduced or   expanded  to  provide a hierarchy of
system models*   These   system  models  can  be  represented
mathematically   and  evaluated  by  simulation  to  provide
descriptions of vinyl chloride behavior at various levels of
abstraction or  generality*

-------
       Products
 Free Radical Reaction
       Products
 Direct Photochemical
   Reaction Products
 Indirect Photochemical
   Reaction Products
 Microbial Degradation
      Products
Coordination Complexes
                                   INPUT
    Vinyl Chloride
    in Atmosphere
Elimination Reaction
Products

Hydrolysis Reaction

1-



    1
OUTPUT
                                                                                                      Surface Active Agents
Vinyl Chloride in Water
    Vinyl Chloride
 Sorbed on Particulates
                                                        Sediments
                         Vinyl Chloride
                          in Bacteria
                                                  Vinyl Chloride in Algae
                                                          I
                                                                                                         Vinyl Chloride
                                                                                                        in Filter Feeders
                             I
                                                                                                          Vinyl Chloride
1


ide in
ts


\
































in Predators




Vinyl Chloride in
Danthif* FpPflPr^










                       Figure  3*    Working conceptual  model  of  vinyl  chloride
                                       interactions  in  an aquatic  system*

-------
    The quantitative  aspects of  the  possible  behavior  of
vinyl  chloride   in  aquatic  systems may be approximated by
simulation and analysis  of a system model of a  sample  lake
and   stream*     The   conclusions   resulting   from  these
hypothesesf howeverf  are only as  good  as  the  assumptions
made in their formulation*  These assumptions may be changed
to Incorporate new information or to apply the analysis to a
particular aquatic system*
ASSUMPTIONS

    The most  significant assumption in this type of analysis
is  the  model   itself*   The choices of components and their
couplings  represent  a mixture of logical analysis,  physical
intuition,  and  personal  biases*  These choices affect the
parameters, inputs,  outputs, and responses of the model*

    A best estimate  approximation of the behavior  of  vinyl
chloride   in  a  sample  lake or stream was obtained assuming
the most reasonable  estimates of the rates of transformation
processes   as    determined   from    laboratory    results*
Experiments   indicated  that  rates for all processes except
volatilization  are essentially zero (Section IV, V, VI,  and
VII)*   This  assumption  results in the simplified model of
Figure 4*

    To evaluate the  boundaries of  possible  vinyl  chloride
behavior,   two   additional   system  models  were  derived
describing extreme behavior at two levels of resolution*  In
these worst   case analyses,  all  chemical  and  biological
transformation   processes  were assumed to proceed at a rate
that  is   Just   below  the  level  of  measurement  in   the
experimental    procedures   used  for  their  determination*
Conditions in the aquatic  environment  (£.*£*•  turbulence,
stratification, sediment scouring) were assumed to be at the
extreme  of   the  environmentally realistic range that would
cause worst case system  responses*   The  system  models  of
Figures  5 and  6 were  analyzed subject to these worst case
assumptions*

    A  set  of   linear,   first-order  ordinary  differential
equations  was assumed to be a reasonable mathematical appro-
ximation   of  the dynamic behavior of vinyl chloride in the
hypothesized  structures*  This is Justified by  recourse  to
the  theory of  linearization about an operating path (4) and
assumes that  vinyl chloride input represents a small  system
perturbation*

-------
                      Vinyl Chloride
                      in Atmosphere
                          T
        a
         1,2
    INPUT.
Vinyl Chloride
  in Water
OUTPUT
Figure 4«   Best estimate  model of vinyl chloride in the
                   aquatic environment*
                             10

-------
                 Vinyl Chloride
                 in Atmosphere

INPUT
Vinyl Chloride
   in Water
                     1
a3,2
                  OUTPUT
             Chemical and Biological
            Reaction Products in Water
                       OUTPUT
Figure 5.   System model with worst case chemical and
     biological transformation reaction rates*
                           11

-------
                                                       "8.3
        I
         "3
 Chemical and Biological
Reaction Products in Water
 Chemical and Biological
Reaction Products in Water
                                   Vinyl Chloride
                                   in Atmosphere
        1
                                  Vinyl Chloride in
                                 Benthic Organisms
  Vinyl Chloride in
Filter Feeding Organsims
                                                               Vinyl Chloride in
                                                             Filter Feeding Organisms
                                                                     1
           "9.1
                                                        '10.6
   Vinyl Chloride in
  Predator Organisms
                                                                        a10.9
                   "10.7
                                                                Vinyl Chloride in
                                                             Omnivorous Organsims
                                                             fls.9
                                                             «5.7
 Figure  6.    System model o±  vinyl  chloride  in stratified
               lake with  a  simple  idealized  food web*
                                           12

-------
    The  system  diagrams  of  Figures 4  through 6 therefore
were directly  translated to a set of equations  that  can  be
written in vector form as
                      •    »  AX + BU                       (1)
                      at
where the  x^  represent the variable quantities  stored in the
boxes;  the a^^  represent the rate coefficients for transfer
from box J to box i; and the u.. represent the inputs to  box
i.

    The  typical  or sample lake is assumed  to  be  10* m2 and
10 m deep* It has a residence time of 10 days   and  strati-
fies  in   summer with a metalimnion 0*5 m wide  centered at a
5—meter depth*  It is completely mixed above and  below  the
thermocline   when stratified and completely  mixed  otherwise*
The typical or sample stream parameters  were   derived  from
Tsivoglou  and  Wallace's  (5) data on the Chattahoochee and
Jackson rivers*

    For the best estimate modelt equation (1) reduces to
                   dx
                   	L  =  a    x  + u                     (2)
                   dt       »,2  2    i
The  rate  coefficient value, e-i ,21 of the best  estimate model
of the  lake is a bulk gas exchange coefficient between water
and  atmosphere of  0*436  day"1  (6t  Section   VII   of  this
report)•    The  input  was set at 1 mg  I'1 vinyl  chloride in
the  influent water as a reference value*

     The gas exchange coefficient* a1)2t in the best estimate
stream  model is 0.96 clay"1 (5, Section  VI of   this   report),
and  the input is again 1 mg I'1 vinyl chloride*
                              13

-------
    The  worst   case model was analyzed using  values for a^j
listed in Table  1.    It  should  be  noted  that   these  are
extreae  values   and  would  not  be  expected to  apply in a
typical  lake  or  stream*   The  values  for   each  of  the
coefficients were chosen as described*

    •  a-i ,2 — as discussed for best estimate  model.
    •  a3 2 and  an 4 — represent the combined effects  of
       the  hypothesized  chemical  and  biological reaction
       pathways  for vinyl chloride in  water*   Values  were
       determined  either  by  assuming  that   the  reaction
       occurred  at  a rate immediately  below   the   level  of
       detection or  by extrapolating laboratory  conditions
       to their  extreme analog in the aquatic  environment*
    •  a* 2 and  a2  « — are the results of an   approximation
       for  eddy current  transport  across   a thermocline,
       which  was  extrapolated  to  the  hypothetical  lake
       morphology (7)*
    •  a6,2» *7,4t  and aa s —— were based upon the  fraction
       of  the   lower  trophic  level  biomass assumed to be
       assimilated  per year (8)*
    *  &9,6t *9,7t  and a.9 s ~~ were  based  on the  trophic
       level  assumption  used  for a6 2t a? 4» and as s and
       the  assumption  of  an   evenly   distributed   food
       preference•
    *  aio,6» aio,7? and ato a ~~~ were based on the  trophic
       level assumption used for a« zi a7 *t and a8 s and an
       evenly distributed food preference*
    *  as,6f as,7t  as, a» and a.s,9  ~~~  were  based  upon  an
       average  10—day turnover time and a population loss of
       90% of ingested material averaged over  a year (8 )•
    *  as»* ~~~ assumes an average settling rate for particu—
       lates of   0*1  cm  sec"1  (7)  and  diffusion-limited
       transport in  unmixed  interstitial  waters  with an
       effective surface fraction of 0*38 for  several  sizes
       of closely—packed spheres*  The diffusion coefficient
       for  vinyl  chloride was estimated from the diffusion
       coefficient  for oxygen and the ratio of gas  exchange
       coefficients (9)*
    •  a*, s ~~ assumes diffusion limited  transport  and  no
       scouring  of  sediments*

    The  sorption  of  vinyl  chloride onto particulates was
assumed  to  be   reversible  and  very  fast   so    that   an
equilibrium  with a K  =10 (see Section VI) was maintained.
The concentration  of  organic  particulates   was   taken  as
constant (.!.•£• t  input = output) at 1*66 rag I'1 (7)*
                              14

-------
           Table  1.   WORST CASE MODEL PARAMETERS
Svmbql
.Interactions
Value <
  ai,2
  a3,2
  an,*
  a*,2
  a6,2
  as, s
    , 61 a9, 7
     a
  aio, 6*
  as, 6* as, 7
  as, 8 ! as^ 9
  as, 4
  a*,s
  Ji*
Volatilization of vinyl
chloride

Chemical  and biological
degradation

Chemical  and biological
degradation

Transport across theraocline

Transport across thermocline

Uptake by filter feeding
organisms

Uptake by filter feeding
organisms

Uptake by benthic organisms

Uptake by predator


Uptake by omnivore


Turnover  rate of organisms


Water to  sediment transport

Sediment  to water transport

Loss from compartment

Input to  water

Input to  water	
0.436


0.115


0.115


0.0178

0.0178

0.000292


0.000292


0.000292

9.73 (10~s)


7.3 (10~5)


0.1


0.107 (10~2)

3.45 (10"*)
 I
•j aJi
1 ppm
                              15

-------
    Complexation of vinyl chloride with  silver or copper was
assumed  to   be  negligible since typical Cu+  and Ag* concen-
trations in  aquatic systems are less than  30  rag m 3f as much
as 80% of which  is adsorbed onto organic colloids  (7).   In
addition*  complexation  would  probably  be   very rapid and
reversible*   Finally,  the concentration  o± vinyl chloride in
the air above the water was  assumed  to  be   maintained  at
essentially  zero by surface replacement*
RESULTS AND  DISCUSSION

    The concentration of vinyl chloride  in  the water and the
cumulative   loss  to  the  air  for  the best  estimate model
(Figure 4) of  the sample lake are shown  in  Figure 7*   These
results  are  for  a  vinyl chloride input  of  1 mg I"1 and a
fractional input of  10%  of  the  total water  volume*   A
similar result for a volume of water in  the sample stream as
it  travels  downstream  is  indicated   in   Figure 8*  These
results indicate that with a volume input of 10%  water  per
day containing 1 mg l~l vinyl chloride,  the concentration of
vinyl  chloride  in the sample stream and lake would be less
than 0*2 mg  I"1.

    If the chemical and biological  reaction  pathways  with
worst case rates are added to the preceding examples (Figure
5),  the  resultant  distribution  of  vinyl  chloride is as
indicated in Figures 9 and 10*  It should be noted  that  in
this worst case no losses of degradation products other than
washout   or   dilution   are   postulated*   Even  so*  the
degradation  products  reach  a  steady—state   concentration
below 0.3 mg I"1.

    The  behavior  of vinyl chloride in  the worst case model
of Figure 6, which  represents  a  stratified  lake  with  a
simplistic   food  web, is indicated in the  graphs of Figures
11 through 14*  The results are self-explanatory except  for
the  concentrations in sediments and benthic organisms*  The
assumptions  of diffusion—limited exchange between water  and
unmixed lower  sediment layers and of lack of scour dictate a
relatively   long   half—life  for  vinyl   chloride  in  the
sediment—benthic organism-predator—orainivore cycle ( tu  =  3
yr )•     With    these   assumptions   the    vinyl   chloride
concentration  in  the  sediment  approaches  a  steady—state
value of 0*358 mg I'1 in about 15 years* The vinyl chloride
in  benthic  organisms reaches a steady—state value of 0*013
mg l~* in the  same time period while the concentrations  in
other organisms are less*

                              16

-------
        0.662
        0.331 -
                                  Vinyl Chloride  in  Water
                          	  Vinyl Chloride  in  Air
                           TIME, days
Figure 7«  Lake  simulation with best estimate model*
                            17

-------
                                  Vinyl Chloride in Water

                                  Vinyl Chloride in Air
        0.896
        0.448
      o


                               5
                           TIME, days
                                              /
10
Figure 8.   Stream simulation with  best estimate model.
                            18

-------
                                 Vinyl Chloride  in  Water
                           	 Vinyl Chloride
                                   Degradation Products
       0.274
                             25
                          TIME, days
50
Figure 9.  Lake  simulation of the model  of  Figure 5.
                           19

-------
                             	 Vinyl Chloride in Water

                             	 Vinyl Chloride
                                      Degradation  Products
           9.68
       S

       X

       o
       __l
                                25
                             TIME, days
50
Figure 10.   Stream simulation of the model  of Figure 5.
                             20

-------
                               Vinyl Chloride  in Epilimnion
                           • — Vinyl Chloride  Degradation

                                 Products  in Epilimnion
                               Vinyl Chloride  in Sediments
         0.176
       *>
      UJ
      o


      I


      o



      •z.
0.0879
              0
                       100

                    TIME, days
200
Figure 11•   Stratified lake simulation  of  the model in

                       Figure 6.
                            21

-------
                             Vinyl  Chloride  in Hypolimnion
                      	 Vinyl Chloride  Degradation
                               Products  in Hypolimnion
         13.50
V \
0
25
TIME, days
5(
Figure 12.  Stratified lake simulation  of  the  model in
                      F i gure  6•
                             22

-------
                                   Vinyl  Chloride  in Filter
                                      Feeding  Organisms
                                      (Hypolimnion)

                                   Vinyl  Chloride  in
                                      Predator Organisms

                                   Vinyl  Chloride  in
                                      Omnivorous  Organisms
              0
   25
TIME, days
Figure 13*  Stratified lake simulation of the  model in
                      Figure  6«
                             23

-------
                                   Vinyl Chloride  in Filter
                                     Feeding Organisms
                                     (Epilimnion)

                                   Vinyl Chloride  in
                                     Benthic Organisms
          6.59
        O
        i—I
        X

        2 3.29

        g
        n:
        o
              0
   25
TIME, days
50
Figure 14.  Stratified lake simulation of the model  in
                       Figure 6.
                            24

-------
    A  diagnostic  input consisting of a pulse o± vinyl chlo-
ride can produce a characteristic response for each  compon-
ent*   This  response  is a very concise way of demonstrating
the behavior predicted by the system hypothesis*  The  total
response  to   a  pulse  input  contains  all the information
necessary to   characterize  the  system  (10)*   Figures   15
through  17 show the component responses to a pulse input  of
1 mg I"1 vinyl chloride to the  epilimnion  waters  for  the
model  of Figure 6*  In Figure 18, the beginning of the slow
loss of vinyl  chloride from the sediments can be seen  after
about 60 days*

    The  results of a  pulse input of 1 mg I"1 vinyl chloride
to the sediments are shown in Figures 19  through  21*   The
slow   but  continuous  loss  of  vinyl  chloride  from  the
sediments is evident*   This loss occurs to the air (rate - 7
x 10"6 mg l~l  day"1 ) and to downstream waters (rate = 3.9  x
10~* mg I"1 day"1 ).

    All of the results assume steady—state levels of biomass
components and particulates and do not include any low level
toxic effects  or biomagnification (i»e», selective retention
of  vinyl  chloride )•    From  the  results  of  these  model
simulations it appears that vinyl chloride should not remain
in an ao;uatic  ecosystem under most natural conditions*
                              25

-------
                                    Vinyl Chloride in
                                      Epilimnion Water

                                    Vinyl Chloride Reaction
                                      Products in Epilimnion
                                      Water
            1.0
          3 0.5
          31
          O
          _i
                                 25
                              TIME, days
50
Figure 15«  Stratified  lake  model's response to pulse input
           of vinyl chloride to epilimnion water.
                              26

-------
                            Vinyl Chloride in Filter Feeding
                              Organisms (Hypolimnion)
                 	  Vinyl Chloride in Benthic
                              Organisms
                            Vinyl Chloride in Predator
                              Organisms

                            Vinyl Chloride in Omnivorous
                              Organisms
                                 25
                             TIME, days
Figure 16*  Stratified lake model's response to pulse input
           of vinyl chloride to epilimnion water*
                              27

-------
                              Vinyl  Chloride  in Hypolimnion
                                Water
                   	 Vinyl  Chloride  in Sediments
                              Vinyl Chloride  Reaction
                                Products  in Hypolimnion
                                Water

                              Vinyl Chloride  in  Filter
                                Feeding Organisms
                                (Epilimnion)
                                 25
                             TIME, days
50
Figure 17.  Stratified lake model*s response  to  pulse input
           of vinyl chloride to epllimnion water*
                              28

-------
                                   Vinyl Chloride  in  Sediments
                                     (Extended Time Scale)
                                  50
                               TIME, days
100
Figure 18*   Stratified: lake model's response to pulse  Input
            o~f vinyl chloride  to  epiliranlon water*
                               29

-------
                                 Vinyl  Chloride in Sediments
           1.000
                0
   50
TIME, days
100
Figure 19*  Stratified lake model's  response to pulse input
               of  vinyl chloride to sediments*
                               30

-------
                              Vinyl Chloride in Hypolimnion
                                Water
                      	 Vinyl Chloride in Benthic
                                Organisms
                              Vinyl Chloride in Filter
                                Feeding Organisms
                                (Hypolimnion)
c.ou
CT>
s
X
LU
21.43
o
o
1
^J
0
s"~ 1 ""
/
/
/
_ / _
/
/
/
i

) 50 10
TIME, days
Figure 20.  Stratified  lake model's  response to pulse input
              of vinyl  chloride  to sediments.
                               31

-------
                              Vinyl  Chloride in Eplimnion
                                Water
                       ———  Vinyl  Chloride in Atmosphere
1O.V
ir\ "
O
X
LU
|8.43
3
•^P»
j_
o
0
(
1 /
•//
/
/
^^m J
/
/
,
^ 1
) 50 10
TIME, days
Figure 21*  Stratified lake model's  response  to  pulse input
              of vinyl chloride  to sediments*
                               32

-------
                          SECTION IV

                    CHEMICAL INTERACTIONS
    No reference  to studies  of  the  degradation  of  vinyl
chloride   in   water  could  be  found  in  the  literature.
However* considerable  data  are  available  concerning  the
chemistry  of   vinyl chloride and related compounds that can
be extrapolated to  reaction conditions  anticipated  in  the
environment.    Evidence  supporting  such extrapolations was
obtained in a  few preliminary experiments*

    Four pathways were postulated  as  potential  mechanisms
for  chemical  degradation or alteration of vinyl chloride in
the  environment:   substitution  (ll)t  elimination   (12),
addition (13),  and  oxidation (14).

    In   nucleophilic  substitution,  the  chloride  ion  is
displaced by a nucleophilic  species  (Nu)  (11).   Reactive
nucleophiles    common to the aquatic environment are amines,
thiols, water,  and   hydroxide  ion.   The  reaction  can  be
either  first   or  second  order  depending  on the specific
mechanism.

    The  most   probable   elimination   reaction   in   the
environment  is one in which hydrogen chloride is eliminated
from vinyl chloride  in  the  presence  of  base,  producing
acetylene  (12 )•    This  is  a second—order reaction and the
rate is dependent upon  the  concentrations  of  both  vinyl
chloride  and   base.   The  most significant base present in
natural water  would be hydroxide ion:
             H       H
               \ = CX    Base    HC=CH +
               /     \
             H       Cl
    The  addition reaction most  likely  to  occur  to  vinyl
chloride in the aquatic environment is the addition of water
across   the  carbon-carbon  double  bond,  catalyzed by acid
(13).
                              33

-------
H       H
 \     X       H+
  C = C       —2—>
 X     \      H20
H       CI
                               H  OH
                                I  I
                             H-C-C-H
                                I  I
                               H  Cl
    0
    II
CH -C-H
This reaction  is second order with  its  rate  dependent  upon
concentrations of both vinyl chloride and acid*

    Based  on   kinetic  studies  in  mixed systems, only a few
oxidative  processes  are  potentially   important  for  vinyl
chloride   in   the  environment   (14)*     Autooxidation (with
molecular  oxygen) (16) is a possibility;  but since its  rate
is  dependent   upon  the  rate   of  homolytic cleavage of the
strong carbon—hydrogen bond, the rate of oxidation of  vinyl
chloride would be slow*

    Free   radicals are anticipated  to react with the carbon-
carbon double  bond (14), resulting  in   oxidation*   However,
since literature data are not available to evaluate the role
of   free  radicals  in  natural waters,   extrapolation  of
laboratory data to natural waters is tenuous*

    The reactivity of vinyl chloride was studied, and  known
structure—reactivity relationships  and  activation parameters
were used  to evaluate the significance  of the above pathways
for vinyl  chloride disappearance in the environment*
MATERIALS  AND METHODS

    Vinyl   chloride  was  obtained  from  Matheson  Chemical
Company and used as received*  Distilled water was  used   in
all  experiments  except  for  natural  water  studies*  The
Oconee River water sample was obtained in  Athens,  Georgia,
and  filtered through a 0.22-y filter prior to use ( pH 6*1)*
The Okefenokee Swamp water sample  was obtained at Kingfisher
Landing, Okefenokee Swamp, Georgia,  and was used as obtained
(pH  4*2)*    Hydrogen  peroxide  was  purchased  from  Baker
Chemical Company*

    A  special  reaction  vessel   (Figure  22)  designed   to
eliminate  volatilization, was made for these studies*
                              34

-------
                            SEPTUM
                              TEFLON STOPCOCK
                        INSIDE DIAMETER 6 MM
        VOLUME APPROX. 2.9 ML
Figure 22*   Vinyl chloride reaction vessel*
                      35

-------
    The vessel  was filled to the top with water and 20 ml  of
vinyl chloride  was added*  The filled  vessel was placed  in a
constant  temperature bath (+ 2°C ) and   removed  at  recorded
intervals  for analysis*  The concentration of vinyl chloride
at  each   time   interval was determined by comparison of glc
peak heights using  a  vinyl  chloride-carbon  tetrachloride
standard   solution*  Experimental error was determined to  be
± 10%.

    Glc analysis was carried out on a  Tracor  Microtech  220
Gas  Chromatograph fitted with a 3 m x 0*63 cm column packed
with 0.4% Carbowax 1500 on Carbopack;  injection, column, and
detector   temperatures  were   210°C,    40°C,   and   210°C,
respectively*
RESULTS AND DISCUSSION

oH Studies

    In  reaction  mixtures  at  pH  3*0  (HCl),  7.0. and 11.0
(NaOH) at 85°C,  no  reaction  could  be   detected  after  27
hours.    Extrapolation   of   data,   assuming  hydrolysis,
elimination,  addition* or substitution mechanisms, indicates
that these  reactions would have half—lives on the  order  of
years.

    Literature   information  was used to estimate half—lives
for several  possible  reactions  of  vinyl  chloride  under
environmental  reaction conditions (Table 2)*  The estimated
half—lives  were  in  good  agreement  with  our  experimental
data*   In  view  of these half—lives, any contribution to the
disappearance of vinyl chloride by chemical degradation  via
these pathways  normally would not be significant since other
processes are faster.

    In   environments   like  municipal   water  chlorination
facilities, however, high concentrations of  chlorine  would
exist*   Based   on  the  reactivity  of  carbon—carbon double
bonds  with  chlorine  and  hypohalous   acid,   under   such
conditions   vinyl  chloride  may be converted to more highly
chlorinated compounds*
Oxidation Studies

    The reactivity of vinyl chloride  with  molecular  oxygen
was  also   investigated.  Experiments were carried out at 20

                              36

-------
          Table  2.   ORDER OF MAGNITUDE ESTIMATES FOR  HALF-LIVES
                      FOR VINYL CHLORIDE REACTIONS
Reactior^
Elimination3
Substitution1*
Addition0
Additiond
Addition6
Hydrolvsis
Li terature data
Temp*
C °C»
95.53
130
25
25
25
120
Reactant
Methoxide
C2H5S-
H2O
C12
HOCl
H7O
Maximum rate
constant M * sec~*
10~7
10~9
10~*
10~*
10~2
No RX
Estimated t,
at *
25°C8
<10 yr
<10 yr
<1 yr
140 hr
1000 hr
<10 vr
^Reference  17t  methanol solvent,  10  3M methoxide.
 Reference  18,  reaction of 1— chloropropene in ethanol  at  1 x 10~~3M
 thiol.
f*
 Reference  19,  acid catalyzed hydration at pH 3.
 Reference  20,  1,3,3—trichloropropene  in aqueous acetic acid——1 mg I"1
 chlorine*
eReference  21,  hypohalous acid  addition to allyl alcohol  at pH 4*5	
 1 mg  I"1 hypohalous acid*
 Reference  15*
&Calculated assuming pseudo first—order kinetics*

-------
mg I * vinyl  chloride  in  water  saturated   with  molecular
oxygen at elevated temperatures*  After  12 hours at 85°C, no
degradation   of  the  vinyl  chloride could  be detected*  At
temperatures  and oxygen concentrations   in   natural  waters,
therefore*  vinyl chloride will not be degraded by molecular
oxygen at a significant rate*

    As anticipated* at elevated temperatures vinyl  chloride
was   degraded  by  hydrogen  peroxide*   At  85°C  hydrogen
peroxide decomposes to give hydroxy  radicals  (HO*),  which
react  with   vinyl  chloride*   With  1  x   10~2  M hydrogen
peroxide and  1 x 10~* M vinyl chloride,  the   reaction  obeys
zero-order    kinetics,   indicating  that  decomposition  of
hydrogen peroxide is the rate—determining step*

    The significance of this reaction pathway  is  difficult
to  assess  because  no  data  are  available concerning the
concentration  and  species  of  free  radicals  in  natural
waters*   These  experiments  do  indicate   that if reactive
radicals were  present  in  natural  waters   at  significant
concentrations, they may potentially degrade vinyl chloride*
Natural  Waters

     Vinyl   chloride was shown to be chemically stable in two
natural  water samples*  No degradation could be detected  in
Oconee   River  water (pH 6*1) and Okefenokee Swamp water (pH
4*2) after  41  hours  at  room  temperature  and  at  85°C*
Assuming the pathways previously discussed,  extrapolation of
the   elevated  temperature  data to environmental conditions
would indicate a minimum half—life of  at   least  one  year*
Although   only   two   representative   water  samples  were
employed,   the  results  obtained  are   in  agreement   with
behavior  predicted  based  on  known chemical reactivity of
vinyl chloride*
Comolexation

    To  study the effect of complexatlon  with metal  ions  on
the  persistence of vinyl chloride in  water, three important
points  should be considered:

    •   How strong are the complexes?
    •   What are the concentrations of  the  metal species?
    •   What are the concentrations of  the  competing ligands?
                              38

-------
A survey o± the  literature did not disclose any  equilibrium
constants  for the  formation of coordinate complexes between
vinyl chloride   and  metal  ions*   However*  data  for  the
formation of complexes between structurally related olefinic
compounds  and Ag+  and Cu+ (Table 3) indicate that electron-
withdrawing groups  attached to the double—bonded carbon atom
of the olefin decrease the equilibrium constant*  Assuming a
concentration of 10 mg I"1 for the silver—ethylene  complex*
equilibrium calculations show the complex to be greater than
99%   dissociated*    Similarly*  the  cuprous—/9—chloro—allyl
alcohol complex  at  6*2 mg  l~*  is  also  greater  than  99%
dissociated*   The   effect  of  other  ligands common to the
aquatic environmentt which would be competing for the  metal
ions* are neglected in these calculations*  Thus we conclude
that at low metal ion and vinyl chloride ion concentrations*
complexatlon by  these metal ions is not important*
                             39

-------
     Table 3.  EQUILIBRIUM  CONSTANTS FOR SOME COMPOUNDS
           STRUCTURALLY  RELATED TO VINYL CHLORIDE3
Olefin (L)
Ethylene
Trans— dichlo roet hylene
Cis— dichloroethylene
Allyl alcohol
Allyl alcohol
ft— chloroallyl alcohol
Metal CM)
Ag+
Ag+
Ag+
Ag+
Cu*
Cu*
I OB k
1.93b
-0.509C
-0.796C
1.15d
4.72e
1.34e
                     where L   =  number of Uganda present«
^Reference 22*
cReference 23*
^Reference 24*
eReferencc 25.
                            40

-------
                          SECTION  V

                  PHOTOCHEMICAL  INTERACTIONS
    Several   possible mechanisms  exist for the decomposition
of vinyl chloride by light (Figure  23).  Mechanism I, direct
photolysis*  involves direct absorption  of  light  by  vinyl
chloride followed by reaction from  its excited state (VCM)*.
Several  studies  have  indicated that vinyl chloride in the
vapor phase   decomposes  when   irradiated  with  very  short
wavelength  ultraviolet  light  « 200  nm) (20f 27, 28).  The
primary reaction processes  are  homolysis  of  the  carbon-
chlorine   bond  yielding  a chlorine atom and elimination of
molecular  HCl.    Twisting  around  the  double   bond*   an
undetectable reaction* may also occur.

    Mechanism   II*   photosensitized   reaction  via  energy
transfer*  involves  absorption  of light  by   a   triplet
sensitizer  followed by energy  transfer to vinyl chloride to
form its first excited triplet  state*   (VCM)*.   Studies  by
Bellas  e_t  al»  (29)* for example*  indicated that photolysis
of vinyl chloride can be sensitized in the  vapor  phase  by
mercury atoms.  The authors concluded  that in this case* the
primary  photochemical  process for triplet VCM in the vapor
phase  involved  elimination  of  molecular  HCl.   However*
homolysis  of the carbon—chlorine  bond  could not be ruled out
by  their  data.   In  solution*  the major photoreaction for
triplet chlorinated olefins was found   to  involve  twisting
around the double bond (30).

    Mechanism   III*   which    we  have   called   chemical
sens!tization, involves  direct  chemical  reaction  between
sensitizer and olefin.  Such reactions are known to occur in
the  condensed  phase with simple olefins and electronically
excited ketones (31).

    Mechanism   IV*   free   radical     decomposition    and
polymerization  of  VCM initiated by photochemical homolysis
of a species like a peroxide* is  also   a  possible  pathway.
Examples   of  the  light-initiated  polymerization  of vinyl
monomers are discussed by Walling (32).  Url and  co-workers
found   that   polymerization   of  vinyl  monomers  can  be
"photosensitized" by chlorophyll  (33)  and by iron  complexes
(34,  35).   The "photosensitization"  in these cases clearly
did not Involve energy transfer*  but rather  the  generation
of free radicals followed by polymerization (Mechanism IV).


                              41

-------
            Mechanism I. Direct Photolysis
            VCM ^.(VCM)*
            (VCM)* -* products

            Mechanism II. Photosensitized Reaction (Energy Transfer)
            S ^1S*
            1S* -*3S*
            3S* + VCM -»S + 3(VCM)"
            3(VCM>* -» products

            Mechanism III.  Chemical Sensitization
             S* + VCM -» products

            Mechanism IV. Light-initiated Free Radical Decomposition
             A-B ^i-A*  + B'
             A' + VCM -»ACH2CHC!'
             ACH2CHCr  + VCM -* polymer
             ACH2CHCr  + O2 -* ACH2CHCI02*
             ACH2CHCI02' + VCM -» polyperoxides
             ACH2CHCI'  + B' -*ACH2CHCIB
             2ACH2CHCI* -^ACH=CHCI + ACH2CH2CI
             2ACH2CHCI' -^(ACH2CHCI42
Figure 23*  Pathways for  light induced decomposition of
                        vinyl chloride*
                                42

-------
    The   photodegradation  of   vinyl chloride was studied  to
determine whether the above processes are  possible  in  the
aquatic environment, and whether their ratest it they occur,
are sufficiently high to compete with other processes*
MATERIALS AND METHODS

    Vinyl  chloride  gas  from  Matheson  Company  was  used
without  further purification.    Laboratory  distilled  water
was redistilled from basic  permanganate immediately prior to
use*

    Natural  waters  were   obtained from the Oconee River in
Athensf  Georgia, and the Okefenokee Swamp (Big  Water  Lake)
in  South  Georgia*  Commercial  humic acid was obtained from
Aldrich  Chemical Company*

    Stock solutions of vinyl chloride were prepared in small
bombs  equipped with gas-tight  Teflon  stopcocks*   Aliquants
of  VCM   in  gas—tight syringes  were added to the bombs that
were   completely  filled  with  known  volumes   of   carbon
tetrachloride;  the  gas  rapidly  dissolved  into the CCl* •
Aqueous   solutions  were    prepared   following   the   same
procedures;  the  concentration   in  water was then measured
exactly  by comparison to the CCl« stock solutions*  Analyses
for VCM  were performed by gas—liquid chromatography on a 2 m
x 0*32 cm glass column packed  with  0*4%  Carbowax  1500  on
Carbopack  A*   The column  was cured by heating at 200°C for
48 hours with slow purging  by  nitrogen*

    Glc   analyses  were  performed  on   a   Tracor   MT—220
Chromatograph  using  a  flame detector*  Photolysis studies
were conducted on a rotating turntable apparatus,  described
in  detail by Moses, Liu, and  Monroe (36).  A 450-watt high-
pressure mercury lamp was the  light source*  The ultraviolet
spectrum of VCM in water was obtained  with  a  Perkin-Elmer
602  Digital Spectrophotometer using a specially constructed
quartz cell equipped with a gas-tight Teflon stopcock.   All
photolysis  studies  were   carried  out  in  reaction  cells
equipped  with   gas-tight   Teflon   stopcocks.    Controls
established that no leakage of VCM occurred from these cells
over a period of at least two  weeks.

    Kinetic  studies  were  generally  carried  out  at  VCM
concentrations of 10 to 20  mg  l"1.   The  light  from  the
mercury   lamp was filtered  through a 3 mm-thick Pyrex sleeve
(cutoff  at 300 nm) for most of the studies.  Singlet  oxygen

                             43

-------
studies were  conducted using 1.00 x  10~*  M methylene blue as
sensitizer    and   578   nm  monochromatic  light*   Acetone
sensitization studies employed  10% (by volume)  acetone  in
water  and  313  nm  light.  Filter  solutions (1.0 cm thick)
were as follows:  573 nm - 50 g cupric chloride  (hydrated),
150  g  anhydrous  calcium  chloride,   and  150  g potassium
dichromate  in 500 ml distilled water slightly  acidified  by
hydrochloric  acid; 313 nm - 0.001 M  potassium chromate in 3%
aqueous   potassium  carbonate,  and  3  nm—thick Pyrex sleeve.
The actinometer for the acetone sensitized photolysis was   a
solution  of   0.05  M  benzophenone  and   0.100  M  cis-1,3-
pentadiene  in benzene (37).
RESULTS  AND DISCUSSION

Direct Photolysis

    The   rate   of  direct  photolysis   of  a  pollutant   is
proportional to the degree of overlap  between the electronic
absorption   spectrum of pollutant:  and  the  spectrum of light
source,  vinyl  chloride and sunlight, respectively,  for  the
present   study.   Atmospheric ozone prevents essentially all
sunlight of wavelengths  below  295  nm  from  reaching  the
earth's   surface.   Vinyl  chloride,   in  the  vapor  phase,
however, does  not absorb above 220 nm  (28), and our  studies
show   that   in  water  it does not absorb above 218 nm.  The
longer   wavelength  singlet—triplet  transitions of   simple
ethylene derivatives that occur at wavelengths > 295 nm are
highly forbidden and  thus  have  extremely  low  extinction
coefficients (38).

    The   lack   of  overlap between vinyl chloride absorption
and   sunlight   radiation  spectra  indicates   that   direct
photolysis   of  vinyl  chloride  would  be  very slow in the
aquatic  environment.  To  confirm  this  experimentally,  we
exposed   solutions  of  vinyl  chloride  (10 mg l~*) in pure
water to filtered (> 300 nm) light from a mercury lamp.   No
photolysis   occurred  over a 90—hour period.  The integrated
intensity of the  300—370  nm  light   in  our  photochemical
apparatus  was  found  to  be about eight times more intense
than  midday—June sunlight (lat. 34°N)  in the  same  spectral
region.
                             44

-------
Indirect Photolysis

    Although  direct  photolysis (Mechanism I) is immeasurably
slowt   the   literature  indicates  that  the  light-induced
transformations  of   vinyl  chloride  could  occur    through
indirect   pathways    (Mechanisms   II-IV).    For  example*
substances found dissolved in certain  natural  waters  were
found   to  greatly accelerate the photodecomposition  of some
pesticides (39, 40).  Photolysis experiments were  therefore
conducted    in   natural   waters  and  in  distilled water
containing  model photosensitizers  that  absorb  light  of
wavelengths > 300 run.

    Vinyl  chloride   was  not  readily  degraded  by  singlet
oxygen* an excited form of  oxygen  generated  by  methylene
blue    photosensitization.   However*  in  the  presence  of
acetone*  a   high-energy  triplet  sensitizer*  or  hydrogen
peroxide* a  free radical source* VCM decomposed rapidly when
irradiated    with   ultraviolet  light*   The  disappearance
quantum yield (313 nm ) for the  acetone—sensitized  reaction
(3*0 x  10~2  M VCM) was 0.75.  A colorless precipitate formed
during  photolysis* but it was not identified.

    Since  the  major photochemical process for triplet 1*2—
dichloroethylene    and    other    mono—olefins    involves
isomerization  (30)*  twisting  about its carbon—carbon bond
would be expected to be the primary process for triplet VCM.
Other studies have indicated that reaction  between   triplet
ketones  and   olefins   ( 41 )   to  form  oxetanes   is  not
particularly  efficient.  Therefore  the  high  disappearance
quantum yield  for  the acetone—sens!tized photolysis of VCM
was surprising.   The  photolysis  may  involve  inefficient
homolysls  of  the  carbon-chlorine  bond  of  triplet  VCM*
followed by  free-radical polymerization of VCM*  i.e.*  most
of the  VCM would be  consumed by secondary thermal reactions.

    The importance of photosensitization via energy transfer
for the disappearance of VCM in the environment is difficult
to predict.   Such sensitization occurs efficiently only when
the triplet  state energy of the sensitizer equals or  exceeds
that  of  the  acceptor, i.e., VCM.  Since the triplet state
energies of  mono-olefins are very high (78-82  kcal   mole"1)
(38),   only  high energy sensitizers such as acetone (triplet
energy  80 kcal mole"1 ) are effective.  Unfortunately, little
is known about the concentrations and distribution of high-
energy  sensitizers   in the aquatic environment.  The matter
is further complicated by the  fact  that  competing  energy
acceptors  such  as  dissolved oxygen are also present in the
aquatic environment.

                            45

-------
    The high susceptibility of  VCM to free radical attack in
water was demonstrated by  its   rapid  disappearance  in  the
presence  o£ hydroxy  free  radicals generated by photoysis of
hydrogen peroxide (Figure  24)•   Since  PVC  plant  effluents
are  likely  to  contain small  amounts of peroxides, such as
peroxydisulfate (32), that are  used  in  the  polymerization
process*   sunlight—induced  decomposition   of   VCM   was
considered as a possible pathway for its disappearance  from
PVC plant effluent water*

    Howevert  using   the   same   apparatus  employed  in  the
present direct photolysis  studies, Thruston (3)  found  that
VCM photolyzed very slowly (half-life 40 hours) in PVC plant
effluent*   When  exposed   to   sunlight*  it photolyzed even
slower*  Very little  reaction was detected after 25 hours of
exposure*

    Our natural water studies were carried out in unfiltered
waters  collected  from  the Oconee  River,  a   moderately
polluted  river  in Athens,  Georgia, and from the Okefenokee
Swamp,  an  unpolluted  water   that  is  highly  colored  by
dissolved  humlc  materials* In both natural waters, and in
water containing  20  mg   I"1   commercial  "humlc  acid"  (a
derivative  of  decayed plants), no decomposition of VCM (10
mg l~*) occurred during a  20—hour irradiation period*
                            46

-------
      100
     o
     I 80
       60
     o
     >
     o 40
     e
     Q_
       20
                                    I
                      1            2
                             TIME, hrs
Figure  24»   Decomposition of vinyl chloride in water by
    attack  of free radicals generated by photolysis
              (300 nm)  of hydrogen peroxide.
                            47

-------
                          SECTION VI

                MICROBIOLOGICAL INTERACTIONS
    In natural watersf  the interactions  of  vinyl   chloride
with  living organisms  must also be considered as a  possible
mechanism for disappearance of the compound*   Two   possible
pathways  were  considered—-—sorption  to microorganisms  and
degradation by bacteria*   The toxicity of the vinyl  chloride
to bacteria was also  investigated*
MATERIALS AND METHODS

    Five mixed bacterial  populationst  three  mixed   fungal
populationst  and   two   single  organism  cultures C Bacilluq
subtilis. and Flavobacterjum harriaonii) were isolated  from
natural  aquatic   systems  in  and near Athensf Georgia*   An
alga* ChioreIIa ovrenoidoaa• was  obtained  from  the   Starr
Collection* University  of Indiana* Bloomington, Indiana*

    A  saturated   solution of vinyl chloride was prepared by
bubbling the gas into sterile distilled water for one   hour*
Vinyl  chloride  solutions for the bacterial degradation and
toxicity studies were prepared by aseptically  diluting  the
saturated  solution to  varying  extents with a solution of
nutrient broth that was diluted 1:20, 1:40, 1:80,  or   1:100
in  basal  salts medium (42)*  The pH of the medium was 6*9*
For the sorption studies, the  saturated  VCM  solution  was
diluted with distilled  water*

    Analyses   for  VCM  were  done  by  direct  gas-liquid
chromatography ( glc) using  a  Tracor  MT-220  Chromatograph
equipped  with  dual flame ionization detectors*  Peak areas
were obtained using a Varian Aerograph Model 477 integrator*
VCM amounts were determined by comparison of glc peak   areas
from  the  experimental  solutions  with  those from VCM gas
standards in air prepared by  MG  Scientific  Company*   VCM
eluted  in  approximately  two  minutes  as  a single, sharp
symmetrical  peak   from  a  1*5  meter  Porapak  Q   (Waters
Associates, Inc.)  column (4 mm ID) at an oven temperature of
125°C, an injection port temperature of 215°C, and a carrier
gas (nitrogen) flow rate of 90 ml/min*

    For  the degradation and toxicity studies, 250—ml  flasks
with side arms and screw caps, as illustrated in Figure  25,

                             48

-------
                                 HOLE
                SCREW CAP
                                    RUBBER SEPTUM
                          enzsna "^TEFLON FILM LINER
Figure 25.  Apparatus for vinyl chloride degradation and
                    toxicity studies*
                            49

-------
were used*  The  VCM stock solution was introduced by syringe
through  the   hole  in  the screw top into  flasks containing
dilute  nutrient  broth  and  bacteria*   Samples  for   glc
analysis  were removed in the same manner*   The Teflon liner
covering the  top was sealed with cellulose  tape  immediately
after the syringe was removed*

    The  side-arm  tube  was  designed  to   fit  the  Klett-
Summerson photoelectric colorimeter in  which  turbidity  of
the culture was  measured using a blue filter (425 nm)*  This
allowed growth to be monitored without opening the flasks*

    Each  isolated  bacterial population was inoculated into
two flasks containing 1:20 nutrient  broth*    The  saturated
VCM  solution was  added  to  one of the cultures to give a
final concentration of 20  mg  VCM  per  liter*   The  other
culture,  the control,  received  no  VCM*    Each series of
cultures included a flask containing medium and VCM  but  no
organisms*    The  cultures  were  incubated  at  21°C  on  a
gyratory shaker  under an exhaust hood*

    After  one   week   the   resultant   populations   were
transferred   to  a 1:20 nutrient broth solution containing 40
mg I"1 VCM*   Weekly transfers were made for a period of five
weeks*  decreasing  the  nutrient  broth  concentration  and
increasing  the   VCM  concentration until nutrient broth was
diluted 1:80  and VCM concentration was 120   mg  l"1.   After
five  weeks,  bacteria for degradation studies were harvested
from the 1:80 nutrient broth  containing  120  mg  I'1  VCM,
washed  three times,  and transferred to basal salts medium
containing 54 mg l~l VCM as the only carbon source*  Inocula
from the same series of flasks were  used   to  continue  the
toxicity  studies*   The concentration of nutrient broth was
decreased to  a ratio of 1 part nutrient broth to  100  parts
basal  salts   medium  and  the  concentration  of  the vinyl
chloride was  increased at each 48-hour  transfer  until  the
VCM concentration was 900 mg l~*.

    Bacteria   used  in  sorption  studies were grown in 1:10
nutrient broth for 24 hours,  harvested,  and  washed  three
times*   Enough   bacteria were transferred  to 5—ml graduated
centrifuge  tubes  with  ground  glass  stoppers   to   give
approximately 5  g dry weight of bacteria per liter of water*
                                    -^
    Fungi  from   three  field  sites  were   isolated on Rose
Bengal (Difco) plates and maintained  on  Saboraud*s 'medium
(Difco) slants*   Inocula for fungi were suspensions prepared
by  agitating 10  ml of sterile water in a plate containing
the sporulating  fungi*  The suspension was   introduced  into

                             50

-------
medium  containing  6.0  g  glucose  per   liter.   Medium was
decanted and  enough fungi were transferred to  5-ral graduated
centrifuge  tubes  with  ground  glass  stoppers    to   give
approximately 5 g dry weight of fungi per  liter of water.

    Chlorella  ovrenoidosft was grown in Bensen-Fuller medium
containing  0.1%  Hutner's  trace   element    solution   and
incubated   on  a shaker at 15°C under 170  ft-c of  continuous
light.  Cultures were centrifuged, washed  three  timest   and
transferred  to  5-ml graduated centrifuge tubes with ground
glass stoppers for sorption studies to give approximately  4
S  dry  weight  of  algae  per liter of water.  To eliminate
corrections for volatilization of VCM to the air   above   the
solution*   tubes  were  filled  to the top and all data  were
compared  with  data  from  control  tubes (containing    no
organisms).

    To  determine  dry weights of algae and bacteria  used in
sorption  studies*  cultures  were   centrifuged    and   the
organisms   were  washed  three  times.   The   organisms  were
quantitatively transferred to tared beakers and dried to  a
constant  weight  at  90°C.   Fungi were separated from  test
cultures  for  dry weight determinations by  filtering*  first
through  tared  pre—filters*  then through tared 0.22 micron
Nucleopore  filters* and by drying to a  constant   weight  at
90 °C.
 RESULTS AND DISCUSSION

 Sortition o-t Vinvl Chloride to Microorganisms

     In  systems in which sorption  is linear Cvery  low solute
 concentrations), the simple  distribution  coefficient  
 may be used to describe the extent of  sorption of  a compound
 to  microorganisms
                           K,  -  2£E                     (3)
                            d     ce
 where  c  =  concentration (mg/mg)  of  solute in solution  at
              equilibrium

                              51

-------
       x  =  amount   (mg)  of  material  s orbed  per  mg  of
             solution   
-------
containing  only  basal  salts  and 54 mg l~» VCM without  an
additional carbon source.    These  cultures  were  monitored
daily for  one week.  No degradation was detected at any time
in any of  the cultures.

    Byington    and    Liebman    (43)   have   shown    that
trichloroethylene was transformed to chloral hydrate by rat,
rabbitt  and dog liver microsomes  in  a  reaction  requiring
NADPH  and oxygen.  Based  on the structures of the compounds
and the  requirement of NADPH,  alcohol dehydrogenase  may  be
the  active  enzyme.   If  so,  degradation of VCM by bacteria
could be possible via the  following pathway:
 H    H          H H       Alcohol        H   H           HO
  V/    _*  H-C-C-C1   Pehydrogenase >   H_£ _ ^  __*  H-C-C-H
  /   \            V/        NADPH H'   '            '
 H    Cl          0        flAU^ti, ti       cl  QH           cl
If the bacteria  were  capable  of  degrading  VCM  by  this
pathway,   a system in which  oxygen was not a limiting factor
would  be  needed.  The closed flask systems described earlier
could  limit the oxygen in  the system.   Therefore,  six  one-
liter  flasks containg the  five bacterial populations in 1:40
nutrient  broth and an uninoculated control were bubbled with
0.1%   VCM  in  air  for  96  hours and monitored for possible
products  by glc analysis at   low  column  temperature  using
FID.    No  degradation  products were detected in any of the
cultures.
Toxicitv of Vinyl Chloride  to  Bacteria

    The  toxicity of VCM to  five  actively  growing  bacterial
populations  was  tested.    Testing could not be done at VCM
concentrations up to its solubility in water (1700  mg  I"1)
because   of  the  difficulty  in supplying the bacteria with
sufficient oxygen for growth above a  VCM  concentration  of
900  mg   I""1.   Because  even  at  900 mg I"1 VCM the oxygen
concentration was low, a low  nutrient  broth  concentration
was  used  also  (1:100)  to  insure that any differences in
growth would be due to  the  presence  of  VCM  rather  than
insufficient   oxygen.   No  difference  could  be  detected
between  bacterial growth in  cultures and  in  test  cultures
containing  up to 900 mg l"1 VCM.  The VCM was therefore not
toxic to bacteria at these  concentrations.

                              53

-------
                         SECTION VII

                    PHYSICAL INTERACTIONS
    The conceptual  model  for  vinyl  chloride   behavior  in
aquatic  systems  suggests  that  volatilization  may  be an
important process in determining  the  distribution  of  the
compound*   A   preliminary  study  of the stability of vinyl
chloride in water (3)  indicates  that  the   loss  of  vinyl
chloride  from  water  through  volatilization  is relatively
rapid*  Gas exchange experiments were  therefore  undertaken
to  provide  data   for determination of the  specific rate of
volatilization  of vinyl chloride from water*

    The specific  rate of gas exchange (K)  at  an  interface
between water and atmosphere is a function of properties (P)
of   the   gas   molecules   (e»g*t  diffusivity,  molecular
diameter)* and  the  turbulence (T) in the watert
                         K  -  f(P.T)                      (4)
If the specific  rates  are  determined  from   concentrations
measured for  two gases (denoted 1 and 2) simultaneouslyf the
common  parametert   turbulencef  can  be eliminated from the
functional  relationship
                 K.
                        f(P.T)
for constant properties PI and PZ»  This ratio (equation  5)
of   specific    rates   is  not  significantly  affected  by
temperature changes between 10°C and 30°C» by  the  level  of
turbulencet  by   the  direction  of  gas transfer)  or by the
presence of dissolved  solids  (9)*   In  the   gas   exchange
experiments)   the  specific  rate of vinyl chloride loss was
determined relative to and concurrently  with   the   specific

                              54

-------
rate   of   oxygen  reaeration  to   eliminate  the  need  for
measurement of  turbulence  and  to relate   vinyl  chloride
volatilization  to available environmental determinations of
oxygen reaeration*

    For  comparison, the ratio of  specific   rates  was  also
calculated using estimates of molecular  diameter.
MATERIALS AND METHODS

    Nitrogen-sparged, deionized water  (900  ml) and saturated
vinyl   chloride  solution (10 ml) were added to each of four
beakers in an exhaust hood*  The contents of beakers  1,   2,
3,  and  4  were stirred to create vortices with depths of 0
(quiescent), 1*5 cm, 5 cm, and 10 cm,  respectively*   Oxygen
and  vinyl  chloride  concentrations   were  measured every 10
minutes for 180 minutes using a dissolved—oxygen meter and a
gas chromatograph*  Six replications   of  these  experiments
were performed*
RESULTS AND DISCUSSION

     The   gas   exchange  dynamics   at   the   interface  were
represented as a first—order approach to  equilibrium  using
the  equation
                            =   K(C-C)                     (6)
 where  C  =  gas concentration
        t  =  time
        K  =  specific rate
        C  =  saturation concentration
         s

 The  concentrations of oxygen  and  vinyl  chloride  for  each
 beaker  in each replicate were  used to determine the sums of
 squares for the best least  squares fit  to  the  logarithmic
 form  of  the solution to equation 6.  The corrected sums of
 squares  for  all  beakers  stirred  alike  were  pooled  to

                               55

-------
estimate  the  specific  rates tor each of the four levels  of
mixing*  These specific  rates are presented in Table 4  with
their 95% confidence  intervals*   A linear regression of
on KQ  resulted  in  the equation
                      KVCM
giving a constant  ratio  of
                              2.30 + 0.31                  (8)
at  a  95% level  of  confidence*   The constant ratio line and
ratios at each mixing  level  are  graphed in Figure 26*

    The ratio of   gas   exchange   coefficients  may  also  be
estimated  as  the  reciprocal  of  the  ratio  of molecular
diameters (9)*  Two  different values for the vinyl  chloride
diameter  may be  obtained depending upon the method by which
it is calculated*  The diameter  calculated using a  critical
volume of 168*9 ml mole'1 (44) in the van der Waals equation
is 3*55 A*  Assuming a molecular diameter for oxygen of 2*95
At  the  resulting ratios of gas exchange coefficients using
the two different  diameters  are
                             0.83  and 0.87                 (9)
respectively*

    The experimentally determined estimate of the  ratio   of
gas  exchange  coefficients  (K   /K  )  indicates  that  the
                                VCM  02
                              56

-------
 Table 4.   RATE COEFFICIENTS FOR OXYGEN AND VINYL CHLORIDE
              GAS EXCHANGE AT FOUR MIXING LEVELS
Vortex
depth
 f emJ	
  0

  1.5

  5.0

  10.0
•3.54( 10~3 )±2.28( 10""* )

•1.24( 10~2 )±1.4S( 10""3)

-3.85( 10~2)±1.16< 10~2)

•8.03(10~2 )±3.86(10~2)
-3.03C 10~3 )±2.74( 10~* )

       10~2)±1.22( 10~3)

       10~2)±1.06( 10~3)

       10~» )±7.88(10~2)
                                57

-------
     -0.729
      -1750
         -0.0803
-0.0419
                                 min
-0.00354
                                    '1
Figure 26.   K    versus K    at four  mixing  levels.
                             58

-------
specific rate of exchange   of  vinyl  chloride  gas  between
water and air is about  twice that of oxygen*
                              59

-------
                          REFERENCES
1.  U. S. Environmental  Protection Agency.   Vinyl  Chloride
    Monitoring  Near   the  B.  F. Goodrich Chemical Company  in
    Louisvillet    Kentucky.     Surveillance   and   Analysis
    Division* Athens»  Georgia.   June 1974.  45p.

2.  Glllett, J. W., J. Hill,  IV, A. W. Jarvinen, and  W.   P.
    Schoor.    A   Conceptual  Model  for  the  Movement   of
    Pesticides   Through    the    Environment.     National
    Environmental  Research  Center, Corvallis, Oregon.  EPA—
    660/2-74-024.  December,  1974.  80p.

3.  Thruston, A. D.,  Jr. and A. W. Garrison.   Stability   of
    Vinyl  Chloride   Monomer  in  Water.   Internal  Report,
    Southeast  Environmental  Research  Laboratory,  Athens,
    Georgia.  1974.   2p.

4.  Director, S. W.   and  8.   A.  Rohrer.   Introduction   to
    System  Theory.    New  York,  McGraw  Hill,  Inc.,  1972.
    441p.

5.  Tsivoglou, E.  C.  and J.  K.  Wallace.  Characterization  of
    Stream  Reaeration  Capacity.   Georgia   Institute   of
    Technology.    Office    of   Research   and  Monitoring,
    Washington, D. C.  EPA-R3-72-012.  October, 1972*   315p.

6.  Baca, R. G«, M. W. Lorenzen,  R.  D*  Mudd,  and  L.   V.
    Kimmel.  A Generalized Water Quality Model for Eutrophic
    Lakes  and  Reservoirs.   Pacific Northwest Laboratories.
    Richland, Washington.  211B01602.   Office  of  Research
    and  Monitoring,   U. S.  Environmental Protection Agency.
    August, 1974.  140p.

7.  Hutchinson, G. E.  A Treatise on Limnology.   Volume   I.
    New York, John Wiley and Sons, Inc., 1957.  1015p.

8.  Russell—Hunter, W. D.  Aquatic  Productivity.   Toronto,
    Collier Macmillan, 1970.   305p.

9.  Tsivoglou,  E.  C.     Tracer   Measurement   of   Stream
    Reaeration.     Georgia     Institute    of   Technology.
    Washington,    D.     C*     Water    Pollution    Control
    Administration.   June, 1967.  86p.
                              60

-------
10* Martens*  H.  R.  and D* R. Allen*  Introduction  to  Systems
    Theory*   Columbus, Ohio, Charles E. Merrill Books,  Inc.,
    1969.  611p.

11. Giorgio Modena*  Accounts Chem* Res*  4:73, 1971.

12. Cockerill, A.  F.  In: Comprehensive  Chemical   Kinetics,
    Volume  9,   Bamford,  C*  H. and C. F. H. Tipper  (eds. )•
    New York, American Elsevler Scientific  Publishing   Co.,
    Inc., 1973.  p. 163.

13. Bolton, R.   In: Comprehensive Chemical Kinetics,  Volume
    9,  Bamford, C. H. and C. F. H. Tipper (eds).   New  York,
    American  Blsevier Scientific Publishing Co., Inc.,  1973.
    p. 1.

14. Walling,  C.  Free Radicals in Solution.  New York,   John
    Wiley and Sons, Inc., 1957.  p. 397

15. Rappoport,  Z.  and A. Gal.  J. Am. Chem.  Soc.   9j: 5246•
    1969.

16. Kalinin,  A.  I., B. M. Perepletehikova, I. A.   Korshunov,
    and B. N. Zil'berman.  Zh. Obshch. Khim.  £6:1563,  1966.
    C. A. 6_6_:61277C.

17. Miller,  S.  I.   J. Org. Chem.  £6.: 2619, 1961.

18. Jones* D. B.,  R. O. Morris, C. A. Vernon, and  R.  F.  M.
    White.   J.  Chem. Soc.  2349, 1960.

19. Bhernson, S. ,  S. Seltzer, and  R.  Duffer back.    J.   Am.
    Chem. Soc*   £2:563, 1965*

20. Shelton,  J.  R. and L. H. Lee.  J.  Org*  Chem.    25:428,
    1960.

21* Israel,  G.  C., J* K* Martin, and F. G. Soper*   J.   Chem.
    Soc.   1282,  1950.

22. Brandt,  P.   Acta Chem. Scand.  13.: 1639, 1959.

23. Andrews,  L.  J. and R. M. Keefer.  J.  Amer.  Chem.   Soc.
    7_3:5733,  1951.

24. Winstein* S. and H.  J.  Lucas.   J.  Amer.  Chem*   Soc.
    6£:836,  1938.
                              61

-------
25. Keefer, R.  M. f  L.  J. Andrews,  and  R.   B«   Kepner.   J.
    Amer. Chem.  Soc.   21*3906, 1949.

26. Rennert, A.  If*  Diss. Abstr*  H, £9.: 1630,  1968*

27* Ausloost P.,  R* E. Rebbert, M. H. J.  Wijnen.    J*  Res*
    Nat. Bur. Stand.   Sect. A.. 22:243. 1973.

28. Fijimoto, T.f A.  M. Rennert,  M.  H.  J.   Wijnen*   Ber*
    Bunsenges.  Phys.  Chem.  24: 2 82 f 1970.

29. Be I Iast M.  G. t  J.  K. S. Wan, W. F. Allen ,  O.  P. Strausz,
    and H. Grunning.   J. Phys. Chem.  Ms 2170,  1964.
30. Hammond,  G.  S.»  N. J. Turro , and P. A.   Leermakers*   J*
    Phys. Chem.   6Jj:1144, 1962.

31. Arnold, D. R.  Ad van. Photochem.  6.: 301,  1968.

32. Walling,  C.   Free Radicals in Solution.   New York,  John
    Wiley and Sons., Inc., 1957.  p. 179.

33. Uri, N.   J.  Araer. Chem. Soc.  24=5808,  1952.

34. Evans, M. C.  and N. Uri.  Nature.  164:404.  1949.

35. Evans, M. G., M. Santappa, and N. Uri.   J.  Polymer  Sci.
    2:243, 1951.

36. Moses, F. G. , R. S. H. Liu,  and  B.  M.  Monroe.   Mol.
    Photochem.   1:245, 1969.

37. Lamola,   A.   A.   and  G.  S.  Hammond.    J.   Chem  Phys.
    41:2129,  1965.

38. Merer, A. J.  and R. S. Mulliken.   Chem.  Rev*    69; 639 •
    1969.

39. Zepp, R.  G.,  N.  L. Wolfe, and G* L. Baughman.  Southeast
    Environmental  Research  Laboratory,  Athens,   Georgia.
    (Presented   in part at the 168th National Meeting o± the
    American  Chemical Society.  Atlantic  City.    September,
    1974.)                     r

40. Ross, R.  D.  and  D.  C.  Crosby.   J*   Agr*   Food  Chem*
    21:335, 1973.

41* Wagner, P. J. and I. H. Kochewan.  J. Amer.   Chem.  Soc.
    33:5742,  1970.

                              62

-------
42. Payne*   W.   J.   and  V.  E.  Feisal.    Appl.   Microblol.
    11:339-344,  1963.

43. Byington,  K. H. and  E.  C.  Leibman.    Mol.   Pharraacol.
    K 3): 247-254,  1965.  C. A. 6.4:11457e,  1966.

44* Dreisback,   R.   R.   Physical  Properties   of   Chemical
    Compounds.    Advances  in  Chemistry  Series,  Numbers 15,
    22,   and  29.    Washington,  D.  C.,   American  Chemical
    Society, 1955-1961.  407p.

45. Weast,  R.  C. (ed).  Handbook of Chemistry   and  Physics.
    Cleveland,   Ohio,  Chemical  Rubber Co*, 1971.  p.  F173-
    F177.
                               63

-------
                                TECHNICAL REPORT DATA
                         (Please read Instructions on the reverse before completing)
 1. REPORT NO.
 EPA-600/3-76-001
2.
                                                     3. RECIPIENT'S ACCESSION-NO.
 4. TITLE AND SUBTITLE

 DYNAMIC BEHAVIOR OF VINYL CHLORIDE IN  AQUATIC
 ECOSYSTEMS
                                                     5. REPORT DATE
                           January 1976  (Issuing Date)
                           6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)
 James  Hill  IV,  Heinz  P.  Kollig,  Doris  F
 N.  Lee Wolfe,  and Richard G.  Zepp
                                                     8. PERFORMING ORGANIZATION REPORT NO
                    Paris
 9. PERFORMING ORG-\NIZATION NAME AND ADDRESS
 Environmental  Research  Laboratory
 Office of Research and  Development
 U.S.  Environmental Protection  Agency
 Athens,  Georgia  30601
                           10. PROGRAM ELEMENT NO. 1BA023
                           ~AP 04AEM;Task 005,RQAP 03ACO,
                          task 009	
                           11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
 Same  as above
                                                     13. TYPE OF REPORT AND PERIOD COVERED
                                                     Task Milestone  Rept. FY75
                                                     14. SPONSORING AGENCY CODE
                                                      EPA-ORD
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT
      To evaluate the behavior  of  vinyl  chloride  in aquatic ecosystems,
 best estimate  and worst case  models of  lake and stream  ecosystems were
 analyzed through the  use of mathematical  simulation.  The characteristic
 of  the chemical, biological,  and physical transformations of vinyl
 chloride indicated in the models were  determined by laboratory  experi-
 mentation and  extrapolation of  reaction data for similar  compounds.
 These transformations included  oxidation, substitution,  elimination,
 hydrolysis,  and free  radical  reactions;  complexation; direct and
 indirect photochemical  reactions;  microbial degradation  and toxicity;
 bacterial,  algal, and fungal  sorption;  and volatilization.   Loss  of
 vinyl chloride from the aquatic  environment by  volatilization appeared
 to  be the most significant process in  its distribution.
 7.
                            KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
              b.lDENTIFIERS/OPEN ENDED TERMS  C.  COSATI Field/Group
 Systems  analysis
 Vinyl  chloride
                Chemical  degradation
                Biodegradation
                Aquatic environment
   12A
   6F
   8H
 8. DISTRIBUTION STATEMENT

 RELEASE  TO PUBLIC
               19. SECURITY CLASS (ThisReport)
                UNCLASSIFIED
21. NO. OF PAGES
    74
                                         20. SECURITY CLASS (Thispage)
                                          UNCLASSIFIED
                                       22. PRICE
EPA Form 2220-1 (9-73)
                                        64
                                               U.S. GOVERNMENT PRINTING OFFICE: 1976-657-695/5363 Region No. 5-11

-------