J'/
                    United States
                    Environmental Protection
                    Agency
 Robert S. Kerr Environmental
 Research Laboratory
 Ada OK 74820
                    Research and Development
 EPA-600/S2-83-089  Nov. 1983
&EPA          Project  Summary

                    Characterization  and
                   Treatment of Aqueous
                   Wastes  and  Residue  from
                    Petroleum Refineries

                    S.L. Burks and J. Wagner
                     This research project was designed to
                   identify process wastewaters which
                   contained a significant proportion of
                   the total load of contaminants in
                   petroleum refinery wastewaters and to
                   evaluate methods for intensively treat-
                   ing these highly  concentrated  low-
                   volume streams. In addition, selected
                   waste residues from API gravity separa-
                   tor, dissolved air flotation units, and
                   "slop" oil emulsions were analyzed to
                   determine the presence of hazardous
                   chemicals as listed by the U.S. Environ-
                   mental Protection Agency (EPA) Office
                   of Solid Waste.
                     Process wastewaters from the fluid
                   catalytic cracking units, crude desalting
                   unit,  coking unit, and barometric
                   condenser contained the highest levels
                   of contaminants. These process waste-
                   water streams were major contributors
                   to the total load of phenol, ammonia,
                   sulfide, and organic carbon contamina-
                   tion of the combined  refinery waste-
                   waters. On-site evaluations of mixed
                   media filtration-activated carbon  ad-
                   sorption and a biological oxidation
                   system indicated both systems were
                   capable of reducing phenol, sulfide, and
                   organic carbon levels by greater than
                   90 percent.
                     This Project Summary was developed
                   by EPA's Robert S. Kerr Environmental
                   Research Laboratory, Ada, OK, to
                   announce key findings of the research
                   project that is fully documented in a
                   separate report of the same title (see
                   Project Report ordering information at
                   back).
 Introduction
  The major objective of this project was
 to determine the relative contribution of
 aqueous wastes from fluid catalytic
 cracking (FCC) units and other selected
 process units to the total  quantity of
 aqueous wastes produced within a
 refinery. A parallel objective was to
 evaluate the effectiveness of physical-
 chemical and biological treatment systems
 for intensively treating highly concen-
 trated process unit wastewater systems.
  Many refineries have adapted a practice
 of using wastewaters from FCC units for
 desalting crude oil stocks. This practice
 reduces concentration of hydrocarbon
 type  compounds in the  FCC process
 wastewater by partitioning hydrocarbons
 between the aqueous and oily phases. In
 addition, the total volume of water used is
 reduced. Most  of the refineries are
 attempting to conserve as much waste-
 water as possible through recycle-reuse
 practices. However, complete recycle-
 reuse may not be economically feasible
 at this time. As an alternative, existing
 refineries may have to adopt a combination
 of recycle-reuse and intensive treatment
 of highly contaminated process waste-
 water streams in order to achieve 1983-
 85 effluent standards.

 Phases of Investigation

 Phase I (First Year)
  Phase I was devoted to characterization
of the influent and effluent concentration
of aqueous wastes from FCC and other
selected process units at three refineries

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in  Oklahoma and  nearby  states.  The
characterization phase was designed to
provide quantitative  information for
determination of the percentage contri-
bution from all other sources within the
refinery. Major emphasis was placed on
measurement of significant waste compo-
nents  such as organic compounds,
ammonia, and sulfides.

Phase II (Second Year)
  In  the second year  of the project, a
small, pilot-scale (0.25-gpm) dual media
filter-activated carbon treatment system
was  established to operate in parallel
with an existing aerated lagoon (biopond)
system which was used to treat wastewa-
ters from a FCC unit A comparison of the
effectiveness of the  pilot-scale system
with that of the full-sized aerated lagoon
system  was made by measuring the
percent reduction m  significant parameters
between the influent and effluent streams
The  pilot-scale system and the full-sized
aerated lagoon system were sampled at
six different intervals during a 30-day test
period.

Phase III (Third Year)
   The objective of this phase of the
project was to characterize priority pollu-
tants in residuals  from  the  petroleum
refining industry. The residuals were col-
lected  from the dissolved air  flotation
unit, API gravity separator, and "slop" oil
residuals. The residuals  were extracted
by the EPA-RCRA "Extraction Procedure"
(EP) for evaluation of solids to determine
if  they  contain toxic  substances  (CFR
45(98)33127, May  19, 1980) and by con-
ventional laboratory techniques.
  Extracts  from the residuals  were
analyzed for toxic heavy metals by atomic
absorption spectrometry and for "priority"
organic pollutants  by combination gas
chromatography-mass  spectrometry
(GC-MS).

Results and  Discussion

Phase 1.  Collection and
Analysis of Contaminants in
Process Wastewaters
  The concentration of contaminants in
the process wastewaters indicated that
the  overhead contact waters  from the
FCC unit contained the highest levels of
phenol, sulfide, and BOD.  The  FCC
process wastewater stream also contained
the second highest level of ammonia. The
overhead receiving water from the coking
unit  contained highest levels of TOC and
second highest levels of BOD.  The
highest levels of oil and grease detected
in  a process  wastewater stream were
from the barometric condenser.
  The concentration of mercury, vana-
dium, cadmium, and nickel was below
detection limits for the atomic absorption
spectrometer. Detectable quantities of
lead were found in process wastewaters
from the crude desalting unit and in the
combined wastes into the API separator.
The caustic neutralizer process waste-
waters appeared to be a major contributor
of chromium, zinc, copper, iron, potassium,
and sodium.  Most  of the calcium was
found in the crude desalting unit waste-
waters,  although  several other waste
streams contributed significant quantities
of calcium also.
  Analyses of specific organic compounds
in  the process wastewaters by GC-MS
indicated that  the waste from the caustic
neutralizer and  the  influent to  the  API
separator contained the greatest number
of compounds which could be identified.
The  most common  classes of organic
compounds identified  in the  process
waste streams were aliphatic (Cio H22to
C23 HUa), monocyclic aromatics, and alkyl
aromatrcs. Only three polynuclear aro-
matic hydrocarbons were  identified —
fluorene, phenanthrene/anthracene,
and methyl anthracene. These compounds
were  found in  the caustic neutralizer
wastewater. None of the aromatic, alkyl
aromatic, or polynuclear aromatic com-
pounds  were  detected in the final
effluent, which  would indicate that the
biological  treatment system  at this
refinery was effectively removing these
compounds The major class of compounds
identified  in the  final effluent  was
aliphatic hydrocarbons, a  homologous
series from Ci3 H2s to C2oH42.

Phase 2. Comparison of Pilot-
Scale Mixed Media Filter-
Activated Carbon (MMF-AC)
versus Biopond Treatment of
Sourwater Stripper Process
Wastewater
  The calculated mean  percentage re-
moval  of phenol  by the biopond was
99.8% and for the MMF-AC pilot-scale
treatment unit  99.99% (Table 1).  The
mean concentration of phenol in the
effluent from the SWS unit was  203
mg/l with a range from 175 to 233 mg/l
in the first on-site evaluation. The mean
concentration of  phenol in the effluent
from  the  biopond  system was 0.269
mg/l with a range from 0.031 to 0.449
mg/l. The mean concentration of phenol
in the effluent from the MMF-AC pilot-
scale treatment system was 0.002 mg/l
with a range from <0.001 to 0.004 mg/l.
  The biopond system  with the large
stabilization basin appearedtobecapable
of  absorbing  "shock" loads of high
concentrations  of  organics without
malfunction  of the biodegradation capa-
city. Therefore, this system while not cap-
able of achieving  the  same overall
reductions as the MMF-AC during initial
stages of  the test,  would appear to be
more reliable for  handling the large
fluctuations  in concentration of waste
organics. In addition, the biopond required
minimal supervision by refinery personnel.


Ozone Treatment of Sourwater
Stripper Effluent
  Samples of the  sourwater stripper
effluent were transported to the laboratory
for ozonation. Two tests were performed
at  high  pressure (100 psig) on effluent
samples collected September 14, 1981,
Run I and  Run II. The percent removal of
COD was 73% in Run I and 74% in Run II.
The percent  removal of TOC was not as
high,  57% and 56% in Run I  and II,
respectively, as COD removals. The ratio
of COD  to TOC decreased from 3.21 at
start of  run to 2.00 at end. Ammonia
concentration was analyzed in Run II to
determine if ammonia was  creating  a
chemical oxygen  demand.  The concen-
tration of ammonia  was not significantly
altered by ozone treatment.
  Two tests were  performed at  low
pressure (8  psig) on effluent samples
collected October 8, 1981, Run III  and
Run IV. The percent removal of COD was
56% in  Run III and 57% in Run IV. As
in  Runs I and II, the percent  removal of
TOC was less than that for COD, i.e., 35%
in Run III and 46% in Run IV. The ratio of
COD to TOC was also decreased. Phenol
was completely oxidized by  the ozone
treatment at the end  of 4 hours. The
phenol concentration was  monitored at
1-hour intervals in  Run IV and revealed
almost complete oxidation of phenol after
2 hours of treatment. No detectable levels
 Table 1.    Calculated Mean Percent Removal of Contaminants from the SWS Process
          Wastewaters by the Fu/l-Scale Biopond and the Pilot-Scale MMF-AC Units

B'opond
MMF-AC
Phenol
99.87
99.99
Sulfide
100
100
Ammonia
24.8
116
BOD
90.1
95.3
TOC
90.9
969
Oil &
Grease
95.5
99.8

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of sulfides were found  after ozone
treatment.
  The results clearly indicate ozonation
could be  used for  reduction of COD,
phenol,  and sulfides in process waste-
waters. Ozone treatment for 4 hours was
not as effective as activated carbon or the
biopond system  in  percent removal of
TOC.  Extension of time of treatment
would probably improve percent removal
of TOC by ozonation.
  Based  upon comparisons of percent
removal of degradable organic contami-
nants, the pilot-scale MMF-AC and lab-
scale ozonation unit could  be utilized to
treat concentrated process wastewaters
from petroleum refineries. The full-sized
biopond system  at Refinery C achieved
equivalent  or  better  efficiencies  in
removal of COD, TOC, oil and grease,
phenol,  sulfides  and ammonia than the
pilot-scale MMF-AC or lab-scale ozonation
unit. No attempt was made to estimate
capital costs of installation or operation
costs of the units evaluated; however, it
would appear that the biopond  system
would be more economical than either of
the more advanced types  of treatment
systems. The MMF-AC or ozone treatment
units might be more practical for addition
to an existing refinery where space to
install a biopond system was not available.

Characterization of Residuals
from Petroleum Refining
  Residuals from selected process units
in four petroleum refineries were analyzed
by the  EPA  Extraction Procedure  to
determine if these  waste  products
contained sufficient quantities of chemical
contaminants to be classified as hazardous
materials. The EPA Office of Solid Waste
published guidelines defining hazardous
materials  based  upon properties of
ignitability, corrosivity, reactivity, and
toxicity (Federal Register 45:33084-
33139, May 19, 1980). If the EP extract of
a waste contained  concentrations of
contaminants in excess of those listed in
the Federal Register, it would be classified
as hazardous and  subject to special
regulations for transport and disposal.
  Five specific  waste residuals  from
petroleum refining were listed as hazard-
ous by the EPA — dissolved air flotation
(DAF), slop oil emulsions, heat exchange,
bundle cleaning sludge, API separator
sludge,  and tank bottoms from leaded
gasoline storage. The following were
collected: residuals from API separators
at four refineries and samples of slop oil
emulsion, dissolved air flotation, bottoms
from light oil API separator, solids from a
cooling  tower blowdown,  and sludges
from an aerated biopond at three refineries.
  The results of the  herbicide  and
 chlorinated hydrocarbon pesticide analyses
 revealed  no cases  of  the petroleum
 refinery residuals which exceeded EPA
 criteria. The concentration of mercury in
 the petroleum refinery residues analyzed
 was below detection  limit.
  The EP extracts from  the oil refinery
 residuals were also analyzed for organic
 contaminants by extraction with methy-
 lene chloride at pH <11 and pH <2 to
 obtain a  base-neutral  and weak  acid
 fraction,  respectively. The base-neutral
 fraction was then separated into alipha-
 tics, aromatics, and neutral compounds
 by silica gel chromatography. The aromatic
 fraction  was  analyzed by GC-MS  to
 determine specific compounds which
 might occur in these  residues.  The
 number of compounds identified in the
 aromatic fractions ranged from zero  in
 the cooling tower residues from Refinery
 C to 42  in  the Refinery B slop oil
 emulsions. The classes of hydrocarbon-
 type compounds identified ranged from
 simple monocyclic aromatics such as
 toluene to complex polynuclear aromatics
 such as  anthracene/phenanthrene.
 Some compounds containing oxygen and
 sulfur substitutes were  also  identified.
 The alkylated  bicyclic  and  polycyclic
 aromatic compounds were most abundant
 in the extracts.

 Summary and Conclusions

 Phase I
  Chemical characterization of selected
 process wastewaters from petroleum
 refineries  indicated that contact waters
 from fluid  catalytic cracking units, coking
 units, barometric condensers, and crude
 desalting units were  major contributors
 of organic contaminants to  refinery
 wastewaters. At  Refinery A, where a
 reasonable estimate of wastewater
 volumes could be obtained, four process
 wastewater streams were responsible for
 greater than 60% of the  phenol, sulfide,
 ammonia,  BOD, TOC, and oil and grease
 contaminants which occurred in the
 combined  wastewaters from the entire
 refinery.  Either elimination  of these
 process contact wastewaters by installa-
 tion  of equivalent non-contact units or
 intensive treatment of  the  process
 wastewaters would improve  overall
 effluent quality from the  refineries.

 Phase II
  The percentage removal efficiency of the
full-scale biopond system at Refinery C
for  conventional pollutant parameters
such as phenol, sulfide,  BOD,  TOC, and
 oil and grease was greater than 90%.
While not  as efficient as the pilot-scale
MMF-AC treatment system during initial
stages, i.e. greater than 95% removal, the
biopond system achieved a better overall
removal  efficiency than the pilot-scale
MMF-AC. The adsorption capacity of the
pilot-scale carbon columns for TOC
was exceeded by second day during the
second  on-site test. However, break-
through of phenol did not occur until the
16th day of the test. The biopond system
appeared to be comparable to the MMF-
AC system from  an  overall viewpoint.
Laboratory evaluations of the capability of
ozonation to reduce organic pollutant
loads in concentrated  process waste-
waters indicated that greater than 73%
removal of COD could be achieved within
4 hours of  treatment at 100 psig.  Low-
pressure (8  psig) ozonation  achieved
greater than 56% removal of COD within
4 hours of  treatment. The on-site  scale
and laboratory evaluations showed that
advanced type of treatment  systems
could be used to reduce total concentration
of organic pollutants from highly contam-
inated  process  wastewaters.  However,
these systems would not be as practical or
economically feasible as biological
oxidation units.

Phase III
  Chemical characterization of EP extracts
from selected petroleum refinery residuals
indicated that the residuals analyzed
would  not  be classified  as  "toxic" by
EPA's criteria. Based upon the results of
this project, it would appear that the API
separator residuals,  and possibly DAF
and slop oil  emulsions, should not be
categorically listed as hazardous wastes
but should be analyzed on a case by case
basis. Admittedly, the number of petroleum
refinery residuals sampled  during this
project  was  too  few to permit us to
determine that these  residuals are
generally  not  hazardous. However,
sufficient samples  were analyzed to
determine  that  not  all API separator
residuals should be categorically classified
as hazardous. The overall results of the
three phases of this  project  clearly
indicate  the  complexity of  petroleum
refinery wastewaters and residuals.
Application of the nigh resolution capacity
of capillary chromatography  coupled
with the identification  capabilities of
mass spectrometry resulted in a bewild-
ering list of specific organic contaminants
identified  in the petroleum refinery
process wastewaters. The significance of
some of the compounds identified is
difficult to ascertain, at this time. Perhaps
the most significant finding was the
absence of detectable quantities of
"priority"  pollutants  in biologically

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   treated refinery wastewaters, thus
   illustrating  the  effectiveness of biode-
   gradation processes for removal of most
   of these hazardous organic contaminants
   or at least reduction of concentrations to
   non-deleterious levels.
          S. L. Burks and J.  Wagner are with the Oklahoma State University, Stillwater,
            Oklahoma 74078.
          Leon H. Myers is the EPA Project Officer (see below).
          The  complete report, entitled  "Characterization  and Treatment of Aqueous
            Wastes and Residue from Petroleum Refineries," (Order No. PB 83-260 281;
            Cost: $14.50, subject to change) will be available only from:
                  National Technical Information Service
                  5285 Port Royal Road
                  Springfield, VA 22161
                  Telephone: 703-487-4650
          The EPA Project Officer can be contacted at:
                  Robert S. Kerr Environmental Research Laboratory
                  U.S. Environmental Protection Agency
                  Ada, OK 74820
                                                                                               GOVERNMENT PRINTING OFFICE 1983-659-017/7232
United States
Environmental Protection
Agency
Center for Environmental Research
Information
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