v-xEPA
                                 United States
                                 Environmental Protection
                                 Agency
                                 Industrial Environmental Research
                                 Laboratory
                                 Cincinnati OH 45268
                                 Research and Development
                                 EPA-600/S7-81-081  May 1981
Project Summary
                                 Assessment  of Oil Shale
                                 Retort  Wastewater
                                 Treatment  and  Control
                                 Technology—Phases  I  and  II

                                 J. R. Klieve, G. D. Rawlings, and J. R. Hoeflein
                                  Oil shale retorting is a synthetic fuel
                                production technology on the verge of
                                commercialization  in   the  United
                                States. In order to ensure that the
                                emerging oil shale industry will have
                                minimal adverse effects upon surface
                                and/or groundwater where recover-
                                able reserves of oil shale are found,
                                demonstrated technologies to
                                upgrade oil shale wastewaters must
                                be available to developers. To this end,
                                the U.S. Environmental Protection
                                Agency has contracted with Monsanto
                                Research  Corporation  (MRC)  to
                                conduct a   three-year,  five-phased
                                study  to:  (1) summarize  known
                                information concerning oil shale retort
                                wastewater sources and characteris-
                                tics; (2) identify potentially applicable
                                control technologies capable of treat-
                                ing the identified wastewater streams;
                                and (3) design, construct, and operate
                                pilot-plant facilities to evaluate the
                                selected technologies.  This report
                                presents results Of Phases I and (I, in
                                which literature and other information
                                sources were surveyed to obtain rele-
                                vant  data about oil shale retorting
                                technologies,  wastewater  sources
                                and characteristics, potential waste-
                                water uses, and potentially applicable
                                treatment technologies. As a result of
                                the study, data gaps were identified,
                                and recommendations  for bench-
                                scale treatability studies were made.
                                  This Project Summary was develop-
                                ed by EPA's Industrial Environmental
                                 Research Laboratory, Cincinnati. OH,
                                 to  announce  key  findings  of the
                                 research project that is fully docu-
                                 mented in a separate report of the
                                 same title (see Project Report ordering
                                 information at back).

                                Technical Discussion
                                  In-situ retorting, which consists of
                                heating  shale underground  after
                                modification of the permeability of the
                                rock formation, is being investigated by
                                Dow Chemical Co., Equity Oil Co., Geo-
                                kinetics, Irfc., Occidental Oil Shale, Inc.,
                                and Rio Blanco Oil Shale Co., all of
                                which are  now conducting process
                                development efforts.  Processes being
                                developed  by Paraho  Development
                                Corp., Superior Oil Co., TOSCO Corp.,
                                and Union Oil Co., are classified as
                                surface  retorting,  in which mined,
                                crushed shale  is  heated in above-
                                ground metal vessels  to produce crude
                                oil. Although many process variations
                                exist  within the two major retorting
                                process categories, in-situ and surface,
                                distinct wastewater streams  are
                                common to most processes within each
                                category. From in-situ retorting, three
                                major streams emanate:  mine water,
                                retort water, and gas condensate. Mine
                                water is thatwater pumped from a shale
                                formation prior to ignition. Retort water
                                is formed when water  vapor condenses
                                in cool,  rubblized shale ahead of the
                                flame front during retorting. Gas con-
                                densate is that water which leaves the

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retort as a gas and is recovered when
gas from the in-situ retort is cooled.
  From  surface retorting,  three major
streams are envisioned:  gas conden-
sate, product water, and spent shale pile
leachate.  Water normally  leaves the
surface retort in the vapor phase and is
recovered as gas condensate when the
retort gas  is cooled prior to purification.
In addition, water  separates from the
product oil following oil/gas separation
and is termed product water.
  Since spent shale from surface retort-
ing is to be disposed of above ground,
leachate  through  the shale  pile  is
another potential wastewater stream.
  Mine water has been found to exhibit
high  levels  of alkalinity,  chemical
oxygen demand (COD), chloride, fluo-
ride, sulfate, boron and sodium. Exis-
tence of trace  metals are of particular
concern, since some mi'ne water will be
discharged to the environment.
  Retort   wastewater  and  product
wastewater contain high levels of most
pollutants identified. Gas condensate
wastewaters  exhibit  high  levels  of
ammonia,  alkalinity,  and  organics;
however,   concentrations   of   trace
metals are significantly lower in gas
condensate than in retort wastewater.
Limited data are available to character-
ize  leachate;  however, high levels  of
organics,  total dissolved  solids (IDS),
sulfate,   and  sodium  have   been
exhibited.
  Water-use  schemes developed  by
industry  and government contractors
have  been reviewed. Most water-use
schemes  suggest  use of wastewater
within the retorting facility; however,
there appears to  be  little technical
information  to support this  approach.
Available  information  relating  to the
treatability of individual retort streams
was summarized and significant  data
were obtained only for the treatability of
mine water and combined retort/prod-
uct water.
  In the case of mine water, activated
alumina absorption, precipitation with
phosphoric  acid  and lime,  and  ion
exchange have been demonstrated in
bench-scale screening tests to remove
fluoride and/or boron. Additional tech-
nologies should be used for dissolved
gas removal, suspended solids removal,
IDS removal, and disinfection, particu-
larly if the water is discharged or used
for. potable needs.
   Many research studies have focused
on the  treatment  of  retort/product
water.  There   remain,  however,  key
technical questions in the area of emul-
sified  oil  separation  and  organics
removal.  Steam  stripping  has  been
identified as a promising technology for
dissolved gases removal. Granular acti-
vated carbon and polymeric resins have
been demonstrated  for gross organics
removal;  however, for cost considera-
tions,  aerobic  biological  treatment
should be the  focus for gross organics
removal,  with  carbon  and polymeric
resins  used  to remove   refractory
organics.
  No research  activity in the area of gas
condensate  treatment  was identified;
however, steam stripping should ade-
quately treat  gas condensate for  in-
plant use.
  In the case  of leachate,  it  is recom-
mended that funds be used to identify
leachate as a major wastewater stream
and characterize it, rather than investi-
gate treatment alternatives. If leachate
is found to be  a significant wastewater
stream, serious  questions  regarding
leachate collection arise.
  Several treatability screening studies
have been conducted to fill many treat-
ment step needs identified in Figures 1
and 3, particularly in the case  of mine
water and retort water treatment. Be-
cause of their  design and intent, these
studies have generally been useful to
screen some potential technologies and
eliminate others. Many key technical
questions still remain unanswered such
as:
  •  How should emulsified  oil  be
     separated  in retort and  product
     water?

  •  What  is  the best system for  re-
     moval of organics from  retort and
     product water?

  •  Will state-of-the-art technologies
     treat  gas condensate and
     leachate?
To answer these questions, and to size
pilot-plant equipment,  MRC  recom-
mends  conducting  additional bench-
scale  treatability  studies.  Presently,
there are several opportunities for MRC
to obtain relevant  samples  of retort
wastewaters with  which to conduct
these studies, namely:

  •  Rio  Blanco  — mine water  and
     retort water

  •  Tosco — gas condensate
  •  Geokinetics — retort water

  •  Occidental — retort water and gas
     condensate

  In the case of mine water treatment,
only   Battelle  N.W.  has  conducted
bench-scale treatability studies for the
removal of fluoride and boron which are
of primary concern  if the excess mine
water is to be  discharged or used for
potable  purposes.  Activated alumina
absorption and precipitation with phos-
phoric acid and lime were identified as
promising technologies for the removal
of boron. The literature reported  that
electrodialysis  and reverse  osmosis
could produce  a  more than adequate
effluent;  however,  reverse  osmosis
appears to be more cost-effective at the
high TDS levels expected and has other
technical advantages as well.
  Thus, additional research is needed to
demonstrate  the feasibility of reverse
osmosis treatment of mine water and to
size pilot-plant equipment in the case of
other treatment steps.
  Suggested  technology options to be
investigated in these studies are listed
in Figure 1.
  Many more studies  have been  con-
ducted with retort water; however, key
technical questions remain; e.g., no
studies have been conducted to investi-
gate  emulsified  oil separating  from
retort and product water. Steam strip-
ping  has been identified by several
investigators as the  best technology for
dissolved gases removal, though fouling
of column  packings has been experi-
enced. Emulsified oil  separation  may
alleviate  the  problem. Although many
studies have been conducted to assess
technologies  for  organics   removal,
many questions remain. Aerobic bio-
logical treatment has classically been
the  most  cost-effective  method  of
organics  removal   from   municipal
wastes, but various pretreatments are
required  for these systems to operate
with retort water; also, a large portion of
the organics (—50%) appear to be refrac-
tory. Therefore, additional studies are
needed   to  identify methods  which
would enhance -the ability of aerobic
biological treatment to remove organic
compounds. The sensitivity of biological
systems  to variations in retort water
composition  has serious implications
for commercial  operations. If it is found
that wastewater cannot be treated bio-
logically, it may become necessary to
test  physical/chemical methods such .
as  wet  air  oxidation  and  granular'

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  Potential End Use
  • Reinfection
Treatment Steps
                                  Mine Water
Treatment Options
                               Dissolved Gases
                                   Removal
                                 Clarification
                                   Fine S.S.
                                   Removal
  • Cooling Tower
     Makeup
  • Discharge
                              TDS/Trace Metals
                                   Removal
                                   Residual
                                  Inorganics
                                   Removal
  • Boiler Feed
 • Potable Use
                          • Aeration
                          • Chemical Addition/
                              Flocculation/
                              Sedimentation
                          • Multimedia
                             Filtration
                             Reverse Osmosis
                             Ion Exchange
                             Ion Exchange
                                                          • Cl2
retort water  are envisioned.  Bench-
scale studies conducted at this time are
still recommended to complete  a retort
treatability data base which would be
used by  industry and government in
making water-use decisions.
  Although no known studies exist for
the treatment of gas condensate, this
stream should not be difficult to treat,
compared to retort water. At this time,
the extent to  which emulsions  are
present in gas condensate is not known.
If present, they will have to be removed
prior to subsequent treatment steps.
Steam stripping studies are necessary
to assess organics removal as  well as
inorganic dissolved  gases removal.  If
organics remain following steam strip-
ping, studies for their removal will have
to be initiated.
  Suggested technology options for gas
condensate  treatment  are  listed  in
Figure 3.
  Since  it  is  not  known  whether
leachate from spent-shale piles will be
present  in  significant quantities,  and
leachate  quality  is  still  not  fully
understood, research funds should be
directed to address these issues rather
than investigating  treatment alterna-
tives. If spent-shale piles are found to be
porous,  and  the  leachate from
percolation through the piles is  toxic or
unacceptable  for  groundwater
discharge,  serious  questions about
leachate collection in full-scale systems
exist.
  This report was submitted  in partial
fulfillment of Contract No. 68-03-2801
by  Monsanto   Research  Corporation
under  the  sponsorship of the  U.S.
Environmental Protection Agency. This
report covers the period May 1979 to
March 1980; work was completed as of
February 1980.
 Figure  1.    Mine water treatability options.
 activated carbon adsorption. It is unlike-
 ly that retort water would be discharged
 from a full-scale retorting facility; how-
 ever, if discharge  is necessary,
 treatment  for trace  organics,  trace
 metals, and TDS will become necessary.
 Several  investigators  have  used
 granular  activated  carbon  and
 polymeric  resins  for  gross  organics
 removal; however, studies are needed
 to assess these technologies for their
, ability to remove refractory organics
         present in the effluent from the gross
         organics  removal  treatment   step.
         Studies  of  TDS  and  trace  metals
         removal  by  reverse osmosis  and ion
         exchange would also  become neces-
         sary.
           Suggested treatment options to treat
         retort water to discharge quality are
         shown in Figure 2.
           Treatment to discharge quality will
         probably not be necessary in full-scale
         systems  since many in-plant  uses for

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Potential End Use    Treatment Steps
             Retort Water, Product Water
• Steam
  Generation
  Via Thermal
  Sludge Oxidizer
Emulsified (?) Oil
   Separation
                   Dissolved Gases
                      Removal
                      Organics
                      Removal
                      Fine S.S.
                      Removal
• Dust Control
  Shale
  Moistening
  Scale Control
  Cooling Tower
   Makeup
• Discharge
• Gravity Separation
• Chemical Addition/DAF
• Chemical Emulsion
   Breaking/Separation
• Ultrafiltration
                    • Steam Stripping
                     • Aerobic Biological
                        Treatment With One or
                        More Pretreatments:
                          -pH Adjustment
                          -Chemical Coagulation
                          -Wet Air Oxidation
                          -Ozonation
                          -PAC Addition
                     • Wet Air Oxidation
                     • Granular Activated Carbon
                      Multimedia Filtration
                      • Chemical Addition
              Trace Organics
                   Removal
                               TDS/Trace Metals
                                        Removal
          • Granular Activated Carbon
          • Polymeric Resins
                              • Reverse Osmosis
                              • Ion Exchange
Figure 2.    Retort wastewater treatability options.

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Potential End Use"1
Treatment Steps     Technology Options
                              Gas Condensates
• Cooling Tower   '
  Makeup
• Dust Control
• Shale Moistening
  Discharge
                              Emulsified (?) Oil
                                 Separation
                              Dissolved Gases
                                  Removal
                                  Organics
                                  Removal
                                  Fine S.S.
                                  Removal
                               Trace Organics
                                  Organics
                   • Gravity Separation
                   • Chemical AdditionYDAF
                   • Chemical Emulsion
                      Breaking/Separation
                   • Ultrafiltration
                                                 • Steam Stripping
                   • Aerobic Biological
                       Treatment
                     (See Figure 2)
                   • Multimedia Filtration
                   • Granular Activated Carbon
                   • Polymeric Resins
Figure 3.     Gas condensate wastewater treatability options.

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J. R.  Klieve.  G. D. Rawlings, and J. R. Hoeflein are with Monsanto Research
   Corporation, Dayton, OH 45407.
 W. W. Liberick. Jr.. is the EPA Project Officer (see below).
 The complete report, entitled "Assessment of Oil Shale Retort Wastewater
   Treatment and Control Technology—Phases I andII, "(Order No. PB 81-187 288;
   Cost: $9.50, 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:
        Industrial Environmental Research Laboratory
        U.S. Environmental Protection Agency
        Cincinnati, OH 45268
» US GOVERNMENT PRINTING OFFICE. 1981 -757-01Z/7H7

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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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