United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
«>EPA
Research and Devejppment
EPA-600/S2-81-053 July 1981
Project Summary
Physical/Chemical
Treatment of Coke
Plant Wastewater
Richard Osantowski, Anthony Geinopolos, and Gary Rollinger
The full report documents a pilot-
plant study of the use of advanced
waste treatment methods in upgrading
metallurgical cokemaking wastewaters
to Best Available Technology (BAT)
levels. Mobile treatment units, oper-
able at a flow rate of 19 l/min, were
used. Two physical/chemical treat-
ment trains were studied: (a) alkaline-
chlorination/filtration/activated-car-
bon, and (b) alkaline-chlorination/
sodium-bisulfite-dechlorination/fil-
tration. For each treatment studied,
samples (including toxic pollutants)
and operational data were obtained
for later use in assessing and com-
paring treatment adequacy. Chlorina-
tion was effective in consistently
reducing pollutant concentrations to
below BAT levels, except for total
cyanide. Filtration was essential as an
adjunct to alkaline chlorination for
post-treatment suspended solids re-
moval. Activated carbon and sodium
bisulfite were efficient in removing
excess chlorine resulting from treat-
ment by alkaline chlorination, although
carbon was more effective in removing
organic priority pollutants.
This Project Summary was devel-
oped by EPA's Industrial Environmen-
tal Research Laboratory, Research
Triangle Park. NC, 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 purpose of this project was to
investigate the effectiveness of selected
advanced waste treatment technologies
for treating By-Product Cokemaking
Subcategory wastewater to Best Avail-
able Technology (BAT) Economically
Achievable levels. The wastewaters
generated from the by-product recovery
process include excess ammonia liquors,
benzol plant wastes, final cooler waste-
waters, desulfunzer wastes, scrubber
blowdown, and tar decanter waste-
waters. Pollutants contained in these
wastewaters typically include suspended
solids, ammonia, phenolic compounds,
cyanide, sulfide, oil and greases, and
many toxic pollutants.
The investigation was conducted
using the U S Environmental Protec-
tion Agency's (EPA's) mobile physical/
chemical treatment system. This pilot
plant is housed in two semi-trailer vans
and includes four chamber rapid mix
tanks (alkaline chlorination) with a
chemical feed system, a dual media
filter skid, and activated carbon columns.
The advanced waste treatment trams
that were investigated on a pilot scale
included.
1. ACL + FIL + AC
2. ACL + SBD + FIL
Key
AC: activated carbon
ACLj alkaline chlorination
FIL dual media filtration
SBD: sodium bisulfite dechlorination
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In the first pilot treatment train, the
coke plant pre-treated wastewater was
passed through a two-stage alkaline
chlormation process for cyanide, phenol,
sulfide, thiocyanate and ammonia re-
moval. The wastewater was then filtered
for suspended solids removal and de-
chlorinated on activated carbon. The
second treatment train again consisted
of alkaline chlorination which was
followed by sodium bisulfite dechlori-
nation and dual media filtration.
Prior to conducting the pilot studies,
in-depth bench tests were performed to
obtain preliminary information on treat-
ment feasibility, expected magnitude of
treatment efficiency and optimum treat-
ment train process element arrange-
ment.
During the pilot study, samples were
collected for both conventional and toxic
pollutants. Operational data were also
recorded on a daily basis to evaluate the
effectiveness of the respective treat-
ment trains. The pilot study results were
evaluated using the three primary criteria
listed below:
1. process and/or treatment tram
performance
2. capital and annualized costs
3. space requirements
The advanced wastewater treatment
technologies evaluated would normally
be ipplied to an effluent stream that met
the 1977 Best Practicable (Control)
Technology (BPT) requirements. How-
ever, during the study, pollutant levels
were consistently higher than BPT
levels because of pretreatment equip-
ment problems
Summary and Conclusions
Two physical/chemical treatment
trains were investigated. Train 1 con-
sisted of alkaline chlorination, filtration,
and activated carbon. Train 2 consisted
of alkaline chlorination, filtration, and
sodium bisulfite dechlormation.
1. The results of the pilot program
indicated that alkaline chlorination
was effective in reducing influent
concentrations of ammonia, oil
and grease, phenol, sulfide, sus-
pended solids, and thiocyanate to
below future BAT levels. The pres-
ence of complexing agents in the
coke plant effluent prevented com-
plete oxidation of the cyanide by
chlorine; as a result, BATcyamde-T
values could not be met consist-
ently. An estimated capital cost of
$711,000 and annualized cost of
$17.47/3,785 liters ($1 7.477
1,000 gal.) would be realized for a
1,022 mVday (0.27 mgd) treat-
ment facility, assuming current
wastewater pollutant concentra-
tions. If the proposed BAT system
were applied to a waste stream
that met BPT pollutant parameters,
the annualized cost could be re-
duced to $9.26/3,785 liters ($9.26/
1,000 gal.).
2. Filtration provided effective pol-
ishirig of the alkaline chlorinated
coke plant wastewater, removing
71 percent of the influent sus-
pended solids. Suspended solids
removal could be increased to 93
percent with the addition of 3 mg/l
polymer. A 1,022 mVday (0.27
mgd) filtration system without
polymer addition would have an
estimated capital cost of $218,000,
with an annualized cost of $0.48/
3,785 liters ($0.48/1,000 gal.) A
similar system with polymer addi-
tion would have a capital cost of
$243,000 and an estimated an-
nualized cost of $0.58/3,785 liters
($0.58/1,000 gal.).
3 Activated carbon and sodium bi-
sulfite were investigated as de-
chlormatmg agents. Activated
carbon was found to consistently
remove 95 percent of the incoming
total chlorine. The treatment cost
for a 1,022 mVday (0.27 mgd)
activated carbon dechlormatio
system was estimated at $ 1,122,00
capital outlay with an annualize
cost of $5.47/3,785 liters ($5.47
1,000 gal.). Sodium bisulfite pro
vided 100 percent chlorine remove
at a bisulfite:chlorine ratio of 2.1
A 1,022 mVday (0.27 mgd)sodiur
bisulfite dechlorination syster
has an estimated capital treat
ment equipment cost of $174,001
with an annualized cost of $0 98,
3,785 liters ($0.98/1,000 gal.).
4. During the pilot study, 63 sample
were analyzed for priority pollu
tants. The results concluded tha
the physical/chemical treatmen
trains investigated created severe
volatile organic priority pollutants
Tram 1 technologies removed 73
percent of the volatile organic
priority pollutants to non-detect-
able limits, Tram 2 technologies
were effective in treating only 1"
percent of incoming volatile organii
toxics to non-detectable levels
Semivolatile organics were al
effectively reduced for Tram 1
Train 2 also reduced all semivola
tile organics to less than 100/jg/
except for naphthalene. The phys
ical/chemical treatment trains
removed only negligible concen-
trations of metals.
Richard Osantowski, Anthony Gemopolos, and Gary Rollmgerare with Rexnord,
inc., Milwaukee, Wl 53214.
Robert V. Hendriks is the EPA Project Officer (see below)
The complete report, entitled "Physical/Chemical Treatment of Coke Plant
Wastewater," (Order No PB 81-206 021; Cost: $17 00, 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
Research Triangle Park, NC 27711
•fr US GOVERNMENT PRINTING OFFICE 1981 --757-01? 7255
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Environmental Protection
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