FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
1 TITLE OF THE INVENTION :
A SYSTEM FOR EFFLUENT TREATMENT AT COKE OVEN PLANT AND A METHOD FOR SUCH TREATMENT.
2 APPLICANT (S)
Name : JSW STEEL LIMITED.
Nationality : An Indian Company.
Address : Jindal Mansion, 5-A, Dr. G. Deshmukh Marg, Mumbai - 400 026,
State of Maharastra, India.
3 PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to a system for effluent treatment at coke oven byproduct plant and a method for carrying out such effluent treatment using such a system. More particularly, the present invention relates to an efficient system and method for treatment of contaminated effluent water and condensates generated during cleaning of coke oven gases involving bio-degradation process so as to eliminate oil, phenol, total dissolved solids (TDS), total suspended solids(TSS) and comply with norms of central pollution control board for waste water discharge and recycling of treated water. Importantly, the effluent treatment process of the invention involves innovative method of cleaning water contaminated with oils, phenol, cyanides, TDS,TSS in recovery coke oven byproduct plant is done through a combination of MBR and RO. The activated sludge present in MBR helps in removing organics before RO and reduces the pressure on RO membrane, thereby, cleaning the water efficiently.
BACKGROUND ART
The applicant has the facility of recovery type coke oven plant for producing coke required for their Blast Furnace (BF). In recovery type coke-ovens, the gas evolved during carbonization is recovered and is termed as coke oven gas. This gas contains impurities such as carbon, tar, ammonia etc. and has to be cleaned before using the gas for heating purposes. Purification of coke-oven gas is done in coke-oven byproduct plant. Separation of tar, hydrogen sulphide and ammonia from coke-oven gas takes place through different intermediate processes. Water is used for scrubbing the gas and, condensates generated during the processes are treated in Effluent Treatment Plant (ETP) with the help of bio-degradation process.
The treated water is supposed to be fit for recycling in the byproduct plant for cleaning of coke oven gases.

The conventional effluent treatment process suffers from a number of deficiencies that indicate inadequacy of treatment of water /condensate by ETP making treated water unsuitable for recycling. These deficiencies are as follows:
(i) Presence of oil in treated water;
(ii) Presence of Total Suspended Solids (TSS) and Total Dissolved Solids (TDS);
(iii)Color and odor present in treated water;
(iv)Not meeting the norms of waste water discharge;
There has been thus a need in the art to developing an efficient effluent treatment system/ plant and method using such system for cleaning of exhaust water and condensate produced for cleaning coke oven gases in byproduct plant of coke oven adapted to eliminate the contaminates effectively to conform to pollution control norms and make the treated water fit for recycling.
OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to system for effluent treatment in coke oven plant and a method for cleaning waste contaminated water generated in recovery byproducts coke oven plant capable of removing all contaminants from the effluent so as to meet norms for waste water discharge.
A further object of the present invention is directed to providing a system and method for effluent treatment in coke oven byproduct plant adapted to eliminate oils, phenol, cyanides, total suspended solids, total dissolved solids so that the treated water can be recycled.
A still further object of the present invention is directed to providing a system and method for effluent treatment involving biological degradation for cleaning waste water contaminated with oils, phenol, cyanides, TDS in recovery coke oven

byproduct plant through a combination of Membrane Bio Reactor and Reverse Osmosis.
A still further object of the present invention is directed to providing a system and method for effluent treatment in recovery coke oven byproduct plant capable of complete removal of odor and color in treated water.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is thus directed a system for effluent treatment at coke oven plant comprising:
i) gravity separation and air floatation unit;
ii) bio-degradation unit;
iii) filtration unit;
iv) membrane bio reactor (MBR) ;and
v) Ultra filtration in pre-treatment unit for reverse osmosis.
A further aspect of the present invention is directed to providing said system for effluent treatment such that:
(i) all the contaminated water and gas condensates from coke oven
are collected at a sewage lifting pool and then sent to an oil
removing pool; (ii) the condensates from distillation unit are mixed with contaminated
water in oil removing pool whereby the heavy oils are removed by
gravity separation and the Light oils are removed in flotation pool
with the help of flocculants addition; (iii) water free from oils is sent to regulation pool for maintaining
essential parameters including COD, phenol, ammonia etc. before
it is sent to anaerobic pool; (iv) anaerobic stage being the first stage of biodegradation where
reduction of heavy hydrocarbons including phenol and COD takes
place.; (v) from anaerobic pool water is sent to anoxic poof for removal of
nitrates through Denitrification;

(vi) aerobic pool comprises an oxidizing pool where ammonia is
converted to nitrites through nitrification; vii) from aerobic pool water goes to intermediate sedimentation pool
for separation of sludge from water. viii) the treated water is thereafter sent to second oxidizing tank for
further reduction of left over impurities such as nitrites, ammonia
etc. ix) water is then sent to final sedimentation tank for sludge and water
separation; x) finally, water is passed through the sand filters and activated
carbon filters for separation of odor and color; xi) the contaminants in the effluent treated water are next subjected
to membrane bio reactor (MBR) and then ultra filtration in said pre-
treatment unit for reverse osmosis.
A stilt further aspect of the present invention is directed to a method of effluent treatment at coke oven plant comprising:
i) subjecting to gravity separation and air floatation;
ii) subjecting to bio-degradation;
iii) subjecting to filtration;
iv) subjecting to membrane bio reactor (MBR) ;and
v) ultra filtration in pre-treatment unit for reverse osmosis.
Importantly, said method is carried out using the system as described above.
A still further aspect of the present invention is directed to a method wherein said step of subjecting the contaminated effluent to membrane bio reactor is done to clean water contaminated with paints in industries.
A still further aspect of the present invention is directed to a method comprising cleaning water contaminated with oils, phenol, cyanides, TDS in recovery coke oven byproduct plant through a combination of membrane bio reactor and reverse osmosis membrane.

According to yet another aspect of the present invention is directed to a method as providing for
(a) simpler removal of TSS, TDS, Phenol, and Cyanide ;
(b) reducing conductivity of water reduced due to insignificant presence of TDS.
(c) attaining the norms of waste water discharge by providing treated water
having
(i) COD