Treatment Of Coking Wastewater By Highly Immobilized Bacteria Technology

Coking wasterwater is difficult to tackle due to its being complex,toxic and containing alagre number of refractory organic matters.The research combine bioaugmentation technologyand immobilized microorganism technology to SBR reactor.Through parallel experiment wecheck that SBBR reactor within nano-attapulgitly hydrophilic polyurethane foam and biologicsponge iron as carrier and SBBR reactor within nano-attapulgitly hydrophilic polyurethanefoam as carrier treat coking wastewater, determine the best technological conditionand treatment effect.Basis on it, coking wasterwater is rearched in coking plant by ammoniadistillation、iron-carbon microelectrolysis+baffled reactor、coagulation-sedimentation processusing lab parameter to check treating effect. Biochemical effluent and raw coking wastewateris treated by new coagulator to check treating effect.Results showed that:（1）Nano-attapulgitly hydrophilic polyurethane foam and biologic sponge iron as carrier,SBBR reactor is in order to treat coking wastewater,and determine the best process controlconditions: DO>4mg/L、pH=9.00、NaHCO34.4g.and on this condition, effluent COD is213mg/L,removal of it is75%. Effluent NH₃-N is287mg/L,removal of it is19%.Nano-attapulgitly hydrophilic polyurethane foam as carrier, SBBR reactor is in order totreat coking wastewater,and determine the best process control conditions: DO>4mg/L、pH=9.00、NaHCO38.8g.and on this condition, effluent COD is304mg/L,removal of it is65%.Effluent NH₃-N is303.2mg/L,removal of it is14%.Compared with nano-attapulgitly hydrophilic polyurethane foam+biologic sponge ironSBBR reactor and nano-attapulgitly hydrophilic polyurethane foam SBBR reactor,the fomer`sremoval rate of COD in this study is high than10%, NH₃-N5%.（2）adding Fe²⁺、Fe³⁺to SBBR reactor and using iron-carbon micro-electrolysis couplingSBBR reactor treat coking wasterwater,resoults show, using iron-carbon micro-electrolysiscoupling SBBR reactor gets better effect. effluent COD is500mg/L,removal of it is87%,effluent NH₃-N is678mg/L,removal of it is52.5%.（3） the removal of ammonia is researched by ammonia distillation with differenttime.The resoults show, when ammonia distillation time is6h,best removal effect is obtained.effluent NH₃-N is500mg/L,removal of it is84%.but effluent COD is changed little.（4）Coking wasterwater after ammonia distillation is researched by combined process ofiron-carbon micro-electrolysis+baffled reactor.The resoults show, effluent COD is3200mg/L, removal of it is10%, effluent NH₃-N is435mg/L,removal of it is5%by processof iron-carbon micro-electrolysis. coking wasterwater after process of iron-carbon micro-electrolysis is researched by baffled reactor.The resoults show,the HRT is48h, effluentCOD is393mg/L, removal of it is90%, effluent NH₃-N is33.5mg/L,removal of it is93%.（5）Coagulation experiment for biochemical treatment effluent, obtain optimal processconditions:optimal process conditions for biochemical treatment effluent: coagulant dosingquantity6mL、temperture30℃、pH11、PAM dosing quantity2.5mL.Under these conditions,effluent COD is65mg/L, effluent NH₃-N is19.2mg/L.（6）On the basis of it,the experiment is researched using ammonia distillation-iron-carbonmicroelectrolysis-baffled reactor-coagulation-sedimentation combined process.The resoultsshow, Influent quality of COD is from3100mg/L to4500mg/L and Influent quality ofNH₃-N is from2500mg/L to3700mg/L, effluent COD is65mg/L mg/L, effluent NH₃-N is19.2mg/L.Through Coagulation experiment, the COD of coking wastewater effluent meetintegrated wastewater discharge standard class1,and the NH₃-N of coking wastewatereffluent meet integrated wastewater discharge standard class2.The effluent quality ismeet the discharging stand,and it provide a technical support for actual project.