Comparative Study On Several Kinds Of Biological Treatment To Slaughterhouse Water

Slaughterhouse wastewater from the slaughter of livestock,poultry and fish hasbecome one of the main source of organic compounds,which results in seriouspollution to the environment.Therefore,the development of simple, efficient andenergy saving wastewater treatment technology is proved to be the trend ofslaughtering industry and social development,as is urgent as for environmentalsectors.Slaughterhouse wastewater contains large amounts of animal fur,blood,oil andfat, smash bone and flesh and viscera,which is very malodorous.In addition, it isdifficult to treat for its high concentration of nonbiodegradable organics.For thefeatures of slaughterhouse wastewater,two combined processes i.e. AF+SBR andUASB+SBR were used in this study for treatment of slaughterhouse wastewater toinvestigate their treatment effect according to its characteristics,and their treatmenteffect was compared with erach other. The research results are as follows:(1)In the condition of water quality (COD_cr:200～500mg/L,BOD₅:100～300mg/L,NH₄⁺-N:100～200mg/L,TP:20～30mg/L,TKN:100～300mg/L), Theconcentrations of COD_cr,NH₄⁺-N,TP and TKN in the effluent were50mg/l,5mg/L,7mg/L and6mg/L, respectively, undering the optimal operational conditions ofAF+SBR combined process, which met the standards for irrigation water quality..(2) UASB+SBR combined process was used for slaughterhouse wastewatertreatment under a given conditions(inflow=3L/d,HRT=18h in the UASB and SBR6h,a aeration time=4h,eration=0.2m³/h)removal rate of COD_cr,and NH₄⁺-N,TP were80%,90%and60%,respectively, corresponding concentrations in the effluent were70mg/L,10mg/L and9mg/L, respectively, with stabled running state under thiscondition,which basically made up with sewage discharge standard.(3)Study on the comparison between treatment effect of the two combinedprocesses showed that optimal HRT of AF and UASB were12h and10h, HRT inSBR is6h.While corresponding COD_crremoval rate were96%and90%,respectively.And the former was better than the latter for the treatment effect ofNH₄⁺-N and TP. Optimal volume loading rate for AF+SBR was2.0KgCOD_cr/m³·dand1.5KgCOD_cr/m³·d for UASB+SBR,lower than the former. For the removalefficiency of COD_cr, the former was better than the latter.The NH₄⁺-N and TP removalefficiency had no significant difference,and the two processes had little effect on thepH of effluent.In addtion, optimal temperature of AF in the AF+SBR system was27℃,and above37℃for UASB in the UASB+SBR system, experiment condition forthe former was widely available. Through the investigation of the treatment effect of the two combined processesfor treating slaughterhouse wastewater and comparative study on operationeffectiveness between them, operating parameters were proposed and optimized inthis study, which has reference value for design and operation of practicalengineering.