The effects of heat pretreatment in cultured hydrogen-producing granular sludge was studied in upflow anaerobic sludge bed (UASB) reactor.Using a kind of mud and the thermal pretreatment of sludge as seeds,and under the conditions of the influent COD concentration 4 000 mg/L,the temperature 37 ℃,the effluent pH 4.6 ~ 5.0,HRTdecreased from 24 h to 7 h,both reactor successfully cultivated mature granular sludge atHRT8 ~ 7 h.At this time,the organic load of the original sludge inoculation group is 45 kg(COD)/（m3· d）,gas production is 41 L/d,hydrogen content is 52%,COD removal rate is 23%,total volatile acids is 1 380 mg/L,the organic load of the heat pretreatment group is 57 kg(COD)/(m3· d),gas production is 44.5 L/d,hydrogen content is 47.5%,COD removal rate is 12%,total volatile acids is 1 086 mg/L.The results showed that,the thermal pretreatment has a significant effect on the formation and stability of hydrogen-producing granular sludge,while in the process of the granular sludge formation,it's poor stability and easy to float,but after start-up,the running state is more stable,can adapt to a shorterHRTand got higher hydrogen yield.
