将Fenton试剂与骨架构建体联用作为复合调理剂开展了污泥调理及脱水试验.结果表明,赤泥与水泥作骨架构建体调理后,污泥脱水性能和脱水液pH均优于石灰与水泥调理污泥.以污泥比阻(SRF)为评价指标,开展了Fenton反应时间、初始pH及调理剂投加量对污泥脱水性能影响的单因素试验.当Fenton反应时间为90 min,初始pH为5,水泥、赤泥、Fe2+和H2O2的投加量(以污泥干固体质量计)分别为300、30040和32 mg·g-1时,污泥比阻降低率可达94.25%±0.21%.在此基础上,以泥饼含水率为响应指标,利用表面响应法对调理剂投加量进行优化.结果表明,水泥、赤泥、Fe2+和H2O2的投加量分别为287、287、46和37 mg·g-1,泥饼含水率可降至47.7%±0.8%.调理后污泥的粒径减小,比表面积增大,粘度减小,Zeta电位由负变正,说明该复合调理剂能有效地破解胞外聚合物(EPS),提高污泥脱水性能.
Dewatering performance of sewage sludge conditioned with Fenton's reagent and skeleton builders as composite conditioner was investigated in this study. The results indicated that both dewatering performance and pH of filtrate of sludge conditioned by red mud and cement as skeleton builders were better than those of sludge conditioned by lime and cement. The effects of Fenton's reaction time, initial pH and the dosage of conditioner on sludge dewatering performance were studied in single-factor experiments by using specific resistance to filtration (SRF) as evaluation index. SRF reduction rate achieved 94.25% +0.21% when process parameters were as follows: Fenton's reaction time of 90 min, initial pH of 5, and dosages (calculated by sludge dry solids) of cement, red mud, Fe2+ and H202 of300 mg·g-1 , 300 mg·g-1 , 40 mg·g-1 and 32 mg·g-1 , respectively. Based on the single- factor experiments, response surface methodology (RSM) was used to optimize the dosage of conditioner by using water content of sludge cake as response index. The optimum dosages of cement, red mud, Fe2+ and H2O2 were 287 mg·g-1, 287 mg·g-1 , 46 mg·g-1 and 37mg·g-1 , respectively, in which the water content of sludge cake was reduced to 47.7%±+ 0.8%. After the conditioning process, the particle size decreased, the specific surface area increased, the viscosity decreased, and Zeta potential changed from negative to positive. It was demonstrated that the composite conditioner can effectivelydegrade extracellular polymeric substances (EPS), and then enhance the dewatering performance of sludge.