基质投加量对生物调理改善污泥脱水性能的影响

通过在剩余污泥中投加FeSO_4及S~0的生物基质进行生物调理的方法改善污泥脱水性质.在确定两者的投加质量比为7∶3(FeSO_4的质量以Fe~(2+)计)的条件下,分别投加质量为污泥干重的10%、15%、20%、25%、30%的混合基质,结果表明当基质投加量为污泥干重的20%时,污泥的脱水性能最佳.其中,毛细吸水时间(CST)较对照组降低了38.71%,粘度下降了81.91%,泥饼含固率为对照组的135.19%.同时,污泥中的胞外聚合物(EPS)总量有了显著的下降,污泥絮体中的有机质从与污泥细胞更紧密结合的紧密型EPS(TB-EPS)中释放到较外层的疏松型EPS(LB-EPS)中,且Zeta电位接近中性,从而使得污泥脱水性能得到改善.

Effect of agent dosage on sludge dewaterability by biological conditioning

Effect of FeSO₄ coupled with S⁰ addition on the dewaterability of sewage sludge by bioleaching was investigated. The dosage of agent was 10%, 15%, 20%, 25%, and 30% of the dried sludge in which the ratio of FeSO₄ and S was 7:3 (the quantity of FeSO₄ was considered by Fe²⁺). The results show that among the five dosages, 20% addition rate exhibited the most effectiveness in improving the sludge dewaterability. Under the optimal condition, the CST was reduced to 38.7%, lower than that of the control group, while the viscosity and solid content of sludge cake were 81.9% and 135% of that of the control group, respectively. Furthermore, the EPS in the sludge reduced rapidly, implying the organisms in the flocs could release from the TB-EPS into the LB-EPS or supernatant. The Zeta potential was also increased to near zero at the 20% dosage. The results obtained from this study indicated FeSO₄ coupled with S could effectively improve sludge dewaterability.