城市污水处理厂污泥的化学调理特性研究

Study on the characteristics of sludge chemical conditioning for urban sewage treatment plants

向5种不同来源污泥投加聚合氯化铝(PAC),通过比阻(SRF)的变化确定PAC最优投加量。探讨了污泥中束缚水含量、Zeta电位(ZP)对SRF的影响,并考察污泥胞外聚合物(EPS)中蛋白质、多糖含量与束缚水、ZP电位的关系。结果表明:污泥束缚水含量升高、ZP降低均不利于SRF减小。而EPS的多糖、蛋白质含量增加,导致原污泥的束缚水含量升高、ZP降低,PAC最优投加量增加。相对于蛋白质,多糖含量的变化对PAC最优投加量的影响更为明显。

Five kinds of sludge collected from different sources are conditioned chemically by dosing polyaluminium chloride（PAC）. The optimal dosages of PAC are determined based on the changes of specific resistance to filtration （SRF）. The effects of the bound water content and Zeta potential （ZP） of sludge on SRF are discussed,and the relation-ship between the contents of protein,polysaccharide in extra-cellular polymeric substance （EPS） of sludge and bound water Zeta potential are investigated. The results show that both of the increase of bound water content and the decrease of ZP of sludge are unfavorable to the lowering of SRF. The increase of the contents of polysaccharide and protein in EPS would lead to the increase of the bound water content,the decrease of ZP and the increase of optimum PAC dosage. Compared with protein,the effect of the variation of polysaccharide content on the optimal PAC dosage is more remarkable.