不同混凝剂对污泥脱水性能的影响研究

Study on effect of chemical conditioning using different coagulants on sludge dewatering performance

采用无机和有机混凝剂对污泥进行调理,通过测定污泥比阻、Zeta电位以及污泥上清液中蛋白质、多糖和DNA含量,同时结合污泥上清液的三维荧光光谱分析,研究了不同混凝剂及其投加量对污泥脱水性能的影响.结果表明:当聚合氯化铝(PAC)、高效聚合氯化铝(HPAC)和氯化铁(FeCl3)的投加量在干污泥量的10%附近时,污泥比阻值最小,同时三维荧光强度值也最小,Zeta电位以及上清液中蛋白质、多糖和DNA的含量基本趋于稳定.无机混凝剂与有机混凝剂联合作用调理污泥后其脱水效果明显优于单一混凝剂调理.有机混凝剂与无机混凝剂投加顺序对污泥脱水性能影响显著,先投加无机混凝剂再投加有机混凝剂的脱水效果最佳,研究筛选出两种混凝剂联合作用调理污泥后,其脱水效果顺序为10%PAC+0.5%PAM>10%FeCl3+0.5%PAM>10%HPAC+0.5%PAM.

This study investigated sludge dewatering characteristics by using inorganic and organic coagulants.The effect of different coagulants on sludge dewatering was evaluated by means of specific resistance to filtration（SRF）.Zeta potentials,the concentrations of protein,polysaccharide and DNA in the supernatant of the sewage sludge was also measured.In addition,three-dimensional excitation emission matrix fluorescence（3DEEM） was adopted to characterize the organic matters in supernatant.The results showed that the lowest intensity for SRF and 3DEEM analyses was observed when the ratio of spiked ferric chloride（FeCl3）,polymeric aluminium（PAC） and polyaluminium chloude（HPAC） to dewatered sludge was 10%,while zeta potentials,protein concentrations,polysaccharide and DNA kept constant.It was noticeable that combination of inorganic and organic coagulants significantly improved the sludge dewaterability in comparison to that using single coagulant.Our results also demonstrated that the addition of inorganic prior to organic coagulant could provide notably higher efficiency for sludge dewatering than that spiking in reverse order.By combining coagulants in various ratios of coagulant to sludge,the order of optimal dewatering was：10%PAC＋0.5%PAM10%FeCl3＋0.5%PAM10%HPAC＋0.5%PAM.