过氧乙酸破解和化学重絮凝改善活性污泥过滤脱水性能  

Enhancement of activated sludge dewatering performance with combined peroxyacetic acid oxiution and chemical re-flocculation with inorganic coagulants

作　　者：曹秉帝 张伟军[2] 王东升[3] 段晋明[1] 

机构地区：[1]西安建筑科技大学市政与环境工程学院,西安710055 [2]中国地质大学(武汉)环境学院,武汉430074 [3]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085

出　　处：《哈尔滨工业大学学报》2016年第2期100-108,共9页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金(51178360;51338010)

摘　　要：活性污泥中的胞外聚合物(EPS)高度亲水,破坏EPS结构是促使结合水释放的必要过程.为此,研究利用过氧乙酸(PAA)预氧化破解污泥和化学絮凝过程以同步实现污泥减量和脱水性改善,深入解析组合调理过程中污泥絮体形态特征及EPS分布和组成的变化特征.结果表明:PAA处理污泥对其过滤特性影响不大,但有效降低滤后泥饼的含水率;PAA能够有效破解污泥,破坏EPS中蛋白质类有机物,促使结合水释放;随着p H的降低,PAA对污泥脱水性的改善效果更佳,这主要是因为酸性环境有效提高了PAA对污泥EPS的氧化效率;高剂量PAA处理污泥后未见到有完整结构的絮体.投加聚合氯化铝(PAC)和氯化铁后,污泥絮体重新形成,同时污泥更容易过滤且脱水性随之提高.由于具有更强的吸附架桥能力,PAC在改善脱水性方面的效果优于氯化铁.Extracellular polymeric substances （EPS） in sewage sludge are highly hydrophilic, and the destruction of EPS structure is very essential for the high-performance dewatering process. In this study, the peracetic acid lysis and chemical re-flocculation was used to achieve the volume reduction and dewaterability improvement of waste activated sludge. Moreover, dynamic variations of the floc morphology and EPS properties of sludge were also investigated. The results indicated that PAA treatment had very limited effeet on sludge filterability, while filtration drying performance was effectively improved. PAA could effectively solubilize the sludge particle and destroy the protein-like substances, resulting in an efficient releasing of bound water. Sludge dewatering was enhanced under a low pH level after PAA oxiution, ascribing to the higher oxiutive ability of PAA under acid conditions. No integral sludge floc could be observed after PAA treatment at high dosages. Floc reformed after the additive of PAC and ferric chloride, meanwhile both filterability and dewaterability were improved. Furthermore, PAC performed better in improving sludge dewatering performance than ferric chloride due to its high adsorption and bridging abilities.

关 键 词：污泥 过氧乙酸 胞外聚合物 脱水性 氧化 化学絮凝 

分 类 号：X799[环境科学与工程—环境工程]