城市污泥水热脱水处理的工业应用与研究进展

Research on hydrothermal treatment of sewage sludge and its industrial applications

城市污泥是人类生活活动的副产品,对其脱水处理是污泥处置的关键。其中,水热脱水技术由于其能有效提高污泥脱水效率与低能耗等优势,成为污泥减量化与资源化处理的研究热点。文章首先介绍了城市污泥的特点及其处理现状,然后总结了近年来国内外关于污泥水热脱水工艺的发展历程与工业应用情况,并进一步对比分析了污泥水热脱水与其他脱水技术之间的能耗优势。此外,重点综述了污泥水热脱水的影响因素与机理,包括温度、时间、p H等处理条件以及水热过程中污泥水分形态与胞外聚合物(EPS)对污泥脱水性能的影响,并分析了目前机理研究上存在的矛盾与原因。最后对污泥水热脱水的发展前景作出展望,指出通过优化EPS分层提取从而深入分析污泥中各组分在水热过程中的迁移与结构变化是研究污泥水热脱水机理的重要途径。

Sewage sludge is the by-product of human activities and its dewatering treatment is essential for sludge disposal.Among these dewatering technologies,hydrothermal dewatering has been the research focus of sludge reduction and utilization because of its advantages of improving dewatering and low-energy consumption.This paper introduced the characteristics of sewage sludge and its disposal status,then comprehensively summarized the development process of sludge hydrothermal dewatering and its industrial application.Besides,the advantage of energy consumption for hydrothermal dewatering was compared with other dewatering technologies.After that,the latest studies relate to the effects of hydrothermal conditions,moisture distribution and extracellular polymers substance(EPS)on the dewaterability of sludge were analyzed in detail.Finally,the future developing perspectives of sludge hydrothermal dewatering treatment were also put forward,and studying the transformation of sludge components and structure via modified EPS extraction was considered as important ways to understand the mechanism of hydrothermal dewatering.