市政污泥热力干化过程中黏滞特性研究进展

Progress in sticky characteristics of sewage sludge during thermal drying process

黏滞现象是城镇污泥脱水干化过程中面临的主要问题之一,污泥在干化设备中的黏附和结团,导致干化设备运行效率大幅降低,给污泥干化系统的经济性和安全性带来显著的负面影响。本文从污泥黏附力和结团力入手,简要介绍了污泥黏滞现象的形成机理以及低含水率条件下污泥黏滞性的主要测量方法,包括搅拌法、平板法、黏附-结团失效特性法、阻抗法、黏附量法和滑板黏度法等,并对比分析了各种分析方法的优缺点。综述了包括胞外聚合物(EPS)、温度和污泥含水率等主要因素对污泥黏滞特性的影响规律,并简要探讨了各因素的影响机理。概述了国内外污泥降黏方法的研究进展,讨论了各种降黏方法的工业应用前景,同时探讨了污泥黏滞特性研究领域未来值得深入研究的方向。

Sticky phenomenon is one of the main problems encountered during dewatering and drying of sewage sludge. The operating efficiency of drying equipment will be greatly influenced by adhesion and cohesion of sewage sludge,which brings negative impact to the economy and security of the system. The formation mechanism of sticky phenomenon of sewage sludge was briefly introduced based on the illustration of adhesive and cohesive force,as well as the testing methods of sticky properties of sewage sludge under low moisture content,such as agitation method,plate method,adhesive-cohesive failure method,electrical resistivity method,build-up method and sliding plate viscosity method,etc. The merits and drawbacks of the different testing methods were also discussed. The influencing of extracellular polymer substances（EPS）,temperature and moisture content on sticky properties of sewage sludge were reviewed,and mechanisms were also briefly discussed. The research progress in the viscosity reduction method of sewage sludge was also discussed,as well as the industrial application aspects of the different viscosity reduction methods. The future trends of the research on sticky properties of sewage sludge were represented.