碳化强度对污泥脱水及裂解液性质的影响--基于Ruyter模型分析

Effects of carbonization intensity on dewatering performance of municipal sludge and characteristics of lysate--based on Ruyter model

采用Ruyter模型,建立碳化强度评价指标,并以此分析碳化温度和碳化时间对污泥脱水性能和产生裂解液理化特征的耦合影响,阐明水热碳化提升污泥脱水性能的机制.结果表明,实验室条件下,碳化强度大于0.12时,水热处理后的污泥经抽滤脱水,含水率可降至55%,达到自持燃烧水平,这是由于在一定碳化强度下,污泥中蛋白质、多糖等大分子物质发生水解、缩聚、脱羧等一系列反应,但过高碳化强度(0.21)加深了芳构化程度,使裂解液可生化性变差.

The study used Ruyter model and proposes index of‘carbonization intensity’.On the basis of the index,the coupling effects of both carbonization temperature and carbonization time on dewaterability of sludge and physicochemical characteristics of produced lysate were analyzed.Furthermore,the mechanism of dewatering performance improvement by hydrothermal carbonization was illustrated as well.Results show that in the lab condition,at the carbonization intensity of higher than 0.12,the water content of treated sludge reduced to 55%after suction filtration,which reached to the level of self-sustaining combustion.The reason for good dewatering performance was due to a series of reactions of macromolecular substances(eg.protein or polysaccharide)under a certain carbonization intensity,such as hydrolysis,polycondensation,decarboxylation.However,in an excessive high carbonization intensity condition(0.21),the degree of aromatization was deepened,which resulted in worse biodegradability of lysate.