微米Fe3O4磁粉调理-压力电场污泥脱水工艺过程研究  

Magnetic Fe_3O_4 Microparticles Conditioning-Pressure Electro-osmotic Dewatering(MPEOD) of Sewage Sludge

作　　者：钱旭[1] 王毅力[1] 赵丽[1] 

机构地区：[1]北京林业大学环境科学与工程学院,北京市污染水体源控制技术重点实验室,北京100083

出　　处：《环境科学》2016年第5期1864-1872,共9页Environmental Science

基　　金：国家自然科学基金项目(21177010,51078035)

摘　　要：研究了微米Fe_3O_4磁粉调理污泥的投加量的优化以及微米磁粉调理-压力电场污泥脱水工艺(MPEOD)的操作参数(电场作用时间、机械压力、电压)对脱水效果和能耗的影响,分析了磁化调理后污泥上清液、污泥絮体理化性质及接触能变化特征.结果表明,微米Fe_3O_4磁粉最佳调理投加量为0.15 g·g^(-1);结合能耗与脱水效果,电场作用时间、电压和机械压力分别确定为2 h、30~50 V和400~600 k Pa.当MPEOD工艺的机械压力、电场作用时间和电压分别为400 k Pa、2 h和50 V时,污泥含水率由初始的99.18%降低至44.46%,水分脱除率和污泥减量化分别可达99.34%和98.30%,相应的能耗仅为0.013 3k W·h·kg^(-1).微米磁粉调理污泥时,絮凝作用机制的影响很小,污泥脱水性能得到提高的主要原因是微米磁粉大大降低了污泥颗粒间的路易斯酸碱作用,致使污泥絮体聚集,絮体间孔径增大,利于脱水.较之经典的DLVO理论,扩展后的EDLVO理论能准确描述污泥颗粒的凝聚及分散行为.For magnetic Fe3O4 microparticles conditioning—pressure electro-osmotic dewatering（ MPEOD） process of activated sludge（ AS）,the effects of operating parameters（ optimal dosage of Fe3O4,electric field duration,mechanical pressure and voltage） on the dewatering efficiency and energy consumption were investigated,and the optimal conditions were determined. Moreover,the properties of supernatant and sludge along MPEOD process were studied as well as the interaction force between the sludge biosolids. Taking the energy consumption into consideration,the results showed that the optimal dewatering effect for AS could be achieved with a magnetic Fe3O4 microparticles dosage of 0. 15 g·g^-1,an electric field duration of 2 h,a mechanical pressure of 400-600 k Pa and a voltage of30-50 V. When MPEOD was conducted at 400 k Pa and 50 V for 2 h,the sludge reduction rate reached 98. 30%,the percentage of water removal was 99. 34% and the moisture content of AS decreased from 99. 18% to 44. 46%. The corresponding consumption of energy was 0. 013 3 k W·h·kg^-1. The coagulation mechanism played a slight role in the AS conditioning with magnetic Fe3O4 microparticles. In fact,magnetic Fe3O4micro-particles could greatly decrease the acid-base interaction（ WAB） between AS biosolids,cause floc growth and enlarge pores in AS aggregates,which will be beneficial to AS dewatering. Compared to DLVO theory,the extended DLVO theory could accurately describe the aggregation and dispersion behavior of sludge particles.

关 键 词：活性污泥 微米Fe3O4磁粉调理 脱水效果 能耗 接触能 

分 类 号：X703.1[环境科学与工程—环境工程]