污泥电脱水过程重金属迁移规律研究  

Heavy Metal Migration during Sludge Electro-dewatering Process

作　　者：熊杰[1] 张鹤清[1] 王玉珏[2] 

机构地区：[1]西门子(中国)有限公司,北京100102 [2]清华大学环境学院,北京100084

出　　处：《环境科学与技术》2017年第4期30-35,共6页Environmental Science & Technology

基　　金：Siemens CKI Seed Fund Program:Mechanism Study and Development on SMART Sludge Electro-dewatering Process for Potential Commercial Application(201232)

摘　　要：以市政污泥和添加外源重金属的污泥为对象,研究了污泥中重金属(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)及常见金属元素(Fe、Ca、Al和Na)在电脱水过程中的迁移规律。在特定电脱水条件下,分别考察了2种污泥的脱水效果和脱水速率,解析了电脱水过程中重金属的迁移程度及迁移速度。结果表明,电脱水可以有效降低污泥中的水分,市政污泥和添加外源重金属污泥的含水率分别由84.2%和82.3%降至54.7%和52.6%。电脱水后,重金属基本保留在泥饼中。市政污泥中重金属保留在泥饼中的比例高达88.1%~96.7%,添加外源重金属污泥则为90.2%~95.4%。常见金属保留在泥饼中的比例为82.3%~94.1%,仅有Na大部分迁移至滤液,脱水后其保留在泥饼中的比例为17.6%。该研究还发现重金属从污泥至滤液的迁移程度主要取决于其物理存在形态,而重金属的迁移速度则主要取决于其化学形态。The migration behavior and characteristics of heavy metals （As, Cd, Cr, Cu, Mn, Ni, Pb and Zn） and common metals （Fe, Ca, Al and Na） were studied during electro-dewatering process of municipal sludge and municipal sludge added with extraneous heavy metals. The electro-dewatering experiments were carded out under a specific operational condition in the purpose of investigating sludge dewatering performance, distribution of heavy metals in sludge cake and filtrate, and the rate of metal migration, respectively. The experimental study showed that the moisture contents were reduced from 84.2%- 54.7% for municipal sludge and from 82.3%-52.6% for sludge with extraneous heavy metals, respectively. The heavy metals retained in dewatered sludge cake ranged from 88.1%-96.7% for municipal sludge, and from 90.2%-95.4% for sludge with extraneous heavy metal, respectively; on the other hand, the common metals retained in dewatered municipal sludge ranged from 82.3%-94.1%, excepting for Na, which was only 17.6% remained in the dewatered sludge, mostly migrated to the filtrate. In addition, the migration degree of heavy metal depended on its physical morphological character, while the migration rate related to its chemical morphological character.

关 键 词：污泥 电脱水 重金属 迁移 

分 类 号：X703[环境科学与工程—环境工程]