调控絮体形态强化电絮凝减缓膜污染  

Enhanced Mitigation of Membrane Fouling by Regulations on Floc Morphology in Electrocoagulation

作　　者：赵凯[1,2] 杨春风[1] 孙境求[2,3] 李静 胡承志[2] 

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]中国科学院饮用水科学与技术重点实验室,中国科学院生态环境研究中心,北京100085 [3]中国科学院大学,北京100049

出　　处：《环境科学》2016年第11期4255-4260,共6页Environmental Science

基　　金：国家自然科学基金项目(51378490);国家水体污染控制与治理科技重大专项(2015ZX07402003-3)

摘　　要：本研究通过调节电絮凝工艺参数来实现对絮体形态的调控,进而达到减缓膜污染的目的.主要考察了电流密度、初始pH、初始电导率对絮体性质以及膜通量的影响,并解析了超滤膜对不同形貌结构絮体的膜污染响应机制.结果表明,电絮凝减缓膜污染的关键是在膜表面形成疏松多孔的滤饼层,电絮凝-超滤(electrocoagulation-ultrafiltration,EC-UF)工艺不但能够有效地减缓膜污染,而且还极大提升了出水水质.增加电流密度,以及在pH中性水质条件下,EC-UF工艺中膜通量保持更高.j=20 A·m^(-2)、初始pH=7、初始电导率=1 000μS·cm^(-1),EC-UF工艺对水中的腐殖酸(humic acid,HA)去除率为97%,平衡阶段归一化通量J/J0达到81%.In this study,the electro chemical parameters were regulated to control the floc morphology in order to mitigate membrane fouling. The main effects of current density,initial pH and conductivity on the floc characteristics and flux were studied,and the mechanisms of interaction between flocs with different morphology structures and ultrafiltration membranes were analyzed. The results showed that the key to mitigate the membrane fouling by electrocoagulation was to form a loose and porous cake layer on the membrane surface. The electrocoagulation-ultrafiltration（ EC-UF） technology could not only effectively mitigate the membrane fouling,but also greatly enhance the water quality of the effluent. By increasing the current density and keeping water quality conditions at neutral pH,the EC-UF technology could maintain a higher flux. Under conditions of j = 20 A·m^-2,initial pH = 7 and initial conductivity = 1 000μS·cm^-1,the removal rate of humic acid（ HA） was 97%,and the normalized specific flux of J/J0 was 81%.

关 键 词：电絮凝 超滤 滤饼层 膜污染 膜通量 

分 类 号：X703.1[环境科学与工程—环境工程]