摘要
采用外加电场构建了电强化膜生物反应器(electrically enhanced membrane bioreactor,E-MBR)用以处理海水冲厕水,分析了在不同电流密度下污染物的去除效果、活性污泥特性和膜污染行为的变化规律。结果表明:电流密度由2 A·m^(-2)增大至2.6 A·m^(-2)再增加至3.2 A·m^(-2)的过程中,E-MBR中化学需氧量(COD)和氨氮(NH_(4)^(+)-N)的平均去除率呈先增加后降低的趋势,COD的平均去除率由90.88%增加至94.81%而后降低为86.74%,NH_(4)^(+)-N的平均去除率由95.31%增加至96.37%而后降低为88.33%。由于外加电场产生的电絮凝作用以及菌种对电场的耐受差异,不同电流密度下E-MBR中总磷(totalphosphorus,TP)的去除率均稳定在99%以上,而对照MBR(control membrane bioreactor,C-MBR)中TP的平均去除率仅为20%。E-MBR中混合液悬浮固体质量浓度(MLSS)均高于C-MBR系统,电流密度为2.6 A·m^(-2)时E-MBR中MLSS增长最快,电流密度为3.2 A·m^(-2)时EMBR中MLSS增长最缓慢。随着电流密度增大,污泥粒径逐渐增大,污泥Zeta电位(绝对值)均小于C-MBR系统的Zeta电位。溶解性微生物代谢产物(SMP)和胞外聚合物(EPS)中多糖和蛋白质的含量随着电流密度的增大而降低。增大电流密度时,跨膜压差(TMP)的增长速率会随之降低,滤饼层阻力在系统总阻力中所占比例减少,说明外加电场可有效缓解膜污染。
In this study,an electrically enhanced ceramic membrane bioreactor(E-MBR) was constructed in the form of an external electric field to treat simulated seawater toilet flushing water.The effect of pollutant removal in the system at different current densities,the changing laws of activated sludge characteristics and membrane fouling behavior were analyzed.When the current density increased from 2 A·m^(-2) to 2.6 A·m^(-2) and then to3.2 A·m^(-2),the average removal rates of COD and NH_(4)^(+)-N in the E-MBR system increased first and then decreased,the average removal rate of COD increased from 90.88% to 94.81% and then decreased to 86.74%,and the average removal rate of NH_(4)^(+)-N increased from 95.31% to 96.37% and then decreased to 88.33%.Due to the electric flocculation produced by the external electric field and the difference of bacteria tolerance to electric field,the removal rate of TP in the E-MBR system at different current densities was stable above 99%,while the average removal rate of TP in C-MBR was only 20%.MLSS in E-MBR was higher than that in CMBR system,when the current density was 2.6 A·m^(-2),the fastest increase of MLSS in E-MBR occurred,and when the current density was 3.2 A·m^(-2),the slowest increase of MLSS in E-MBR occurred.As the current density increased,the sludge particle size gradually increased,and the sludge Zeta potential(absolute value) was less than that of the C-MBR system.The content of polysaccharide and protein in soluble microbial product(SMP) and extracellular polymeric substance(EPS) also decreased with the increase of current density.As the current density increased,the growth rate of TMP decreased,and the proportion of the cake layer resistance in the total resistance of the system decreased,which showed that an external electric field can effectively alleviate membrane fouling.
作者
吴香梅
金春姬
张思敏
张雪
高孟春
郭亮
WU Xiangmei;JIN Chunji;ZHANG Simin;ZHANG Xue;GAO Mengchun;GUO Liang(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Key Laboratory of Marine Environmental Science and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2022年第6期1968-1978,共11页
Chinese Journal of Environmental Engineering
基金
中央高校基本科研业务费专项基金(201964004)。
关键词
电流密度
电强化膜生物反应器
脱氮除磷
污泥性质
膜污染
current density
electrically enhanced membrane bioreactor
nitrogen and phosphorus removal
sludge properties
membrane fouling
