颗粒活性炭-纳滤处理二级出水中有机物膜污染机制研究  

Membrane fouling mechanisms on organic matter in the secondary effluent by GAC-NF combined process

作　　者：孙丽华[1] 邓斯 梅筱禹 王春芳 SUN Li-hua;DENG Si;MEI Xiao-yu;WANG Chun-fang(Key Laboratory of Urban Rainwater System and Water Environment,Ministry of Education,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;School of Environmental and Energy Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Beijing Water Planning Institute,Beijing 101117,China)

机构地区：[1]北京建筑大学,城市雨水系统与水环境教育部重点实验室,北京100044 [2]北京建筑大学环境与能源工程学院,北京100044 [3]北京市水务规划研究院,北京101117

出　　处：《中国环境科学》2024年第7期3749-3758,共10页China Environmental Science

基　　金：国家自然科学基金资助项目(52070011,52370004);北京建筑大学研究生创新项目资助(PG2024085)。

摘　　要：采用颗粒活性炭(Granular Activated Carbon,GAC)、生物活性炭(Biological Activated Carbon,BAC)两种过滤单元分别与纳滤(Nanofiltration,NF)组合对污水厂二级出水进行深度处理,分析二级出水直接NF、GAC-NF以及BAC-NF三种不同处理工艺对有机物的去除效果以及膜污染机制.研究发现,BAC-NF组合工艺对溶解性有机碳(DOC)、微生物代谢副产物类和腐殖酸类有机物的去除效果更好,去除率分别为85.2%、76.2%和82.0%;BAC-NF组合工艺的膜比通量(J/J0)最高,每个周期末的J/J0分别为0.69、0.65和0.63,膜污染总阻力最低,仅为5.97×10^(10)m^(-1);膜污染特征曲线表明二级出水直接NF为滤饼层污染,GAC-NF和BAC-NF先发生中间堵塞之后形成滤饼层污染;其中,BAC-NF以膜孔中间堵塞污染为主,膜污染程度最轻;通过扩展的德亚盖因-兰多-弗韦-奥弗比克(Extended Derjaguin-Laudau-Verwey-Overbeek,xDLVO)理论分析发现BAC-NF组合工艺污染后膜表面的疏水性最弱,膜表面Zeta电位值最大;BAC-NF组合工艺在过滤初期,水中有机物不容易到达膜表面,膜污染程度最轻.在过滤中后期,水中有机物与膜表面有机物之间很难产生粘附,形成的滤饼层最疏松.综上,BAC-NF组合工艺能有效缓解膜污染,可为再生水深度回用提供一种可靠的技术.This study utilized two types of filtration units(GAC and BAC)in combination with NF to evaluate the effects of three different treatment processes(direct NF,GAC-NF,BAC-NF)on organic compounds in the secondary effluent from wastewater treatment plant,as well as analyze the mechanisms of membrane contamination.Based on the findings,BAC-NF exhibited the highest removal efficiencies for DOC,microbial metabolism by-products,and humic acids,with the removal rates of 85.2%,76.2%and 82.0%,respectively.BAC-NF offered the greatest membrane specific fluxes of 0.69,0.65 and 0.63 at the end of each cycle,whereas the total membrane contamination resistance was the lowest(5.97×10^(10)m^(-1)).In addition,the characteristic curve of membrane contamination suggests that the direct NF was filter cake layer pollution,which is attributed to the middle blockage caused by GAC-NF and BAC-NF.It is noteworthy that the membrane middle pore blocking was dominant for BAC-NF,whereas the degree of membrane pollution was the mildest.According to xDLVO theory,the membrane surface polluted by BAC-NF offered the lowest hydrophobicity,corresponding to the highest Zeta potential.The organic matters in water were less reachable to membrane surface at the initial filtration stage using BAC-NF technology,resulting in less membrane pollution.During the middle and late stages of filtration,the adhesion of organic matters in water and on membrane surface rarely occurred,leading to the formation of loosest cake layer.Overall,BAC-NF is able to effectively mitigate membrane contamination,holding the potential for advanced treatment and reuse of reclaimed water.

关 键 词：二级出水 纳滤 颗粒活性炭 膜污染 xDLVO理论 

分 类 号：X703[环境科学与工程—环境工程]