Removal of perfluorooctane sulfonates from water by a hybrid coagulation-nanofiltration process
Removal of perfluorooctane sulfonates from water by a hybrid coagulation-nanofiltration process
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DOI：
10.1016/j.cej.2015.12.048
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发表时间：
2016-04
影响因子：
15.1
通讯作者：
Yang Yu;Changwei Zhao;Ling Yu;Pei Li;Tao Wang;Yi Xu
中科院分区：
文献类型：
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作者：
Yang Yu;Changwei Zhao;Ling Yu;Pei Li;Tao Wang;Yi Xu
全氟辛烷磺酸（PFOS）作为一种具有持久性、生物累积性和毒性的污染物，近年来在世界范围内的地表水中被检测到，引起了人们的广泛关注。因此，开发有效的PFOS去除技术具有重要的现实意义和紧迫性。研究了混凝预处理对纳滤去除PFOS效果的影响。采用两种纳滤膜对去离子水、腐殖酸溶液和混凝剂溶液中的PFOS截留率进行了测试。通过HA和PFOS在膜上的累积、扫描电镜（SEM）和膜表面电位分析等表征手段，对膜的分离机理进行了研究。实验结果表明，混凝可以部分去除PFOS。在单一NF工艺中，NF 270膜的全氟辛烷磺酸截留率（>95%）高于HYDRACORE膜（40-60%）。两种纳滤膜在过滤混凝出水后表面负电荷密度均达到最小值，这可能是絮体吸附在膜表面的结果。混凝预处理是有效的，以提高NF膜的PFOS的截留率。特别地，在0.4MPa的跨膜压力下，HYDRACORE膜的截留效率从55%增加到86%。SEM照片显示，絮体形成的污染层疏松，渗透性强。
Perfluorooctane sulfonates (PFOS) as a persistent, bioaccumulative and toxic pollutant has been detected in surface water around the world and attracted great attention in recent years. It’s important and urgent to develop effective technology to remove PFOS. The effect of coagulation pretreatment on the removal efficiency of PFOS by nanofiltration (NF) was investigated. Two types of NF membranes were used to test the PFOS rejections in three different solutions including DI water, humic acid (HA) solution and coagulation solution. The characterizations such as HA and PFOS accumulation on the membranes, scanning electron microscopy (SEM) and surfaceζpotential analysis of virgin and fouled membranes were conducted to study the separation mechanism. The experimental results showed that PFOS can be partly removed by coagulation. The NF270 membrane exhibited a higher PFOS rejection (>95%) than the HYDRACORE membrane (40–60%) in single NF process. The surface negative charge density of both NF membranes reached a minimum value after filtering coagulation effluent, which might be a result of floc adsorption on the membrane surface. Coagulation pretreatment was effective to enhance the PFOS rejection of the NF membranes. In particular, the rejection efficiency of the HYDRACORE membrane increased from 55% to 86% at a trans-membrane pressure of 0.4 MPa. The SEM images showed that the fouling layer formed by flocs was loose and highly permeable.