Effective arsenic removal using polyacrylonitrile-based ultrafiltration (UF) membrane
Effective arsenic removal using polyacrylonitrile-based ultrafiltration (UF) membrane
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DOI：
10.1016/j.memsci.2008.03.068
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发表时间：
2008-07-15
影响因子：
9.5
通讯作者：
Kharul, U. K.
中科院分区：
文献类型：
--
作者：
Lohokare, H. R.;Muthu, M. R.;Kharul, U. K.
聚丙烯腈（PAN）为基础的负电荷超滤膜（UF）的适用性，有效地去除砷已被证明，据我们所知，第一次。根据Donnan排阻原理，PAN基超滤膜表面被NaOH水解，形成羧酸根（-COO-），初始孔径减小，从而具有As-V截留能力。水通量的降低和蛋白质和聚乙二醇（PEG）的截留率的升高表明孔径的降低。FTIR-ATR表明NaOH处理导致膜表面形成羧酸基团，而接触角测量表明亲水性增加。该处理使得膜表面平滑，如通过SEM和AFM分析所证实的。发现NaOH处理后的截留分子量类似于6 kDa。研究了不同进料浓度、错流速度、压力、温度和pH条件下，这些表面改性膜对五价砷（As-V）的截留率。对50 ppb As-V进料的实验表明，砷的截留率接近100%，且在6 h内保持不变。进料样品浓度为1000 ppb和50 ppm的As-V在pH 7和室温下显示>95%的截留率，但对于1000 ppm进料浓度，截留率为40- 65%。对于浓度
Applicability of polyacrylonitrile (PAN)-based negatively charged ultrafiltration (UF) membrane for effective arsenic removal has been demonstrated, to our knowledge, for the first time. The hydrolysis of PAN-based UF membrane surface by NaOH leading to the formation of carboxylate (-COO-) groups and reduction in initial pore size rendered As-V rejection capability by Donnan exclusion principle. A lowering in pore size was indicated by the reduction in water flux and elevation in rejection of protein and polyethylene glycol (PEG). NaOH treatment leading to formation of carboxylate group on the membrane surface was indicated by FTIR-ATR, while contact angle measurement indicated increased hydrophilicity. This treatment rendered membrane surface smoothening as confirmed by SEM and AFM analyses. The molecular weight cut off after the NaOH treatment was found to be similar to 6 kDa. The rejection of pentavalent arsenic (As-V) by these surface modified membranes was studied with different feed concentration, cross-flow velocity, pressure, temperature and pH. Experiments with 50 ppb As-V in feed showed that arsenic rejection was close to 100% and remained constant up to 6 h. Feed sample concentration of 1000 ppb and 50 ppm of As-V showed >95% rejection at pH 7 and room temperature, but for 1000 ppm feed concentration, the rejection was 40-65%. For concentrations