Lee Jungju, Walker Harold W
Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Avenue, Columbus, Ohio 43210, USA.
Environ Sci Technol. 2006 Dec 1;40(23):7336-42. doi: 10.1021/es060352r.
The release of cyanobacterial toxins, such as microcystin-LR, in drinking water supplies is of increasing concern. In this study, we investigated the use of ultrafiltration (UF) combined with adsorption on powdered activated carbon (PAC) for the removal of microcystin-LR from drinking water. Process variables examined included PAC type, PAC dosage, membrane characteristics (material and pore size), and the presence of natural organic matter (NOM). Due to greater mesopore volume, wood-based activated carbon was up to 4-times more effective at removing microcystin-LR than coconut-based carbon, depending on contact time. Cellulose acetate (CA) membranes with a molecular weight cutoff (MWCO) of 20,000 Da did not reject or adsorb microcystin-LR. Membranes composed of polyethersulfone (PES) of similar pore size, on the other hand, adsorbed microcystin-LR presumably through hydrophobic interactions. A PES membrane with a MWCO of 5000 Da sorbed microcystin-LR, and also rejected 8.4% of the toxin through a size exclusion mechanism. When PAC was coupled to UF using PES membranes, greater removal of microcystin-LR occurred compared to when CA membranes were used due to sorption of the toxin to the PES membrane surface. The presence of Suwannee River fulvic acid (SRFA) reduced microcystin-LR removal by PAC-UF, primarily due to competition between SRFA and microcystin-LR for sites on the PAC surface.
饮用水供应中蓝藻毒素（如微囊藻毒素-LR）的释放日益受到关注。在本研究中，我们考察了超滤（UF）与粉末活性炭（PAC）吸附相结合用于去除饮用水中微囊藻毒素-LR的效果。所考察的工艺变量包括PAC类型、PAC投加量、膜的特性（材料和孔径）以及天然有机物（NOM）的存在情况。由于中孔体积更大，根据接触时间的不同，木质活性炭去除微囊藻毒素-LR的效果比椰壳活性炭高出多达4倍。截留分子量（MWCO）为20,000 Da的醋酸纤维素（CA）膜对微囊藻毒素-LR既不截留也不吸附。另一方面，孔径相似的聚醚砜（PES）膜大概通过疏水相互作用吸附微囊藻毒素-LR。MWCO为5000 Da的PES膜吸附微囊藻毒素-LR，并且还通过尺寸排阻机制截留了8.4%的毒素。当使用PES膜将PAC与UF结合时，与使用CA膜相比，微囊藻毒素-LR的去除率更高，这是因为毒素吸附在了PES膜表面。苏万尼河富里酸（SRFA）的存在降低了PAC-UF对微囊藻毒素-LR的去除率，主要原因是SRFA与微囊藻毒素-LR在PAC表面位点上存在竞争。
