Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA.
J Appl Microbiol. 2012 Nov;113(5):1196-207. doi: 10.1111/j.1365-2672.2012.05411.x. Epub 2012 Aug 30.
To develop an anti-microbial filter media using an attached quaternary ammonium compound (QAC) and evaluate its performance under conditions relevant to household drinking water treatment in developing countries.
Silica sand was coated with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride via covalent silane chemistry. Filter columns packed with coated media were challenged with micro-organisms under different water quality conditions. The anti-bacterial properties were investigated by visualizing Escherichia coli (E. coli) attachment to coated media under fluorescence microscopy combined with a live/dead stain. A 9-cm columns with a filtration velocity of 18 m h(-1) achieved log(10) removals of 1·7 for E. coli, 1·8 for MS2 coliphage, 1·9 for Poliovirus type 3 and 0·36 for Adenovirus type 2, compared to 0·1-0·3 log(10) removals of E. coli and MS2 by uncoated sand. Removal scaled linearly with column length and decreased with increasing ionic strength, flow velocity, filtration time and humic acid presence. Escherichia coli attached to QAC-coated sand were observed to be membrane-permeable, providing evidence of inactivation.
Filtration with QAC-coated sand provided higher removal of bacteria and viruses than filtration with uncoated sand. However, major limitations included rapid fouling by micro-organisms and natural organic matter and low removal of viruses PRD1 and Adenovirus 2.
QAC-coated media may be promising for household water treatment. However, more research is needed on long-term performance, options to reduce fouling and inactivation mechanisms.
开发一种使用附着季铵化合物（QAC）的抗菌过滤介质，并评估其在发展中国家家庭饮用水处理相关条件下的性能。
通过共价硅烷化学将二甲基十八烷基[3-（三甲氧基硅基）丙基]氯化铵涂覆在硅砂上。用涂覆的介质填充过滤柱，在不同水质条件下用微生物进行挑战。通过荧光显微镜结合活菌/死菌染色来观察大肠杆菌（E. coli）附着在涂覆介质上的情况，研究其抗菌性能。在过滤速度为 18 m h(-1) 的 9 cm 柱中，大肠杆菌、MS2 噬菌体、脊髓灰质炎病毒 3 型和腺病毒 2 型的对数去除率分别为 1.7、1.8、1.9 和 0.36，而未涂覆的砂中的大肠杆菌和 MS2 的对数去除率为 0.1-0.3。去除率与柱长呈线性关系，随离子强度、流速、过滤时间和腐殖酸的增加而降低。观察到 QAC 涂覆砂中的大肠杆菌附着在膜上是可渗透的，这提供了失活的证据。
与未涂覆砂的过滤相比，用 QAC 涂覆砂进行过滤可更有效地去除细菌和病毒。然而，主要的限制因素包括微生物和天然有机物的快速堵塞以及 PRD1 和腺病毒 2 的低去除率。
QAC 涂覆介质可能是家庭水处理的有前途的选择。然而，需要更多关于长期性能、减少堵塞的选择和失活机制的研究。
