Division of Environmental Science & Engineering, National University of Singapore, 1 Engineering Drive 1, Singapore 117576, Singapore.
Water Sci Technol. 2011;64(9):1843-50. doi: 10.2166/wst.2011.147.
Due to the intrinsically small sizes of enteric viruses (20-100 nm) and their relatively high resistance to most disinfectants, detection of viruses in treated drinking water is not a rare phenomenon. This study therefore evaluates various aspects involved in a hybrid alum coagulation-ultrafiltration (UF) system for virus removal. Coagulant doses (0, 1 and 10 mg Al(3+)/L) and pH conditions relevant to drinking water (pH 6-8) were investigated. With this hybrid system, removal was not attributable merely to MS2 adsorption to flocs and subsequent retention by UF membranes. MS2 removal comprises of inactivation by the effect of pH and coagulant and subsequently, rejection of virus-associated flocs by UF membrane. Coagulation with 1 mg Al(3+)/L at pH 6 and 7 resulted in an overall reduction brought about by an average of 0.62 log inactivation via the pH effect, 1.2 log inactivation by alum coagulant, and >5.4 log rejection by the 100 kDa polyethersulfone UF membrane. In contrast, negligible upstream inactivation was noted with a coagulant dose of 1 mg Al(3+)/L at pH 8, but 5.8 log rejection was attained with downstream UF filtration. By optimizing the conditions appropriate for upstream inactivation and subsequent membrane rejection, virus removal efficiencies can be enhanced.
由于肠病毒的固有尺寸较小（20-100nm），且对大多数消毒剂具有较高的抗性，因此在处理后的饮用水中检测到病毒并不罕见。本研究因此评估了混合铝混凝-超滤（UF）系统在病毒去除方面的各个方面。考察了不同的混凝剂剂量（0、1 和 10mg Al3+/L）和饮用水相关的 pH 值条件（pH 6-8）。在该混合系统中，去除不仅仅归因于 MS2 吸附到絮体上，然后被 UF 膜截留。MS2 的去除包括 pH 和混凝剂的作用导致的失活，以及随后 UF 膜对病毒相关絮体的排斥。在 pH 值为 6 和 7 时，用 1mg Al3+/L 混凝，通过 pH 值效应平均实现了 0.62 个对数的灭活，用铝混凝剂实现了 1.2 个对数的灭活，用 100kDa 聚醚砜 UF 膜实现了>5.4 个对数的截留。相比之下，在 pH 值为 8 时，用 1mg Al3+/L 的混凝剂剂量几乎没有上游灭活，但通过下游 UF 过滤实现了 5.8 个对数的截留。通过优化适合上游灭活和后续膜截留的条件，可以提高病毒去除效率。
