Evaluation of reduction efficiencies of pepper mild mottle virus and human enteric viruses in full-scale drinking water treatment plants employing coagulation-sedimentation-rapid sand filtration or coagulation-microfiltration
Evaluation of reduction efficiencies of pepper mild mottle virus and human enteric viruses in full-scale drinking water treatment plants employing coagulation-sedimentation-rapid sand filtration or coagulation-microfiltration
复制标题
采用混凝-沉淀-快速砂滤或混凝-微滤的大型饮用水处理厂对辣椒轻度斑驳病毒和人类肠道病毒的去除效果评价
DOI：
10.1016/j.watres.2022.118160
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发表时间：
2022
期刊：
影响因子：
12.8
通讯作者：
S.
中科院分区：
文献类型：
--
作者：
Shirakawa;D.;Shirasaki;N.;Matsushita;T.;Matsui;Y.;Yamashita;R.;Matsumura;T. and Koriki;S.
在这里，我们评估了四个使用 CS-RSF（工厂 A 和 B）或 C-MF（工厂 C 和 D）的全规模饮用水处理厂中本土辣椒轻度斑驳病毒（PMMoV，人类肠道病毒的潜在替代品，用于评估通过凝固-沉淀-快速砂滤 [CS-RSF] 和凝固-微滤 [C-MF] 去除病毒）和代表性人类肠道病毒的减少效率。首先，我们开发了一种利用正电过滤器和切向流超滤膜从大量水中有效浓缩和回收PMMoV的病毒浓缩方法：当100L添加PMMoV的脱氯自来水样品浓缩至20mL时，PMMoV的回收率为100%；即使加标水量为 2000 L，回收率也能保持 >30%。使用该方法测定的原水和处理水样中本地 PMMoV 的浓度始终高于实时聚合酶链式反应测定的定量限。因此，我们能够确定其缩减比率：全尺寸 CS-RSF 中为 0.9-2.7-log10，全尺寸 C-MF 中为 0.7-2.9-log10。尽管由于 MF 孔径较小，与 RSF 相比，MF 的颗粒分离能力高于 RSF，但 C 厂 C-MF 中的 PMMoV 还原率 (1.0 ± 0.3-log10) 低于 A 厂 (1.7 ± 0.5-log10) 和 B 厂 CS-RSF (1.4 ± 0.7-log10)。模拟全尺寸 C-MF 的实验室规模病毒掺加 C-MF 实验表明，主要从防止膜污染的角度确定，C-MF 中使用的低剂量混凝剂（聚合氯化铝 [PACl]）可能导致 C-MF 中 PMMoV 的降低率较低。这意味着在之前的实验室规模病毒加标 C-MF 研究中实现的高病毒减少率 (>4-log10) 不一定在全面的 C-MF 中实现。尽管混凝剂剂量相似，但 D 厂的 C-MF 中的 PMMoV 减少率 (2.2 ± 0.6-log10) 高于 C 厂。在实验室规模的 C-MF 中，PMMoV 减少率从 1-log10（使用 PACl [碱度 1.5]，如工厂 C）增加到 2–4-log10（使用高碱度 PACl [碱度 2.1]，如工厂 D），这表明使用高碱度 PACl 可能会导致工厂 D 的 PMMoV 减少率高于工厂 C。最后，我们比较了本土工厂的减少率PMMoV 和全尺寸 CS-RSF 和 C-MF 中的代表性人类肠道病毒。在 D 工厂，原水中的人类诺如病毒基因组 II (HuNoV GII) 浓度有时超出定量限；然而，无法判断其在C-MF中的减少率是否高于PMMoV，因为HuNoV GII的减少率>1.4-log10，PMMoV的减少率>1.4-2.9-log10。 B厂原水中肠道病毒（EVs）和HuNoV GII浓度曾一度超过定量限，且CS-RSF中EVs（>1.2-log10）和HuNoV GII（>1.5-log10）的去除率高于PMMoV（0.9-log10）。这一发现支持 PMMoV 作为人类肠道病毒的潜在替代物来评估 CS-RSF 病毒清除的有用性。
Here, we evaluated the reduction efficiencies of indigenous pepper mild mottle virus (PMMoV, a potential surrogate for human enteric viruses to assess virus removal by coagulation-sedimentation–rapid sand filtration [CS–RSF] and coagulation–microfiltration [C–MF]) and representative human enteric viruses in four full-scale drinking water treatment plants that use CS–RSF (Plants A and B) or C–MF (Plants C and D). First, we developed a virus concentration method by using an electropositive filter and a tangential-flow ultrafiltration membrane to effectively concentrate and recover PMMoV from large volumes of water: the recovery rates of PMMoV were 100% when 100-L samples of PMMoV-spiked dechlorinated tap water were concentrated to 20 mL; even when spiked water volume was 2000 L, recovery rates of >30% were maintained. The concentrations of indigenous PMMoV in raw and treated water samples determined by using this method were always above the quantification limit of the real-time polymerase chain reaction assay. We therefore were able to determine its reduction ratios: 0.9–2.7-log10in full-scale CS–RSF and 0.7–2.9-log10in full-scale C–MF. The PMMoV reduction ratios in C–MF at Plant C (1.0 ± 0.3-log10) were lower than those in CS–RSF at Plants A (1.7 ± 0.5-log10) and B (1.4 ± 0.7-log10), despite the higher ability of MF for particle separation in comparison with RSF owing to the small pore size in MF. Lab-scale virus-spiking C–MF experiments that mimicked full-scale C–MF revealed that a low dosage of coagulant (polyaluminum chloride [PACl]) applied in C–MF, which is determined mainly from the viewpoint of preventing membrane fouling, probably led to the low reduction ratios of PMMoV in C–MF. This implies that high virus reduction ratios (>4-log10) achieved in previous lab-scale virus-spiking C–MF studies are not necessarily achieved in full-scale C–MF. The PMMoV reduction ratios in C–MF at Plant D (2.2 ± 0.6-log10) were higher than those at Plant C, despite similar coagulant dosages. In lab-scale C–MF, the PMMoV reduction ratios increased from 1-log10(with PACl [basicity 1.5], as at Plant C) to 2–4-log10(with high-basicity PACl [basicity 2.1], as at Plant D), suggesting that the use of high-basicity PACl probably resulted in higher reduction ratios of PMMoV at Plant D than at Plant C. Finally, we compared the reduction ratios of indigenous PMMoV and representative human enteric viruses in full-scale CS–RSF and C–MF. At Plant D, the concentrations of human norovirus genogroup II (HuNoV GII) in raw water were sometimes above the quantification limit; however, whether its reduction ratios in C–MF were higher than those of PMMoV could not be judged since reduction ratios were >1.4-log10for HuNoV GII and 2.3–2.9-log10for PMMoV. At Plant B, the concentrations of enteroviruses (EVs) and HuNoV GII in raw water were above the quantification limit on one occasion, and the reduction ratios of EVs (>1.2-log10) and HuNoV GII (>1.5-log10) in CS–RSF were higher than that of PMMoV (0.9-log10). This finding supports the usefulness of PMMoV as a potential surrogate for human enteric viruses to assess virus removal by CS–RSF.