Shirakawa D, Shirasaki N, Hu Q, Matsushita T, Matsui Y, Takagi H, Oka T
Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, N13W8, Sapporo, 060-8628, Japan.
Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, N13W8, Sapporo, 060-8628, Japan.
Water Res. 2023 Jun 1;236:119951. doi: 10.1016/j.watres.2023.119951. Epub 2023 Apr 7.
Here, we examined the efficiencies of drinking water treatment processes for the removal and inactivation of human sapovirus (HuSaV). We applied a recently developed in vitro cell-culture system to produce purified solutions of HuSaV containing virus concentrations high enough to conduct virus-spiking experiments, to develop an integrated cell culture-polymerase chain reaction (ICC-PCR) assay to quantify the infectivity of HuSaV, and to conduct virus-spiking experiments. In virus-spiking coagulation-sedimentation-rapid sand filtration (CS-RSF) and coagulation-microfiltration (C-MF) experiments, HuSaV removals of 1.6-3.7-log and 1.2->4.3-log, respectively, were observed. The removal ratios observed with CS-RSF were comparable and correlated with those of murine norovirus (MNV, a widely used surrogate for human noroviruses) and pepper mild mottle virus (PMMoV, a potential surrogate for human enteric viruses in physical and physicochemical drinking water treatment processes), and those observed with C-MF were higher than but still correlated with those of MNV and PMMoV, indicating that MNV and PMMoV are both potential surrogates for HuSaV in CS-RSF and C-MF. For astrovirus (AstV, a representative human enteric virus), removal ratios of 1.8-3.3-log and 1.1->4.0-log were observed with CS-RSF and C-MF, respectively. The removal ratios of AstV observed with CS-RSF were comparable and correlated with those of PMMoV, and those observed with C-MF were higher than but still correlated with those of PMMoV, indicating that PMMoV is a potential surrogate for AstV in CS-RSF and C-MF. When the efficacy of chlorine treatment was examined by using the developed ICC-PCR assay, 3.8-4.0-log inactivation of HuSaV was observed at a CT value (free-chlorine concentration [C] multiplied by contact time [T]) of 0.02 mg-Cl·min/L. The infectivity reduction ratios of HuSaV were comparable with those of MNV. For AstV, 1.3-1.7-log and >3.4-log inactivation, as evaluated by ICC-PCR, was observed at CT values of 0.02 and 0.09 mg-Cl·min/L, respectively. These results indicate that HuSaV and AstV are both highly sensitive to chlorine treatment and more sensitive than a chlorine-resistant virus, coxsackievirus B5 (1.3-log inactivation at a CT value of 0.4 mg-Cl·min/L, as evaluated by the ICC-PCR assay).
在此，我们研究了饮用水处理工艺对人札幌病毒（HuSaV）的去除和灭活效率。我们应用了最近开发的体外细胞培养系统来制备HuSaV纯化溶液，其病毒浓度高到足以进行病毒加标实验，开发了一种整合细胞培养-聚合酶链反应（ICC-PCR）检测方法来量化HuSaV的感染性，并进行病毒加标实验。在病毒加标混凝沉淀-快速砂滤（CS-RSF）和混凝-微滤（C-MF）实验中，分别观察到HuSaV的去除率为1.6 - 3.7个对数级和1.2 -> 4.3个对数级。CS-RSF观察到的去除率与鼠诺如病毒（MNV，一种广泛用于替代人诺如病毒的病毒）和辣椒轻斑驳病毒（PMMoV，在物理和物理化学饮用水处理过程中作为人肠道病毒潜在替代物的病毒）的去除率相当且相关，C-MF观察到的去除率高于但仍与MNV和PMMoV的去除率相关，这表明MNV和PMMoV在CS-RSF和C-MF中都是HuSaV的潜在替代物。对于星状病毒（AstV，一种代表性的人肠道病毒），CS-RSF和C-MF分别观察到的去除率为1.8 - 3.3个对数级和1.1 -> 4.0个对数级。CS-RSF观察到的AstV去除率与PMMoV的去除率相当且相关，C-MF观察到的去除率高于但仍与PMMoV的去除率相关，这表明PMMoV在CS-RSF和C-MF中是AstV的潜在替代物。当使用开发的ICC-PCR检测方法检测氯处理的效果时，在CT值（游离氯浓度[C]乘以接触时间[T]）为0.02 mg-Cl·min/L时，观察到HuSaV有3.8 - 4.0个对数级的灭活。HuSaV的感染性降低率与MNV的相当。对于AstV，通过ICC-PCR评估，在CT值分别为0.02和0.09 mg-Cl·min/L时，观察到1.3 - 1.7个对数级和>3.4个对数级的灭活。这些结果表明，HuSaV和AstV对氯处理都高度敏感，且比耐氯病毒柯萨奇病毒B5更敏感（通过ICC-PCR检测方法评估，在CT值为0.4 mg-Cl·min/L时为1.3个对数级的灭活）。
