Department of Environmental Science, Water and Energy Sustainable Technology (WEST) Center University of Arizona, Tucson, AZ, USA.
Department of Environmental Science, Water and Energy Sustainable Technology (WEST) Center University of Arizona, Tucson, AZ, USA.
Water Res. 2020 Jun 15;177:115812. doi: 10.1016/j.watres.2020.115812. Epub 2020 Apr 12.
Increased water demands have led to a notable interest in the use of treated wastewater for reuse. Typically, this results from the implementation of advanced treatment of final effluent from wastewater treatment plants prior to reuse for potable or non-potable purposes. Soil aquifer treatment (SAT) is a natural treatment process in which water from sources of varying quality is infiltrated into the soil to further improve its quality. The goal of this study was to determine the log reduction values (LRVs) of viruses naturally present in treated effluent and evaluate two potential indicators of virus removal and transport, pepper mild mottle virus (PMMoV) and crAssphage, during SAT of treated effluent. Groundwater was sampled at three wells with different attributes within the Sweetwater Recharge Facility (SWRF) in Tucson, AZ. These sites vary greatly in operational parameters such as effluent infiltration rates and wetting/drying cycles, which may influence virus removal efficiency. Detection of adenovirus, enterovirus, PMMoV, and crAssphage were determined by qPCR/RT-qPCR and log reduction values (LRVs) were determined. PMMoV and crAssphage were detected in groundwater associated with a set of recharge basins that exhibited shorter wetting/drying cycles and faster infiltration rates. LRVs for crAssphage and PMMoV at this site ranged from 3.9 to 5.8, respectively. Moreover, PMMoV was detected downflow of the SAT sites, indicating the potential degradation of microbial groundwater quality in the region surrounding managed aquifer recharge facilities. Overall, PMMoV and crAssphage showed potential as conservative process indicators of virus removal during SAT, particularly for attribution of LRV credits. Moreover, the detection of these viruses indicated the potential influence of wetting/drying cycles on virus removal by SAT, a parameter that has not yet been studied with respect to biological contaminants.
用水需求的增加导致人们对使用处理后的废水进行再利用产生了浓厚的兴趣。通常，这是由于在将废水处理厂的最终出水用于饮用水或非饮用水再利用之前，对其进行了高级处理的结果。土壤-含水层处理（SAT）是一种自然处理过程，其中来自不同来源的水被渗透到土壤中以进一步提高其质量。本研究的目的是确定处理废水中天然存在的病毒的对数减少值（LRV），并评估两种潜在的病毒去除和传输指标，即辣椒轻斑驳病毒（PMMoV）和 crAssphage，在处理废水的 SAT 过程中。地下水是在亚利桑那州图森市 Sweetwater 补给设施（SWRF）内具有不同属性的三个井中采集的。这些地点在操作参数（如废水渗透率和湿/干循环）方面差异很大，这些参数可能会影响病毒去除效率。通过 qPCR/RT-qPCR 检测腺病毒、肠道病毒、PMMoV 和 crAssphage，并确定对数减少值（LRV）。在与一组具有较短湿/干循环和较快渗透速率的补给盆地相关的地下水中检测到 PMMoV 和 crAssphage。该地点的 crAssphage 和 PMMoV 的 LRV 分别为 3.9 至 5.8。此外，在 SAT 点的下游检测到 PMMoV，表明管理含水层补给设施周围地区地下水微生物质量有潜在退化的可能。总体而言，PMMoV 和 crAssphage 显示出作为 SAT 过程中病毒去除的保守过程指标的潜力，特别是对于归因于 LRV 学分。此外，这些病毒的检测表明湿/干循环对 SAT 去除病毒的潜在影响，这是一个尚未针对生物污染物进行研究的参数。
