Institute of Environmental Science & Research Ltd, PO Box 29181, Christchurch, New Zealand.
Water Res. 2010 Feb;44(4):1255-69. doi: 10.1016/j.watres.2009.11.034. Epub 2009 Dec 3.
Viruses are often associated with colloids in wastewater and could be transported with colloids into groundwater from land disposal of human and animal effluent and sludge, causing contamination of groundwater. To investigate the role of colloids in the transport of viruses in groundwater, experiments were conducted using a 2m long column packed with heterogeneous gravel aquifer media. Bacteriophage MS2 was used as the model virus and kaolinite as the model colloid. Experimental data were analyzed using Temporal Moment Analysis and Filtration Theory. In the absence of kaolinite colloid, MS2 phage traveled slightly faster than the conservative tracer bromide (Br), with little differences observed between unfiltered and filtered MS2 phage (0.22 microm as the operational cut-off for colloid-free virus). In the presence of kaolinite colloids, MS2 phage breakthrough occurred concurrently with that of the colloidal particles and the time taken to reach the peak virus concentration was reduced, suggesting a colloid-facilitated virus transport in terms of peak-concentration time and velocity. Meanwhile mass recovery and magnitude of concentrations of the phages were significantly reduced, indicating colloid-assisted virus attenuation in terms of concentrations and mass. Decreasing the pH or increasing the ionic strength increased the level of virus attachment to the aquifer media and colloids, and virus transport became more retarded, resulting in lower peak-concentration, lower mass recovery, longer peak-concentration time, and greater apparent collision efficiency. Increasing the concentration of dissolved organic matter (DOM) or flow rate resulted in faster virus transport velocity, higher peak-concentrations and mass recoveries, and lower apparent collision efficiencies. The dual-role of colloids in transport viruses has important implications for risk analysis and remediation of virus-contaminated sites.
病毒通常与废水中的胶体有关，并可能随胶体一起从人类和动物污水及污泥的土地处置中被运移到地下水中，从而造成地下水污染。为了研究胶体在病毒在地下水中的运移中的作用，本研究使用 2 米长的砾石含水层柱进行了实验。噬菌体 MS2 被用作模型病毒，高岭石被用作模型胶体。使用时间矩分析和过滤理论对实验数据进行了分析。在不存在高岭石胶体的情况下，MS2 噬菌体的迁移速度略快于保守示踪剂溴化物（Br），未过滤和过滤 MS2 噬菌体之间几乎没有差异（胶体自由病毒的操作截止值为 0.22 微米）。在存在高岭石胶体的情况下，MS2 噬菌体的穿透与胶体颗粒的穿透同时发生，并且达到峰值病毒浓度的时间减少，这表明在峰值浓度时间和速度方面，胶体促进了病毒的运移。同时，噬菌体的质量回收率和浓度显著降低，这表明胶体在浓度和质量方面辅助了病毒的衰减。降低 pH 值或增加离子强度会增加病毒与含水层介质和胶体的附着水平，从而使病毒运移变得更加滞后，导致较低的峰值浓度、较低的质量回收率、较长的峰值浓度时间和较大的表观碰撞效率。增加溶解有机物（DOM）的浓度或流速会导致病毒运移速度更快、峰值浓度和质量回收率更高，以及较低的表观碰撞效率。胶体在病毒运移中的双重作用对病毒污染场地的风险分析和修复具有重要意义。
