Ecosystems Research Division, United States Environmental Protection Agency, 960 College Station Road, Athens, Georgia 30605, USA.
Environ Sci Technol. 2012 Oct 16;46(20):11145-53. doi: 10.1021/es3028764. Epub 2012 Sep 25.
In this study, we investigated the influence of inorganic ions on the aggregation and deposition (adsorption) behavior of human adenovirus (HAdV). Experiments were conducted to determine the surface charge and size of HAdV and viral adsorption capacity of sand in different salt conditions. The interfacial potential energy was calculated using extended Derjaguin and Landau, Verwey and Overbeek (XDLVO) and steric hindrance theories to interpret the experimental results. Results showed that different compositions of inorganic ions have minimal effect on varying the iso-electric point pH (pH(iep)) of HAdV (ranging from 3.5 to 4.0). Divalent cations neutralized/shielded virus surface charge much more effectively than monovalent cations at pH above pH(iep). Consequently, at neutral pH the presence of divalent cations enhanced the aggregation of HAdV as well as its adsorption to sand. Aggregation and adsorption behaviors generally agreed with XDLVO theory; however, in the case of minimal electrostatic repulsion, steric force by virus' fibers can increase the energy barrier and distance of secondary minimum, resulting in limited aggregation and deposition. Overall, our results indicated that subsurface water with low hardness residing in sandy soils may have a higher potential of being contaminated by HAdV.
在这项研究中，我们研究了无机离子对人腺病毒（HAdV）聚集和沉积（吸附）行为的影响。实验测定了不同盐条件下 HAdV 的表面电荷和粒径以及沙粒的病毒吸附容量。采用扩展德加古林-朗道-维韦（XDLVO）和空间位阻理论计算了界面位能，以解释实验结果。结果表明，不同组成的无机离子对 HAdV 等电点 pH（pH(iep)）的影响最小（范围为 3.5 至 4.0）。在 pH(iep)以上，二价阳离子比单价阳离子更有效地中和/屏蔽病毒表面电荷。因此，在中性 pH 下，二价阳离子的存在会增强 HAdV 的聚集及其对沙粒的吸附。聚集和吸附行为通常与 XDLVO 理论一致；然而，在静电排斥最小的情况下，病毒纤维的空间力可以增加二次最小的能垒和距离，从而导致聚集和沉积受限。总的来说，我们的结果表明，位于砂质土壤中的低硬度地下水可能有更高的被 HAdV 污染的潜力。
