428 UCB, Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, CO 80309, USA.
Water Res. 2010 Feb;44(4):1104-13. doi: 10.1016/j.watres.2009.09.039. Epub 2009 Sep 22.
To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using microelectrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter had no significant effect on the zeta potential of the oocysts. Low concentrations of dissolved organic matter were responsible for reversing the charge of the ferric oxyhydroxide-coated sand surface from positive to negative. The charge reversal and accumulation of negative charge on the ferric oxyhydroxide-coated sand led to increases in oocyst breakthrough and decreases in oocyst collision efficiency with increasing dissolved organic matter concentration. The increase in dissolved organic matter concentration from 0 to 20mg L(-1) resulted in a two-fold decrease in the collision efficiency.
为了评估有机物对隐孢子虫卵囊在地球化学非均一饱和多孔介质中传输的影响，我们在一个含有三价铁氢氧化物涂覆砂的流动柱中测量了卵囊的穿透和碰撞效率作为溶解态有机物浓度的函数。我们分别使用微电泳和流动电势来表征卵囊和三价铁氢氧化物涂覆砂的表面特性，并研究了作为溶解态有机物（佛罗里达大沼泽地水中分离出的富里酸）浓度函数的三价铁氢氧化物涂覆砂上有机物的吸附量。溶解态有机物对卵囊的动电电位没有显著影响。低浓度的溶解有机物负责将三价铁氢氧化物涂覆砂表面的电荷从正变为负。电荷反转和三价铁氢氧化物涂覆砂上负电荷的积累导致卵囊穿透增加，卵囊碰撞效率随着溶解有机物浓度的增加而降低。溶解有机物浓度从 0 增加到 20mg/L 导致碰撞效率降低了一倍。
