Facilitation of bacterial transport through porous media by changes in solution and surface properties
Facilitation of bacterial transport through porous media by changes in solution and surface properties
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DOI：
10.1016/0927-7757(95)03349-1
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发表时间：
1996-02-20
影响因子：
5.2
通讯作者：
Logan, BE
中科院分区：
文献类型：
--
作者：
Johnson, WP;Martin, MJ;Logan, BE
为了对污染物降解进行生物强化而促进细菌的迁移，可以通过一些方法来实现，这些方法通常涉及改变地下水的性质或改变细菌表面的特性。在实验室实验中监测石英砂和玻璃珠微柱中的细菌截留，研究了促进细菌转运。利用稳态过滤方程从细菌截留率估算细菌附着效率。paradoxus，保留的数量级下降伴随着离子强度的数量级下降。还检查了七种测试化学品改变细菌表面性质和增强细菌转运的能力。在七种测试化学品中，表面活性剂导致细菌保留最显著的减少。A.在玻璃珠上的paradoxus从不存在Tween-20时的0.38降低到存在0.1 vol. % Tween-20，并且从不存在十二烷基硫酸钠（SDS）时的0.064到存在10 mg l（-1）SDS时的0.0067。细胞表面修饰化学物质，如蛋白酶-k，EDTA和焦磷酸盐降低细菌附着效率。然而，即使在使用的最高浓度下，减少量也不到一个数量级。细菌附着效率从不存在蛋白酶-k的0.055降低到存在0.1 mg l（-1）蛋白酶-k的0.044，从不存在EDTA的0.61降低到存在0.001 M EDTA的0.34，从不存在焦磷酸的0.27降低到存在0.01 M焦磷酸的0.11。观察到A.在0.1 mg l（-1）溶菌酶存在下（0.74）对不存在溶菌酶（0.0048），以及在0.01 M高碘酸盐存在下（0.10）对不存在高碘酸盐（0.052），在玻璃珠上的paradoxus。观察到萨凡纳河菌株A1264在石英砂介质上的保留小于在氧化铁涂覆的石英砂介质上的保留的一半。涂层的氧化铁-石英吸附腐殖酸导致在细菌的保留，一个值略大于石英多孔介质的44%的下降。除了沉积物有机物的存在下，溶解的有机物（DOM）的存在下改变细菌保留在多孔介质上。DOM降低了石英表面的细菌截留率（约20%），增加了氧化铁-石英表面的细菌截留率（约10%）。
Facilitation of bacterial transport for the purpose of bioaugmentation of contaminant degradation may be achieved by a number of methods typically involving changes in the properties of the groundwater or changes in the characteristics of the bacterial surface. Facilitated bacterial transport was investigated in laboratory experiments monitoring bacterial retention in quartz sand and glass bead mini-columns. Bacterial attachment efficiencies were estimated from bacterial retention using a steady-state filtration equation.Decreased ionic strength resulted in decreased retention of A. paradoxus, with roughly order-of-magnitude decreases in retention accompanying order-of-magnitude decreases in ionic strength. Seven test chemicals were also examined in terms of their ability to modify bacterial surface properties and enhance bacterial transport. Of the seven test chemicals, the surfactants resulted in the most dramatic decreases in bacterial retention. The attachment efficiency of A. paradoxus on glass beads was lowered from 0.38 in the absence of Tween-20 to 0.0016 in the presence of 0.1 vol.% Tween-20, and from 0.064 in the absence of sodium dodecyl sulfate (SDS) to 0.0067 in the presence of 10 mg l(-1) SDS. Cell-surface modifying chemicals such as proteinase-k, EDTA, and pyrophosphate reduced bacterial attachment efficiencies. However, the reductions were less than an order of magnitude, even at the highest concentrations used. Bacterial attachment efficiencies were reduced from 0.055 in the absence of proteinase-k to 0.044 in the presence of 0.1 mg l(-1) proteinase-k, 0.61 in the absence of EDTA to 0.34 in the presence of 0.001M EDTA, and 0.27 in the absence of pyrophosphate to 0.11 in the presence of 0.01 M pyrophosphate. Increased bacterial attachment efficiencies were observed for A. paradoxus on glass beads in the presence of 0.1 mg l(-1) lysozyme (0.74) vs. the absence of lysozyme (0.0048), and in the presence of 0.01 M periodate (0.10) vs. the absence of periodate (0.052).Changes in porous media surface characteristics were also examined. Retention of Savannah River strain A1264 on quartz sand media was observed to be less than half that on iron oxide coated quartz sand media. Coating of iron oxide-quartz by sorbed humic acids resulted in a 44% decrease in bacterial retention, a value slightly greater than that on quartz porous media. In addition to the presence of sediment organic matter, the presence of dissolved organic matter (DOM) altered bacterial retention on the porous media. DOM decreased bacterial retention on quartz (approximate to 20%), and increased bacterial retention on iron oxide-quartz (approximate to 10%).