Enhanced transport of bacteria in porous media by sediment-phase and aqueous-phase natural organic matter
Enhanced transport of bacteria in porous media by sediment-phase and aqueous-phase natural organic matter
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DOI：
10.1016/0043-1354(95)00225-1
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发表时间：
1996-04-01
期刊：
影响因子：
12.8
通讯作者：
Logan, BE
中科院分区：
文献类型：
--
作者：
Johnson, WP;Logan, BE
实验室微柱实验表明，水相溶解的天然有机物（DOM）和沉积物有机物（SOM）会影响细菌在多孔介质中的迁移。细菌的附着效率从它们在石英、氧化铁涂层石英（Fe-石英）和涂覆有SOM的Fe-石英（SOM-Fe-石英）上的保留来估计。使用Suwannee河腐殖酸（SRHA）和土壤腐殖酸（SHA）代表有机质（SOM和DOM），并在运输前将其加入放射性标记的细菌悬液（10（6）个细胞/ml，pH = 7.7）中。涂层石英与氧化铁增加细菌保留160%，相对于未涂覆的石英。涂层铁石英与SOM降低细菌保留，导致在一个分数保留只有33%以上，保留在未涂覆的石英。与这些影响相比，DOM对细菌截留的影响是次要的，反映了DOM在多孔介质上的吸附程度。当DOM不与多孔介质相互作用时，如在石英的情况下，在DOM存在下的细菌保留减少了20%。然而，当DOM吸附到多孔介质中增加涂层的石英与氧化铁，细菌保留铁石英增加了10%。当Fe-石英表面负载有DOM到平衡条件以产生SOM-Fe-石英时，在所施加的溶液中存在DOM也使细菌保留增加10%。DOM的影响是相同的两种类型的胡敏酸（SHA或SRHA）。这些结果表明，SOM和DOM影响细菌的运输，通过增加石英和细菌的表面负电荷，分别。在细菌保留（60%）的最大降幅与涂层的Fe-石英SOM在DOM的情况下。
Aqueous-phase dissolved natural organic matter (DOM) and sediment organic matter (SOM) were shown in laboratory mini-column experiments to affect the transport of bacteria within porous media. Attachment efficiencies of bacteria were estimated from their retention on quartz, iron oxide coated quartz (Fe-quartz), and Fe-quartz coated with SOM (SOM-Fe-quartz). Suwannee River Humic Acid (SRHA) and Soil Humic Acid (SHA) were used to represent organic matter (SOM and DOM), and were added to radiolabeled bacterial suspensions (10(6) cells/ml, pH = 7.7) prior to transport. Coating quartz with iron oxide increased bacterial retention 160% relative to uncoated quartz. Coating Fe-quartz with SOM lowered bacterial retention, resulting in a fraction retained only 33% greater than retained on uncoated quartz. Compared to these effects, the effect of DOM on bacterial retention was secondary, and reflected the extent of DOM adsorption to the porous media. When DOM did not interact with the porous media, as in the case of quartz, bacterial retention in the presence of DOM was reduced by 20%. However, when DOM adsorption to the porous media was increased by coating the quartz with iron oxide, bacterial retention on the Fe-quartz increased by 10%. When Fe-quartz surfaces were loaded with DOM to equilibrium conditions to produce SOM-Fe-quartz, the presence of DOM in the applied solution also increased bacterial retention by 10%. The effects of DOM were the same for both types of humic acids (SHA or SRHA). These results suggest that SOM and DOM affect bacterial transport by increasing the negative surface charge of the Pe-quartz and bacteria, respectively. The largest decrease in bacterial retention (60%) was associated with coating of Fe-quartz by SOM in the absence of DOM.