Effect of surface coatings, grain size, and ionic strength on the maximum attainable coverage of bacteria on sand surfaces
Effect of surface coatings, grain size, and ionic strength on the maximum attainable coverage of bacteria on sand surfaces
复制标题
DOI：
10.1016/s0169-7722(01)00106-1
复制
发表时间：
2001-08-01
影响因子：
3.6
通讯作者：
Herman, JS
中科院分区：
文献类型：
--
作者：
Bolster, CH;Mills, AL;Herman, JS
在地下注入细菌已被认为是原位清理受污染含水层的潜在方法。对于高细菌负载量，先前沉积的细菌的存在可能会导致沉积速率降低，这种现象称为阻塞。在短沙柱（类似于 5 厘米）上进行混相置换实验，以确定先前沉积的细菌的存在如何影响带正电的金属羟基氧化物涂层沙子上的细菌沉积。将大约8孔体积的浓度类似于1 X 10(9)细胞ml(-1)的放射性标记细菌悬浮液引入柱中，然后用2孔体积的无细胞缓冲液冲洗。研究发现，铝和铁涂层砂的存在增加了沉积物表面细菌的沉积速率和最大表面覆盖率。然而，颗粒尺寸对最大细菌截留能力的影响并不显着。将离子强度从 10(-1) M KCl 降低到 10(-2) M KCl 会导致清洁硅砂的粘附效率 (a) 和最大表面覆盖率 (Om) 显着降低，结果与 DLVO 理论一致。然而，在含有带正电的铝和铁涂层砂的柱中，由于离子强度降低而导致的 α 和 θ（最大值）变化很小。这些发现证明了地球化学控制对沙子最大细菌保留能力的重要性。 (C) 2001 Elsevier Science B.V. 保留所有权利。
The injection of bacteria in the subsurface has been identified as a potential method for in situ cleanup of contaminated aquifers. For high bacterial loadings, the presence of previously deposited bacteria can result in decreased deposition rates-a phenomenon known as blocking. Miscible displacement experiments were performed on short sand columns ( similar to 5 cm) to determine how bacterial deposition on positively charged metal-oxyhydroxide-coated sands is affected by the presence of previously deposited bacteria. Approximately 8 pore volumes of a radiolabeled bacterial suspension at a concentration of similar to 1 X 10(9) cells ml(-1) were introduced into the columns followed by a 2-pore-volume flush of cell-free buffer. It was found that the presence of Al- and Fe-coated sand increased both deposition rates and maximum fractional surface coverage of bacteria on the sediment surfaces. The effect of grain size on maximum bacterial retention capacity, however, was not significant. Decreasing ionic strength from 10(-1) to 10(-2) M KCl resulted in noticeable decreases in sticking efficiency (a) and maximum surface coverage (Om) for clean silica sand-results consistent with DLVO theory. In columns containing positively charged Al- and Fe-coated sands, however, changes in alpha and theta (max) due to decreasing ionic strength were minimal. These findings demonstrate the importance of geochemical controls on the maximum bacterial retention capacity of sands. (C) 2001 Elsevier Science B.V. All rights reserved.