Natural Attenuation of Aromatic Hydrocarbons in a Shallow Sand Aquifer
Natural Attenuation of Aromatic Hydrocarbons in a Shallow Sand Aquifer
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DOI：
10.1111/j.1745-6592.1987.tb01063.x
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发表时间：
1987-03
影响因子：
1.9
通讯作者：
J. Barker;G. Patrick;D. Major
中科院分区：
文献类型：
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作者：
J. Barker;G. Patrick;D. Major
汽油等石油产品无意中释放到地下可能会引发地下水污染，特别是有毒、水溶性和可移动的汽油成分：苯、甲苯和二甲苯 (BTX)。本研究旨在研究控制浅层无承压砂质含水层地下水中溶解的 BTX 的运动速率和持久性的过程。将含有约 7.6 毫克/升总 BTX 的水引入地下水位以下，并使用密集采样网络监测污染物通过沙质含水层的迁移情况。由于吸附延迟，BTX 组分的迁移速度比地下水稍慢。由于生物降解，基本上所有注射的 BTX 质量在 434 天内都消失了。所有单芳烃的质量损失率相似；苯是唯一能持续超过 270 天的成分。即使初始 BTX 浓度不同，实验室生物降解实验也产生相似的速率。对 BTX 生物降解的主要控制是溶解氧的可用性。 BTX 在现场溶解氧含量较低的层中持续存在。现场实验中观察到的质量损失率随着时间的推移而减少，这不太可能是由于一级脱氧率，而是由于缺氧层中小部分 BTX 质量的持续存在。
Inadvertent release of petroleum products such as gasoline into the subsurface can initiate ground water contamination, particularly by the toxic, water-soluble and mobile gasoline components: benzene, toluene and xylenes (BTX). This study was undertaken to examine the processes controlling the rate of movement and the persistence of dissolved BTX in ground water in a shallow, unconfined sand aquifer. Water containing about 7.6 mg/ L total BTX was introduced below the water table and the migration of contaminants through a sandy aquifer was monitored using a dense sampling network. BTX components migrated slightly slower than the ground water due to sorptive retardation. Essentially all the injected mass of BTX was lost within 434 days due to biodegradation. Rates of mass loss were similar for all monoaromatics; benzene was the only component to persist beyond 270 days. Laboratory biodegradation experiments produced similar rates, even when the initial BTX concentration varied. A dominant control over BTX biodegradation was the availability of dissolved oxygen. BTX persisted at the field site in layers low in dissolved oxygen. Decreasing mass loss rates over time observed in the field experiment are not likely due to first-order deeradation rates, but rather to the persistence of small fractions of BTX mass in anoxic layers.