The role of indigenous microorganisms in the biodegradation of naturally occurring petroleum, the reduction of iron, and the mobilization of arsenite from west bengal aquifer sediments.
The role of indigenous microorganisms in the biodegradation of naturally occurring petroleum, the reduction of iron, and the mobilization of arsenite from west bengal aquifer sediments.
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DOI：
10.2134/jeq2008.0223
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发表时间：
2009-07
影响因子：
2.4
通讯作者：
H. Rowland;C. Boothman;R. Pancost;A. Gault;D. Polya;J. Lloyd
中科院分区：
文献类型：
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作者：
H. Rowland;C. Boothman;R. Pancost;A. Gault;D. Polya;J. Lloyd
在孟加拉国西孟加拉邦和东南亚其他地区的浅层含水层中发现了高水平的天然砷。这些含水层被当地居民广泛用于饮用水和灌溉。其释放机制尚不清楚，尽管越来越多的证据指向微生物控制。存在的有机物的类型至关重要，因为它对微生物活动的速度和释放到地下水中的砷的量有直接影响。在西孟加拉邦富砷含水层中发现的天然碳氢化合物为这一过程提供了潜在的电子供体来源。在不添加外部电子供体的情况下，在厌氧条件下，将来自西孟加拉邦一个含有天然碳氢化合物的地点的7种沉积物与合成地下水一起培养28天。砷释放和铁（III）还原似乎是微生物介导的，与铁（III）还原相比，砷的动员率不同，这表明涉及多个过程。在培养过程中，所有沉积物都表现出石油源正烷烃优先于陆源沉积烃正烷烃的损失，这意味着石油源正烷烃的使用可以直接或间接地支持微生物对Fe（III）的还原。砷（III）释放最大的样品中含有大量的硫螺旋藻，这是一种已知的砷(V)还原细菌，首次提供了此类生物可能介导西孟加拉邦含水层砷释放的证据。
High levels of naturally occurring arsenic are found in the shallow reducing aquifers of West Bengal, Bangladesh, and other areas of Southeast Asia. These aquifers are used extensively for drinking water and irrigation by the local population. Mechanisms for its release are unclear, although increasing evidence points to a microbial control. The type of organic matter present is of vital importance because it has a direct impact on the rate of microbial activity and on the amount of arsenic released into the ground water. The discovery of naturally occurring hydrocarbons in an arsenic-rich aquifer from West Bengal provides a source of potential electron donors for this process. Using microcosm-based techniques, seven sediments from a site containing naturally occurring hydrocarbons in West Bengal were incubated with synthetic ground water for 28 d under anaerobic conditions without the addition of an external electron donor. Arsenic release and Fe(III) reduction appeared to be microbially mediated, with variable rates of arsenic mobilization in comparison to Fe(III) reduction, suggesting that multiple processes are involved. All sediments showed a preferential loss of petroleum-sourced n-alkanes over terrestrially sourced sedimentary hydrocarbons n-alkanes during the incubation, implying that the use of petroleum-sourced n-alkanes could support, directly or indirectly, microbial Fe(III) reduction. Samples undergoing maximal release of As(III) contained a significant population of Sulfurospirillum sp., a known As(V)-reducing bacterium, providing the first evidence that such organisms may mediate arsenic release from West Bengali aquifers.