US-Bangladesh Cooperative Research: Geochemistry, Petrology, and Microbiology of As-Contaminated Alluvial Sediments and Groundwater, Bangladesh

0352936Uddin 描述：该项目支持阿拉巴马州奥本大学地质系 Ashraf Uddin 博士和孟加拉国达卡大学地质系 Kazi M. Ahmed 博士之间的合作项目。 他们计划研究孟加拉国受砷污染的冲积沉积物和地下水。 浅层地下水的天然砷污染对世界许多地区的人类健康构成重大威胁。 最近的研究表明，年轻的（全新世）河漫滩含水层问题最严重，因为当地砷含量较高，而且发展中国家有数百万人将其用于饮用。 有一种理论认为，砷是通过洪泛区含水层中含砷水合氧化铁 (HFO) 的还原溶解而释放出来的。 这种 As-HFO 假说可能是砷地质、生物、水力 (GBH) 循环的一部分。 PI 最近的研究产生了砷地下水循环过程的现场微生物数据，并使用培养和分子生物学 (16S rDNA) 技术从与孟加拉国、印度和越南受影响地区非常相似的美国现场现场鉴定了涉及的 FeRB 和 SRB 属。 导致河流泛滥平原出现这种水化学现象的情况是普遍存在的，但只有在发展中国家，这些水被开发用于人类消费时，才会引发严重问题。 PI 计划将从美国野外地区得出的结论扩展到世界上受砷污染严重的地区并进行测试，以验证生物地球化学控制对此类天然砷污染的普遍性的假设。 PI 过去的研究也证明了 SRB 在自然界中去除地下水中砷方面发挥着重要作用。 他们将在孟加拉国地下水的现场实验中测试生物修复过程，以去除溶解的金属（包括砷）污染物。 研究团队拥有记录砷问题原因所需的技能和背景，以及潜在的补救工具。 范围：拟议的研究包括研究生和博士后的教育和研究活动。拟议的研究具有重要的技术转让要素，在研究进展过程中，PI将与当地科学家和政府官员合作，在此过程中，如果概念验证研究取得成功，将提供教育他们如何在该领域实施生物修复过程的机会。 由于砷污染是发展中国家的一个紧迫问题，孟加拉国的经验教训应该适用于许多其他国家。

0352936UddinDescription: This project supports a collaborative project between Dr. Ashraf Uddin, Department of Geology, Auburn University, Auburn, Alabama and Dr. Kazi M. Ahmed, Department of Geology at the University of Dhaka, Dhaka, Bangladesh. They plan to study arsenic-contaminated alluvial sediments and groundwater in Bangladesh. Natural arsenic contamination of shallow groundwater poses a major human health threat in many parts of the world. Recent research indicates that young (Holocene) river floodplain aquifers are most problematic due to their locally high arsenic levels and because they are exploited for drinking by millions of people in developing nations. There is a theory that As is released by reductive dissolution of the As-bearing hydrous ferric oxides (HFO) in the floodplain aquifers. This As-HFO hypothesis may be part of an arsenic geo-, bio-, hydro- (GBH) cycle. Recent research by the PIs has generated field microbiologic data for the As-groundwater cycling processes and has identified genera of FeRB and SRB involved using culturing and molecular biology (16S rDNA) technique from field sites in the USA very similar to affected areas of Bangladesh, India and Vietnam. The condition that lead to this water chemistry in river floodplains is universal, but only rises to a serious problem in the developing nations where this water is exploited for human consumption. The PIs plan to extend and test the conclusions drawn from field areas in USA to a seriously As-affected region of the world, to seek verification of the hypothesis about the universality of biogeochemical controls on this type of natural arsenic contamination. Past research by the PIs has also demonstrated an important role that SRB play in nature in removing As from groundwater. They will test bioremediation process to remove dissolved metal (including As) contaminants in field experiments in Bangladeshi ground waters. The research team has the needed skills and backgrounds to document the cause of the arsenic problem, as well as a potential remediation tool. Scope: The proposed research includes educational and research activities for graduate students and post-docs. The proposed research has significant technology transfer elements in it, during the progress of the study, the PIs will be cooperating with local scientists and government officials, and in the process, will provide the opportunity to educate them how to implement the bioremediation process in the field should this proof-of-concept research prove successful. Because As-contamination is a pressing problem in the developing world, lessons learned in Bangladesh should be applicable to many other countries.