Assessment and remdiation of As enrichments in groundwater

地下水砷富集度评估与修复

• 批准号: 6660057
• 负责人: Alexander Van Geen
• 金额: $ 15.33万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-11 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6660057
• 关键词: arsenic; environmental contamination; environmental toxicology; environmental transport; field study; hazardous substances; iron; oxidation reduction reaction; water flow; water pollution; water pollution control; water sampling /testing

Groundwater naturally or anthropogenically enriched in As poses serious health hazards in many parts of the world, including the US. This project builds on the growing realization that the particular high affinity of As for Fe-oxyhydroxides is a key factor regulating dissolved As concentrations in groundwater. The particular affinity of As for Fe-oxyhydroxides has been exploited for recommended value to 10 mug/L in the near future, a better fundamental understanding of different treatment options and the influence of groundwater composition on the efficacy of treatment is needed. Them (I) As mobilization into reducing groundwater: Field material from US Superfund sites at Winthrop, ME and Vineland, NH (Project) and Bangladesh (PROJECT 5) will be used to quantify the exchange of As between the dissolved and the particular phase under oxic and reducing conditions. In a first set of experiments, the potential integrated release of As by reductive dissolution will be determined with hydroxylamine extraction from archived aquifer material covering a range of redox conditions. The spatial patterns of As and FE released by reductive dissolution will be compared to the oxygen distribution in the aquifers. In a second set of experiments, fresh cores of aquifer from selected sites will be incubated to quantify the rate of As and Fe exchange (adsorption or desorption). In a third set of experiments, state-of-the-art surface analytical techniques will be used to characterize arsenic binding at model Fe oxide surfaces under a range of conditions representative of the natural environment. Theme (II) As removal from reducing groundwater: Co-precipitation treatment with ferric chloride is an effective technique commonly used for the removal of arsenic form water. A different approach for removing As from groundwater that is promising but has not yet been fully evaluated relies on the adsorptive properties of Fe filings. This method was found to be very effective but has not yet been fully evaluated relies on the adsorptive properties of Fe filings. This methods was found to be very effective at the Winthrop, ME, Superfund site and will be tested at another site in Vineland, NJ. The mechanisms of As removal by Fe filings will also be probed using surface spectroscopy. Another objective under this theme is to develop practical ways of reducing the scale of As remediation and hereby meet the needs of users of domestic wells in the US and Bangladesh. We will focus on Fe-oxyhydroxide-based treatment using, whenever possible, the natural Fe content of groundwater. The As- removal potential of existing Iron Removal Units in Bangladesh will be explored in collaboration with local government researchers. The potential of filings as an alternative source of Fe for co-precipitation to treat water from domestic cells in the US and Bangladesh will also be examined.

自然或人为富含砷的地下水对包括美国在内的世界许多地区造成严重的健康危害。该项目建立在人们日益认识到砷对氢氧化铁的特殊高亲和力是调节地下水中溶解砷浓度的关键因素的基础上。在不久的将来，As 对 Fe-羟基氧化物的特殊亲和力已被利用，建议值达到 10 微克/升，需要更好地了解不同处理方案以及地下水成分对处理效果的影响。 (I) 作为减少地下水的动员：来自缅因州温思罗普和新罕布什尔州瓦恩兰（项目）和孟加拉国（项目 5）的美国超级基金站点的现场材料将用于量化含氧和还原条件下溶解相和特定相之间的砷交换。在第一组实验中，将通过从覆盖一系列氧化还原条件的存档含水层材料中提取羟胺来确定还原溶解引起的砷的潜在综合释放。还原溶解释放的 As 和 FE 的空间模式将与含水层中的氧气分布进行比较。在第二组实验中，将对选定地点的新鲜含水层核心进行培养，以量化砷和铁交换（吸附或解吸）的速率。在第三组实验中，将使用最先进的表面分析技术来表征在代表自然环境的一系列条件下模型氧化铁表面的砷结合。主题（二）作为还原性地下水的去除：氯化铁共沉淀处理是一种常用的去除水中砷的有效技术。另一种从地下水中去除砷的方法很有前景，但尚未得到充分评估，该方法依赖于铁屑的吸附特性。人们发现这种方法非常有效，但尚未根据铁屑的吸附特性进行充分评估。人们发现这种方法在缅因州温思罗普的 Superfund 站点非常有效，并将在新泽西州瓦恩兰的另一个站点进行测试。还将使用表面光谱法探讨铁屑去除砷的机制。该主题的另一个目标是开发减少砷修复规模的实用方法，从而满足美国和孟加拉国国内油井用户的需求。我们将尽可能利用地下水的天然铁含量，重点进行基于羟基氧化铁的处理。将与当地政府研究人员合作探索孟加拉国现有除铁装置的除砷潜力。还将审查申请作为共沉淀铁的替代来源来处理美国和孟加拉国家庭电池水的潜力。