Environmental Engineering Program, Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA, USA.
Water Res. 2010 Nov;44(19):5813-22. doi: 10.1016/j.watres.2010.07.072. Epub 2010 Aug 4.
In Bangladesh and the neighboring state of West Bengal, India, over 100 million people are affected by widespread arsenic poisoning through drinking water drawn from underground sources containing arsenic at concentrations well above the permissible limit of 50 μg/L. The health effects caused by arsenic poisoning in this area is as catastrophic as any other natural calamity that occurred throughout the world in recent times. Since 1997, over 200 community level arsenic removal units have been installed in Indian subcontinent through collaboration between Bengal Engineering and Science University (BESU), India and Lehigh University, USA. Approximately 200,000 villagers collect arsenic-safe potable water from these units on a daily basis. The treated water is also safe for drinking with regard to its total dissolved solids, hardness, iron and manganese content. The units use regenerable arsenic-selective adsorbents. Regular maintenance and upkeep of the units is administered by the villagers through formation of villagers' water committee. The villagers contribute towards the cost of operation through collection of a small water tariff. Upon exhaustion, the adsorbents are regenerated in a central facility by a few trained villagers. The process of regeneration reduces the volume of disposable arsenic-laden solids by nearly two orders of magnitude and allows for the reuse of the adsorbent material. Finally, the arsenic-laden solids are contained on well-aerated coarse sand filters with minimum arsenic leaching. This disposal technique is scientifically more appropriate than dumping arsenic-loaded adsorbents in the reducing environment of landfills as currently practiced in developed countries including the United States. The design of the units underwent several modifications over last ten years to enhance the efficiency in terms of arsenic removal, ease of maintenance and ecologically safe containment and disposal of treatment residuals. The continued safe operation of these units has amply demonstrated that use of regenerable arsenic-selective adsorbents is quite viable in remote locations. The technology and associated socio-economic management of the units have matured over the years, generating promise for rapid replication in other severely arsenic-affected countries in Southeast Asia.
在孟加拉国和印度的邻邦西孟加拉邦，超过 1 亿人因饮用地下水源而受到广泛的砷污染，这些水源中的砷含量远远超过 50μg/L 的允许限值。该地区的砷污染对健康造成的影响与近年来世界上任何其他自然灾害一样具有灾难性。自 1997 年以来，通过印度孟加拉工程科学大学（BESU）和美国利哈伊大学之间的合作，在印度次大陆安装了 200 多个社区级别的除砷装置。每天约有 20 万村民从这些装置中收集安全的饮用水。处理后的水在总溶解固体、硬度、铁和锰含量方面也可安全饮用。这些装置使用可再生的砷选择性吸附剂。村民通过成立村民水委员会来管理和维护装置的正常运行和维护。村民通过收取少量水费来为运营成本做出贡献。吸附剂耗尽后，由少数经过培训的村民在一个中央设施中进行再生。再生过程将含砷废物的体积减少近两个数量级，并允许重复使用吸附剂材料。最后，将含砷废物置于充氧粗砂过滤器中，砷浸出量最小。与目前发达国家（包括美国）在垃圾填埋场中采用的将含砷吸附剂进行还原处理的方法相比，这种处置技术在科学上更为合理。该装置的设计在过去十年中经历了多次修改，以提高除砷效率、易于维护以及生态安全的处理残余物的封存和处置。这些装置的持续安全运行充分证明，在偏远地区使用可再生的砷选择性吸附剂是可行的。该技术及其相关的社会经济管理多年来已经成熟，为在东南亚其他受严重砷污染的国家迅速推广提供了希望。
