Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, UK.
Mahavir Cancer Sansthan and Research Centre, Phulwarisharif, Patna 801505, Bihar, India; Indian Institute of Technology Patna, Patna 801106, Bihar, India.
Sci Total Environ. 2022 Jul 15;830:154580. doi: 10.1016/j.scitotenv.2022.154580. Epub 2022 Mar 15.
The presence of arsenic (As) and other inorganic contaminants in groundwater is a key public health issue in India and many other parts of the world. Whilst a broad range of remediation technologies exist, performance can be highly variable, and appropriate selection and management of remediation approaches remains challenging. Here, we have identified and tested the performance of a range of small-scale remediation technologies (e.g. sand filters, multi-stage filtration and reverse osmosis (RO)-based systems; n = 38) which have been implemented in Bihar, India. We have undertaken spot-assessments of system performance under typical operating conditions in household and non-household (e.g. community, hospital, hostel/hotel) settings. The removal of As and other inorganic contaminants varied widely (ranging from ~0-100%), with some solutes generally more challenging to remove than others. We have evaluated the relative importance of technology type (e.g. RO-based versus non-RO systems), implementation setting (e.g. household versus non-household) and source water geochemistry (particularly concentrations and ratios of As, Fe, P, Si and Ca), as potential controls on remediation effectiveness. Source water composition, particularly the ratio ([Fe] - 1.8[P])/[As], is a statistically significant control on As removal (p < 0.01), with higher ratios associated with higher removal, regardless of technology type (under the site-specific conditions observed). This ratio provides a theoretical input which could be used to identify the extent to which natural groundwater composition may be geochemically compatible with higher levels of As removal. In Bihar, we illustrate how this ratio could be used to identify spatial patterns in theoretical geochemical compatibility for As removal, and to identify where additional Fe may theoretically facilitate improved remediation. This geochemical approach could be used to inform optimal selection of groundwater remediation approaches, when considered alongside other important considerations (e.g. technical, managerial and socio-economic) known to impact the effective implementation and sustainability of successful groundwater remediation approaches.
砷（As）和其他无机污染物在地下水中的存在是印度和世界许多其他地区的一个主要公共卫生问题。虽然存在广泛的修复技术，但性能可能差异很大，因此仍然具有挑战性的是对修复方法进行适当的选择和管理。在这里，我们已经确定并测试了一系列小规模修复技术（例如砂滤器、多级过滤和基于反渗透（RO）的系统；n = 38）的性能，这些技术已在印度比哈尔邦实施。我们在家庭和非家庭（例如社区、医院、宿舍/酒店）环境中的典型操作条件下对系统性能进行了现场评估。As 和其他无机污染物的去除率差异很大（范围从~0-100%），有些溶质通常比其他溶质更难去除。我们已经评估了技术类型（例如基于 RO 的系统与非 RO 系统）、实施环境（例如家庭与非家庭）和水源地球化学（特别是 As、Fe、P、Si 和 Ca 的浓度和比值）相对重要性，作为修复效果的潜在控制因素。水源组成，特别是（[Fe]-1.8[P]）/[As]比值，是 As 去除的一个重要控制因素（p < 0.01），无论技术类型如何，较高的比值与较高的去除率相关（在观察到的特定地点条件下）。该比值提供了一个理论输入，可以用来确定天然地下水组成在多大程度上与较高的 As 去除率在地球化学上是兼容的。在比哈尔邦，我们展示了如何使用该比值来识别 As 去除的理论地球化学相容性的空间模式，并识别在理论上哪里可以添加 Fe 以改善修复。这种地球化学方法可以在考虑到其他重要因素（例如，技术、管理和社会经济因素）的情况下，为地下水修复方法的优化选择提供信息，这些因素已知会影响成功地下水修复方法的有效实施和可持续性。
