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Mitigation and Remedy of Groundwater Arsenic Menace in India

Mitigation and Remedy of Groundwater Arsenic Menace in India

Mitigation and Remedy of Groundwater Arsenic Menace in India

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Roadmap for Achiev<strong>in</strong>g Envisaged Targets(iv)Revisit to revise National St<strong>and</strong>ard for <strong>Arsenic</strong> <strong>in</strong> dr<strong>in</strong>k<strong>in</strong>g water: to considerrevision <strong>of</strong> the National St<strong>and</strong>ard for <strong>Arsenic</strong> <strong>in</strong> dr<strong>in</strong>k<strong>in</strong>g water <strong>in</strong> the light <strong>of</strong> the WHO'spresent guidel<strong>in</strong>es.8.1.1 Emerg<strong>in</strong>g R & D ActivitiesThe technological opportunities, to resolve water scarcity <strong>in</strong> arsenic affected areas <strong>and</strong>,to get rid <strong>of</strong> groundwater arsenic menace, can be thought to be as under:i) In-situ remedy <strong>of</strong> aquifers by decontam<strong>in</strong>at<strong>in</strong>g arsenic from <strong>in</strong>fested aquifers,ii) Use <strong>of</strong> groundwater after ex-situ treatment by arsenic removal devices,iii) Use <strong>of</strong> surface water source as an alternate to the contam<strong>in</strong>ated groundwater source,iv) Explor<strong>in</strong>g possibilities <strong>of</strong> tapp<strong>in</strong>g risk free deeper aquifers for supply <strong>of</strong> arsenic freegroundwater.Out <strong>of</strong> these four technological options, the most fasc<strong>in</strong>at<strong>in</strong>g one is the <strong>in</strong>-situ removal <strong>of</strong>arsenic from aquifers <strong>and</strong> restor<strong>in</strong>g the aquifers from arsenic vulnerability. Ensur<strong>in</strong>g supply <strong>of</strong>dr<strong>in</strong>k<strong>in</strong>g water to the populace <strong>in</strong> the arsenic affected areas is the primary requirement while theirrigation water requirement <strong>in</strong> the arsenic affected areas can't be overlooked. Agriculture is thelife l<strong>in</strong>e <strong>of</strong> rural people <strong>and</strong> groundwater is the primary source for agricultural waterrequirement. Exploitation <strong>and</strong> usages <strong>of</strong> arsenic contam<strong>in</strong>ated groundwater for agriculturalpurposes will not only spread the health hazards through the agricultural products but also help towiden the arsenic contam<strong>in</strong>ated area. Thus, one has to look for a comprehensive solution toensure supply <strong>of</strong> arsenic free water to meet dem<strong>and</strong>s <strong>of</strong> both dr<strong>in</strong>k<strong>in</strong>g <strong>and</strong> irrigation requirement.Although there are some commonly accepted hypotheses, expla<strong>in</strong><strong>in</strong>g occurrences <strong>and</strong>mechanisms <strong>of</strong> arsenic <strong>in</strong> groundwater, however, causes, sources <strong>of</strong> parental materials <strong>in</strong>clud<strong>in</strong>gtheir geo-chemical behaviors <strong>and</strong> processes <strong>in</strong> different hydro-geological sett<strong>in</strong>gs <strong>and</strong> speciationare still to be established. Techniques <strong>and</strong> technologies, available globally <strong>and</strong> <strong>in</strong>digenously, forarsenic removal mostly, deal with ex-situ arsenic removal methods i.e., removal <strong>of</strong> arsenic fromcontam<strong>in</strong>ated water after it is taken out from contam<strong>in</strong>ated aquifers. As such, no specifictechnique except an approach claimed by 'Queen's University researchers <strong>in</strong> Belfast' has beenfound stat<strong>in</strong>g withdrawal <strong>of</strong> arsenic free groundwater or <strong>in</strong>-situ treatment <strong>of</strong> arseniccontam<strong>in</strong>ated aquifer. The claim <strong>of</strong> eco-friendly treatment technique <strong>of</strong> arsenic removal, thatcan ensure safe irrigation <strong>and</strong> potable water supply at an affordable cost, by the 'Queen'sUniversity researchers <strong>in</strong> Belfast', needs verification <strong>and</strong> on field application, before thetechnique is accepted for large scale adaptation. Further, a variety <strong>of</strong> ex-situ treatmenttechnologies, which are ma<strong>in</strong>ly based on oxidation, co-precipitation, adsorption, ion-exchange<strong>and</strong> membrane process, have their own merits <strong>and</strong> limitations, <strong>and</strong> are mostly foundunwarranted; <strong>in</strong> terms <strong>of</strong> efficiency, operation <strong>and</strong> ma<strong>in</strong>tenance, applicability/appropriateness <strong>of</strong>the technologies. The ma<strong>in</strong> disadvantages associated with those are: (i) they produce large140NIH & CGWB

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