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2.6 CONCLUDING REMARKS
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2.5 ARSENIC AND FLUORIDE REMOVAL IN RURAL AND SEMI-URBAN
Technologies for Arsenic, Fluoride and Iron Removal
developing country like India, the high prevalence of contamination, isolation and poverty of the rural population, and the high cost and complexity of removal technologies have imposed a programmatic and policy challenge on an unprecedented scale.
The ‘Water Technology Initiative’ of the Department of Science and Technology, Government of India aims to promote research and development activities to provide safe drinking water at affordable cost and in adequate quantity using appropriate science and technological interventions. The focus is to develop holistic solution to the problem of water contamination and water scarcity through development of indigenous systems/devices to provide safe and adequate drinking water to individual households even in rural settings. The development of low cost domestic water purification technologies to remove contaminants in drinking water, demonstration and field trials of indigenous successfully developed technologies for removal of contaminants and substantial improvements in available technologies to remove their short comings are some of the major objectives of the programme (WTI, 2008).
On the directive of Hon’ble Supreme Court of India to mount research on war footing for finding out technical solutions to the water related challenges, the Union Ministry of Science and Technology, Government of India has prepared a plan document highlighting the need for imminent technical solutions to the problems of water scarcity in the country (WAR, 2009). Inability to use available water on account of natural contaminations such as arsenic, fluoride and iron has been listed as one of the major challenges relating to water scarcity in the country. Therefore, the technology mission WAR for Water is developed on the principle that timely, urgent, cost effective, socially viable and sustainable techno-management solutions are required for solving problems of water scarcity (WAR, 2009) through undertaking research and development of demonstratable technical solutions for (a) geological contamination through arsenic, (b) contamination through fluoride and (c) contamination through iron amongst 25 water related identified and prioritized challenges for immediate attention to scientific and academic communities through out the country. Hence, the technology
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mission WAR for water aims to focus on adaptation and absorption aspect of developed technologies in differing social contexts keeping in mind the local constraints of the individual household as well as the communities as a whole.
Defluoridation of drinking water is the only practicable option to overcome the problem of excessive fluoride in drinking water where alternate sources are not available. During the years following discovery of fluoride as the cause of fluorosis, extensive research has been carried out on various methods for removal of fluoride from water. Also the problem of treatment of arsenic-contaminated water arises from the requirement for its removal to very low levels to meet the stringent drinking water quality standards and guideline values for arsenic. Arsenic removal technologies have improved significantly over the last few years but many of the technologies do not work satisfactorily for natural groundwater. Reliable, cost-effective, and sustainable treatment technologies which are socially adaptable are yet to be identified and further developed. All the technologies that have been developed so far have their strengths and weaknesses and are being refined to accommodate rural conditions.
Iron, fluoride and arsenic removal has been a subject of intensive research for the last couple of decades in developing countries. This intensive research work has yielded many different designs of filtration units especially for removal of iron from the groundwater to be used/applicable at community levels – even our own country is no exception to this. But surprisingly, none of these community level units has found wide spread application in rural and semi-urban area of Assam. Instead, the rural and semi- urban population of Assam has preferred different variants of indigenous household iron filter units, which is designed (using local materials) and operated solely based on experiences of local populations gained over the period and passed from one generation to the other. Very scanty literatures are available on the performance of these indigenous household iron filter units. In addition, there are reports that some of the locations in Assam also contain fluoride and arsenic in groundwater beyond permissible levels and whether these household units are able to reduce concentrations of fluoride and arsenic along with the iron is a question open for investigation. Therefore, the urgent need of the hour is to assess and to improve the indigenous household iron filter
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Technologies for Arsenic, Fluoride and Iron Removal
units of rural and semi-urban area of Assam to produce water of potable quality by removing iron as well as fluoride and arsenic from the groundwater. This will ensure potable quality of drinking and cooking water to rural and semi-urban population on sustainable basis at an affordable cost in this part of the country as well as also meet the national needs as per initiative of the Union Ministry of Science and Technology, Government of India prepared on the directive of the Hon’ble Supreme Court of India issued in the very recent past. As a first step in this direction, there is a need to evaluate and assess the potential of adsorbent media (i.e. wooden charcoal and river sand used in the indigenous household iron filter units of rural and semi-urban area of Assam) for removal of iron, fluoride and arsenic from the groundwater. This is likely to help in design of an improved version of filter unit capable to remove all these contaminants simultaneously.
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Objective and Scope