The world is facing the issue of availability of fresh water. It is turning into critical resource which if not addressed properly will have greater consequences for humanity. A large geographical area of the world is facing problems of water supplies and quality of water remains a challenge for all developed and developing nations.
In the last few decades, the consequences of population growth, industrialization and urbanization, and the associated consumerist culture have interfered with the natural hydrological cycle of rainfall, soil moisture, groundwater, surface water and storage of all sizes. This has led to overuse, abuse and pollution of our vital water resources and has disturbed the quality and the natural cleansing capacity of water.
The sources and causes of groundwater contamination are numerous. The wide range of contamination sources is one of many factors contributing to the complexity of a groundwater quality assessment. Natural contamination of water resources mainly results from normal geological phenomena such as ore formation
Mining is one of the most important sources of heavy metals in the environment. Mining milling operations and disposal of tailings (the finely-ground remains of milled ores) in addition to smelting and metal refining provide significant sources of pollution. Unchecked mining can cause water and soil contamination and other environmental problems (e.g., forest degradation and air pollution). Groundwater contamination is one of the major environmental concerns at ores mining sites.
As the source of arsenic is the Himalayan mountain and the Tibet Plateau, the flood plains of all the rivers that originated from those sources are expected to be arsenic contaminated. Therefore, in the present study an attempt has been made to gain an understanding of the Arsenic (As) contamination status and the health risk of the people by investigating the water and sediment chemistry as well as the urine and hair of the people who are drinking arsenic contaminated water. Ground water sample was obtained from mining areas of Bihar-Jharkhand and the Brahmaputra alluvial basin of West Bengal and Assam Arsenicosis is not confined to Bihar, West Bengal and Bangladesh but several other countries like Taiwan, Thailand, Inner Mongolia (China), Pakistan, Japan, Sweden, UK, USA, Canada, Chekoslovakia, Chile and many other countries as well.
In the present study, surveys have been conducted at various locations in the above areas to understand the magnitude of contamination. Drinking water sample was analyzed for the elevated arsenic content. The arsenic concentration ranged from 0.30 mg/Kg to 1.48 mg/Kg.
To know the present arsenic body burden to population, biological samples were collected and analyzed from the arsenic affected villages.
Water treatment and development of an effective arsenic removal technology were also main objectives of the study. The experiments carried out during this study successfully addressed the removal of both arsenate and arsenite using surface functionalized ultrafine iron oxide nano particles. It was found that surface functionalized ultrafine iron oxide nano particles (10 nm) can absolutely remove arsenic from arsenic contaminated water. The efficiency of arsenic removal has been drastically improved by considering nano particles of size. The mechanism for adsorption was identified through electron microscopic and spectroscopic studies
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