Arsenic Crisis
Of all the naturally occurring ground water contaminants, arsenic is by far the most toxic. Natural geochemical weathering of subsurface soil has caused an unacceptable level of dissolved arsenic in groundwater in many regions of India, Bangladesh, Vietnam, Cambodia, Mexico, Argenatina and the United States. Over 100 million people in the Indian subcontinent alone are affected with arsenic poisoning resulting from exposure to arsenic rich ground water. Elevated arsenic contamination in ground water in a wide region of Mekong River flood plain comprising Vietnam, Cambodia and Laos has put more than a million people at risk. The dissolved arsenic concentration in ground water exceeds 200µg/L in many of these areas while the World Health Organizations (WHO) recommends maximum arsenic concentration of 10µg/L in drinking water.
With the availability of numerous arsenic selective adsorbents media, the major environmental challenge lies in harnessing arsenic-free water in a sustainable way through a long-term, safe disposal of arsenic-wastes with no adverse ecological impact.
Our projects provide arsenic-safe drinking water through installation of arsenic removal unit in remote village locations using regenerable adsorbents, decreasing volume of arsenic-wastes significantly through regeneration process and containing arsenic-sludge in a well-aerated coarse sand filter with possibility of minimum arsenic leaching. This disposal technique is scientifically more appropriate than dumping arsenic-loaded adsorbents into the reducing environment of landfills. During the last ten years, Bengal Engineering and Science University (BESU) in Howrah, India in association with Lehigh University in Pennsylvania have installed more than 175 community-based well-head arsenic removal units (ARUs) in remote villages bordering Bangladesh and the State of West Bengal, India. No chemicals, pH adjustment or electricity are required to run these units. Production of minimum amount of arsenic-laden sludge through regeneration and reuse of sorbents; and ecologically safe containment of arsenic wastes truly ensures a sustainable solution.
