Arsenic mobilization in groundwater aquifiers and as removal in drinking water filters - causes and solutions for the world's largest mass poisoning
Worldwide more than 100 million people ingest detrimental concentrations of arsenic by consuming groundwater contaminated with arsenic from natural geogenic sources. Many Asian countries, in particular Vietnam, Bangladesh, India, and Cambodia, are known to be affected by high groundwater arsenic concentrations as a result of reducing aquifer conditions. In this presentation, I will explain how the mobility of arsenic depends on iron biogeochemical cycling, how arsenic is mobilized in the subsurface, and how iron(II)-oxidizing and thus mineral-precipitating bacteria can contribute to arsenic immobilization and thus to removal of arsenic from solution. Finally, I will show how household sand-filters in Vietnam and Bangladesh function and how they can be used safely to lower the arsenic concentrations to values below the drinking water limit.