Sediment geochemistry and arsenic mobilization in shallow aquifers of western Hetao Basin, Inner Mongolia

摘要

Arsenic(As) has become increasingly important for environmental studies because of its significance to human health. Especially in Asia, endemic As poisoning has caused widespread health problems among millions of people (Charlet & Polya, 2006). The Hetao Basin of Inner Mongolia is one of the most representative arsenicosis-affected areas in China, with about 250,000 victims. High As groundwater (up to 1 mg/L) is widely distributed in HangjinhouqiCounty, in the northwestern HetaoBasin, an arid region with slow groundwater flow. There are about 76,000 people exposed in 35 villages from 9 towns, more than half the residents are still using groundwater with high As, TDS or high fluoride (F~-) as the only source of potable water. Many researchers proposed that iron (Fe) oxyhydroxides, clay minerals, and organic matter can release bound As to groundwater under high pH and anaerobic conditions (Lin et al., 2002; Guo et al., 2008; Deng et al., 2009).