Source, migration, distribution, toxicological effects and remediation technologies of arsenic in groundwater in China

Groundwater with high arsenic (As) content seriously threatens human life and health. If drinking high-As groundwater for a long time, excessive intake of arsenic will lead to various pathological changes such as skin cancer, liver cancer and kidney cancer. High-As groundwater has become one of the most serious environmental geological problems in China and even the international community. This paper aims to systematically summarize the sources, migration, distribution, hazard assessment and treatment techniques of arsenic in natural groundwater in China based on a large number of literature surveys. High-As groundwater in China is mainly distributed in the inland basins in arid and semi-arid environments and the alluvial and lacustrine aquifers in river deltas in humid environments, which are in neutral to weakly alkaline and strongly reducing environments. Content of As in groundwater varies widely, and As(III) is the main form. The main mechanism of the formation of high-As groundwater in China is the reduced dissolution of Fe and Mn oxides under the action of organic matter and primary microorganisms, alkaline environment, intense evaporation and concentration, long-term water-rock interaction and slow groundwater velocity, which promote the continuous migration and enrichment of As in groundwater.