Element Case Studies: Arsenic

Arsenic contaminated soil is a major issue in PR China. The discovery of an As hyperaccumulator fern, Pteris vittata opens a door for phytoextraction of As-contaminated soils. In situ phytoextraction projects using P. vittata have been established that achieved high removal rates of As. The first phytoextraction project in the world was established in Chenzhou, Hunan Province. Subsequently, more phytoextraction projects were established in Guangxi Zhuang Autonomous Region, Yunnan Province, Henan Province and Beijing. During these field-based projects, the safe disposal and re-utilization of P. vittata biomass were considered essential processes. Incineration technologies for P. vittata biomass are well developed. Safe landfilling has been applied for the disposal of the burned ash of P. vittata when the amount of that ash is small. When the ash amount is large, a recycling method has to be applied. Agromining of Ni has been successfully achieved, but agromining of As is at present only an idea, owing to the low commercial value of As. Nevertheless, production of a biofuel resulting from the incineration process, together with the recycling of As, could be a potential opportunity for agromining of this metalloid.