Iodide and sulfite synergistically accelerate the photo-reduction and recovery of As(V) and As(III) in sulfite/iodide/UV process: Efficiency and mechanism.

Photo-reduction of arsenic (As) by hydrated electron (e) and recovery of elemental arsenic (As(0)) is a promising pathway to treat As-bearing wastewater. However, previously reported sulfite/UV system needs large amounts of sulfite as the source of e. This work suggests a sulfite/iodide/UV approach that is more efficient and consumes much less chemical reagents to remove As(III) and As(V) and recover valuable As(0) from wastewater, hence preventing the production of large amounts of As-containing hazardous wastes.