New Technology for Arsenic Removal from Mining Effluents

Arsenic is a persistent, toxic, and bioaccumulative element. Water with arsenic contamination has been reported in many parts of the world, and the World Health Organization considers arsenic one of the main contaminants in aqueous waste streams. Ferric co-precipitation treatment process, considered the state-of-the-art (the technology used industrially at present), produces large amounts of secondary waste with low stability, which leads to arsenic eventually being released back to the medium through natural oxidation processes. Current treatment technologies are quite effective at meeting the present environmental legislation discharge criteria (0.2 mg/L - COPAM 10/86 Brazilian Legislation) of removing aqueous oxy anionic contaminants, such as arsenic. An innovative treatment technology was developed for arsenic removal, allowing the reduction of arsenic levels in the effluent generated during the mining processes to a level below the criteria for discharge (reaching 0.1885 mg As/L).