Bacterial sulfate reduction treatment of mining-related wastewaters: pilot plant results

Abstract

Bacterial sulfate reduction treatment (BSRT) is a treatment and metal recovery process for industrial wastewaters that contain high concentrations of SO ²⁻₄ and heavy metals. This process has primary treatment capability and does not require polishing to meet strict heavy metal discharge standards. Currently, it is the only primary treatment process that can remove sufficient SO ²⁻₄ to meet an EPA-proposed discharge standard of 500 mg L⁻¹. The process is flexible, allowing for the selective recovery of certain metals (e.g. Cu, Zn) as metal sulfide concentrates. The concentrates can then be sent to smelters for metal recovery. The process can also segregate a heavy metal containing sludge from a more voluminous sludge that only contains innocuous metals. This reduces the volume of sludge that is considered to be hazardous waste, and can significantly reduce sludge disposal costs.