A PROCESS FOR REDUCING THE SULFATE CONCENTRATION IN A WASTEWATER STREAM

摘要

A method of reducing a sulfate concentration in wastewater comprises directing the wastewater stream to a precipitation reactor and mixing the wastewater stream with a calcium source and a calcium salt seed material to precipitate calcium sulfate. The precipitated calcium sulfate is then separated from a treated effluent and directed to a settling tank where the precipitated calcium sulfate is separated into heavier calcium sulfate precipitants and lighter calcium sulfate precipitants. The heavier calcium sulfate precipitants and the lighter calcium sulfate precipitants are separately recirculated to the precipitation reactor. A predetermined mass ratio of solids is maintained in the precipitation reactor.