Process for the removal of sulfate and metals from aqueous solutions

摘要

A process is provided for reducing the concentrations of water soluble ionic selenium species, sulfate ion and ionic heavy metal species in aqueous waste solutions containing the same. The process comprises passing said waste solution through a treatment zone containing a porous matrix on which are retained populations of at least one anaerobic bacteria of the genus Clostridium and at least one anaerobic bacteria selected from the group consisting of bacteria of the genera Desulfovibrio and Desulfotomaculum. The passing of said aqueous solution through said treatment zone is carried out at predetermined rates of flow and contacts between said solution and said bacteria is conducted under anaerobic conditions and at predetermined pH and temperature levels. The process provides for the conversion of the water soluble ionic selenium species to water insoluble selenium metal and the conversion of the water soluble ionic heavy metal species to water insoluble heavy metal species, both of which are substantially retained on the porous matrix and both of which can be recovered therefrom.