Abstract: The present invention relates to methods for biological wastewater treatment for Se control in Se-laden wastewater. The Se contaminants in the wastewater include the Se oxyanions selenate (SeO42-) and selenite (HSeO3?), which are biochemically reduced and transformed to elemental selenium (Se0) by microorganisms through anaerobic biological reduction. The resulting Se0 is entrained in the biomass, which is further processed to enable the efficient recovery of concentrated Se0.

Abstract: A biofilm membrane bioreactor system with a bioreactor, at least two membrane plates positioned within the bioreactor, and a plurality of biofilm carriers suspended within the wastewater in the bioreactor. The bioreactor has at least one inlet and at least one outlet. The at least two membrane plates are configured to filter the wastewater to generate permeate and may be formed of a ceramic material. Each of the at least two membrane plates are separated from adjacent membrane plates by a membrane gap that is at least two times larger than a smallest dimension of one of the biofilm carriers.