MULTI-STEP SYSTEM FOR TREATING SELENIUM-CONTAINING WASTEWATER

摘要

This specification describes a process and apparatus 10 for treating water comprising selenium. A process is described having the steps of treating the wastewater influent 100 using a biological reduction process to produce an intermediary stream and reducing the concentration of unconsumed constituents in the intermediary stream by means of filtration optionally with upstream coagulation or flocculation. When compared to the wastewater influent, the intermediary stream preferably has reduced concentration of the selenium species when compared to the wastewater influent. When compared to the intermediary stream, the effluent preferably has reduced concentration of one or more of the inorganic non-metallic constituents (such as nitrogen, phosphorous and sulphur), metallic constituents or organic constituents. An apparatus 10 is described herein having a fixed film reactor 16 configured to receive a wastewater influent 100, and a membrane filter 80 configured to receive effluent from the fixed film reactor 16.