Development of a combined BAC and bz reactor for removal of nitrogen in wastewater from sludge drying process

Abstract

A combined biological activated carbon (BAC) and biological zeolite (BZ) reactor is under development to remove organics and nitrogen from wastewater which contains both inhibitory organics to nitrification and high concentration of ammonium nitrogen. In this study, the combined BAC and BZ reactor was applied to treatment of scrubber-washed wastewater from sludge drying process. Successful treatment performance was accomplished by decreases in concentrations of the inhibitory organics (in BAC tank) and ammonium nitrogen (in BZ tank) occurred by both adsorption to the mediums and biological reaction. Appropriate nitrogen loading rate for fine and stable treatment was shown to be less than 7 mgNOx⁻−N −(gGAC−d)⁻¹ for denitrification in BAC tank and less than 4 mgNH₄+−N−(gZeolite−d)⁻¹ for nitrification in BZ tank. DOC/NOx⁻−N loading ratio to BAC tank is required to be more than 2.0 mgDOC−(mgNO^x−−N)⁻¹ for successful denitrification.