AnCMBR-AFB-integrated process for the treatment of high nitrogen and phosphorus wastewater

Abstract

Improving the nitrogen and phosphorus removal rates and efficiently controlling membrane fouling are the keys to fully exploiting the applicability of anaerobic membrane bioreactor (AnMBR) process in high-concentration wastewater treatment. To that purpose, an integrated reactor composed of an anaerobic ceramic membrane bioreactor and N anaerobic fluidized bed (AnCMBR-AFB) was built and pollutant removal efficiency, nitrogen and phosphorus recovery characteristics, and membrane pollution features of this integrated reactor were investigated. The results revealed that the integrated reactor had good pollutant removal efficiency, with turbidity, chromaticity, and UV254 average values of the effluent being 0.470 NTU, 0.011 A, and 0.057 cm−1, respectively, and the average CODCr removal rate was 80%. The nitrogen and phosphorus recoveries were significantly higher than the nitrogen and phosphorus removal rates of conventional AnMBR at 23.20 ± 1.17% and 43.34 ± 1.54%, respectively. Microscopic analysis revealed the formation of magnesium ammonium phosphate (MAP) crystals on the carrier's surface, and friction between the carrier and the membrane surface could delay membrane fouling while allowing the contaminated membrane surface to retain significant roughness. Membrane fouling was mostly brought on by amides and saturated hydrocarbons, and inorganic metal ions also played a role to some extent. HIGHLIGHTS Pollutant removal during the operation of the AnCMBR-AFB-integrated reactor.; The AnCMBR-AFB-integrated reactor recovers nitrogen and phosphorus by the MAP crystallization process higher than AnMBR.; Membrane fouling is decreased by the friction between the fluidized carrier and the ceramic membrane.;

Keywords

• anaerobic ceramic membrane bio-reactor
• anaerobic fluidized bed
• high nitrogen and phosphorus wastewater
• magnesium ammonium phosphate crystallization
• membrane fouling control