Novel simultaneous anaerobic ammonium and sulfate removal process: A review

Abstract

With rapid economic development worldwide, large quantities of wastewaters are discharged into natural water. Ammonium (NH 4 + ) and sulfate (SO 4 2 − ) are the frequently encountered components and thus leads to serious contamination of the environment when not effectively treated. A remarkable breakthrough is in the discovery of the novel Sulfate. Anammox bacteria species are capable of treating both ammonium and sulfates including Anammoxoglobus sulfate and Bacillus benzoevorans . Sulfate-reducing anaerobic ammonium oxidation is a chemobiological reaction using NH 4 + as electron donor and SO 4 2 − as electron acceptor that produces nitrogen and elemental sulfur as final products based on Fdz-Polanco 2001 investigation. As depicted in this review, the simultaneous anaerobic ammonium oxidation and sulfate reduction reactions are mediated by sludge and bacteria. Their Gibbs free energy change ( Δ G θ )under tested conditions will change from positive to negative, which is an essential reaction indicator. The most influencing substrates are ammonium chloride (NH 4 Cl) and sodium sulfate (NaSO 4 ) sources in the start-up of Sulfate Anammox reactors. However, due to the long time of biomass division and reactors operation, only very few articles on this topic have been carried out. This review provides an overview of Sulfate-reducing ammonium oxidation process researches • Simultaneous removal of NH 4 + & SO 4 2 − is achieved by the SRAO process. • New Sulfate Anammox species Anammoxoglobus sulfate & Bacillus benzoevorans . • Low Gibbs free energy change ( Δ G θ ) value promotes NH 4 + & SO 4 2 − reduction reactions. • High substrate concentrations & low oxidation–reduction potential raise SRAO process. • NH 4 Cl & NaSO 4 substrates are the most influent NH 4 + & SO 4 2 − sources in SRAO reactors.