Removals of Total Nitrogen and Sulphate from Rubber Industrial Wastewater by Coupling of Sulfammox and Sulphide-Driven Autotrophic Denitrification in the Anmbr

The coupling of sulphate-dependent ammonium oxidation (Sulfammox) and sulphide-driven autotrophic denitrification (SDAD) processes within an anaerobic membrane bioreactor (AnMBR) is used in this study to treat high-strength natural rubber industrial wastewater at the average values of 22,158.33 mg/L COD, 1441.82 mg/L NH4+-N and 477.08 mg/L SO42--S, respectively. During 225 days of continuous operation, the maximal average COD, Total Nitrogen (TN), NO3--N and SO42--S removal efficiencies of 58.3%, 31.20%, 85.5% and 45.1%, respectively, were obtained in the AnMBR system at full strength wastewater operation. TN is predominantly removed through the sulfammox, SDAD, and conventional denitrification pathways, while sulphate removal is accomplished via the sulfammox, SDAD, and sulphate reduction bacteria (SRB) processes. Desulfovibrio and Sulfurospirillum were predominant during sulfammox and SDAD processes. This study sheds light on the key enzymes involved in the sulfammox and SDAD pathways, and reveals the impact of tricarboxylic acid (TCA) cycle enzymes on metabolisms.