The biological treatment of landfill leachate using a simultaneous aerobic and anaerobic (SAA) bio-reactor system

A set of simultaneous aerobic and anaerobic (SAA) bio-reactor system was used for the removal of organic pollutants and ammonia in the landfill leachate generated from Datian Shan Landfill in Guangzhou, China. The influent concentrations of COD and NH4+-N were 1000–3300 and 80–230 mg L−1, respectively. The average effluent concentrations of COD and NH4+-N were 131 and 7 mg L−1, respectively. The concentrations of COD and NH4+-N had reached the Chinese second grade effluent standard (COD < 300 mg L−1, NH4+-N < 25 mg L−1) for this kind of wastewater. Gas chromatogram–mass spectrum (GC/MS) analysis was used to measure the organic pollutants in the landfill leachate. About 87 organics were detected in this landfill leachate, and 16 of them belong to the list of environmental priority pollutants established by the US Environmental Protection Agency. About 31 of the 87 organic pollutants were completely removed by the SAA bio-reactor, the concentrations of further 14 organic pollutants were reduced by more than 80%, and the removal efficiencies of the other 25 organic pollutants were over 50%.