Efficient Treatment of Leachate from Municipal Solid Waste Transfer Stations via a Bioreactor–Nanofiltration System: A Pilot-Scale Study

The management of municipal solid waste leachate has emerged as a pivotal challenge in sustainable urban development. Currently, there is limited information on the practical engineering applications of bioreactors and nanofiltration systems on the pilot scale. This work employs a bioreactor–nanofiltration pilot system for the treatment of leachate in municipal solid waste transfer stations. The results demonstrate that the bioreactor–nanofiltration system exhibits excellent and stable efficiency in removing organic pollutants and heavy metal ions. The effluent qualities of COD, TN, and TP are 50, 28, and 2 mg/L, and the removal rates are 99.4%, 99.3%, and 96.1%, respectively. All types of heavy metal ions also comply with the standard limits specified in the “Wastewater quality standards for discharge to municipal sewers” (GB/T 31962-2015). More importantly, using waste materials such as mineralized waste and animal aggregates as bioreactor fillers increases the diversity of the microbial community in the system, and provides an engineering basis for the resource utilization of waste materials. The bioreactor–nanofiltration process is expected to become an ideal solution for the treatment of leachate in transfer stations.