Bioenergy, ammonia and humic substances recovery from municipal solid waste leachate: A review and process integration

•EGSB + AnMBR is suggested to maximize CH4 production.•NH3 recovery by biogas recirculation with simultaneous Ca removal can be achieved.•Humic substances can be recovered by membrane from nanofiltration concentrate.•The integrated leachate treatment process is promising for resources recovery.•Environmental and economic benefits of the integrated process are analyzed.