Upgrading of biological treatment for landfill leachate by nano-membrane systems

Treatment of landfill leachate is challenging, due to its characteristics such as age, dumping place, composition and origin of wastes. For this reason, the application of hybrid processes is helpful for complete treatment of contaminants present in the leachates. The addition of membrane operations to biological treatment technology offers new advantages for this method. For this aim, a bench-scale integrated process based on submerged aerobic MBR has been designed and fabricated. Also, Nanofiltration process as a post-treatment was used to upgrade MBR effluent. The results showed that the submerged UF-MBR system effectively removed biodegradable trace organic compounds with the average removal rate of about 75% at optimum food-to- microorganism (F/M) ratio (BOD basis) of 0.2 gBOD/g.d under a HRT of 24 h. The addition of NF process increased the treatment efficiency up to 98%. The effluent COD was reduced from 3500 mg/l to below 50 mg/l. Further, the effect of PAC addition was studied. NH3 –N, TKN and Heavy metals removal efficiency were obtained 97 ± 2%, 96 ± 2% and 99 ± 2%, respectively.