Mechanism of Improving Membrane Treatment Efficiency of Landfill Leachate Under Multifactor Synergistic Optimization

With the growing use of membrane technology for landfill leachate, the nanofiltration (NF) clear liquid occasionally shows excessive total nitrogen (TN) concentrations. To solve this problem, this study adopts a single‐factor analysis method, the effects of different combinations of reverse osmosis (RO) and NF membranes, membrane‐tube ratio, NF membrane flux and RO membrane flux on the removal efficiency of ammonia nitrogen and TN in leachate were systematically investigated. The results show that compared with the parallel mode, the series combination of RO and NF membranes performs better in treatment effect, especially when the membrane‐tube ratio is 2:1, the removal rates of ammonia nitrogen and TN in the series combination are as high as 90% and 93%, respectively. In addition, when the NF membrane flux is 55.2 L/m 2 h and the RO membrane flux is 11.3 L/m 2 h, the system shows the best nitrogen removal efficiency. Based on research results, an integrated NF‐RO deep treatment system was designed and developed, and its treatment efficiency and stability were successfully verified.