Treatment of Landfill Nanofiltration Concentrated Leachate by Flocculation Combined with a Multistage Ozone/Bioreactor Based on a Field Scale

Abstract

Nanofiltration concentrated leachate (NFCL) is a high-concentration organic wastewater produced from landfill leachate during the process of membrane advanced treatment, which is more difficult to treat than landfill leachate. In this study, the effect and cost of treating NFCL by flocculation combined with a multistage ozone/bioreactor process based on a field scale are discussed. The results show that the process has a good effect on the removal of organic matter and nitrogen pollutants in NFCL, with removal efficiencies of chemical oxygen demand, ammonia nitrogen, nitrate, and total nitrogen being 96.6%, 90.1%, 38.2%, and 75.8%, respectively. The effluent can meet the discharge standard of China’s standard with a direct operating cost of approximately USD 18.48–20.82/m3. This study proved the effectiveness, structural rationality, and economic benefit of the process in a practical engineering application, and provided a certain theoretical basis and engineering reference for the wide application of the process in the treatment of leachate membrane concentrate.