A case of treatment of landfill leachate in late stage and closure stage by full quantification process

Abstract

In view of the low biodegradability of the leachate in the late stage of domestic landfills and closures，it cannot be effectively treated by biochemistry. Furthermore， the membrane concentrate is recharged for a long time，and the increasingly accumulated salinity of the leachate cannot be solved. Aiming to these problems，they proposed a combined process of full quantitative treatment，namely “softening pretreatment， DTRO， special separation membrane， low temperature negative pressure evaporation technology and three-phase curing technology”，which is suitable for terminal leachate with high salinity，high ammonia nitrogen and low biochemical properties. The operation results showed that the recovery rate of clean water can reach 90%-95%，and the landfill after solidification was only 5%-10%. The advantages of liquid and solid phase treatment systems complemented each other，and the system run stably，with low energy consumption. The desalination rate reached more than 99.5%，effluent COD≤60 mg/L，BOD5≤20 mg/L，ammonia nitrogen≤8 mg/L，total nitrogen≤20 mg/L，SS≤6 mg/L. And the produced water met the limit requirements specified in Table 3 of the Standards for Pollution Control of Domestic Waste Landfills （GB 16889—2008）.

Keywords

• late stage and closure leachate
• full quantification process
• special separation membrane
• low temperature negative pressure evaporation technology
• three-phase curing technology