The Domestic Waste Landfill Site of Tongliang District, Chongqing, is responsible for landfilling district-wide domestic waste. It is able to landfill about 500T waste and generate about 150T leachate each day. Landfill leachate is sewage generated by leaching of water from decomposition of organic matter in the garbage, free water in the garbage, rainwater, and groundwater when the garbage is landfilled and stacked. With a complex composition and high concentration, landfill leachate is able to change the composition and structure of the soil and cause serious pollution to surface water and groundwater, so it is particularly harmful to people and the environment. But it is difficult to conform to the tail water discharge standard by adopting ordinary sewage treatment processes .
This project adopts the process of integrated pretreatment + two-stage DTRO treatment. Under this process, the leachate undergoes the first-stage DTRO treatment after being pretreated in the raw water storage tank, and the generated percolate enters the second-stage DTRO for further treatment; then, the regenerated percolate enters the degassing facility and reaches the tail water discharge standard before being discharged. The membrane separation technology adopted in the "MBR+DTRO" process replaces the traditional mud-water separation technology, as it is so efficient that MBR is better than all traditional biochemical processes in terms of tail water quality, space occupied and impact resistance.