Application of MVR evaporator in landfill leachate

Landfill leachate refers to high concentration waste water, formed through landfill and overlying soil, by the water contained in the landfill itself, the rain and snow water and other moisture entered in the landfill, and deducts the saturation moisture capacity of the landfill and overlying soil. Its composition is complex, the quantity and quality of the water changes greatly. The main sources of landfill leachate are direct rainfall, surface runoff, surface irrigation, the moisture of the garbage itself, water content of covering materials and generated water from the waste biochemical reaction. The main factors affecting the composition of landfill leach-ate are: Waste composition, landfill site climate conditions, landfill site hydro-logical address rainfall, landfill conditions, landfill time and so on. This determines the change of the quality and quantity of water of landfill leachate, and the change rule is complex. The content of ammonia nitrogen, CODcr, BOD5 is high. With the increase of landfill time, organic nitrogen is converted into inorganic nitrogen, and the mass concentration of ammonia nitrogen increased. Due to the dissolution of CO2 produced by waste degradation, the landfill leachate contains a high concentration of metal ions. As for the characteristics of landfill leachate with high concentration of organic pollutants, toxic and harmful heavy metals that have an inhibitory effect on organisms, the large load change and complex pollutant composition, it results in poor biodegradability of the landfill leachate.  And the traditional sewage treatment technology cannot meet the new discharge requirements. 

According to the customer's demand, Shandong ShengPuTe developed the "MVR evaporation concentration" process which left most of the pollutants in the concentrated solution in order to obtain the treatment effect of energy saving and environmental protection.  Specific process is as follows: The landfill leachate enters the preheater along the pipe, and after preheating, it is introduced into the evaporator. In the evaporator, the landfill leachate is heated, evaporated, condensed, and condensed by heating steam, and the distilled water formed flows into the distilled water collection tank, while the secondary steam and the concentrated liquid enter in the vapor-liquid separator together. In the vapor-liquid separator, the concentrated liquid is separated from the secondary steam, and the concentrated liquid flows into the concentrated liquid collecting tank, while the separated secondary steam is introduced into the mechanical compressor. In the mechanical steam compressor, the secondary steam is compressed, heated, pressurized, and introduced into the evaporator, and then the landfill leachate is heated, concentrated, evaporated and distilled. By using secondary steam repeatedly, the whole treatment process is completed, and the dual goals of landfill leachate treatment and energy saving are realized.