Leachate treatment for waste-to-energy plants
Comprehensive overview
Refuse leachate is a highly concentrated wastewater that originates from the water contained in the refuse itself in the landfill, rain, snow and other water entering the landfill, less the saturated water holding capacity of the refuse and the overburden, and is formed by going through the refuse and overburden layers.
The water quality of garbage leachate is quite complex, generally containing high concentrations of organic matter, heavy metal salts, SS and ammonia nitrogen, garbage leachate not only pollutes the soil and surface water sources, but also pollutes the groundwater, and for different water requirements of garbage leachate to design a different water process, the rate of water ≥ 95%.
Process system
Pretreatment + secondary A / O + UF + MBR + NF + RO + DTRO
Process characteristics
- Low operating costs
- Stable equipment operation
- Odorless and tasteless
Application case
Through the provision of development, system integration and technical services of complete sets of equipment for leachate treatment in waste incineration power plants, we can meet the needs of customers for waste leachate treatment, in which the complete sets of equipment can realize the full quantitative treatment of leachate in waste incineration power plants through such technologies as “anaerobic + MBR + NF + RO”, “anaerobic + MBR + DTRO”, “anaerobic + MBR + STRO + RO”, “material membrane / DTRO / evaporation” and others, “Anaerobic + MBR + STRO + RO”, “material membrane / DTRO / evaporation” and other technologies to achieve the full quantitative treatment of leachate from waste incineration power plants, the specific process flow and examples of actual cases are as follows:
Project Profile
This phase of the project daily average incineration treatment of 3,000 tons of domestic garbage (annual treatment of 100 × 104 tons of garbage), configured with four 850-ton / day grate incinerators, four evaporation capacity of 96 tons / hour of medium-temperature and low-pressure (6.4MPa, 450 ℃) waste heat boilers, two sets of stand-alone capacity of 50MW condensing turbine-generator sets。
The design scale of leachate treatment station construction is 1500m³/d (including leachate 700m³/d, low concentration production wastewater 100m³/d and 700m³/d methane for the kitchen plant), divided into four side-by-side biochemical treatment lines, each biochemical line with a treatment scale of 400m³/d, and each biochemical line corresponds to a set of ultrafiltration system.
Process
The main process adopted in this project is “pretreatment + anaerobic + external MBR (secondary A/O) + NF + RO” NF concentrate adopts two-stage material membrane treatment process, and RO concentrate adopts chemical hardness removal + tubular softening membrane + high-pressure membrane treatment process; it consists of water quality equalization system, UASB system, MBR system, NF system, RO system, NF concentrate reduction system, RO concentrate reduction system.
The effluent of the system reaches the water quality standard of urban wastewater recycling industrial water quality standard of open circulating cooling water system after reuse, running 365 days per year.
