Features of waste incineration plant leachate
MSW in China has some features, including high content of kitchen waste, high moisture content, high organic matter content, mixed collection and low relative calorific value. MSW has been stored in dump pit form 3-7 days before grabbed into incinerator, in which process leachate can be drained and calorific value can be increased. So leachate in incineration plant has features including:
1. Composition of pollutants is complex and changeable, and leachate quality changes greatly;
2. Concentration of organic pollutants is high;
3. Content of ammonia nitrogen is high;
4. Proportion of nutrients is unbalanced;
5. Content of heavy metal and salts is high;
6. Water quantity of leachate in incineration plant fluctuates greatly.
Leachate treatment process of the incineration plant must have a good function of removing ammonia nitrogen and COD. WELLE recommends process of "Pretreatment system + Anaerobic reactor + MBR + Membrane treatment system" as the main process.
Effluent of incineration plant generally needs to meet Supplementary Water Standard of Open Circulating Cooling System for Industrial Water for Urban Sewage Recycling (GB/T19923-2005).
Leachate treatment solution for landfill leachate
Landfill leachate quality will change with landfill service life increase, which is reflected in decrease of organic pollutant concentration, increase of ammonia nitrogen concentration and decrease of biodegradability.
Specific water quality characteristics:
1. Complex pollutant composition and large water quality fluctuation;
2. High concentration of organic matter, i.e. high concentration of COD and BOD;
3. High concentration of ammonia nitrogen;
4. High concentration of heavy metal and salt.
The process recommended is "Equalization + MBR + Membrane advanced treatment". Advanced treatment is usually "NF"and "RO"
The effluent quality of landfill leachate generally needs to meet The Control Standard for MSW Landfill (GB 16889-2008).
Leachate treatment solution for waste transfer station
Typical characteristics of domestic waste in China are high moisture content, high organic content, mixed collection and low relative calorific value. During domestic waste storage process in transfer station, leachate is generated from fermentation and dehydration process.
The leachate of waste transfer station has the following characteristics:
1. The water quality is complex and fluctuates greatly;
2. The concentration of COD and BOD is high;
3. The content of animal and vegetable oil is high;
4. The quantity of leachate in transfer station fluctuates greatly.
Recommended process is: "Pretreatment+Equalization tank + External CJMBR (two-stage biochemical) + Advanced treatment".
Discharge effluent shall meet standard of Water Quality Standard for Sewage Discharged into Urban Sewers (GB/T 31962-2015),