Characteristics and process difficulties of leachate from waste liquid incinerators

Characteristics and process difficulties of leachate from waste liquid incinerators

The main methods for treating household waste include incineration, composting, mechanical treatment, and landfill. During the process of stacking, transferring, squeezing, transporting, landfilling, or incineration of garbage, various metabolic products and water are generated, forming highly concentrated organic wastewater with extremely complex components - garbage leachate; Untreated leachate from garbage flows through the surface or seeps into groundwater, disrupting the ecological balance of surrounding soil and causing soil or water pollution, which will cause serious secondary pollution to the environment.

The leachate from garbage contains ammonia nitrogen and various dissolved cations, heavy metals, phenols, soluble fatty acids, and other organic pollutants. It has significant characteristics such as complex water quality, large water quantity changes, high concentrations of organic matter such as BOD5 and COD, high ammonia nitrogen content, and high metal content. Therefore, when choosing a garbage leachate treatment process, the following conditions need to be met:

1. To meet the characteristics of large changes in water volume, sufficient margin should be left in the process design of the waste liquid incinerator;

2. Strong resistance to water quality impact load, with significant fluctuations in the quality of leachate. Therefore, it is required that the waste liquid incinerator treatment process has extremely strong resistance to impact load;

3. High COD and BOD removal capacity, with a wide range of COD concentration changes in landfill leachate, up to 80000mg/L or even higher. Therefore, the treatment process needs to have extremely high organic pollutant removal capacity;

4. High ammonia nitrogen treatment capacity, the ammonia nitrogen concentration in the leachate generally ranges from hundreds to several thousand mg/L, generally believed to be around 1500-3000mg/L. But it can also reach around 4000mg/L. Require the treatment process to have a high ammonia nitrogen removal rate;

5. Minimize secondary pollution from waste liquid incinerators as much as possible.