Introduction

There is a significant difference in the properties of leachate between waste incineration plants and landfills. The organic matter concentration and salt content of leachate from incineration plants are higher than those from landfills, but its biodegradability is better than that of leachate from landfills. The water quality of leachate from incineration plants is only related to the type of garbage collected, while leachate from landfills will decrease in organic matter concentration, increase in ammonia nitrogen concentration, deteriorate biodegradability, and increase the difficulty of treatment as the service life of the landfill increases.

There are also certain differences in the selection of treatment processes for leachate from incineration plants and landfills, but the main process is generally "pretreatment+biochemistry+membrane deep treatment".

The general process for treating leachate from incineration plants is "homogenization tank+anaerobic+A/O+external ultrafiltration (UF)+softening microfiltration (SMF)+reverse osmosis".

The general treatment process for landfill leachate is "homogenization tank+A/O+external ultrafiltration (UF)+multi-stage membrane treatment process".

Technical advantage

The COD of leachate from general incineration plants is very high, up to 40000-80000mg/L, and it has good biodegradability. Efficient anaerobic reactors should be used first to significantly degrade organic pollutants. Anaerobic effluent flows automatically to the biochemical system to remove biodegradable organic matter and perform biological denitrification. The ultrafiltration effluent treated by external MBR still contains COD and hardness formed by difficult to biodegrade organic matter, and the chromaticity still exceeds the standard. After using softened microfiltration to remove hardness, the effluent enters the reverse osmosis system to achieve standard discharge.

Due to the decreasing B/C ratio year by year, the biodegradability of landfill leachate has deteriorated. After homogenization and filtration, the raw water undergoes biochemical reactions and an external ultrafiltration system to remove most organic pollutants and biological denitrification. According to the characteristics of ultrafiltration effluent quality, various membrane treatment processes such as nanofiltration, material membrane or reverse osmosis, high-pressure reverse osmosis, etc. are selected to ensure stable and compliant effluent.

Application Cases

Liupanshui Municipal Solid Waste Incineration Power Generation Project Leachate Treatment Project, Mengcheng County Municipal Solid Waste Incineration Power Generation Project Leachate Treatment Station Project, Xuancheng City Landfill Leachate Treatment Station Project, Leshan City Landfill Leachate Treatment Station Project, and Fuyang City New 300m ³ d Municipal Solid Waste Leachate Treatment Station Project.