Landfill leachate is heavily loaded wastewater containing various types of organic and inorganic contaminants and represents a major risk to natural water resources. Compared to other wastewater, leachate has characteristics such as large variations in water volume and quality, high concentrations of pollutants, high concentrations of non-biodegradable substances, and an imbalanced nutrient ratio.

Quality and quantity of landfill leachate vary with landfill age and climate conditions. Leachate from the acid phase is therefore characterized by high BOD5 values (commonly > 10.000 mg/l), high BOD5/COD ratios (commonly > 0,7) and acidic pH values (typically 5-6), and therefore suitable for biological treatment. At methanogenic phase, the composition of leachate is characterized by relatively low BOD values and low ratios of BOD/COD. Ammonia continues to stay at a relatively high level, making the biological treatment less effective. Biological processes are effective for young leachate (BOD5/COD ratio closes to 0,5), which mainly consists of volatile fatty acids, but less so for leachate in themethanogenic phase. In many cases, a single biological process, however, has not proven efficient to eliminate the large amount of non-biodegradable organic substances to the required discharge standards, necessitating the application of reverse osmosis technologies which complement and support the major process. Due to the development of high rejection DTRO/STRO membranes to retain both organic and inorganic contaminants at high rejection, the use of DTRO/STRO membrane either as a main step in a landfill leachate treatment chain or as single post_x0002_treatment step has shown to be the more efficient, adaptable and indispensable means of landfill leachate treatment. Containerized

/skid mounted leachate treatment systems were originated from Germany. They have advantages such as short time for start up, less space requirement, easy to operate and can start and stop at any time, lower investment and operation costs, excellent effect on the removal of salt and emerging compound. DTRO/STRO technology is very flexible to include pre-filtration or post_x0002_evaporation, as required.

Characteristics of this type of treatment station:

The mobile leachate treatment plant is specially designed for leachate stations without centralized leachate treatment plant. Leachate from scattered sources in towns and rural areas has the characteristics of low flow rate, widespread distribution. It is not cost effective to built large-scale centralized leachate treatment plant. Therefore, containerized leachate treatment systems are more suitable for towns and rural areas and can solve leachate pollution problem and meet the discharging standard.

Advantages of mobile leachate treatment plant:

DTRO membrane is effective to against fouling and scaling; Strong ability to against high loading rates; System is very compact and easy to maintain; Can be moved from place to place; Higher recovery rate can be achieved; Plug and play and can be commissioned in less than one week.

The mobile treatment equipment mainly adopts the DTRO disk tube reverse osmosis membrane technology. This technology does not rely on complex pretreatment equipment and has good stability, safety and adaptability. Due to the above characteristics, the DTRO membrane module can treat leachate directly without pretreatment.

In some projects, the pre-treatment system can be optional. For systems with pre-treatment, the reverse osmosis system can secure the discharging standard. At the same time, due to its independence from biological treatment, the disk tube reverse osmosis has good adaptability to the leachate at various stages of the landfill.

Treatment capacity:

According to the market demand and the actual situation, our company has developed modular products of mobile leachate treatment systems with capacities ranging from : 50T/d, 100T/d, 150T/d, 200T/d, 250T/d to 300T/d.

Leachate Treatment for MSW Waste Incineration Plants

Pretreatment + Anaerobic UASB + MBR - Tubular Ultrafiltration + DTRO/STRO High Pressure Reverse Osmosis

Anaerobic UASB is mainly used to remove pollutants such as COD from leachate, with removal rates reaching 75%-90%; MBR is mainly composed of denitrification tank, nitrification tank, and an external ultrafiltration system, which is used to remove ammonium nitrogen (with a removal rate of 99%) and the remaining COD from leachate.

The biological pre-treated leachate enters the DTRO/STRO reverse osmosis system. The high pressure DTRO/STRO membrane system can achieve an improved recovery rate of 80-85%, and the produced water consistently meets discharging standards.

Leachate Treatment for MSW Landfill Sites

Pretreatment + Hydrolysis Tank + MBR - Tubular Ultrafiltration + STRO(DTRO) High Pressure Reverse Osmosis