SCWO solutions for treating landfill leachate
Challenges in landfill operations
Many organic compounds contained in landfill leachate are hardly degradable and the nitrogen content in leachate is high compared to the carbon content. This makes leachate from landfills and rubbish dumps difficult to treat adequately at municipal wastewater treatment plants.
Municipal treatment plants also cannot adequately remove the heavy metals contained in the leachate. As a consequence, wastewater treatment plants enforce strict regulations on leachate heavy metal content.
For many landfill operations the option to send leachate to municipal treatment plants does not exist, and some are forced to discharge leachate directly to the sea or let it seep into the ground. These operations may pollute the local environment by contamination of groundwater and soil. Therefore, an alternative and more environmentally friendly method for treating leachate on-site is needed.
Aquarden solutions can easily be configured to deal effectively with the specific chemical composition of the leachate, flow rates, and the required treatment efficiency.
Our SCWO reactor is the core component of the system while pre and post-treatment processes can be designed and optimized to meet specific client needs. The pre-treatment process can for example consist of a mechanical filter, an ion-exchanger, or a reverse osmosis (RO) unit concentrating the leachate. The concentrated leachate is then treated in the SCWO reactor. The end result is a minimal investment solution offering outstanding treatment results while keeping operational costs low.
Possible application of SCWO for landfills: The leachate is pre-treated with Ion Exchange (IE) and Reverse Osmosis (RO) before entering the SCWO reactor. In this way the leachate can be concentrated by up to 10 times making the operation more cost-efficient. The purified leachate can be discharged directly to the sea.
Benefits of using SCWO in landfill operations:
- Organics and nitrogen-containing compounds are completely oxidized into harmless compounds such as carbon dioxide, nitrogen gas, and water.
- On-site SCWO treatment reduces transportation costs
- The system is fully automated and easy to operate
- SCWO offers easy integration with other systems
- SCWO is continuous and operates around-the-clock
- Operating costs can be kept at those of conventional treatment methods
- Regulation governing the discharge of hardly-degradable organics and ammonium in wastewater can be met today and in the future
- Treated wastewater can be discharged directly to sea
SCWO proves a solid solution
Aquarden has performed several test on landfill leachate and the tests results for the SCWO treatment are remarkable. The COD value of the outgoing distillate was reduced by 99.8 % while the ammonium content was reduced by 99.999 % compared to the ingoing concentrated leachate.