LIFE LEACHLESS - Low energy treatment technology for leachate valorisation
Although recycling rates have increased in Europe much waste is still landfilled, especially in Mediterranean and Eastern European countries. Landfills present long-term threats to soil, air, groundwater and surface water. This is mainly due to leachates, the liquid fraction continuously produced from solid waste that is dispersed when rainfall percolates through it. Approximately 10 m3 of leachate is generated per 115 tonnes of solid waste, and landfills can keep producing leachates up to 50 years after their closure. Although leachate composition varies, it is invariably hazardous to some extent – with potential ecotoxicological effects on terrestrial ecosystems and humans. In the absence of on-site treatment, leachate is circulated back into the waste, resulting in a more concentrated liquid that has a bad odour and attracts disease-spreading flies, creating bigger potential ecological and health risks and unpleasant working conditions. Without treatment, the leachate is also transported to sewer systems or wastewater treatment plants (WWTPs). Due to its high organic and ammonium concentrations, leachates cause extra loading in treatment plants, requiring additional chemical and energy consumption to comply with effluent limits. Moreover, due to the high metal content in leachate, the sludge generated may not be suitable for agricultural applications. The problems are most acute in smaller WWTPs, where leachate is less diluted with municipal sewage. Leachate treatment techniques remain expensive and technically inefficient.
Contact person: María Dolores Hidalgo