CORDIS - EU research results

Modular purification system for heavily polluted leachate

Final Report Summary - PURILEACH (Modular purification system for heavily polluted leachate)

Landfills are a common solution for the disposal of municipal and hazardous waste in Europe. However, they are associated to leakage of potentially toxic liquids to soil and groundwater. Biological and wastewater treatment units are not able to achieve high removal efficiency; therefore the need to develop new effective and inexpensive methodologies, based on both microbial and non-microbial leverage and in accordance to the European Community's Landfill Directive is apparent.

Leachate is generated during aerobic and anaerobic decomposition and its treatment is difficult because of its nature. It is typically highly contaminated with ammonia, organic contaminants, halogenated hydrocarbons and heavy metals and has increased concentrations of inorganic salts. This wastewater profile changes between landfills and within the same landfill with time. Leachate properties and loads, along with costs and effluent discharge regulations are the primary parameters that influence treatment facilities' design.

The PURILEACH project aimed at developing a flexible, modular, site adaptive approach which would use 'smart' feedback for the optimal selection of treatment regimes to process landfill wastewater of varying composition. The on-site treatment system consisted of specific technological modules and an integrated operational system for regime optimisation according to the different cases' requirements.

The developed prototype was installed in numerous landfills in the United Kingdom and continental Europe to allow for its validation and optimisation and provide information on the design aspects that had to be improved and automated. Hence, both field tests and intensive laboratory research were conducted. The sludge that occurred from leachate processing was collected by decanters and removed back to the landfill while part of it was reused. In addition, specific treatment systems were designed to respond to actual customer needs.

The services aimed to cover the entire life cycle of the product, from system design and manufacturing to installation on site. The necessary software and hardware was also developed. The finalised treatment system consisted of five modules that were related to reagent preparation, coagulation and flocculation, decantation, advanced oxidation and filtration. The specifications that were initially set for the project were successfully reached. In addition, it was proved that an increase in the system tank volume would imply a significant cost reduction at the industrial scale.

PURILEACH had specific market penetration targets, while cost reduction in comparison to conventional technologies was also a prerequisite that was successfully achieved. A specific knowledge dissemination plan was implemented after the system finalisation to notify potential users about the project achievements and increase their market share.