Leachate is produced when water moves downward through a landfill, picking up dissolved materials from the decomposing wastes. The amount of leachate produced is directly related to the amount of precipitation around the landfill. Landfill leachate is defined as liquid that seeps through solid waste in a landfill, producing extracted, dissolved, or suspended materials. It is a potential pollutant that may cause harmful effects on groundwater and surface water that surround a landfill site, unless returned to the environment in a carefully controlled manner.
Leachate contains high amounts of organic compounds, ammonia, heavy metals, a complex variety of materials, and many other hazardous chemicals. The quantity of this leachate is generally small compared with that of other wastewater, but its contents are extremely hazardous In this regard, dedicated treatment facilities are required before leachate can be discharged to the environment. Researchers worldwide are still searching for a total solution to the leachate problem.
Various site-specific treatment techniques can be used to treat hazardous wastewater depending on leachate characteristics, operation and capital costs, and regulations. The treatment technology that can be used may differ based on the type of leachate produced. Even after treatment, the effluent characteristics are not always found to comply with discharge standards. Leachate treatment schemes include biological, physical, and chemical processes; their combination and specific modification are greatly influenced by the characteristics of leachate produced.
Leachate in classical wastewater treatment plants is rarely treated because of its nature and high levels of pollutants (i.e., high chemical oxygen demand [COD] and ammonia content and low biodegradability). Treatment by a conventional water treatment system (i.e., a combination of sedimentation, biological treatment, filtration, and carbon adsorption) cannot remove salts or organics, such as harmful recalcitrant compounds. Therefore, the papers of this special issue will address research on advanced processes for landfill leachate treatment and related areas.
Topics include, but are not limited to, the following:
- Advanced leachate treatment using integrated membranes techniques
- Combination of advanced treatment applications on landfill leachate
- Physiochemical treatment processes for landfill leachate
- Sequential and simultaneous processes for the treatment of leachate
- Landfill leachate treatment via combination of biological and physiochemical treatment processes
- Chemical, electrochemical and electrolytic oxidation of landfill leachate
- Biodegradability improving of landfill leachate using advanced treatment processes
- Evaluation of landfill leachate treatment via advanced oxidation processes.
Deadline for paper submission: 31 March 2014
First turn of papers review: 31 June 2014
Second turn of papers review: 31 August 2014
Final papers submission: 31 October 2014