Development of a Strategy for the Treatment of Landfill Leachates
Investigators: Virginia Tech
In 2010, approximately 135.5 million tons out of 249.9 million tons of the municipal solid waste (MSW) generated in the USA was disposed to landfills (US EPA 2011). Each ton of MSW has been estimated to generate 53 gallons of landfill leachate (Water Research). The costs involved in transportation and treatment make leachate management a billion dollar industry.
The discharge of landfill leachates to publically owned treatment works (POTWs) has traditionally been the most economical disposal option. However, leachates have been observed to interfere with UV disinfection and add to the total effluent nitrogen at POTWs. Concerned about interferences with UV disinfection and biologically resistant organic nitrogen compounds in leachates, many landfills are moving to combinations of biological and physico-chemical treatment. These techniques may include reverse osmosis (RO) as a final treatment step, which is a costly and energy intensive alternative.
Earlier studies conducted by Dr. Novak’s research group at Virginia Tech have shown that leachate recirculation is effective for degradation of the ultra-violet (UV) quenching substances. A major goal of this research is to determine if the conditions associated with leachate recirculation can be mimicked in an anaerobic membrane bioreactor (anMBR). If successful, such a system can serve for removal of UV quenching substances and organic nitrogen. These systems are relatively inexpensive, have lower sludge production and a smaller ecological footprint while its by-product methane can be used to produce electricity and heat. The primary objectives of the project are to:
- Optimize the removal of UV quenching substances (humic substances) using an anaerobic membrane bioreactor, coupled with physical/chemical treatment
- Optimize the removal of organic nitrogen (hydrophilic fraction) using an anaerobic membrane bioreactor, coupled with physical/chemical treatment
- Develop a comprehensive approach to treat leachate based on leachate characteristics and effluent discharge requirements