Treatment of Leachate Before Injection into a Bioreactor Landfill: Reduction of the Pipe Clogging Potential
Investigators: University of Manitoba
Landfilling is the most common method of disposal of municipal and industrial solid waste around the world. Organic and inorganic waste material located within waste layers in the landfill is typically anaerobically degraded through biological, chemical and physical interactions with emission of biogas and, depending on the amount of moisture present, leachate production1. Leachate is formed as water percolates through the waste layers, and organic and inorganic components from the waste are solubilized. Leachate from fresh waste contains high amounts of organic material and minerals. To deal with the materials in the leachate, large amounts of engineered infrastructure is integrated in the landfill design to safeguard the environment from these materials. An engineered leachate-collection system and a liner(s) below the waste cells has two purposes:
1) to minimize the transport of leachate to the closest aquifer and surrounding subsurface soil and
2) to transport the leachate outside of the waste cell for storage and treatment purposes2.
The leachate collection system typically consists of a granular material with embedded collection pipes, positioned below the waste and above any lowpermeability landfill liners that may have been constructed. Collected leachate is typically hauled to and treated at a wastewater treatment plant.
In newer landfills the collected leachate is injected back into the landfill through a network of perforated pipes buried in the refuse in an attempt to increase the rate of solubilization into the passing leachate. This enhances refuse degradation and settlement, as well as increases biogas production and on-site treatment of leachate3. These landfills are called bioreactor landfills. Failure of the collection or injection systems to perform can potentially result in increased migration of leachate into the surface and subsurface, slope instability, surface and groundwater contamination, and ineffective landfill gas generation and collection. Their long term efficiency is therefore essential. Landfill studies around the world (Canada, USA, Germany, France, Central America, Europe, Japan) have reported clogging (sometimes called bio-rock) in leachate collection and injection pipes and perforations4,5,6,7,8 resulting in the failure of these engineered systems to perform as designed. In a review of research needs for bioreactor landfills, SCS Engineers9 stated that bioreactor landfills have greater potential to clog compared to conventional landfills, and that there is a need to evaluate the performance of leachate collection system components in bioreactor landfills.
Clogging consists typically of a very hard mineral encrustation (mainly calcium and magnesium carbonate minerals), biological material and solid particles. A clogged collection system can no longer effectively remove leachate from the base of the landfill, resulting in increased potential for contamination of subsurface aquifers and/or surface water. A clogged injection pipe will experience a reduction in hydraulic performance for transmitting leachate, causing a non-uniform infiltration of leachate into the waste, thereby reducing the efficiency of methane gas production. At best, clogged transmission systems seriously limit the long-term viability of the landfill design. At worst, clogging can contribute to local environmental damage. The focus of the laboratory study described here is to assess the use of anaerobic digestion as a leachate treatment method, reducing both the organic and inorganic components associated with clogging. Treatment of leachate before injection will extend the service life of the engineered components of the bioreactor landfill, maximizing its benefits.
- Lozecznik, S., Sparling, R., Clark, S. and VanGulck, J.F. and Oleszkiewicz, J. (2012). Acetate and propionate impact on the methanogenesis of landfill leachate and the reduction of clogging components Bioresource Technology. 104, 37-43.
- Lozecznik, S, Oleszkiewicz, J.A., Sparling, R., Clark, S. and VanGulck, J. (2012). Effects of turbulence and temperature on leachate chemistry. Journal of Environmental Engineering (accepted for publication (October 12, 2011). Lozecznik, S., Sparling, R., Oleszkiewicz, J., Clark, S. and VanGulck, J.F. (2010). Leachate treatment before injection into a Bioreactor Landfill: Clogging potential reduction and benefits of using methanogenesis. Waste Management International Journal 30(11), 2030-2036.<.li>
Conference papers and articles
- Lozecznik, S., Oleszkiewicz, J., Clark, S., Sparling, R., VanGulck, J.F. (2010). Field-scale study of leachate transmission pipe clogging. Global Waste Management Symposium, October 3-6, 2010. San Antonio, Texas.
- Lozecznik, S., Oleszkiewicz, J., Clark, S., Sparling, R., VanGulck, J.F. (2009). Treatment of Leachate Before Injection into a Bioreactor Landfill: Reduction of the Pipe Clogging Potential. Proceedings of the Air & Waste Management Association General Conference, Detroit, Michigan.
- Lozecznik, S., Oleszkiewicz, J., Sparling, R., Clark, S. and VanGulck, J. (2009). Methanogenic degradation of leachate from Brady Road Landfill. Proceedings 2009 Western Canada Water Conference and Trade Show, Winnipeg, Manitoba, Canada. September 20-23, 2009.
- Solid Waste Association of North America (SWANA) Northern Lights Chapter (AB, SK, MB). The cleanup: Disasters and the Aftermath of waste. March 12-14, 2012. Keystone Centre, Brandon Manitoba.
- Issues and trends in Industrial Wastewater organized by Western Canada Water Environment Association (WCWEA) and Manitoba Water and Wastewater Association, February 7 – 8, 2012. Canada Inn Polo Park, Winnipeg.
- Global Waste Management Symposium, October 3-6, 2010. San Antonio, Texas.
- Canadian Society of Civil Engineers (CSCE) â€“ General Conference, June 9-12, 2010 – Winnipeg, Manitoba.
- The International Student Prairie Conference on Environmental Issues. University of Manitoba Water Environment Federation Chapter (UMWEF), North Dakota and South Dakota State Universities Water Environment Federation Chapters (NDSU and SDSU), June 7-8 of 2010. University of Manitoba, Winnipeg, Manitoba.
- Solid Waste Association of North America (SWANA). 15th Annual Landfill Symposium and Planning & Management Conference, April 12-13, 2010. Reno, Nevada.
- Two presentations at the Western Canada Water (WCW) Annual Conference and Trade Show, September 20-23, 2009 â€“ Winnipeg, Manitoba.