Pollution Control & Sustainable Environment

Biography

Biography: Rino Dubé

Abstract

Leachate treatment and the elimination of landfill gas (LFG) are the main environmental challenges faced by operators in the province of Quebec, Canada. CRIQ, in collaboration with its partners (Université Laval and Université de Sherbrooke), has been working for more than ten years on the development of biofiltration processes for the treatment of leachate and methane (CH4). The leachates treatment is intended to comply with the limit values as prescribed in the regulation (in particular BOD: 65 mg/l, ammonium: 10 mgN_NH4/l, zinc: 0.07 mg Zn/l and phosphorus: 0.3 mg Ptot/l). The process makes it possible to envisage, using methanotrophic bacteria that are unique in their ability to use CH4 as a source of carbon and energy, the treatment of landfill gas. The results obtained in laboratory tests over a period of 16 months for simultaneous treatment (leachate-methane) will be shown for parameters such as BOD5, MES, NH4, NO3-, pH, CH4. The behaviors observed for nitrogen are presented in figures 1 and 2. For the period when the conditions were optimal (250th to 450th day) the nitrification process made it possible to reach N-NH4 transformation rates higher than 95% (output concentration of less than 10 mgN NH4/l). Considering the average concentration of N_NH4 contained in the leachates (680 mg N-NH4/l) as well as the observed transformation rates (nitrification), the elimination of N-NO3 in the biofiltration process would be attributable to the activity methanotrophic bacteria (methanotrophic denitrification). Overall, the results obtained make it possible for landfill operators to make significant gains in terms of sustainable development (passive technology, increased treatment of nitrogen (NH4 and NO3), autothermal biological process), reduction of GHG emissions, etc.). Those work led to a patent in 2017. Future work planned is on-site testing using a prototype.