Passive methane oxidation biosystems for long term mitigation of fugitive emissions from old landfills

根据加拿大2015年温室气体清单，在加拿大垃圾填埋场产生的3000万吨二氧化碳当量中，最终排放了19亿吨二氧化碳当量，其中一些以逃逸或不受控制的甲烷（CH4）排放的形式逃逸到大气中。在沼气提取系统达到使用寿命或关闭后，垃圾填埋场的排放可能会持续数十年。成功的土地复垦项目，比如把一个旧的垃圾填埋场变成一个公园，取决于被动的、低维护的技术，这些技术可以应对这些排放。本研究的主要目标是应用PI开发的设计程序，该程序考虑了被动甲烷氧化生物系统（PMOB）的水力行为，在旧Kitchener垃圾填埋场建造和监测一个中试规模的PMOB，最近变成了一个公园（麦克伦南市政公园）。我们的主要假设是，这种设计方法，包括最近在欧洲采用的设计建议，将导致一个有效的PMOB，能够减少目前到达基奇纳垃圾填埋场表面的甲烷逸散性排放到一个可接受的水平。这种设计方法主要基于PMOB的水力特性以及它们如何影响非饱和多孔介质中的气体运移。如果不注意这一点，可能会导致高甲烷负荷，即高表面通量或热点。这个项目的新颖之处在于，它将是第一个在设计PMOB时正式考虑水和气体的不饱和流动的项目。这一试点规模的PMOB的有效性文件将有助于滑铁卢大区市政府（RMW）及其顾问GHD制定一项长期、持久的战略，以减少基奇纳垃圾填埋场和其他由RMW负责的垃圾填埋场的甲烷排放。最终，我们团队的目标是提出一种低维护，高影响的技术，以减少垃圾填埋场的排放，可以被加拿大各地的垃圾填埋场设计师和运营商应用。

According to Canada's 2015 Greenhouse Gas Inventory, 19 Megatonnes (Mt) of carbon dioxide equivalent, out of the 30 Mt generated by Canadian landfills were ultimately emitted, some escaping to the atmosphere in the form of fugitive - or uncontrolled - methane (CH4) emissions. Landfill emissions can continue for decades after biogas extraction systems reach end-of-life or have been turned off. Successful land reclamation projects, such as turning an old landfill into a park, depends of passive, low-maintenance, technologies that can cope with these emissions. The main goal of this research is to apply the design procedure developed by the PI, which takes into consideration the hydraulic behaviour of passive methane oxidation biosystem (PMOB), to construct and monitor a pilot-scale PMOB at the old Kitchener landfill, recently turned into a park (McLennan municipal park). Our main hypothesis is that this design methodology, with inclusion of recent design recommendations adopted in Europe, will lead to an effective PMOB that is capable of abating the methane fugitive emissions that presently reach the surface of the Kitchener landfill to an acceptable level. This design methodology is based mainly on the hydraulic properties of the PMOB and how they can affect gas migration within un unsaturated porous media. Lack of attention to it, may lead to high methane loadings, i.e., high surface fluxes or hotspots. The novelty of this project is that it will be the first where a PMOB will be designed with formal consideration of unsaturated flow of water and gas. The documentation of the effectiveness of this pilot-scale PMOB will be instrumental in helping the Region Municipality of Waterloo (RMW) and its consultant, GHD, develop a long-term, durable, strategy to abate methane emissions at the Kitchener landfill and other landfills under the responsibility of the RMW. Ultimately, our team aims at proposing a low-maintenance, high impact technology to abate landfill emissions that could be applied by landfill designers and operators across Canada.