Modular system for survey and long-term monitoring of soil CO2 exchange and CH4 effluxes

利用包括CO2和CH4通量室在内的各种技术测量CO2和CH4通量已成为全球变化研究的一个组成部分。然而，这些方法在污染物水文地质领域的应用非常有限。根据这一提议，我们需要设备来扩展我们现有的单室二氧化碳通量系统，以方便同时在八个观测点长期分析二氧化碳-土壤气体交换，并同时在调查和长期模式下测量CH4排放。为了充分考虑一个地点CO2和CH4通量的时空变化，有必要在多个地点同时进行分析。该室系统将用于量化土壤/沉积物与大气之间的二氧化碳交换，用于与加拿大资源和环境工业相关的各种应用，包括被碳氢化合物和生物燃料污染的场所、废石和尾矿、垃圾填埋场以及受土壤厌氧影响的自然环境。在被碳氢化合物和生物燃料污染的地点，预计CO2和CH4通量测量将有助于划定污染源区域的范围，限制深度一体化污染物降解速率，并揭示CH4释放到大气或进入附近结构的可能性。在矿场，二氧化碳通量测量将提供一种间接的方法来确定尾矿和废石的风化速率。在含有超基性矿物的尾矿或废石的矿区，测量将揭示这种材料是否能够直接从大气中吸收二氧化碳。在垃圾填埋场，该系统将提供设施排放的二氧化碳和甲烷的定量测量。该设备还将用于评估由土壤厌氧引起的高CH4外排的自然地点的CH4:CO2比率。通量室系统将有利于申请人的研究项目，理想地补充目前在土壤气体浓度、水分含量、同位素分析以及矿物学和微生物学研究方面的专业知识。

The measurement of CO2 and CH4 fluxes using a variety of techniques, including CO2 and CH4 flux chambers, has become an integral part of global change studies. However, these methods have only found very limited use in the field of contaminant hydrogeology. With this proposal, we are requesting equipment to extend our existing single chamber CO2 flux system to facilitate simultaneous long-term analysis of CO2-soil gas exchange at eight observation points and to concurrently measure CH4 emissions both in survey and long-term mode. Simultaneous analysis at multiple locations is necessary to adequately account for the spatial and temporal variability of CO2 and CH4 fluxes at a site. The chamber system will be used to quantify the exchange of CO2 between soils/sediments and the atmosphere for a variety of applications of relevance to Canada's resource and environmental industry including sites contaminated with hydrocarbons and biofuel, waste rock and tailings, landfill sites, and natural environments affected by soil anaerobiosis. At sites contaminated with hydrocarbons and biofuel, it is anticipated that CO2 and CH4 flux measurements will help to delineate the extent of contaminant source zones, constrain depth-integrated contaminant degradation rates, and reveal the potential for CH4 release to the atmosphere or ingress into nearby structures. At mine sites, CO2 flux measurements will provide an indirect means to determine tailings and waste rock weathering rates. At mine sites with tailings or waste rock that contain ultra-mafic minerals, the measurements will reveal if this type of material is capable of directly sequestering CO2 from the atmosphere. At landfill sites, the system will provide a quantitative measure of CO2 and CH4 emissions from the facilities. The equipment will also be used to evaluate the CH4:CO2 ratio at natural sites with high CH4 effluxes caused by soil anaerobiosis. The flux chamber system will benefit the research programs of the applicants by ideally complementing current expertise in the analysis of soil gas concentrations, moisture contents, isotopic analyses, as well as mineralogical, and microbiological studies.