Resource Mining for a Bioreactor Landfill

Background: A new generation of the sustainable landfill is designed to achieve sustainable Municipal Solid Waste (MSW) management. It is hybrid anaerobic/aerobic biodegradation landfill followed by landfill mining. However, there is limited information on landfill mining, especially the criteria and process for the practitioner to determine the end of the landfill biodegradation to commence landfill mining. Objective: Hence the overall objective of this research was to develop a comprehensive resource mining plan for bioreactor landfills. </P><P> Method: When waste decomposition becomes slower or stopped, the landfill can be mined to recover resources and utilize the recovered space. The amount of the gas generated, landfill temperature and landfill settlement are indirect measures of landfill activity. Also, the concentration of cellulose (C), hemicelluloses (H), and lignin (L) can describe the biodegradable fractions of waste. Hence the biodegradation in landfills can be monitored by recording the change in methane production, temperature, settlement and the (C+H)/L ratio of waste. Once methane recovery is minimal, landfill reaches a maximum settlement and, ambient temperature plus the (C+H)/L value reaches a stable value of 0.25 indicating end of biodegradation. At this point landfill resources including compost material, non-recoverable waste, and recyclables such as plastics, metal and glass can be mined and recovered. Compost and recyclables can be sold at market value and the non-recovered waste with high energy content can be used as refuse-derived fuel. Once the landfill has been mined space can be reused thus eliminating the need to allocate valuable land for new landfills. </P><P> Result: The landfill mining detailed in this manuscript utilizes principles from single stream type recycling facilities to ensure feasibility. The first landfill will be excavated and screened to separate the biodegraded soil and compost fraction from the recyclables. Then the screened recyclable materials are transported for further processing in a single stream type separation facility where they will be separated, bundled and sold. Conclusion: A cost calculation was performed for the resource mining of Calgary Biocell and if the mined resources are sold at market values, then the mining of Calgary Biocell would generate approximately $4M.

A unique “icy seep” aquatic habitat in the high Teton Range: Potential refuge for biological assemblages imperiled by climate change

Alpine streams are threatened as meltwater sources diminish. We established baseline monitoring efforts of alpine streams in the Teton Range during 2015 by describing biotic and abiotic conditions of surface glacier and snowmelt streams. Our results indicated a third alpine stream type, icy seeps. Icy seeps are fed by subterranean ice melt, extremely cold but stable water temperature (summer mean <2°C), moderately high streambed stability (Pfankuch Index ~18-25), and relatively high specific conductivity (>50 μS cm-1). In 2016, we documented several icy seeps in the Teton massif, and our data suggest that they have the potential to serve as climate refugia for organisms and processes associated with extremely cold meltwater, due to the subterranean ice sources being more insulated from atmospheric conditions than surface glaciers and snowpack. Our 2016 work focused on locating icy seeps and documenting physical conditions, invertebrates, diatoms, and microbes in these alpine streams. We are processing the biological data, but microbial assemblages in icy seeps are similar to those found in streams fed by dwindling surface glacier ice. We are preparing to submit a paper about the microbial patterns, including how they compare to alpine streams representing comparable hydrological sources in Glacier National Park. Featured photo by Nicole Y-C on Unsplash. https://unsplash.com/photos/9XixVlnUCbk