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Full text release has been delayed at the author's request until December 09, 2025

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An Evaluation of In-vessel Composting System for Food Waste Management

Shahi, Prashant
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1703173139975233

Abstract Details

2023, MS, University of Cincinnati, Engineering and Applied Science: Environmental Engineering.
Higher education institutions like universities accommodate a large number of students, which leads to the generation of large volumes of waste. A major part of this waste is organic, and a sustainable waste management method is needed to divert this waste from sanitary landfills. Commercial in-vessel composting systems are a relatively new technology that has been recently popular for the fast rate of organic waste degradation, convenience of operation, and odor control. Oklin GG-10 is an in-vessel composting system that is able to process organic waste in 24 hours. This system is able to process waste up to 25 kg/day, making it a suitable sustainable waste management option for cafeterias at universities. University of Cincinnati (UC) acquired this system to evaluate the performance of the in-vessel composting system for processing organic waste from one of UC’s dining halls. The operating conditions of the in-vessel system along with the characteristics of the final product and overall environmental impact of the in-vessel composter were evaluated. Further, this evaluation addressed concerns regarding the maturity and applicability of the final product. The composting process reduced the food waste volume by 81±5% (v/v) in a 24-hour period. The compost had an acidic pH (range of 4 to 5) throughout its operation period of five months. The composter was externally heated and maintained above 40°C. The composter had a high aeration rate, and the food waste was consistently turned by rotational blades that lowered the moisture content of the compost by 52% (w/w) in a 24-hour period. This process produced an extremely dehydrated compost that required daily addition of water to maintain an adequate moisture level. Further, the average sodium and chloride amounts of the final compost was 1.2 and 1.7 % (dry weight), respectively, and the Agricultural Index (Ag Index) ranged between 2 to 3, indicating high levels of sodium and chlorides compared to macronutrients N, P and K. The cucumber seed germination test with compost extract showed phytotoxicity, suggesting the compost would require further maturation. In addition, the microbial biomass was low or absent in the final compost with no genomic DNA isolated after various DNA extractions were made. This result indicates that the starting Acidulo™ inoculum does not survive during the composting process. Furthermore, the in-vessel composter had a high energy consumption rate of 1498 kWh/ MT organic waste. This energy consumption rate in the Cincinnati area for the in-vessel composting process would add 1007 kg CO2/ MT of organic waste to the atmosphere. The cost of organic waste processing using the Oklin GG-10 was estimated to be $424 per MT of organic waste per year, while the cost of waste disposal in a sanitary landfill was estimated to be $152 per MT of organic waste per year.
Drew McAvoy, Ph.D. (Committee Chair)
David Wendell, Ph.D. (Committee Member)
Margaret Kupferle, Ph.D. (Committee Member)
113 p.
Environmental Engineering
In-vessel Composting; Food waste composting; Microbiology of compost; Life Cycle Assessment; Organic waste composting; Waste management

Recommended Citations

Citations

  • Shahi, P. (2023). An Evaluation of In-vessel Composting System for Food Waste Management [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1703173139975233

    APA Style (7th edition)

  • Shahi, Prashant. An Evaluation of In-vessel Composting System for Food Waste Management. 2023. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1703173139975233.

    MLA Style (8th edition)

  • Shahi, Prashant. "An Evaluation of In-vessel Composting System for Food Waste Management." Master's thesis, University of Cincinnati, 2023. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1703173139975233

    Chicago Manual of Style (17th edition)

ucin1703173139975233
© 2023, some rights reserved.Creative Commons License An Evaluation of In-vessel Composting System for Food Waste Management by Prashant Shahi is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Cincinnati and OhioLINK.
Release 3.2.12