A Biowaste Treatment Technology Assessment in Malawi

Abstract

In the city of Blantyre, much of the generated municipal waste is biowaste, typically mixed with other waste fractions and disposed at the city’s dumpsite. Energy and nutrients could be recovered; however, with many biowaste options available, choosing what technology to implement is difficult. Selecting Organic Waste Treatment Technology (SOWATT) is a tool that supports decision making for selecting a biowaste treatment option considering social, technical, and environmental aspects. SOWATT was used to evaluate options for Blantyre’s Limbe Market. Anaerobic digestion, black soldier fly processing, slow pyrolysis, in-vessel composting, windrow composting, vermicomposting, and wet-biomass-briquetting were considered as options. The performance of each alternative was assessed based on five objectives by government, NGO, and market-based stakeholders in order to determine the most acceptable option for the greatest number of people: something that is rarely done, or if it is the preferences are not rigorously quantified (e.g., stakeholder workshops) and/or weighted against specific objectives. However, given the novelty of the ranking-solicitation process, some participants struggled with the variety of options presented, and further iterations of SOWATT will address this limitation. Ultimately, vermicomposting scored highest of all alternatives and could best achieve the five objectives as prioritized by the stakeholders when implemented.

Methods of Multi-Criteria Analysis in Technology Selection and Technology Assessment: A Systematic Literature Review

“…A substantial part of the studies concerns wastewater treatment technology selection (Ilangkumaran et al, 2013;Fetanat et al, 2021;Aydiner et al, 2016;Sadr et al, 2013;Meerholz & Brent, 2013;Salamirad et al, 2021 ) with the use of MCA methods. Some authors address problems of waste disposal technology selection (Jiang et al, 2015;Govind Kharat et al, 2019), biowaste treatment technology (Mpanang' ombe et al, 2018) or food waste technology (Chadderton et al, 2017). Many studies address interdisciplinary subjects, for example, sustainable waste disposal management (Torkayesh et al, 2021;Kharat et al, 2020).…”

Biochar from Lignocellulosic Biomass: The Importance of Physicochemical Characterization and Multi-Criteria Decision Analysis for Its Applications

“…The study reported the application of different MCDM techniques, mainly focusing on selecting WtE generation technologies based on environmental, economic, technical, and socio-political [147]. The reviewed literature evaluates the technologies that could efficiently convert biomass by applying technologies WTE to produce different energy carriers [147][148][149][150][151]. However, few studies in the literature applied MCDM, focusing on evaluating and optimizing specific WTE technologies based on the produced biochar properties and their applications.…”

A Tool for the Selection of Food Waste Management Approaches for the Hospitality and Food Service Sector in the UK

“…Economic impacts of AD: AD can be considered a more economically attractive FWM option than IVC [76] due to product revenue arising from the electricity generation (GBP 4/t FW) and the electricity exported to the grid (GBP 13/t FW) [46]. In the UK, the digestate has no market value and operators may force to pay users to take it away (GBP 4/t FW) [46].…”