Kang Yllah Okin, Yabar Helmut, Mizunoya Takeshi, Higano Yoshiro
Graduate School of Science and Technology, Degree Program in Life and Earth Sciences, Doctoral Program in Environmental Studies: Sustainability, Technology & Policy (SUSTEP), University of Tsukuba, Japan.
Heliyon. 2023 Mar 9;9(3):e14372. doi: 10.1016/j.heliyon.2023.e14372. eCollection 2023 Mar.
Like many populated urban agglomerations in Africa, Kinshasa, the capital of Democratic Republic of Congo, faces several challenges to manage its exponentially growing Municipal Solid Waste. With its 12, 000, 000 people daily generating 7800 tons of Municipal Solid waste, the city still struggles with basic services such as waste collection and sanitary landfill. This causes major social, environmental and health related issues. With the aim of contributing to the implementation of a better management system in Kinshasa, this study evaluates the environmental impact and the cost of the existing waste management framework and proposes 6 alternative scenarios. Each scenario attempts to optimize Greenhouse gas emissions and cost, using the Life Cycle Assessment approach. Results show that the current municipal solid waste management in Kinshasa city emits 640,673 tons of CO equivalent per year and costs a total of 17, 776, 169.78USD yearly. Focusing on increasing waste collection coverage and recycling activities in the proposed 6 scenarios, scenario 4 where all municipal solid waste is collected, produces 4,042,402 tons of CO equivalent per year and costs 143, 296, 983.4 yearly. In scenario 7, considered the most optimized management model for Kinshasa in this study, municipal solid waste is valorized through different treatment processes and atmospheric pollution reaches 2,835,491 tons of CO equivalent yearly, with a management cost of 152, 790, 779.4 USD/year. This study finds that the optimization of the Municipal Solid Waste management system in Kinshasa city causes the atmospheric pollution in terms of CO2 equivalent to decrease by half, when all waste is collected. Landfill diversion rate reaches up to 70%, but the overall MSW management cost increases by almost eight times as much as the current operational cost. The optimization of the management system is done by increasing waste collection coverage and implementing diverse streams of waste valorization. Despite the wide use of the Life Cycle Assessment method in waste management and decision making, this method has not yet been, to the best knowledge of the authors, applied in estimating Greenhouse gas emissions and cost of the Municipal Solid Waste in the specific context of Kinshasa city.
与非洲许多人口密集的城市群一样，刚果民主共和国首都金沙萨在管理其呈指数级增长的城市固体废弃物方面面临诸多挑战。该市有1200万人口，每天产生7800吨城市固体废弃物，在垃圾收集和卫生填埋等基本服务方面仍存在困难。这引发了重大的社会、环境和健康相关问题。为了推动金沙萨实施更好的管理系统，本研究评估了现有废物管理框架的环境影响和成本，并提出了6种替代方案。每种方案都试图采用生命周期评估方法来优化温室气体排放和成本。结果表明，金沙萨市目前的城市固体废弃物管理每年排放640,673吨二氧化碳当量，每年总成本为17,776,169.78美元。在所提出的6种方案中，重点是提高垃圾收集覆盖率和回收活动，方案4中所有城市固体废弃物都被收集，每年产生4,042,402吨二氧化碳当量，每年成本为143,296,983.4美元。在方案7中，本研究认为这是金沙萨最优化的管理模式，城市固体废弃物通过不同的处理过程实现增值，每年大气污染达到2,835,491吨二氧化碳当量，管理成本为每年152,790,779.4美元。本研究发现，当所有垃圾都被收集时，金沙萨市城市固体废弃物管理系统的优化使二氧化碳当量方面的大气污染减少一半。填埋转移率高达70%，但城市固体废弃物管理总成本几乎增加到当前运营成本的八倍。管理系统的优化是通过提高垃圾收集覆盖率和实施多种废弃物增值流程来实现的。尽管生命周期评估方法在废物管理和决策中得到广泛应用，但据作者所知，该方法尚未应用于在金沙萨市的特定背景下估算城市固体废弃物的温室气体排放和成本。
