Estimation of Leachate Generated from Zimbabwe’s Municipal Solid Wastes (MSW) Landfills using a Simple Stochastic Water Balance Model

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Andile B. Maqhuzu
Kunio Yoshikawa
Fumitake Takahashi

Abstract

Landfilling remains the predominant component in the waste management hierarchy of most developing nations. The adoption of emerging waste management technologies and the use of recycling or composting is still in its infancy. Among several inadequacies of current waste management practices in Zimbabwe is the absence of sanitary disposal of municipal solid waste (MSW) in landfills. As a result, the leachate generation rate and leachate characteristics are not routinely monitored. Such information is essential when assessing the impact of leachate on ground and surface water or a facility to which the leachate can be conveyed. Indiscriminate disposal of MSW at unsanitary dumpsites poses a double threat as the discharge of hazardous leachate to potable water sources and emissions of toxic odours leads to further environmental degradation. Poor waste management practices are compounded by a lack of financial resources and technical capabilities. The financial incapacitation of local authorities is reflected in the fact that there are no reliable statistics on MSW generation and disposal. This lack of comprehensive data has hampered the quantification of MSW and resultant leachate. Therefore, the objectives of this study are twofold. First, we seek to predict the annual quantity of landfilled MSW, and secondly to quantify the leachate flow from Zimbabwe’s landfills. Both were achieved through the use of probability models and a stochastic water balance method supported by 10,000 Monte Carlo iterations. The calculated 90 % confidence interval indicates that 13-16 million tons of MSW have been landfilled, with about 41-128 million m3 of leachate released since 1980. This is equivalent to a mean of 414,212 tons a-1 of landfilled MSW and 2.2 million m3 a-1 of leachate generated, respectively.

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How to Cite
Maqhuzu, A. B., Yoshikawa, K., & Takahashi, F. (2018). Estimation of Leachate Generated from Zimbabwe’s Municipal Solid Wastes (MSW) Landfills using a Simple Stochastic Water Balance Model. Applied Environmental Research, 40(2), 40–50. https://doi.org/10.35762/AER.2018.40.2.4
Section
Original Article
Author Biographies

Andile B. Maqhuzu, School of Environment and Society, Tokyo Institute of Technology, Tokyo, Japan

Andile Blessings Maqhuzu is a second-year graduate student at Tokyo Institute of Technology in Japan. He received a bachelor’s degree in Chemical Engineering from the National University of Science and Technology from Bulawayo, Zimbabwe. His research interests cover wastewater treatment, landfill disposal and biomass-to-energy technologies

Kunio Yoshikawa, School of Environment and Society, Tokyo Institute of Technology, Tokyo, Japan

Dr. Kunio Yoshikawa
Professor, Frontier Research Center,
Tokyo Institute of Technology, Japan.

He graduated from Tokyo Institute of Technology and obtained PhD in 1986. After graduation from Tokyo Institute of Technology, Prof. Yoshikawa worked for Mitsubishi Heavy Industries for one year, and then went back to his home university to become a research associate, associate professor and professor.

His major research areas are energy conversion, thermal engineering, combustion, gasification, waste treatment technologies and atmospheric environmental engineering, and he wrote more than 200 papers.

His main awards are AIAA (American Institute of Aeronautics and Astronautics) Best Paper Award in 1999, ASME (American Society of Mechanical Engineers) James Harry Potter Gold Medal in 2001, JSME (Japanese Society of Mechanical Engineers) Environmental Technology Achievement Award in 2006 and the Fellow of JSME in 2008.

Fumitake Takahashi, School of Environment and Society, Tokyo Institute of Technology, Tokyo, Japan

Fumitake Takahashi is an associate professor in the Department of Transdisciplinary Science and Engineering, Tokyo Institute of Technology, Japan. His research interests cover waste management and recycling, value-added treatment, environmental risk assessment, socio-psychological factors of waste recycling