Health and environmental impact assessment of landfill mining activities

Zari, Mohammed (2024) Health and environmental impact assessment of landfill mining activities. PhD thesis, University of Nottingham.

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Abstract

The adoption of landfill mining (LFM) has the potential to reduce the negative environmental effects of landfills while also recovering critical and secondary raw materials, energy, and land space by a series of on-site mechanical operations. However, there is a fundamental lack of understanding of how these activities could impact the environment and human health during LFM mining operations through atmospheric transport of contaminants. Therefore, this research aims to bridge this gap and optimize the benefits of LFM activities by shedding light on the potential health and environmental impacts associated with these practices.

A sampling programme was devised for an existing landfill site and recovered waste material characterised for physical, chemical, and biological properties. Almost 40 kg of municipal solid waste (MSW) was collected from 4 different wells (~10 kg each from wells 1901, 1904, 1906, and 1907) using a rotary drilling rig with depth ranging from surface of 7 - 8 metres. Samples were subjected to a wide array of laboratory analysis to meet the objectives for a risk assessment of LFM on human health and the environment. Characterisation results were used to derive pollution and health impact indices and other key indicators. Additionally, a method for computing the amount of dust, coupled with adoption of surface mining activities equations was proposed for each individual LFM activity. Subsequently, air dispersion modelling software (ADMS 5) was used to determine the potential air quality impact of LFM, with a focus on dust emissions as the main emission associated with landfill mining processes. Different scenarios were considered based on locally derived site meteorological data. Well-established statistical methods were used in the assessment to draw meaningful interpretation, identify parameter trends and support the research findings.

Results of potentially toxic elements were assessed against regulatory soil guideline values (SGVs). The concentrations of As, Cd, Cr, Pb, Cu, and Zn were above permissible limits set for soil in the UK. The Zn and Pb concentrations were found to be the highest in wells 1901 and 1904, respectively, compared to the SGVs. The concentrations also varied significantly among the four wells and decreased in the following order: Zn>Mn>Pb>Cu>Ba>Cr>Ni>As>Co>Cd. The pollution load index was >1, indicating that unacceptable pollution could arise. The study predicts that the landfill could pose a significant risk to human health due to LFM, with potential non-carcinogenic risks of Zn and Pb being higher than the levels set by the USEPA. Carcinogenic assessment suggests that Cr was the most prominent metal followed by As, which could cause human health impacts. Emission estimation results showed that point source activities are the major sources of emission, with cover removal loading activity being the highest as an individual activity. Air dispersion modelling results suggest that dust concentrations are most intense in low wind and maximum emission rate scenarios. Results also suggest that some dust concentration values were above the Air Quality Strategy for England PM10s limit, especially with the inclusion of background concentrations. Therefore, the risk to the human health and environment is potentially significant.

Design and implementation of LFM processes must adequately consider environmental and health impacts to allow safe practices from an occupational health (protection of site workers), off-site human health and the surrounding environment.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Smith, Richard
Ferrari, Rebecca
Keywords: Landfill mining; Heavy metals; Municipal solid waste; Pollution assessment; Human health risk assessment; Emission rate; Airborne particle; Dust pollution; Air pollution; Atmospheric dispersion modelling; ADMS
Subjects: T Technology > TD Environmental technology. Sanitary engineering
Faculties/Schools: UK Campuses > Faculty of Engineering > Department of Chemical and Environmental Engineering
Item ID: 76992
Depositing User: Zari, Mohammed
Date Deposited: 12 Apr 2024 08:55
Last Modified: 12 Apr 2024 08:55
URI: https://eprints.nottingham.ac.uk/id/eprint/76992

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