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MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

Studying at Cambridge

Comfort Ayittah

Plastic Waste Management in urban Ghana: A multi-criteria assessment of Polyethene waste management techniques

The use of plastics in packaging and manufacturing has increased significantly but there are many challenges in managing plastic waste. About 50% of the plastics in Ghana’s urban waste stream are polyethene (PE) items mostly in the form of sachets or shopping bags. Due to improper disposal and management, such items litter urban areas, clog drainage systems and pollute water bodies. Around the world different approaches are being used to manage plastic waste. Apart from landfill storage and incineration, mechanical and chemical recycling of some plastic materials have been attempted. Plastic items like carrier bags have either been levied to stimulate a switch to reusable alternatives or banned to address this bane.


This project seeks to evaluate waste management techniques through sustainability and circular economy lenses to identify the viable solution(s) within the Ghanaian context. A robust but relatively simple multi-criteria decision analysis (MCDA) was required to enable key stakeholders in the waste management and urban planning sectors to participate in the assessment. For its robustness, flexibility, ease of use and popularity in similar assessments, the Analytic Hierarchy Procedure was selected.


The literature review aimed to examine the characteristics and limitations of Ghana’s plastic waste management system; identify relevant evaluation criteria and identify the merits, demerits and peculiar conditions related to each of the technique. Additionally, an online survey was administered to gather Ghanaian urban dwellers’ perceptions, practices and possible responses to various waste management practices and policies. This provided insights into Ghana urban context and enhanced the multi-criteria analysis and recommendations.


The results of the AHP indicated that downcycling and ban of selected PE products could address the polyethene waste challenges in Ghana. However, there are interlinked systems challenges, for instance in urban water systems, and externalities that have to be tackled to ensure successful implementation. Overall, this project provides a sound framework that can be used for assessing other waste management techniques. However, proper waste characterization and understanding of interdependencies in urban systems are prerequisites for adaptation of this assessment framework to other contexts.