Influence of Industrial Symbiosis on Solid Waste Reuse in Manufacturing Industries in Kisumu County, Kenya

Industrial symbiosis (IS) is a practical approach to sustainable economic and environmental management involving exchanging materials, energy, water, and by-products among industries. While IS has been extensively studied in developed countries, its implementation in developing countries still needs to be improved. The purpose of the research was to assess the influence of geographical proximity and symbiotic intensity on the exchange of solid waste materials. This study employed a descriptive, cross-sectional research design and examined 41 manufacturing industries in Kisumu County, Kenya. A combination of quantitative and qualitative data was collected through questionnaires administered to technical officers in the industry. Besides, in-depth interviews with industry experts, county administrators, and industry association representatives were conducted, providing valuable insights and perspectives on the subject matter. The findings established that geographical proximity did not significantly influence types of waste exchanged (p = 0.298, p = 0.327, and p = 0.535) using nutrient-value waste as the reference category. This finding was likely due to high variability in distance between industries in the symbiotic exchanges. In contrast, the symbiotic intensity statistically significantly influenced the amount of solid waste reused in the network (Adjusted R2 = 0.113, p = 0.039). Furthermore, it was established that increasing the number of actors in the network (β = 0.324) can significantly impact solid waste reuse more than increasing the number of types of waste being exchanged (β = 0.243). This study underscores IS as a sustainable alternative to conventional manufacturing, especially in developing countries, while indicating that factors other than geographical proximity shape symbiosis.