ASSESSMENT OF CIRCULAR ECONOMY-BASED RESOURCE RECOVERY TECHNIQUES IN WASTEWATER AND SOLID WASTE MANAGEMENT

Abstract

The accelerating depletion of natural resources, escalating volumes of municipal wastewater and solid waste, and the mounting urgency of global sustainability imperatives have collectively foregrounded the circular economy (CE) as a transformative paradigm for waste governance. This dissertation presents a comprehensive, multi-dimensional assessment of circular economy-based resource recovery (CERR) techniques as applied to wastewater treatment systems and solid waste management infrastructure. It investigates the technological, environmental, economic, institutional, and socio-cultural dimensions of resource recovery with the dual objective of synthesising existing knowledge and generating novel empirical and analytical contributions. Drawing on a systematic literature review, primary data from field case studies across India, Germany, Singapore, and Kenya, multi-criteria decision analysis (MCDA), life cycle assessment (LCA), techno-economic analysis (TEA), and material flow analysis (MFA), this research evaluates the performance of fourteen distinct CERR technologies spanning nutrient recovery, energy generation, water reclamation, critical mineral extraction, and bio-material synthesis. Key findings establish that integrated CERR systems operating under supportive regulatory frameworks achieve resource recovery efficiencies 37-62% higher than conventional linear waste treatment models, while reducing lifecycle greenhouse gas emissions by 28-45%. The research demonstrates that phosphorus recovery via struvite crystallisation, bio-electrochemical systems for simultaneous energy generation and contaminant removal, and synergistic biorefinery models integrating wastewater and organic solid waste streams represent the most technically viable and economically promising approaches for mid-to-large-scale implementation. The dissertation further identifies a persistent "policy-implementation gap" in low- and middle income countries (LMICs), characterised by insufficient regulatory clarity, fragmented institutional mandates, and inadequate financial mechanisms, as the primary structural barrier to CERR scale-up. Novel contributions include a Circular Waste-Resource Transition (CWRT) framework, a composite CERR Readiness Index (CERR-RI) applicable across national contexts, and a set of evidence-based policy recommendations aimed at enabling equitable and systemic transitions to circular waste economies. Keywords: Circular economy; resource recovery; wastewater management; solid waste; nutrient recovery; bio-energy; life cycle assessment; techno-economic analysis; sustainability transition; phosphorus; struvite; biorefinery; MCDA; policy frameworks.