Mathematical Model for Sustainable Construction and Demolition Waste Management

Abstract

An estimated 3 billion tons of solid waste (garbage, ashes, residues, combustible and non-combustible, hazardous, and sewage) are generated annually, with 25-30% coming from construction and demolition waste (CDW). Despite relatively high daily waste generation rates per capita, most developing countries do not have a comprehensive waste management system. In order to balance operational costs, environmental effects, and resource recovery, construction and demolition (C&D) waste management necessitates methodical decision-making. This study suggests a generalized Activity-Based Costing (ABC) framework for using a mathematical optimization approach to assess different C&D waste management strategies. The framework unifies recovery benefits, activity costs, environmental and regulatory costs, and costs associated with illegal disposal into a single cost model. Two disposal scenarios are developed: (i) legal disposal that includes resource recovery and recycling, and (ii) illegal disposal that does not include recycling but includes environmental liabilities and regulatory penalties. To allocate recyclable waste in a way that satisfies waste balance constraints and minimizes the overall cost of legal disposal, an optimization model is created. To compare the two disposal strategies' economic performance, a numerical example is provided. The suggested model illustrated the economic benefit of sustainable waste management techniques by showing that illegal disposal led to a significantly higher total cost of Rs. 4,779,060.00, while the legal disposal model decreased the overall waste management cost to Rs. 828,222.50. The result helps converse resource, environmental preservation, and enhanced public health, all of which support sustainable societal development.