Is Multi-Source Solid Waste Co-Disposal Practices in Waste-to-Energy Plants Sustainable?A Comparative Life Cycle Assessment

Abstract

This study assesses the sustainability of co-disposing combustible multi-source solid waste using excess waste-to-energy capacity. A comprehensive life cycle assessment was conducted on four typical co-disposal technologies (food waste, municipal sludge, medical waste, and industrial waste) compared to ten individual disposal methods. Findings show co-disposal technologies achieve over 95% reduction efficiency with energy recovery rates from 27.6% to 63.3%. Food waste co-disposal shows environmental benefits, while municipal sludge has adverse impacts. Medical and industrial waste co-disposal result in significant fossil CO2 emissions but reduce other environmental impacts. Economically, co-disposal projects show IRRs from 16.8% to over 2000%, reducing waste disposal fees by 23.7% to 90.5%. Despite these benefits, co-disposal is less energy-efficient than some individual methods and more carbon-intensive in specific cases. The study recommends using co-disposal as a supplementary approach and calls for clearer industry standards, regional strategies, and improved regulatory frameworks.

Keywords: Solid waste management, Waste to energy, co-disposal, Life Cycle Assessment, life cycle cost