Environmental life cycle assessment of construction and demolition waste recycling: A case of urban India

Abstract

The study compares life cycle environmental implications of two construction and demolition waste (C&DW) management alternatives, inert landfilling and integrated wet recycling, on many impact categories under several scenarios. Integrated wet-recycling valorizes coarse aggregates, sand, and soil, recovering over 95 percent of incoming C&DW waste. Using data from recycling plants operational in New Delhi complemented by the ecoinvent database, the study deploys SimaPro software and explores potential environmental implications of recycling compared to landfilling predominantly inert stony C&DW in urban India. Processes from the ecoinvent database were customized for Indian scenario using mix of primary and secondary data. ReCiPe method was used for impact assessment. Scenarios were developed to capture uncertainties in plant operational efficiencies, the share of carbon neutral electricity in overall generation mix, and avoided transport of natural materials. The results suggest that due to greater material recovery, integrated wet recycling is environmentally sound alternative compared to landfilling under most scenarios. Higher share of cleaner electricity lowered carbon emissions, but increased mineral scarcity and eutrophication among other impact categories, indicating environmental tradeoffs associated with energy intensive recycling process. Integrated recycling promises to lower environmental footprint of urban India while lowering requirement of virgin natural materials.