Cement kiln geared up to dispose industrial hazardous wastes of megacity under industrial symbiosis

Industrial symbiosis promotes circular economies with environmental and economic benefits. China's 14th Five-Year Plan for Circular Economy Development prioritizes waste recycling and co-processing in cement kilns. This research investigates the advantages of establishing symbiotic relationships between industrial park and cement kiln to address industrial hazardous waste (IHW) challenges. Using life cycle assessment and net cost analysis with system expansion, we quantify environmental and economic disparities between industrial park-cement symbiosis and non-symbiosis scenarios. The symbiosis mode reduces carbon emissions by 11 % and saves 8 % cost annually compared to non-symbiosis. Optimizing upstream waste fine management enhances calorific value and fossil fuel substitution, increasing CO₂ reduction and economic benefits but raising acidification and terrestrial ecotoxicity. Upstream-downstream cooperation is vital for systematic environmental relief. Employing carbon capture and ultra-low emissions in cement kilns mitigates environmental impact. These findings guide policies for better hazardous waste management, fostering a "waste-free city" and circular economy.