Low-carbon pathways for hazardous waste treatment: Environmental and economic implications in a zero-waste park

• Source sorting with low-emission incineration cuts 41.8% of emissions. • Optimal strategy offers low cost, low impact, and policy scalability. The rapid growth of hazardous waste (HW) poses significant environmental challenges, particularly regarding carbon emissions from waste treatment. This study employs life cycle assessment (LCA) to quantify the carbon emissions associated with HW disposal from 12 enterprises in an economic park in East China, aiming to inform strategies for constructing a Zero-waste park. Four mitigation scenarios were developed, combining landfill and incineration at varying ratios and incorporating source classification. Results show that HW incineration dominates carbon emissions, with fine distillation residues (HW11) contributing the most due to their high carbon content. Among the scenarios, source classification with centralized low-emission incineration (Scenario 4) achieved a 41.8% emission reduction at the lowest economic and environmental cost, making it the most viable strategy. Environmental impact assessments also revealed that reducing incineration curtails ecotoxicity and fossil fuel depletion. These findings provide practical guidance for optimizing HW management and support the development of low-carbon industrial parks.