Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509031
This study establishes a carbon footprint calculation method and an environmental benefit assessment model for the dismantling process of waste televisions (TVs) based on life cycle assessment (LCA). Activity data on energy consumption and material flows were collected from typical treatment enterprises via field investigation. The ReCiPe 2016 model was applied to quantify midpoint and endpoint environmental impacts. Results show that the dismantling and recycling process yields net environmental benefits in most impact categories. At the midpoint level, significant reductions were observed in fossil resource scarcity (−26,494.23 kg oil eq), freshwater ecotoxicity (−2.21×10^4 kg 1,4-DCB), and greenhouse gas emissions (−956.53 kg CO2 eq). At the endpoint level, reductions in human health damage (−1.59×10^4 DALY), ecosystem damage (−2.35×10^4 species·yr), and resource depletion costs (−4.22×10^4 USD) were achieved. Carbon footprint analysis indicates that the carbon footprint per TV ranges from 0.231 to 0.247 kg CO2 eq per unit, with electricity consumption as the dominant emission source. Sensitivity analysis reveals that electricity consumption significantly influences the carbon footprint. Finally, emission reduction recommendations are proposed from aspects of equipment upgrade and energy management, providing theoretical basis and practical guidance for low-carbon treatment of electronic waste.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509120
The 'Zero-Waste City' initiative, centered on source reduction, resource utilization, and safe disposal of solid waste, aims to minimize environmental impact. To quantitatively assess its carbon reduction contribution, this study took Mianyang as a case, systematically collecting data on solid waste generation, utilization, and disposal across industrial, agricultural, and other sectors from 2021 to 2024. Employing an improved WARM model and emission factor method, and incorporating generation, utilization, and disposal intensities, the carbon reduction benefits before (2021–2022) and after (2023–2024) the initiative were evaluated. Results show that despite significant improvements in comprehensive utilization and safe disposal rates, total solid waste generation increased, leading to a net negative carbon effect of -127.6×10^4 tCO2eq based on absolute quantities. However, after stripping economic and population growth factors, intensity-based accounting revealed a cumulative reduction of 10.8×10^4 tCO2eq, demonstrating significant synergistic benefits. The industrial sector contributed the most, with a reduction of 40.2×10^4 tCO2eq, driven by green transformation and enhanced utilization capacity. Conversely, the rising intensity of domestic solid waste generation resulted in a negative benefit of -46.1×10^4 tCO2eq, highlighting a key area for future improvement. The study underscores the necessity of considering both intensity and absolute quantity dimensions in evaluating rapidly developing cities. These findings provide practical evidence and reference pathways for advancing 'Zero-Waste City' construction and synergistic pollution reduction and carbon mitigation under the 'dual carbon' goals.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608023
Zinc-containing steel dust sludge, a by-product of steelmaking, contains high levels of chlorine (Cl) along with valuable metals such as Fe, Zn, K, and Na. When recycled into the steel production process, Cl accumulates, causing sintering instability and severe corrosion of blast furnace linings. This study investigated water leaching for Cl removal from zinc-containing steel dust sludge. Under optimal conditions (liquid-to-solid ratio 5 mL/g, temperature 70 °C, time 60 min, rotation speed 160 r/min), the Cl leaching rate reached 87%. Furthermore, a three-stage countercurrent water washing process at a liquid-to-solid ratio of 6 mL/g and room temperature for 45 min achieved a Cl leaching rate exceeding 90%. The water washing also reduced the leaching toxicity of metals in the sludge to a certain extent. Characterization via XRD, SEM, FT-IR, and XPS revealed that water washing primarily dissolved soluble chlorides (NaCl, KCl, etc.), increasing the specific surface area from 2.71 to 10.11 m²/g and average pore size from 12.83 to 16.29 nm. These findings provide theoretical and technical support for efficient Cl removal from zinc-containing steel dust sludge, facilitating its safe resource utilization.