Integrated Technical–Economic–Environmental Evaluation of Available Technologies for Heavy Metal Wastewater Treatment Used in Lead–Zinc Smelting in the Yellow River Basin

Evaluating the efficacy of available technology for pollutant treatment is critical for formulating environmental management policies and standards. To address the lack of systematic quantitative methods for evaluating available technology, we propose a method based on the Entropy Weight TOPSIS model which integrates technology, economic efficiency, environmental benefits, and operational feasibility. We applied this approach to evaluate six heavy metal wastewater treatment technologies used in the lead–zinc smelting industry in the Yellow River Basin of China. A total of 4 primary and 16 secondary evaluation indicators were identified. The data were mainly composed of supervised monitoring data collected by local environmental protection authorities and self-monitoring operation data collected from factories; moreover, 10 relevant experts were invited to assess the scoring indicators. The results showed that technical performance had the greatest contribution to the overall efficacy of the treatment technology (62.31% weight), followed by environmental benefits (14.24% weight), economic costs (12.08% weight), and operational feasibility (11.36% weight). The final scores and rankings of the six technologies evaluated showed that a sulfurization precipitation with two-stage lime neutralization and sedimentation technology received the highest score due to its balanced technical performance, economic cost, environmental benefits, and operational feasibility. Conversely, lime neutralization with flocculation precipitation technology ranked lowest due to its non-compliance with the emission limits in China, despite its low economic cost and carbon emission intensity. This study provides a quantitative methodological framework for evaluating available technology, emphasizing the balance of the technical, economic, and environmental benefits of the pollutant treatment technologies chosen and the relevant policies made.