Use-Phase Environmental Risk and Sustainability Assessment of Liquid Polyferric Sulfate Produced Through Comprehensive Utilization of Waste Sulfuric Acid

Comprehensive utilization of hazardous industrial waste can recover resources but may also transfer residual hazardous constituents into downstream products. Preparing water treatment agents with low environmental risk is an important path towards sustainable development for the sulfuric acid industry. Following the framework of hazard identification, exposure assessment, hazard characterization, and risk characterization in the forthcoming Chinese national standard “General Principles for Environmental Risk Assessment of Products from Comprehensive Utilization of Hazardous Wastes”, this case study evaluated the use-phase human-health and aquatic ecological risks of a liquid polyferric sulfate coagulant produced from waste sulfuric acid. As, Pb, Hg, Cr, Zn, and Ni were reported in the product at 8.6 × 10−4, 8.6 × 10−5, 1.5 × 10−7, 4.78 × 10−3, 7.96 × 10−3, and 2.10 × 10−4 mg/L, respectively. Three predefined scenarios were considered: direct worker dermal contact during dosing, indirect dermal contact with receiving water, and aquatic exposure after discharge. Under the case-study parameterization, the total carcinogenic and non-carcinogenic risks were 2.46 × 10−7 and 3.90 × 10−4 for occupational exposure and 8.04 × 10−18 and 5.47 × 10−15 for indirect population exposure, respectively. The available ecological-effect dataset supported only a partial Hg-based screening. Thus, the conclusions are limited to the measured product composition, selected scenarios, assumptions, and benchmarks and do not constitute a comprehensive occupational, life-cycle, or multimedia environmental-safety assessment.