Ecotoxicological assessment of waste foundry sands and the application of different classification systems

• Published in: Integrated environmental assessment and management 2024-11, Vol.20 (6), p.2294-2311
• Main Authors: Alias, Carlotta, Cioli, Flavio, Abbà, Alessandro, Feretti, Donatella, Sorlini, Sabrina
• Format: Article
• Language: English
• Subjects: Aliivibrio fischeri; Aliivibrio fischeri - drug effects; Animals; Bio-assays; Bioassay; Bioassays; Classification; Classification systems; Daphnia - drug effects; Daphnia magna; Dilution; Ecotoxicity; Ecotoxicology - methods; Environmental assessment; Environmental hazards; Environmental Impact Assessment; Environmental management; Environmental Monitoring - methods; Evaluation; Foundry sands; Freshwater crustaceans; Industrial Waste - analysis; Industrial wastes; Integrated environmental assessment; Landfills; Leachates; Leaching; Plant layout; Pseudokirchneriella subcapitata; Sand; Toxic hazards; Toxic waste disposal; Toxic wastes; Toxicity; Toxicity testing; Toxicity Tests - methods; Toxicology; Waste disposal sites; Waste materials; Waste recovery; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity
• ISSN: 1551-3777; 1551-3793; 1551-3793
• DOI: 10.1002/ieam.4983

The application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty‐five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457‐2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348‐3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single‐organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost‐effective and time‐efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment. Integr Environ Assess Manag 2024;20:2294–2311. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points The toxicity of waste foundry sand leachates was assessed using three ecotoxicity tests, and the results were summarized using three different synthetic indices to assess the environmental risk associated with the possible reuse of these materials. The samples of cast steel and a binder system based on sodium silicate‐ester cured were very toxic and were associated with high environmental risk, whereas the samples of cast iron and different binder systems were associated with