An anomalous metal-rich phosphogypsum: Characterization and classification according to international regulations

• Published in: Journal of hazardous materials 2017-06, Vol.331, p.99-108
• Main Authors: Macías, Francisco, Cánovas, Carlos R., Cruz-Hernández, Pablo, Carrero, Sergio, Asta, Maria P., Nieto, José Miguel, Pérez-López, Rafael
• Format: Article
• Language: English
• Subjects: Aquatic life risk; Arsenic anomaly; Hazardousness classification; Leaching tests
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2017.02.015

•Leaching tests used by EU and US environmental rules were applied to phosphogypsum.•Phosphogypsum from Huelva shows anomalously high metal levels.•High mobility of contaminants was found under different weathering scenarios.•Discrepancies between EU and US regulations were observed regarding hazardousness.•We propose a complementary protocol based on the risk for the aquatic life. Phosphogypsum is the main waste generated by the phosphate fertilizer industry. Despite the high level of pollutants found in phosphogypsum and the proximity of stacks to cities, there are no specific regulations for the management of this waste. This study addresses this issue by applying to phosphogypsum, from a fertilizer plant in Huelva (SW Spain), the leaching tests proposed by the current European and US environmental regulations for wastes management and classification. Two main conclusions were obtained: 1) the anomalous metal and metalloid concentrations (e.g. As, Fe, Pb, Sb, Mn, V and Cu) and higher mobility observed in the Huelva phosphogypsum compared to other stacks worldwide, and 2) the discrepancies observed between EU and US regulations dealing with hazardousness classification of these materials. This latter finding suggests the need to use complementary assessment protocols to obtain a better characterization and classification of these wastes. An evaluation of the potential risk to the aquatic life according to the US EPA regulation is proposed in this study. The results warn about the acute and chronic effects on the aquatic life of this waste and suggest the adoption of more strict measures for a safe disposal of phosphogypsum stacks.