RT Journal Article T1 Acid neutralisation capacity (ANC) of biomass ashes and its potential use for phosphogypsum leachate cleaning A1 Soto Cruz, Francisco Javier A1 Pérez Moreno, Silvia María A1 Barba Lobo, Alejandro A1 Bolívar Raya, Juan Pedro A1 Casas Ruiz, Melquiades A1 Martínez García, Verónica A1 Gázquez González, Manuel Jesús AB The production of acidic leachates from phosphogypsum (PGL) stacks is a worldwide problem, since high concentrations of pollutants (heavy metals, metalloids, sulphates, and phosphates, among others) can be released to the environment. PGL should therefore be treated before its discharge. The aim of this study was to develop a neutralisation procedure using ashes and slags from a biomass power plant to clean PGL, thus contributing to the circular economy. To assess the acid neutralisation capacity (ANC) of ashes and slags, the neutralisation curves with nitric acid, phosphoric acid, and PGL were performed after adding each waste type. Furthermore, the removal efficiency (RE) of the cleaning treatment for major and trace elements was obtained. The biomass ash demonstrated a greater degree of pollutant removal efficiency (around 100 % for many heavy metals), exhibiting a 20 % improvement over the slags in the neutralisation process. This can be attributed to the higher quartz content and lower specific area observed in the slags, which ultimately resulted in lower ANC. For the PGL neutralisation, the biomass ash had an ANC range between 7.37 mEq/g and 9.79 mEq/g of residue, and the RE for toxic metals was generally >90 %. Finally, when diluting PGL (1/10), the residue could clean all the elemental pollutants considered by the regulations. PB Elsevier SN 2214-7144 (electrónico) YR 2025 FD 2025 LK https://hdl.handle.net/10272/28016 UL https://hdl.handle.net/10272/28016 LA eng NO Soto-Cruz, F. J., Pérez-Moreno, S. M., Barba-Lobo, A., Bolívar, J. P., Casas-Ruiz, M., García, V. M., & Gázquez, M. J. (2025). Acid neutralisation capacity (ANC) of biomass ashes and its potential use for phosphogypsum leachate cleaning. Journal of Water Process Engineering, 70, 106968. https://doi.org/10.1016/j.jwpe.2025.106968 NO This research was funded by the following projects: Operative FEDER Program-Andalucía 2014-2020 (UHU-1255876, UHU-202020); Grants PID2020-116461RB-C21 and 116461RA-C22 funded by MICIU/AEI/10.13039/501100011033; Research grant UCA/REC44VPCT/2021, by the Universidad de Cádiz; Andalusian government (I+D+i-JAPAIDI-Retos project PY20_00096); Grant TED2021-130361B-I00 funded by MICIU/AEI/10.13039/501100011033 and, by “European Union NextGenerationEU/PRTR”, and Campus de Excelencia Internacional del Mar (CEIMAR) (research project CEIJ-C07.2). The open access fee was co-funded by the QUALIFICA Project (QUAL21-0019, Junta de Andalucía). DS Repositorio Institucional de la Universidad de Huelva RD 31 may 2026