Biochar from palm fiber wastes as an activator of different oxidants for the elimination of pharmaceuticals from diverse classes in aqueous samples

• Published in: Journal of environmental management Vol. 323; p. 116148
• Main Authors: Grisales-Cifuentes, Claudia M., Serna-Galvis, Efraím A., Acelas, Nancy, Porras, Jazmín, Flórez, Elizabeth, Torres-Palma, Ricardo A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2022
• Subjects: Biochar; Carbocatalysis; Environmental analysis; Oxidants activation; Pharmaceuticals removal; Water treatment; Pharmaceuticals removal; Water treatment; Carbocatalysis; Environmental analysis; Biochar; Oxidants activation
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2022.116148

Biochar (BP) obtained from palm fiber wastes was combined with H2O2, peroxymonosulfate (PMS), or persulfate (PDS) to treat valsartan, acetaminophen, and cephalexin in water. BP activated PMS and PDS but no H2O2. Computational calculations indicated that interactions of PMS and PDS with BP are more favored than those with HP. The highest synergistic effect was obtained for the removal of valsartan by BP + PMS. This carbocatalytic process was optimized, evaluating the effects of pH, BP dose, and peroxymonosulfate concentration, and minimizing the oxidant quantity to decrease costs and environmental impacts of the process. SO4•−, HO•, 1O2, and O2•- were the agents involved in the degradation of the pharmaceuticals. The reusability of BP was tested, showing that the carbocatalytic process removed ∼80% of target pollutants after 120 min of treatment even at the fourth reuse cycle. Also, the process decreased the phytotoxicity of the treated sample. Simulated hospital wastewater was treated and its components induced competing effects, but the system achieved the target pharmaceuticals removal in this matrix. Additionally, the analysis of environmental impact using a life cycle assessment unraveled that the carbocatalytic process had a carbon footprint of 2.87 Kg CO2-Eq, with the biochar preparation (which involves the use of ZnCl2 and electric energy consumption) as the main hotspot in the process. [Display omitted] •Biochar combined with H2O2, peroxymonosulfate, or persulfate to degrade pollutants.•Synergy for biochar with persulfate or peroxymonosulfate was found.•Carbocatalytic process optimization led to minimization of oxidant consumption.•SO4.•−, HO•, 1O2, and O2•- participated in the degradation of pharmaceuticals.•High degradation efficiency and biochar reusability in carbocatalytic process.