La 3+ @BC500-S 2 O 8 2- system for removal of sulfonamide antibiotics in water.

Sulfonamide antibiotics (SAs) widely used have potentially negative effects on human beings and ecosystems. Adsorption and advanced oxidation methods have been extensively applied in SAs wastewater treatment. In this study, compared with Al ³⁺ @BC500 and Fe ³⁺ @BC500, La ³⁺ @BC500 for activating persulfate (S ₂ O ₈ ^2- ) had the best effect removal performance of sulfadiazine (SDZ) and sulfamethoxazole (SMX). Morphology, acidity, oxygen-containing functional groups, and loading of La ³⁺ @BC500 were analyzed by techniques, including EA, BET, XRD, XPS, FT-IR. XRD results show that with the increase of La ³⁺ loading, the surface characteristics of biochar gradually changed from CaCO ₃ to LaCO ₃ OH. Through EPR technology, it is proved that LaCO ₃ OH on the surface of La ³⁺ @BC500 can not only activate S ₂ O ₈ ^2- to generate SO ₄ ^- •, but also to produce •OH. In the optimization experiment, the optimal dosage of La ³⁺ is between 0.05 and 0.2 (mol/L)/g. SDZ had a good removal effect at pH (5-9), but SMX had a good removal effect only at pH=3. Zeta potential also proves that the material is more stable under acidic conditions. The removal process of SDZ is more in accord with pseudo-first-order kinetics (R ² =0.9869), while SMX is more in line with pseudo-second order kinetics (R ² =0.9926).
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.
(Copyright © 2023. Published by Elsevier B.V.)