Zinc and sulfur functionalized biochar as a peroxydisulfate activator via deferred ultraviolet irradiation for tetracycline removal

Yixue Qin; Sheng Wang; Bingbing Zhang; Weijie Chen; Mingze An; Zhao Yang; Hairong Gao; Shuhao Qin

doi:10.1039/d3ra07923f

Zinc and sulfur functionalized biochar as a peroxydisulfate activator via deferred ultraviolet irradiation for tetracycline removal

RSC Adv. 2024 Feb 13;14(8):5648-5664. doi: 10.1039/d3ra07923f. eCollection 2024 Feb 7.

Authors

Yixue Qin^{1

2}, Sheng Wang², Bingbing Zhang^{2

3}, Weijie Chen^{2

3}, Mingze An², Zhao Yang², Hairong Gao^{1

2}, Shuhao Qin^{1

2}

Affiliations

¹ College of Materials and Metallurgy, Guizhou University Guiyang 550025 China pec.shqin@gzu.edu.cn.
² National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang 550014 China 1191117410@qq.com.
³ Resources and Environmental Engineering Department, Guizhou University Guiyang 550025 China.

Abstract

To enhance the degradation of tetracycline class (TC) residuals of high-concentration from pharmaceutical wastewater, a novel zinc (Zn) and sulfur (S) functionalized biochar (SC-Zn), as a peroxydisulfate (PDS) activator, was prepared by two-step pyrolysis using ZnSO₄ accumulated water-hyacinth. Results showed that the removal rate of 50, 150, and 250 mg per L TC reached 100%, 99.22% and 94.83% respectively, by the SC-Zn/PDS system at a dosage of 0.3 g per L SC-Zn and 1.2 mM PDS, via the deferred ultraviolet (UV) irradiation design. Such excellent performance for TC removal was due to the synergetic activation of PDS by the biochar activator and UV-irradiation with biochar as a responsive photocatalyst. The functionalization of the co-doped Zn and S endowed the biochar SC-Zn with a significantly enhanced catalytic performance, since Zn was inferred to be the dominant catalytic site for SO₄˙^- generation, while S played a key role in the synergism with Zn by acting as the primary adsorption site for the reaction substrates. The employed SC-Zn/PDS/UV system had excellent anti-interference under different environmental backgrounds, and compared with the removal rate of TC by adsorption of SC-Zn, the increasing rate in the SC-Zn/PDS/UV system (18.75%) was higher than the sum of the increases in the SC-Zn/PDS (9.87%) and SC-Zn/UV systems (3.34%), furtherly verifying the systematic superiority of this synergy effect. This study aimed to prepare a high-performance functionalized biochar activator and elucidate the rational design of deferred UV-irradiation of PDS activation to efficiently remove high-concentration antibiotic pollutants.