Enhanced catalytic degradation of tetracycline hydrochloride by a NZVI@MOF-545 composite with peroxydisulfate: Performance and mechanism

• Published in: Applied surface science 2024-07, Vol.661, p.160069, Article 160069
• Main Authors: Lu, Hao, Wang, Renjuan, Huang, Bowen, Hu, Wenbin, Xu, Hui, Yang, Qiang, Zhou, Qingyun, Chen, Qi, Kong, Yun
• Format: Article
• Language: English
• Subjects: Catalytic mechanisms; Degradation pathways; NZVI@MOF-545; TCH; Toxicity evaluation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2024.160069

•The degradation efficiencies of TCH by NZVI@MOF-545/PDS is 94.1% in 15 min.•The TCH degradation conditions are optimized by the RSM model.•The dominant reactive species toward TCH degradation is 1O2, SO4-•, HO•, and O2-•.•The TCH degradation mechanisms can be identified as three pathways.•The NZVI@MOF-545/PDS system can significantly reduce the toxicity of TCH. Four different porphyrinic zirconium-based metal–organic frameworks (Zr-MOFs) were comparatively studied to activate peroxydisulfate (PDS) for tetracycline hydrochloride (TCH) degradation. Results indicated NZVI@MOF-545 was the optimal catalyst and the NZVI@MOF-545/PDS system exhibited a high TCH (initial concentration of 100 mg L-1) removal efficiency of 95.9 %. The catalytic reaction conditions of NZVI@MOF-545/PDS were optimized using response surface methodology (RSM) and results showed that the TCH (initial concentration of 800 mg L-1) degradation rate of 90.34 ± 0.66 % was obtained under optimal conditions of 1.03 g L-1 PDS, 0.84 g L-1 NZVI@MOF-545 with the initial pH of 9.80, temperature of 45 °C, and rotation speed of 265 rpm. The high degradation rate was attributed to the reactive species generated by the carbon-containing functional groups and metal sites of NZVI@MOF-545, and the relative contribution was 1O2 > SO4-•>HO•>O2–•. Moreover, the LC-MS results suggested that TCH could be degraded into 15 intermediates through three potential degradation pathways. Toxicity evaluation demonstrated an alleviation in median lethal concentration at 96 h (LC50-96 h), low bioaccumulation, significant reductions in developmental toxicity and mutagenicity for most intermediates. In brief, NZVI@MOF-545 possessed remarkable catalytic ability and acceptable reusability to active PDS for TCH degradation, and the toxicity of TCH could be significantly reduced after the degradation.