Study On The Degradation Of Antibiotics By Peroxymonosulfate Activated By Cobalt Supported On Thiol Metal/covalent Organic Framewor

Global consumption of antibiotics was estimated to be 225,000 tons in 2020.China is the largest producer and consumer of antibiotics worldwide,accounting for approximately45%of global annual consumption.Antibiotics are widely used in the prevention and treatment of diseases in humans and animals.However,their negative effects on ecosystems and human health have attracted much attention.Therefore,how to efficiently treat wastewater containing antibiotics is an important issue to be solved urgently.Norfloxacin（NOR）,as a quinolone antibiotic,has been detected in municipal wastewater with the concentration of ng/L toμg/L,and even mg/L in pharmaceutical wastewater.Due to its antibacterial property,traditional aerobic and anaerobic wastewater treatment processes cannot completely remove this compound.At present,the activation of peroxymonosulfate（PMS）based on advanced oxidation processes has become a research hotspot in the efficient degradation of antibiotics.Compared with^·OH produced by H₂O₂ activation,SO₄^·—produced by activated PMS has higher oxidation potential(2.5-3.1V and^·OH（1.8-2.7V）and longer half-life（30-40μs）,showing better performance in pollutant degradation.The key of this technology is how to design and synthesize heterogeneous catalysts with high activity and stability.The metal/covalent organic framework has the characteristics of abundant pore size,large specific surface area and modifiable terminal.It can be used as an excellent catalyst support.The single atoms can be immobilized at the sites of hydroxyl bridges,terminal sulfhydryl groups or intrinsic defects.Given the excellent performance of Co-based catalysts and strong coordination between Co and sulfur,it should be feasible to immobilize Co single-atom on sulfhydryl decorated UiO-66 to obtain efficient SACs for PMS activation.Therefore,the activation of PMS for antibiotic degradation by anchoring single-atom Co in a sulfhydryl modified metal/covalent organic framework was investigated.1.Zr-MSA-Co promotes peroxymonosulfate activation for efficient norfloxacin degradation and mechanism.Firstly,sulfhydryl decorated UiO-66（Zr-MSA）was successfully prepared by a one-step green hydrothermal method,and loaded with Co single-atoms through the strong affinity between sulfhydryl and Co²⁺ions for PMS activation and degradation of NOR.DFT calculations confirmed that the successful loading of Co single-atoms could enhance the adsorption energy and charge transfer between PMS and the catalyst,contributing to the improved degradation performance.Zr-MSA-Co/PMS system showed excellent NOR degradation efficiency in a wide pH range.In practical applications,the degradation efficiency of other typical pollutants and the degradation efficiency of NOR in different water substrates can reach 100%.Importantly,the fixed-bed reactor experiments showed excellent continuous degradation performance（99%within 26 h）for NOR.ECOSAR program simulation and Escherichia coli toxicity experiments have verified that NOR and its intermediate products are not harmful to the environment.2.COF-S-Co promotes peroxymonosulfate activation for efficient SMX degradation and mechanism.Based on the strong affinity of Co and S in the above research,we successfully synthesized COF-SH by a one-step solvothermal method,and loaded with Co single-atoms for PMS activation to degrade SMX for the first time.The degradation performance of COF-SH was significantly enhanced by the successful loading of cobalt single atom.Meanwhile,COF-S-Co/PMS system showed excellent NOR degradation efficiency in a wide pH range.In practical applications,the degradation efficiency of other typical pollutants and the degradation efficiency of NOR in different water substrates can reach 100%.¹O₂ and SO₄^·–are the main active species.This paper reveals that the sulfhydryl metal/covalent organic framework structure loaded with cobalt single atoms by simple chemisorption.The Co single atom supported on metal/covalent organic materials has been applied to the activated degradation of pollutants by PMS for the first time,which broadened its catalytic application range;This study could offer a new approach for designing Fenton-like catalysts by immobilizing single atom onto MOFs or COFs and promote their practical application in wastewater treatment.