A Zn/Co bimetal zeolitic imidazolate framework material as a catalyst to activate persulfates to degrade tylosin in aqueous solutions

Abstract

The Zn,Co bimetallic organic skeleton material ZIF-11(Zn/Co) with different molar ratios was synthesized at room temperature by a one-pot method as a catalyst for the activation of persulfate (PMS) degradation of tylosin (TYL). By comparing the experimental systems of ZIF-11, ZIF-11(Zn/Co)-2, persulfate, and ZIF-11(Zn/Co)-2/PMS, the experimental system with the best effect was selected for subsequent research. X-Ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and specific surface area and porosity analyses were used to describe and characterize the properties of the catalysts. A certain concentration of TYL solution was chosen as the experimental sample, and the pollutant concentration, pH, catalyst dosage, persulfate dosage and reaction temperature were used as the experimental conditions. The influence factors of catalytic removal of TYL by ZIF-11(Zn/Co)-2/PMS were studied. The specific mechanism of catalytic degradation of TYL was investigated using the results of free radical quenching experiments. The results showed that, under acidic conditions and at higher temperatures, the removal rate of bimetal ZIF-11(Zn/Co)-2 to TYL (40 mg L⁻¹) within 30 min reaches more than 80%. Experiments showed that the catalyst has good reusability. According to the data analysis after the addition of a free radical quenching agent in the experimental process, it can be seen that the sulfate free radical plays a leading role in the entire experimental system.