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Compared with the transition metal induced homogeneous catalytic system, the heterogeneous catalytic system based on transition metal-doped metal organic frameworks (MOFs) were stable for the efficient utilization of transition metal and avoiding the metal leaching. The aim of this work is to synthesize Co-doped MIL-53(Al) by one-step solvent thermal method and use it to activate peroxymonosulfate (PMS) to remove tetracycline (TC) in water. The successful synthesis of Co-MIL-53(Al) samples was demonstrated by XDR, SEM and FTIR characterizations. The 25% Co-MIL-53(Al)/PMS system showed the optimal TC removal effect compared to the PMS alone and MIL-53(Al)/PMS system. The catalytic performances of Co-MIL-53(Al)/PMS system in conditions of different pH, co-existing substances and water bodies were investigated. Quenching experiment and electron paramagnetic resonance (EPR) showed that the degradation mechanism by Co-MIL-53(Al) activation PMS was mainly attributed to sulfate radical (SO 4 •-) and singlet oxygen (1O 2) non-radical. The degradation intermediates of TC were also identified and the possible degradation pathways were proposed. Co-MIL-53(Al) showed good activity after four cycles. These findings demonstrated that Co-MIL-53(Al) can be a promising heterogeneous catalyst for activating PMS to degrade TC. [ABSTRACT FROM AUTHOR]

• Mn-MIL-53(Fe) was synthesized by one-step solvothermal method. • The obtained Mn-MIL-53(Fe) could efficiently activate peroxymonosulfate (PMS). • Reaction parameters of Mn-MIL-53(Fe)/PMS system for TC degradation were optimized. • Possible mechanism of tetracycline (TC) degradation and TC degradation pathway were investigated proposed. • The Mn-MIL-53(Fe) system exhibited high efficiency in actual water. Herein, Mn-doped MIL-53(Fe) were fabricated via one-pot solvothermal method and used for peroxymonosulfate (PMS) activation towards tetracycline (TC) degradation from aqueous solution. The characterizations of SEM, FTIR and XRD were utilized to reveal the morphology and structure of the materials. The results showed that Mn-MIL-53(Fe)-0.3 displayed the optimal catalytic performance, the removal efficiency of TC could reach 93.2%. Moreover, the catalytic activity of Mn-MIL-53(Fe) towards TC under different initial pH values, co-existing anions (C l - , CO 3 2 - and SO 4 2 - ) and humic acid (HA) were investigated. The results of thermodynamic experiment suggested that the catalytic process was endothermic. In addition, integrated with capture experiments results and the characterization results of electron paramagnetic resonance (EPR), which revealed that SO 4 · - and H O - were the reactive radicals involving in the reaction. More importantly, the possible activation mechanism was discussed in detail based on the X-ray photoelectron spectroscopy results. The active species were generated by the active sites of Fe(II) and Mn(II) on Mn-MIL-53(Fe) effectively activated PMS. Furthermore, the degradation intermediates and possible degradation pathway were investigated by LC-MS. Finally, the catalyst also showed good performance in actual wastewater and demonstrated good recyclability. The Mn-MIL-53(Fe)/PMS system exhibited a promising application prospect for antibiotic-containing waste water treatment. [ABSTRACT FROM AUTHOR]

Herein, iron-cobalt layered double hydroxide (FeCo-LDH) was synthesized by sacrificing Co-containing zeolite imidazolate framework materials (ZIF-67) in iron ethanolic solution at room temperature. The catalytic performances of catalysts were investigated by activating peroxymonosulfate (PMS) for tetracycline (TC) degradation. Experimental results were demonstrated that FeCo-LDH with molar ratios of Fe and Co was 1.5 (FeCo-LDH-1.5) exhibited the highest catalytic activity, in which the TC degradation efficiency was reached to 92% within 5 ​min. The system of FeCo-LDH-1.5/PMS exhibited high stability and high efficiency in the influencing factor experiments including TC concentrations, initial pH, coexisting anions (Na+, Cl-, SO 4 2−) and humic acid (HA). Results of quenching experiments and electron paramagnetic resonance (EPR) characterization showed that O 2 •- and SO 4 •- radicals were the foremost reactive species for TC degradation. Liquid chromatograph - mass spectrometer (LC-MS) and three-dimensional excitation emission matrix fluorescence spectro photometer (3D EEMs) were conducted to investigate the degradation intermediate and possible degradation pathway. Moreover, high degradation efficiency was implemented in actual wastewater by the FeCo-LDH-1.5/PMS system. Compared to Fe3+/PMS and Co2+/PMS homogeneous system, the FeCo-LDH-1.5/PMS system was exhibited advantages in catalytic activity and high reusability. This study provided a convenient method to synthesis advanced hydrotalcite-like catalysts, which showed remarkable performance in actual wastewater treatment. The formation of FeCo-LDH sample and their catalyst capacity towards PMS activation for TC degradation. Image 1 • FeCo-LDH was prepared by sacrificing ZIF-67 templates in Fe3+ ethanolic solution. • FeCo-LDH can efficiently degrade tetracycline (TC) by activating PMS. • SO 4.•- and O 2 •- radicals were the main reactive species in FeCo-LDH/PMS system. • FeCo-LDH catalyst exhibited high removal efficiency after three recycle test. • The FeCo-LDH/PMS system keep high efficiency in actual water. [ABSTRACT FROM AUTHOR]