Oxidative Degradation of Tetracycline by Magnetite and Persulfate: Performance, Water Matrix Effect, and Reaction Mechanism

Abstract

This study presents a strategy to remove tetracycline by using magnetite-activated persulfate. Magnetite (Fe3O4) was synthesized at high purity levels—as established via X-ray diffractometry, transmission electron microscopy, and N2 sorption analyses—and tetracycline was degraded within 60 min in the presence of both magnetite and persulfate (K2S2O8), while the use of either substance yielded limited degradation efficiency. The effects of magnetite and persulfate dosage, the initial concentration of tetracycline, and the initial pH on the oxidative degradation of tetracycline were interrogated. The results demonstrate that the efficiency of tetracycline removal increased in line with magnetite and persulfate dosage. However, the reaction rate increased only when increasing the magnetite dosage, not the persulfate dosage. This finding indicates that magnetite serves as a catalyst in converting persulfate species into sulfate radicals. Acidic conditions were favorable for tetracycline degradation. Moreover, the effects of using a water matrix were investigated by using wastewater treatment plant effluent. Comparably lower removal efficiencies were obtained in the effluent than in ultrapure water, most likely due to competitive reactions among the organic and inorganic species in the effluent. Increased concentrations of persulfate also enhanced removal efficiency in the effluent. The tetracycline degradation pathway through the magnetite/persulfate system was identified by using a liquid chromatograph-tandem mass spectrometer. Overall, this study demonstrates that heterogeneous Fenton reactions when using a mixture of magnetite and persulfate have a high potential to control micropollutants in wastewater.

Highly Efficient Tetracycline Degradation under Simultaneous Hydrodynamic Cavitation and Electrical Discharge Plasma in Flow

“…The different TC-degradation pathways that occur under various oxidative conditions (AOPs) have recently been documented in the literature. , To the best of our knowledge, no study on the degradation products obtained after the treatment of aqueous TC solutions has ever been reported in the literature. We therefore present, herein, a HPLC-MS analysis of a HC/ED-plasma-treated TC water solution to identify the degradation products that could be seen in total ion chromatography after hybrid treatment.…”

“…The detected TC( 1b ) is probably the result of the loss of the dimethylamino group on the C4 of TC ( m / z = 445). While the formation of the TC( 2b ) product, with m / z = 358, was probably the result of the first dehydration pathway, from C6 of the TC( 1b ), followed by a deamidation reaction at C1 of TC (namely, the loss of the acylamino group) . As can be observed in Figure , the combined HC/ED approach more quickly and effectively degraded the TC structure than HC alone or US treatment.…”

“…While the formation of the TC(2b) product, with m/z = 358, was probably the result of the first dehydration pathway, from C6 of the TC(1b), followed by a deamidation reaction at C1 of TC (namely, the loss of the acylamino group). 13 As can be observed in Figure 10, the combined HC/ED approach more quickly and effectively degraded the TC structure than HC alone or US treatment. screening of inlet pressure was performed to evaluate its effect on the degradation treatment and, subsequently, to compare the prototype reactor's efficiency in degrading three different antibiotics of the same class.…”

“…Moreover, tetracyclines are chemically stable and not easily degradable, making them difficult to remove from the environment. − Suitable processes to effectively degrade antibiotics in wastewater must therefore be developed. Besides adsorption, nanofiltration and hydrothermal treatment, advanced oxidation processes (AOPs) − are the most commonly employed and cost-effective technologies for the complete degradation of persistent organic contaminants, such as TC and other antibiotics, in wastewater . AOPs have recently been successfully coupled with several emerging technologies, such as cavitational treatment and nonthermal plasma technologies, , in order to enhance their ability to degrade antibiotics via OH • radical production.…”

Preparation of Activated Carbon From Tire Derived Pyrolytic Char for Adsorption of Tetracycline Hydrochloride

“…As an effective method to prevent contamination of TCs in water resources, a wastewater treatment unit should be installed. In the literature, several techniques, including membrane filtration, photocatalytic degradation, catalytic oxidation, biodegradation, adsorption, have been investigated to reduce TCs in wastewater [2,4,5,6,7,8]. Among the reported techniques, adsorption is an attractive method because of its simplicity and low operation cost.…”