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In this study, gamma radiation was used for triclosan (TCS) degradation with addition of persulfate (PS) to enhance the mineralization of TCS. The influence of absorbed doses, PS concentration, and initial pH value on TCS degradation and mineralization was examined. The results showed that the degradation and mineralization of TCS were remarkably enhanced in the presence of PS. With addition of 1.5 mM PS, 8 mg/L TCS could be completely degraded at 300 Gy, which was much lower than that of the control group without PS (600 Gy). Furthermore, with addition of PS, higher mineralziaiton of TCS could be observed. The intermediates produced during the decomposition of TCS were identified and the possible degradation pathway was proposed. In addition, the biodegradability of TCS solution, as well as the intermediate products, was evaluated by a Wabo micro-respiration tester for 12 h. It demonstrated that the biodegradability of TCS solution increased after gamma radiation, which could be further enhanced by persulfate, suggesting that the combination of gamma radaition with persulfate could be a promising alternative process for the degradation of antibiotics in the wastewater. • Triclosan (TCS) can be degraded by radiation combined with persulfate. • Persulfate could effectively enhance TCS mineralization by radiation. • The biodegradability of TCS and its intermediate products were assessed. • The influence of initial pH value on TCS degradation was examined. [ABSTRACT FROM AUTHOR]

In this study, Co 3 O 4 -carbon composite was synthesized by calcined metal organic framework (MOF) ZIF-67 and used as efficient catalysts for ozonation of norfloxacin (NOF). The MOF-derived Co 3 O 4 –C composite remained similar polyhedrons structure of ZIF-67, suggesting that Co 3 O 4 was well-dispersed in Co 3 O 4 –C composite. Furthermore, a larger amount of surface carbon-oxygen functional groups were distributed on Co 3 O 4 –C composite, which resulted in the diversification of active sites for catalytic ozonation reaction. NOF degradation and mineralization could be effectively enhanced in Co 3 O 4 –C/O 3 process. Moreover, NOF mineralization by catalytic ozonation strongly depended on the solution pH, while other operational conditions, such as O 3 concentration and catalyst dosage had not obvious influence on it. Co 3 O 4 –C composite could significantly accelerate O 3 decomposition to produce active free radicals (such as •OH), which enhanced the mineralization of NOF. The possible catalytic mechanism of Co 3 O 4 –C composite was proposed. Additionally, after five consecutive use of Co 3 O 4 –C composite in catalytic ozonation process, there was no obvious decrease in TOC removal efficiency, indicating a stable performance of Co 3 O 4 –C composite, which was suitable for the catalytic ozonation for wastewater treatment. Image 1 • ZIF-67 derived Co 3 O 4 –C composite existed a similar polyhedrons structure of ZIF-67. • NOF degradation and mineralization was significantly improved in Co 3 O 4 –C/O 3 process. • The composite enhanced O 3 decomposition and.•OH generation in catalytic ozonation. •.•OH play a crucial role in TOC removal in the Co 3 O 4 –C/O 3 process. [ABSTRACT FROM AUTHOR]

In this study, the degradation of carbamazepine (CBZ) was studied in the presence of persulfate (PS) at various initial pH values (6.5, 7.5, 8.5) and PS dosages (0.5, 1.0, 1.5, 2.0 mM). The experimental results showed that although gamma radiation alone could efficiently degrade CBZ, the combined radiation with PS oxidation could enhance the degradation and mineralization of CBZ. Acidic condition (pH = 6.5) could facilitate PS-oxidization process, when the concentration of PS was 1.5 mM, the mineralization efficiency (34.1% TOC removal) was highest at the absorbed dose of 1.0 kGy. Three carboxylic acids and seven intermediate products were detected during CBZ degradation process by the combined radiation/PS process. Based on the identified intermediate products, the possible mechanism and pathway of CBZ degradation were tentatively proposed. It was found that the biodegradability of CBZ was promoted with the combinative processes of gamma irradiation and PS. • Gamma radiation/persulfate process could effectively degrade carbamazepine (CBZ). • Acidic pH might enhance the degradation and mineralization of CBZ. • Possible degradation schemes of CBZ were proposed. • Both the biological toxicity and biodegradability of CBZ after the treatment by radiation/PS system. [ABSTRACT FROM AUTHOR]