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Recently, visible-light-driven photocatalysis is of great interest in the environmental pollutant remediation. In the present study, a novel heterostructured photocatalyst AgI/BiVO was synthesized by an in situ precipitation procedure. The AgI/BiVO heterojunctions exhibited excellent photoactivity for the refractory pollutant (tetracycline (TC), a typical antibiotic) decomposition under visible light illumination. The synthetic sample with 1:4 mass ratio of AgI:BiVO possessed the highest photocatalytic performance in all of the as-prepared catalysts. The TC molecules were substantially eliminated (94.91%) within 60 min, and degradation efficiency was considerably better than those of bare BiVO (62.68%) and AgI (75.43%) under identical conditions. Simultaneously, 90.46% of TOC removal was also achieved within 120 min, suggesting that the mineralization was superior and further confirmed by three-dimensional excitation-emission matrix fluorescence spectroscopy (3D EEMs). The XRD, XPS, DRS, and PL measurements revealed that a small amount of Ag nanoparticles was produced at the early photodegradation process. The structure transformation from AgI/BiVO (double-type) to AgI/Ag/BiVO (sandwich-like) improved the corresponding visible-light absorption performance. The self-assembly Z-scheme heterojunction that consisted of AgI, Ag, and BiVO also efficiently accelerated photoinduced electron-hole pairs' separation and ultimately improved the efficiency of TC degradation. The responsible photocatalytic mechanism was discussed in detail on the basis of the reactive species capturing tests and ESR analysis, and the experimental results had been validated that superoxide radicals and holes played a vital role during the photocatalytic process. Furthermore, TC degradation efficiency was not of significant loss after four consecutive cycles, suggesting the excellent photostability of AgI/BiVO nanocomposite. These features demonstrate that the AgI/BiVO heterojunction has great application potential for refractory pollutants' removal from wastewater.

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Activated persulfate oxidation technologies based on sulfate radicals were first evaluated for defluorination of aqueous perfluorooctanesulfonate (PFOS). The influences of catalytic method, time, pH and K2S2O8 amounts on PFOS defluorination were investigated. The intermediate products during PFOS defluorination were detected by using LC/MS/MS. The results showed that the S2O8 2− had weak effect on the defluorination of PFOS, while the PFOS was oxidatively defluorinated by sulfate radicals in water. The defluorination efficiency of PFOS under various treatment was followed the order: HT (hydrothermal)/K2S2O8 > UV (ultraviolet)/K2S2O8 > Fe2+/K2S2O8 > US (ultrasound)/K2S2O8. Low pH was favorable for the PFOS defluorination with sulfate radicals. Increase in the amount of S2O8 2− had positive effect on PFOS defluorination. However, further increase in amounts of S2O8 2− caused insignificant improvement in PFOS defluorination due to elimination of sulfate radicals under high concentration of S2O8 2−. CF3(CF2)nCOOH (n = 0–6) were detected as intermediates during PFOS defluorination. Sulfate radicals oxidation and hydrolysis were the main mechanisms involved in defluorination process of PFOS.

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Background Nursing is a high-risk occupation that involves exposure to stress. The physical and mental health of nurses is directly related to the quality of medical services, so the quality of life of nurses cannot be ignored. This study is a Chinese nursing study that investigated occupational stress, job burnout, and quality of life of surgical nurses in Xinjiang, China. Methods This study employed the cluster random sampling method and carried out a questionnaire survey among 488 surgical nurses from five hospitals from May 2019 to September 2019. The study analyzed the relationship between occupational stress, job burnout and quality of life. The Effort-Reward Imbalance questionnaire (ERI), Maslach Burnout Inventory General Survey (MBI-GS) and the 36-item Short Form Health Survey (SF-36) were used to evaluate occupational stress, job burnout and quality of life among surgical nurses. Results A total of 550 questionnaires were distributed in this study, and 488 were retrieved, with an effective recovery rate of 88.73 %. The results revealed that the quality of life score among surgical nurses was not high, and differences were observed in the quality of life score of patients according to gender, age, title, and frequency of night shifts (P < 0.05). There was a positive correlation between occupational stress and job burnout. Higher levels of occupational stress and job burnout were associated with a poorer quality of life score. Occupational stress and job burnout were identified as risk factors for quality of life, and the interaction between high levels of stress and burnout seriously reduced quality of life. The structural equation model revealed that occupational stress and job burnout had a direct impact on quality of life, occupational stress had a direct impact on job burnout, and job burnout was identified as a mediating factor in the relationship between occupational stress and quality of life. Conclusions Surgical nurses have a high level of occupational stress and burnout, and low quality of life score. Quality of life is correlated with occupational stress and job burnout. According to the individual characteristics and psychological state of nurses, managers can implement personalized intervention measures promptly and effectively to relieve their tension and burnout, and improve the quality of life of surgical nurses.