Photocatalytic mineralization and degradation kinetics of sulphamethoxazole and reactive red 194 over silver-zirconium co-doped titanium dioxide: Reaction mechanisms and phytotoxicity assessment
journal contributionposted on 22.06.2018, 09:48 authored by Saraschandra Naraginti, Yi Li, Gianluca Li-PumaGianluca Li-Puma
© 2018 The photodegradation and phytotoxicity of the pharmaceutical antibiotic, sulphamethoxazole (SMX) and the azo-dye reactive-red-194 (RR194) under visible-light irradiation of TiO2nanoparticles modified by silver and zirconium was investigated. The results indicated that sulphamethoxazole and its toxic degradation by product, 3-amino-5-methylisoxazole and RR-194 could be degraded efficiently by the co-doped Zr/Ag-TiO2catalyst. PL studies and ROS generation results suggested that the effective charge separation was carried out while irradiation of the modified TiO2nanoparticles. Phytotoxicity tests demonstrated lower percentage of germination in P. vulgaris (40%), V. radiata (30%) and P. lunatus (30%) of the seeds treated with 50 ppm of SMX, compared to the seeds treated with the degradation products (100%). The results with 50 ppm of RR-194 also showed lower percentage of germination in P. vulgaris (40%), V. radiata (50%) and P. lunatus (30%) compared to the degradation products (100%). Furthermore, significant increase in root and shoot development was observed in the seeds treated with the degraded products when compared with SMX and RR-194. Overall, this study contributes to further understanding the photodegradation mechanisms, degradation products and environmental fate of SMX and RR-194 in water which helps in the evaluation and mitigation of the environmental risk of SMX and RR-194 for water reuse and crop irrigation.
The study was financially supported by the National Natural Science Foundation of China for Foreign Youth Scholars (Grant No. 51650110501), the China Postdoctoral Science Foundation (Grant No. 2016M591767), the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51421006), Program for Environmental Protection in Jiangsu Province (Grant No. 2015037), and Priority Academic Program Development of Jiangsu Higher Education Institutions. The Fundamental Research Funds for the Central Universities (Grant No. 2016B10614), Priority Academic Program Development of Jiangsu Higher Education Institutions, and Top-notch Academic Programs project of Jiangsu Higher Education Institutions (TAPP)
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