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Yttrium orthovanadate (YVO4) powders were synthesized by two different routes: the combustion route (C sample), and the hydrothermal route (H samples). In all samples, oxygen vacancies were observed by Raman, UV–vis diffuse reflectance and photoluminescence (PL) spectroscopy; however they were more significant in C sample. Photocatalytic discoloration of Rhodamine B solutions ranged from 40 to 64% and C and H4 samples presented the highest efficiencies. Although both samples showed similar photocatalytic efficiency, C sample is 11 times more efficient in producing reactive oxygen species than H4 sample, and an interesting effect of the treated solutions was observed in the Fish Embryotoxicity Test, carried out in D. rerio. The C-treated solution was more toxic than the untreated solution, while the H4-treated solution did not show toxicity enhancement. C-treated solution caused a significant mortality of D. rerio embryos beginning at the 4th day of exposure and reached total mortality at the 6th day. Thus, the synthetic route employed in the preparation of C and H4 samples leads to different toxic effects in the treated solutions. These results pointed out that microstructural characteristics and synthetic parameters are not only important for obtaining highly active materials, but they also impact on the toxicity of the effluents.

Made available in DSpace on 2018-12-11T17:18:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-02-20 Etoposide is an antineoplastic agent used for treating lung cancer, testicular cancer, breast cancer, pediatric cancers, and lymphomas. It is a pollutant due to its mutagenic and carcinogenic potential. Disposal of waste from this drug is still insufficiently safe, and there is no appropriate waste treatment. Therefore, it is important to use advanced oxidative processes (AOPs) for the treatment and disposal of medicines like this. The use of strontium stannate (SrSnO3) as a catalyst in heterogeneous photocatalysis reactions has emerged as an alternative for the removal of organic pollutants. In our study, SrSnO3 was synthesized by the combustion method and characterized by X-ray diffraction (XRD), Raman, UV-Vis, and scanning electron microscopy (SEM) techniques, obtaining a surface area of 3.28 m2 g−1 with cubic and well-organized crystallinity and a band gap of 4.06 eV. The experimental conditions optimized for degradation of an etoposide solution (0.4 mg L−1) were pH 5 and catalyst concentration of 1 g L−1. The results showed that the degradation processes using SrSnO3 combined with H2O2 (0.338 mol L−1) obtained total organic carbon removal from the etoposide solution, 97.98% (± 4.03 × 10−3), compared with TiO2, which obtained a mineralization rate of 72.41% (± 6.95 × 10–3). After photodegradation, the degraded solution showed no toxicity to zebrafish embryos through embryotoxicity test (OECD, 236), and no genotoxicity using comet assay and micronucleus test. Instituto de Química Universidade de Brasília-UnB, Campus Darcy Ribeiro, Asa Norte Instituto de Ciências Biologia Departamento de Genética e Morfologia Universidade de Brasília-UnB, Campus Darcy Ribeiro, Asa Norte Unesp Instituto Nacional de Tecnologias Alternativas para Detecção Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos (INCT-DATREM) Instituto de Química, Caixa Postal 355 Unesp Instituto Nacional de Tecnologias Alternativas para Detecção Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos (INCT-DATREM) Instituto de Química, Caixa Postal 355

Etoposide is an antineoplastic agent used for treating lung cancer, testicular cancer, breast cancer, pediatric cancers, and lymphomas. It is a pollutant due to its mutagenic and carcinogenic potential. Disposal of waste from this drug is still insufficiently safe, and there is no appropriate waste treatment. Therefore, it is important to use advanced oxidative processes (AOPs) for the treatment and disposal of medicines like this. The use of strontium stannate (SrSnO

Water is not only an economic, but also an increasingly important social commodity. Potable water is an essential resource for sustaining economic and social development in all sectors. A safe water supply and appropriate sanitation are the most essential components for a healthy and prosperous life. However, increases in human activities have led to exposure of the aqueous environment to chemical, microbial and biological pollutants as well as to micropollutants. Thus, liquid effluents containing toxic substances are generated by a variety of chemistry-related industrial processes, as well as by a number of common household or agricultural applications.

In the present study, selected advanced oxidation processes (AOPs)-namely, photo-Fenton (with Fe(2+), Fe(3+), and potassium ferrioxalate-FeOx-as iron sources), solar photo-Fenton, Fenton, and UV/H2O2-were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H2O2 process were most efficient for mineralizing MTX, with 77, 82, and 90% of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe(3+):MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 10(4) M(-1), indicating high MTX affinity for Fe(3+). Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H2O2 process is usually slower than the photo-Fenton process, but, in this study, the UV/H2O2 process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H2O2 or by UV/H2O2/FeOx at the concentrations tested.