Explore the vast range of titles available.

This work investigates the degradation of Reactive Gray BF-2R dye (a blend of reactive yellow 145, reactive orange 122 and reactive black 5 dyes) using UV/H2O2, Fenton, and photo-Fenton-advanced oxidative processes, with artificial sunlight and UV-C radiations. The photo-Fenton process employing UV-C radiation was the most efficient under the conditions studied. The ideal conditions for the degradation of the dye, determined using a factorial design 23 and a study of the concentration of hydrogen peroxide ([H2O2]), were [H2O2] equal to 40 mg L−1, iron concentration [Fe] of 1 mg L−1, and pH between 3 and 4. The Chan and Chu non-linear kinetic model predicted the kinetic data with a degradation of over 98% for color and 68% for aromatics after 60 min. The behavior of the chemical oxygen demand fitted the first-order kinetic model well, with a degradation of 64% after 60 min. The Multilayer Perceptron 7-11-2 artificial neural network model enabled to model the degradation process of the aromatics and accurately predict the experimental data. Toxicity tests indicated that the post-treatment samples were non-toxic for Escherichia coli bacteria, and Portulaca grandiflora and Basil sabory seeds. However, they inhibited the growth of Lactuca sativa seeds and Salmonella enteritidis bacteria. The photo-Fenton process with UV-C radiation degraded the dye studied efficiently and the degradation percentages were, on average, 7% and 5% higher for color than those observed when employing the Fenton and UV/H2O2 processes, respectively. With the aromatic, however, they were 84% and 62% higher, thus justifying the use of this process.

Population growth has led to an increase in the production and use of synthetic compounds such as drugs, whose different classes are being investigated. However, the antiretrovirals are still poorly studied. Since the conventional treatments used in the effluent treatment plants have not been able to degrade these substances, other treatment techniques have been evaluated. Therefore, the objective of this work was to study and optimize the use of advanced oxidative processes (AOPs) in the degradation of lamivudine. It was found, initially, that the photo-peroxidation degraded 69% of the compound after 60 min of exposure to UV-C radiation, and that after evaluating the effect of the [H2O2], a degradation of 95% was achieved by using 250 mg L−1 of this reagent. The reaction kinetics showed a good fit to the pseudo-first-order model, and the artificial neural network MLP (3-12-1) demonstrated a good accuracy, managing to predict percentages of degradation for the studied AOP. Toxicity tests indicated an increase in the toxic effect on seeds, but the same was not observed in relation to enterobacteria. In general, the appropriateness of the application of AOP in the degradation of the aqueous solution has been demonstrated, with the largest studies regarding the effects of toxicity.

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO 2 /BiPO 4 and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO 2 /BiPO 4 concentration of 87 mg L −1 and a hydrogen peroxide concentration of 1800 mg L −1 , being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient ( R 2  = 0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.

Abstract Advanced oxidation processes (AOP) are known for their efficiency in degrading organic pollutants. In this way, there is a continuous interest in promoting improvements in operating conditions, which can be done through the combination with homogeneous and electrochemical processes. In this work, the degradation of the mixture of dyes applied in the sanitizer industry, acid yellow 36 (AY36) and acid blue 80 (AB80), was evaluated against photo-electrochemical processes, associating individually and combined way UV-A and UV-C radiations. It was verified that the use of UV-C radiation was more efficient, promoting the complete degradation of the chromophore groups and reducing the aromatic groups by 76% when making use of the photo-electro-Fenton system (PEF/FeCl3). The experimental data followed a nonlinear kinetics suitable for pseudo-first-order models. Multilayer perceptron (MLP) artificial neural networks (6–6-3) using the Statistica 8.0 software allowed the modeling of the treatments applied in this work and showed a good prediction of data for the dye mixture. The results of this study show that the use of photo-electrochemical processes is an effective way to treat dyes used in sanitizing industries.

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO2/BiPO4 and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO2/BiPO4 concentration of 87 mg L-1 and a hydrogen peroxide concentration of 1800 mg L-1, being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient (R 2=0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO /BiPO and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO /BiPO concentration of 87 mg L and a hydrogen peroxide concentration of 1800 mg L , being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient (R  = 0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO sub(2)/BiPO sub(4) and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO sub(2)/BiPO sub(4) concentration of 87 mg L super(-1) and a hydrogen peroxide concentration of 1800 mg L super(-1), being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient (R super(2)=0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.