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In this study, we synthesized rGO/Fe0/Fe3O4/TiO2 nanocomposite according to Hummer's, and straightforward sol-gel method. The FESEM, EDX, TEM, FT-IR, XRD, BET, UV spectra, and VSM analysis were applied to determine the catalyst properties. Optimization of influence parameters on photocatalytic process performance to penicillin G degradation in aqueous media. pH (4-8), nanocomposite dose (10-20 mg/L), reaction time (30-60 min), and penicillin G concentration (50-100 mg/L) were optimized via central composite design. In the optimum condition of PCP, supplementary studies were done. As a result of the analysis, the nanocomposite was well synthesized and displayed superior photocatalytic properties for degrading organic pollutants. In addition to being magnetically separable, the synthesized rGO/Fe0/Fe3O4/TiO2 nanocomposite exhibits high recyclability up to 5 times. The quadratic model of optimization is based on the adjusted R2(0.99), and predicated R2(0.97) suggested. According to the analysis of variance test, the model was significant (F-Value = 162.95, P-Value = 0.0001). Photocatalytic process is most efficiently decomposed at pH = 6.5, catalyst dose = 18.5 mg/L, reaction time = 59.1 min, and penicillin G concentration = 52 mg/L (efficiency = 96%). The chemical oxygen demand and total organic carbon decrease were 78, and 65%. The photolysis and adsorption mechanism as a single mechanism had lower performance in penicillin G degradation. Benzocaine had the greatest effect on reducing the efficiency of the process as a radical scavenger. The °OH, h+, and O2â- were the main reactive oxidant species in penicillin G removal. Phenoxyacetaldehyde, Acetanilide, Diacetamate, Phenylalanylglycine, N-Acetyl-l-phenylalanine, Diformyldapsone, and Succisulfone were the main intermediates in penicillin G degradation. The results indicated the photocatalytic process with rGO/Fe0/Fe3O4/TiO2 nanocomposite on a laboratory scale has good efficiency in removing penicillin G antibiotic. The application of real media requires further studies.
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In this research, we synthesized BiOI/NH2-MIL125(Ti) via solvo-thermal method to investigation of oxytetracycline (OTC) degradation in photocatalytic-ozonation process. The results of the XRD, FESEM, EDAX, FTIR, UV-Vis, TEM, XPS, and BET analyzes indicated that the catalyst BiOI/MOF was synthesized with excellent quality. Design of experiment (DOE), ANOVA statistical analysis, interaction of parameters and predicated optimum condition was done based on CCD. The effect of catalyst dose (0.25-0.5 mg/l), pH (4-8), reaction time (30-60 min) and O3 concentration (20-40 mN) at 10 mg/l of OTC on PCO/O3 process was optimized. Based on P-value and F-value coefficients (0.0001, 450.3 respectively) the model of OTC (F-value = 2451.04) and (P-value = 0.0001) coefficients, the model of COD removal was quadratic model. Under optimum condition pH 8.0, CD = 0.34 mg/l, RT = 56 min and O3 concentration = 28.7 mN, 96.2 and 77.2% of OTC and COD removed, respectively. The reduction of TOC was 64.2% in optimal conditions, which is less than the reduction of COD and OTC. The kinetics of reaction followed pseudo-first-order kinetic (R2 = 0.99). Synergistic effect coefficient was 1.31 that indicated ozonation, presence of catalyst and photolysis had a synergistic effect on OTC removal. The stability and reusability of the catalyst in six consecutive operating steps was acceptable and 7% efficiency decreased only. Cations (Mg2+, and Ca2+), SO42- had no influence on performing the process, but other anions, organic scavengers, and nitrogen gas, had an inhibitory effect. Finally, the OTC degradation probably pathway includes direct and indirect oxidation that decarboxylation, hydroxylation, demethylation and were the main mechanism in OTC degradation.
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Following the advent of the coronavirus pandemic, tocilizumab has emerged as a potentially efficacious therapeutic intervention. The utilization of O3-Heterogeneous photocatalytic process (O3-HPCP) as a hybrid advanced oxidation technique has been employed for the degradation of pollutants. The present study employed a solvothermal technique for the synthesis of the BiOI-MOF composite. The utilization of FTIR, FESEM, EDAX, XRD, UV-vis, BET, TEM, and XPS analysis was employed to confirm the exceptional quality of the catalyst. the study employed an experimental design, subsequently followed by the analysis of collected data in order to forecast the most favorable conditions. The purpose of this study was to investigate the impact of several factors, including reaction time (30-60 min), catalyst dose (0.25-0.5 mg/L), pH levels (4-8), ozone concentration (20-40 mMol/L), and tocilizumab concentration (10-20 mg/L), on the performance of O3-HPCP. The best model was discovered by evaluating the F-value and P-value coefficients, which were found to be 0.0001 and 347.93, respectively. In the given experimental conditions, which include a catalyst dose of 0.46 mg/L, a reaction time of 59 min, a pH of 7.0, and an ozone concentration of 32 mMol/L, the removal efficiencies were found to be 92% for tocilizumab, 79.8% for COD, and 59% for TOC. The obtained R2 value of 0.98 suggests a strong correlation between the observed data and the predicted values, indicating that the reaction rate followed first-order kinetics. The coefficient of synergy for the degradation of tocilizumab was shown to be 1.22. The catalyst exhibited satisfactory outcomes, but with a marginal reduction in efficacy of approximately 3%. The sulfate ion (SO42-) exhibited no influence on process efficiency, whereas the nitrate ion (NO3-) exerted the most significant impact among the anions. The progress of the process was impeded by organic scavengers, with methanol exhibiting the most pronounced influence and sodium azide exerting the least significant impact. The efficacy of pure BiOI and NH2-MIL125 (Ti) was diminished when employed in their pure form state. The energy consumption per unit of degradation, denoted as EEO, was determined to be 161.8 KWh/m3-order.
Assuntos
Ozônio , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Ozônio/análise , Anticorpos Monoclonais Humanizados , Compostos Orgânicos , Oxirredução , CatáliseRESUMO
In this study, toluene and ethylbenzene were degraded in the photocatalytic-proxone process using BiOI@NH2-MIL125(Ti)/Zeolite nanocomposite. The simultaneous presence of ozone and hydrogen peroxide is known as the proxone process. Nanocomposite Synthesis was carried out using the solvothermal method. Inlet airflow, ozone concentrations, H2O2 concentrations, relative humidity, and initial pollutants concentrations were studied. The nanocomposite was successfully synthesized based on FT-IR, BET, XRD, FESEM, EDS element mapping, UV-Vis spectra and TEM analysis. A flow rate of 0.1 L min-1, 0.3 mg min-1 of ozone, 150 ppm of hydrogen peroxide, 45% relative humidity, and 50 ppmv of pollutants were found to be optimal operating conditions. Both pollutants were degraded in excess of 95% under these conditions. For toluene and ethylbenzene, the synergistic of mechanisms effect coefficients were 1.56 and 1.76, respectively. It remained above 95% efficiency 7 times in the hybrid process and had good stability. Photocatalytic-proxone processes were evaluated for stability over 180 min. The remaining ozone levels in the process was insignificant (0.01 mg min-1). The CO2 and CO production in the photocatalytic-proxone process were 58.4, 5.7 ppm for toluene and 53.7, and 5.5 ppm for ethylbenzene respectively. Oxygen gas promoted and nitrogen gas had an inhibitory effect on the effective removal of pollutants. During the pollutants oxidation, various organic intermediates were identified.
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One of the popular process in volatile organic compounds removal in gas phase is advanced oxidation process. We in this research, synthesized BiOI@NH2-MIL125(Ti)/Zeolite nanocomposite as a novel nanocomposite to degradation of benzene in hybrid advanced oxidation process. The nanocomposite synthesized via solvothermal method. The effect of airflow, ozone gas concentration, hydrogen peroxide concentration, relative humidity and initial benzene concentration are the main parameters in the UV/O3/H2O2/ nanocomposite hybrid process that were studied. The characterization by XRD, FT-IR, FESEM, EDS element mapping, TEM, BET, and UV-vis spectra indicated that nanocomposite were well synthesized. Optimal operating conditions of the process were determined at air flow of 0.1 l/min, ozone concentration of 0.3 mg/min, hydrogen peroxide concentration of 150 ppm, relative humidity of 45 ± 3% and benzene concentration of 50 ppmv. Under these conditions, more than 99% of benzene was degraded. The synergistic effect coefficient of the mechanisms is 1.53. The nanocomposite had good stability in the hybrid process and remained above 99% efficiency up to 5 times. The ozone concentration residual the system was reported to be negligible (0.013 mg/min). The CO and CO2 emissions in the hybrid process was higher than other processes, which indicates better mineralization in the hybrid process. Formaldehyde, octane, noonan, phenol, decanoic acid were reported as the main by-products. The results indicated that UV/O3/H2O2/ nanocomposite hybrid process has fantastic efficiency in the degradation of benzene as one of the indicators of VOCs.
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In this research work, we investigated the ability of the oxidative degradation of 2, 4-Dichlorophenoxy acetic acid herbicide via ultrasonic-assisted in electro-activation of the persulfate system in the presence of nano-zero valent iron. The effect of experimental parameters such as pH value [4-8], electrical current (0.5-1 A), persulfate concentration (0.25-0.5 mg.l-1), nano zero-valent iron dose (0.05-0.1 mg.l-1), and initial organic pollutant concentration (50-100 mg.l-1) on the ultrasonic-electropersulfate process performance was assessed via central composite design. The combination of ultrasonic waves with the electrochemical process to activation of persulfate showed better efficiency into 2, 4-Dichlorophenoxy acetic acid herbicide degradation compared to their implementation in individual and binary systems. Following optimal conditions (pH = 5.62, 0.80 A applied electrical current, 0.39 mg/L persulfate concentration, 0.07 mg/L nano-zero valent iron, and 50 mg/L 2,4-Dichlorophenoxy acetic acid concentration in 40 min reaction), nearly 91% removal was done. Moreover, the complete removal of 2, 4-Dichlorophenoxy acetic acid, 92% COD, and 88% TOC removal was achieved by this process near 140 min reaction. The scavenging experiment confirmed the role of free oxidizing species in the degradation of 2, 4-Dichlorophenoxy acetic acid during the process. Approximately 50% improved 2, 4-Dichlorophenoxy acetic acid removal in the process against the inclusive efficiency of single mechanisms. The obtained results were fitted to the pseudo-first-order kinetic model with a high correlation coefficient (R2 = 0.96). Five important intermediate products of 2, 4-D oxidation were 2, 4-dichlorophenol (2, 4-DCP), 2, 6-dichlorophenol (2, 6-DCP), 4, 6 dichlororesorcinol (4, 6-DCR), 2-chlorohydroquinone (2-CHQ), and 2-chloro-1, 4-benzoquinone (2-CBQ). In the end, can be employed as a satisfactory advanced oxidation process in high mineralization of 2, 4-D and refractory organic pollutants.
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2-4 Dichlorophenoxy acetic acid is most publicly applied from chlorinated phenoxy acids herbicides. In this research, central composite design for optimization of photo-Elecro/persulfate/nZVI process to degradation and mineralization of this herbicide in aqueous solution to environment protection was applied. The initial pH (2-4), persulfate anion concentration (0.25-0.5 mg/L), direct electrical (0.5-1 A), herbicide concentration (50-100 mg/l), nZVI dose (0.05-1 mg/L), and reaction time (50-100 mg/l) are independent variables optimized. Also, the synergist effect, COD and TOC removal, the effect of radical scavengers, and by-products were investigated. The fitting of the model, suggested a quadratic model (R2 = 0.9926). F-value and P value of ANOVA were 719.81 and 0.0001 respectivelty. After optimizing the PEP/nZVI process, the proposed optimal conditions was pH = 3.4, persulfate concentration equal to 0.49 mg/l, in 1 A direct current, nZVI dose equal to 0.1 mg/l, in 50.05 mg/l herbicide concentration as an initial concentration, in 80 min reaction time. The theoretical and actual removal was evaluated 91.99% and 92%, respectively. In the optimum condition, 45.4% synergist effect indicated. 78.3% and 66.5% of initial COD and TOC were decreased. 39.02% of Cl ion was released form 2,4-D structure. The presence of radical scavengers have an adverse impact on the performance of process. The highest amount of radical scavenging was in methanol, tert-butyl alcohol and bicarbonate ions at concentrations at 50 mM/l. The kinetic data was fitted via pseudo-first-order reaction (R2 = 0.99).The direct and indirect oxidation process lead to formation of several organic by-products which were confirmed by GC-MS analysis.
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With increased population, treatment of solid waste landfill and its leachate is of major concern. Municipal landfill leachate shows variable, heterogeneous and incontrollable characteristics and contains wide range highly concentrated organic and inorganic compounds, in which hampers the application of a solo method in its treatment. Among different approaches, biological treatment can be used, however it is not effective enough to elimination all refractory organics, containing fulvic-like and humic-like substance. In this experimental study, the UV Electroperoxone process as a hybrid procedure has been employed to treat landfill leachate. The effect of various parameters such as pH, electrical current density, ozone concentration, and reaction time were optimized using central composite design (CCD). In the model fitting, the quadratic model with a P-Value less than 0.5 was suggested (< 0.0001). The R2, R2 adj, and R2 pre were determined equal to 0.98,0.96, and 0.91 respectively. Based on the software prediction, the process can remove 83% of initial COD, in the optimum condition of pH = 5.6, ozone concentration of 29.1 mg/l. min, the current density of 74.7 mA/cm2, and process time of 98.6 min. In the optimum condition, 55/33 mM H2O2 was generated through electrochemical mechanism. A combination of ozonation, photolysis and electrolysis mechanism in this hybrid process increases COD efficiency removal up 29 percent which is higher than the sum of separated mechanisms. Kinetic study also demonstrated that the UV-EPP process follows pseudo-first order kinetics (R2 = 0.99). Based on our results, the UV-EPP process can be informed as an operative technique for treatment of old landfills leachates.