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A novel P-doped Fe2O3-TiO2 mixed oxide: Synthesis, characterization and photocatalytic activity under visible radiation
摘要： In this work, a novel P-doped Fe2O3-TiO2 mixed oxide was successfully prepared by a microwave assisted sol-gel method. The synthesized catalyst was characterized by N2 physisorption, SEM, XRD, XPS, and FTIR, UV–vis DRS, and PL spectroscopies. The iron and phosphorus content in the catalyst samples were quanti?ed by AAS and ICP-OES, respectively. The photocatalytic activity of P-doped Fe2O3-TiO2 powders were evaluated in the photocatalytic degradation of sulfamethazine (SMTZ). The Box Behnken design (BBD) and response surface methodology (RSM) were applied for modeling the e?ect and optimizing of the operational parameters levels on the degradation percentage of SMTZ. The complete degradation and mineralization percentage of 30% of SMTZ solution at pH 9 was achieved within 300 min of reaction, with the optimum P doping amount of 1.2 wt % and 1.25 g/L of catalyst loading. The 1.2 wt % P-doped Fe2O3-TiO2 mixed oxide showed considerably higher photocatalytic activity than Fe2O3-TiO2 or TiO2. This enhanced performance could be attributed to the small crystallite size, narrow band gap, high speci?c surface area and increased number of surface hydroxyls on TiO2 nanoparticles. Additionally, the stability and reusability of this catalyst was demonstrated during three cycles of SMTZ degradation.
关键词： Enhanced surface area,Visible light activation,Box behnken design,Reusability,P-doped Fe2O3-TiO2 mixed oxide
更新于2025-09-23 15:23:52
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Photocatalytic degradation of yellow 2G dye using titanium dioxide/ultraviolet A light through a Box–Behnken experimental design: Optimization and kinetic study
摘要： Yellow 2G (Y2G), a type of anionic, synthetic monoazo dye that is widely used in household applications, textiles, and food industries, has been found to have cardiovascular and neurological effects on all living beings. In the present study, heterogeneous photocatalytic degradation of commercial Y2G was conducted using pure titanium dioxide (TiO2) in a batch reactor system under ultraviolet A (UVA) light for 180 min. TiO2 dosage, pH, and initial Y2G concentration were the three experimental parameters selected and studied to obtain preliminary information about the photocatalytic activities within a specified range. The Box–Behnken design method (BBD) was used to determine optimal values of the results using the above parameters of Y2G photocatalysis under response surface methodology (RSM). The optimum conditions were 0.914 g L?1 TiO2, pH 3.45, and an initial Y2G concentration of 20 mg L?1. The Y2G degradation efficiency was 96.19% using a second-order polynomial equation with R2 = 0.999. The experimental results also showed that the photocatalytic process could be successfully explained using the modified Langmuir–Hinshelwood model, where kc and KLH were 0.787 mg L?1 min and 0.010 L mg?1, respectively.
关键词： photocatalysis,Box–Behnken design (BBD),optimization,Yellow 2G (Y2G) dye,response surface methodology (RSM)
更新于2025-09-23 15:23:52
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Spectrophotometric determination of nitrate in hypersaline waters after optimization based on the Box-Behnken design
摘要： Monitoring dissolved nitrate (NO3?) concentrations is essential for conservation efforts in aquatic ecosystems. Spectrophotometric methods are a widely accepted approach for NO3? analysis. They detect NO3? as a colored diazo complex after reduction to nitrite (NO2?) and its consequent reaction with the so-called Griess reagent. This method is commonly used for freshwater and saline water samples, even though it requires applying a heavy metal in powder form (cadmium) or high concentrations of heavy metal salts (vanadium-III), as a reductant. There has been little discussion about applying these methods for hypersaline samples. This study optimizes an existing method for use in high saline conditions based on the Griess reaction. Five factors were studied: incubation temperature, reaction time, concentration of EDTA, concentration of trisodium citrate, and concentration of reductant (VCl3). Optimal conditions were obtained by using the Box-Behnken design and included using VCl3 17.5 mM, trisodium citrate 70 mM, and an incubation temperature of 60 °C for 40 min. These conditions provided a linear range from 0.55 μM to 50 μM NO3?. The method showed a moderate precision (ranging from 4.3% to 15.4%). The proposed protocol was tested with hypersaline natural samples and showed recovery rates between 92.6% and 100.1%. This protocol for NO3? determination is the first specifically described for hypersaline samples.
关键词： Hypersaline water,Nitrate analyses,Griess reaction,Vanadium chloride,Box-Behnken design
更新于2025-09-23 15:22:29
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Optimization of process parameters during laser cutting of Ni-based superalloy thin sheet using response surface methodology
摘要： The present investigation deals with the modeling and optimization of multiple quality characteristics of kerf geometry during pulsed Nd: YAG laser cutting of nickel based superalloy thin sheet along the straight cut profile. Top kerf deviation and kerf taper are considered as quality characteristics. These laser cut quality characteristics are the functions of four input parameters are namely: lamp current, Pulse duration, Pulse repetition rate and Scanning speed. Box-Behnken design (BBD) based experiments have been conducted to obtain experimental results of cut quality characteristics for the study. The experimental results have been analyzed for developing models and optimizing the responses using response surface methodology (RSM).
关键词： Box-Behnken design,laser cutting,Response surface methodology,superalloy sheet
更新于2025-09-12 10:27:22
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Benzimidazoles in wastewater: Analytical method development, monitoring and degradation by photolysis and ozonation
摘要： Pharmaceutical residues are constantly released into natural waters, mainly from wastewater treatment plants (WWTPs) whose processes are unable to completely eliminate them. Among these drugs, the occurrence of benzimidazoles, a class of antiparasitics for human and veterinary use, has been reported in WWTP e?uents and surface waters. In this study, an SPE-UHPLC-MS/MS method was developed and optimized for extraction and quantitation of benzimidazoles in in?uents and e?uents of a local WWTP and in hospital wastewater. The extraction procedure was optimized using response surface methodology (Box-Behnken design) and the optimal parameters were as follows: 2.0 mL of loading solvent consisting of a mixture of water:methanol (95:5, v/v) and temperature at 43 °C. In hospital wastewater, albendazole (ABZ) and its principal metabolite ricobendazole (RBZ) were the main benzimidazole-related contaminants and were found at concentrations of up to 3810 and 3894 ng L?1, respectively. The WWTP system was able to remove from 46% to 95% of the ABZ quanti?ed in the in?uent, discharging an e?uent with 16–441 ng L?1 of ABZ. The concentrations of other benzimidazoles and metabolites in the WWTP e?uents remained below 350 ng L?1. WWTP e?uents forti?ed with 50 μg L?1 of ABZ and RBZ required 26.7 mgO3 L?1 to remove ABZ and RBZ. After ozonation, the COD and BOD5 of the e?uents were reduced by 27%. Photolysis by UVA radiation was not e?ective to remove ABZ and FBZ from the e?uent samples.
关键词： Antiparasitic,Online SPE-UHPLC-MS/MS,Box-Behnken design,Pharmaceutical residue,Albendazole
更新于2025-09-04 15:30:14