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To operationalise the heterogeneous photocatalysis process, the present study investigated the efficiency of TiO2-P25 nanoparticles immobilised on glass beads using the heat attachment method to remove cefazolin (CEF) as an antibiotic contaminant. The characteristics of the glass beads coated with TiO2-P25 nanoparticles were probed by the Scanning Electron Microscopy (SEM) technique. The immobilised TiO2-P25 nanoparticles manifested considerable efficiency in CEF removal in different operational conditions. The impact of various parameters, such as the ultraviolet light radiation time, initial concentration of CEF, light source power, inlet liquid volumetric flow rate, and pH of the solution, on the efficiency of CEF removal were examined. The results reveal that the removal percentage goes up as the irradiation time, volumetric flow rate, pH of the solution, and light source power increase while declining with a rise in the initial concentration of CEF. According to the findings, an initial CEF concentration of 20 mg L−1 is entirely removed by 40 min UV irradiation with a 16 W light source, the volumetric flow rate of 300 mL min−1, and the pH of 9.5. The reaction rate constant and adsorption coefficient of CEF on immobilised TiO2 were estimated at 0.622 mg L−1 min−1 and 0.095 mg−1 L via Langmuir- Hinshelwood kinetics. The outcomes of the mineralisation studies also display a considerable reduction of TOC and evolution of significant mineralisation products, like $$NO_3^ - $$ N O 3 − , $$NO_2^ - $$ N O 2 − , $$NH_4^ + $$ N H 4 + , and $$SO_4^{2 - }$$ S O 4 2 − . The experimental results were modelled by artificial neural networks (ANN). Comparing the experimental results with the ANN-predicted data shows the acceptable efficiency of modelling with ANN. The minimum MSE, R2 value for all data (validation, training, and test), and R2 value for simulated data were obtained at 0.00027811, 0.9971, and 0.9809, respectively. The relative importance of the parameters affecting the process evaluated by the ANN weights indicates that the irradiation time is the most important factor in the photocatalytic removal of CEF. [ABSTRACT FROM AUTHOR]

This study investigates the influence of LDHs (Layered Double Hydroxides) microparticles and steel fibers on the mechanical properties of lightweight concrete. Through a combination of experimental analysis and finite element modeling, the effects of LDHs and steel fibers on flexural strength and crack resistance were evaluated. The experimental results demonstrate a significant increase in flexural strength and toughness with the incorporation of LDHs microparticles and steel fibers. The finite element model corroborates these findings, highlighting the synergistic enhancement of mechanical properties due to LDHs and steel fibers. Additionally, the study discusses the frontier applications of LDHs in improving fracture characteristics and highlights the potential of hybrid reinforcement strategies in lightweight concrete. The findings reveal that both the quantity of microparticles and steel fibers significantly impact the concrete's residual strength. In scenarios without steel fibers, an optimal weight fraction of approximately 1 wt.% LDHs demonstrate a 39% increase in bearing capacity. Notably, under comparable conditions, the influence of LDHs microparticles on enhancing concrete mechanical characteristics appears to surpass the effects induced by steel fibers. However, at 2 wt.% LDHs usage, a decrease in load capacity by 3.3% is observed compared to the 1 wt.% LDHs configuration. This research provides valuable insights into optimizing concrete properties through novel material combinations and paves the way for future advancements in structural engineering. [ABSTRACT FROM AUTHOR]

In this study, a flower-like SnIn4S8/SmVO4 heterostructure was synthesized by applying a hydrothermal approach and used as a visible-light-driven photocatalyst to remove hexavalent chromium (Cr6+) and Rhodamine B (RhB). The process design and optimization were carried out by response surface methodology (RSM). An artificial neural network (ANN) was also used to determine the relative importance of operational factors. Under RSM-based optimal conditions, the Cr6+ and RhB removal efficiency reached 90.93 and 97.57%, respectively. Process modeling by ANN revealed pH as the most influential factor in Cr6+ and dye removal. The predominant photocatalytic activity of SnIn4S8/SmVO4 was attributed to its Z-scheme structure, leading to the significant separation of charge carriers and conserving the redox capacity of the photogenerated electron-holes. Kinetic studies revealed that the SnIn4S8/SmVO4 could achieve considerable rate constants of 0.036 and 0.080 min−1 to remove Cr6+ and RhB, respectively. Furthermore, the catalyst's reusability was confirmed under optimal conditions. [ABSTRACT FROM AUTHOR]

Essential oils with antimicrobial or antioxidant activities have received extensive attention among customers, manufacturers, and food scientists, especially with rising worries about the safety of synthetic food preservatives. However, like other functional lipid compounds their incorporation into aqueous systems is challenging, due to their less water solubility. Furthermore, their susceptibility to light, moisture, heat, and oxygen origins their less chemical and structural stabilities. Consequently, the present research was aimed to encapsulate the thyme essential oil into nanoliposomes, using a thin layer hydration-sonication technique, which can be a proficient solution for revealed problems. The effects of phospholipid and stabilizing agents' concentrations, namely, lecithin, cholesterol, and glycerol, as main formulation parameters were investigated on characteristics of gained nanoliposomes, using a response surface method. Various empirical models were also developed to predict product characteristics by changing the formulation parameters. According to the numerical multiple optimizations, the best thyme oil nanoliposomes can be gained using equal concentrations of all three components as 1% with a mean particle size of 189.6 nm, PDI of 0.3487, the net zeta-potential of 42.48 mV, and DPPH radical scavenging of 12.72%. The prepared nanoliposomes had acceptable physical but limited chemical stabilities. The antibacterial action of manufactured essential oil nanoliposomes against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus has made them efficient candidates as natural food preservatives. [ABSTRACT FROM AUTHOR]

In this research, the cadmium sulfide—graphite carbon nitride (CdS-g-C3N4) nanocomposite was synthesized and characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectrometer (EDX), and transmission electron microscopy (TEM) techniques. The photocatalytic activity of as-prepared nanocomposite was evaluated in the degradation of ceftriaxone sodium (CTX) antibiotic from aqueous solution under visible light irradiation. The influence of the operational variables such as the amount of photocatalyst (g/L), initial CTX concentration (mg/L), pH, and irradiation time (min) on the photodegradation process was investigated and optimized using response surface methodology (RSM)—central composite design (CCD) model. The maximum degradation percentage (92.55%) was obtained in the optimal condition, including 0.06 g/L of CdS-g-C3N4 photocatalyst, 15 mg/L of CTX, pH = 10.5, and irradiation time = 81 min. The efficient photocatalytic performance of CdS-g-C3N4 nanocomposite is due to the appropriate alignment of energy levels between the CdS and g-C3N4, which synergistically impact the charge separation and the degradation efficiency of CTX. The kinetics of the photocatalytic degradation process was well described by Langmuir–Hinshelwood's pseudo-first-order model (kapp = 0.0336 min−1). [ABSTRACT FROM AUTHOR]

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples. [ABSTRACT FROM AUTHOR]

In this study, using response surface methodology (RSM), we focused on optimizing Rhodamine B (RhB) removal via Ag, Mg co-doped ZnO nanoparticles. Statistical analysis and lack of fit indicated that the model was adequate for optimizing the process. The optimum conditions were 240 mg L–1 photocatalyst dosage, 5 mg L–1 RhB concentration and 10 min irradiation time. A mathematical equation was created between RhB removal percent and effective operational parameters. The results calculated through RSM equation were used for modeling the process via artificial neural networks (ANN). Operational parameters such as photocatalyst dosage, initial RhB concentration and irradiation time were selected as the input variables. A three-layered feed forward back propagation ANN model was developed to process modeling. Data used in RSM design was simulated for testing the accuracy of the model generated by ANN. The comparison of the ANN predicted data and the experimental data revealed that the proposed method is significantly more effective in terms of the process modeling. The results obtained via ANN modeling indicated that the photocatalyst dosage with the relative importance of 49.61% can be considered as the most effective parameter for RhB photocatalytic removal. [ABSTRACT FROM AUTHOR]

In this study, TiO2 nanowires (TNWs) were synthesized through hydrothermal method and were characterized using X‐Ray diffraction (XRD), transmission electron microscopy (TEM) and BET techniques. Monoclinic TiO2 (B) is the dominant phase of TNWs up to 600°C which is completely transformed into a highly crystalline anatase phase at 800°C. The photocatalytic activity of TNWs, prepared at various calcination temperatures, was investigated in the removal of Rhodamine B as an organic model pollutant. The results indicated that the photocatalytic activity of TNWs, prepared at 800°C calcination temperature, was better than that of other samples and even TiO2–P25 nanoparticles. [ABSTRACT FROM AUTHOR]

In this article, response surface methodology (RSM) was used to obtain optimum conditions for removal of p-nitrophenol (PNP) by UV/H2O2 process using spinning disk photoreactor (SDP). For this purpose, the effect of five independent variables, the initial concentration of PNP, the initial concentration of H2O2, pH, solution volume, and irradiation time on the PNP removal percent, was investigated. Central composite design, one of the response surface techniques used for process optimization. The results showed a good agreement between the RSM predicted and experimental data with "R2" and "Adjusted R2" of 0.9692 and 0.9480, respectively. In addition, "Predicted R2" of 0.8909 is in reasonable agreement with "Adjusted R2" of 0.9488. At optimal conditions, that is, PNP concentration of 20.78 mg L−1, H2O2 concentration of 1355.83 mg L−1, solution volume of 566.08 mL, irradiation time of 12.30 min, and pH of 4.59 the removal percent predicted by RSM is 100% which has good correspondence with its experimental value (98.67%). [ABSTRACT FROM AUTHOR]

Abstract: In this paper, pure ZnO, Ag, and Mg mono-doped and co-doped ZnO nanoparticles were synthesized via sol-gel method. The synthesized nanoparticles were characterized using XRD, DRS, BET, TEM, SEM-EDX, and PL techniques. The photocatalytic activity of the prepared photocatalysts was evaluated in degradation Rhodamine B (RhB) dye. Response surface methodology (RSM) was used as a statistical technique for optimizing the effect of synthesis variables on the removal efficiency of RhB. The results predicted from RSM were found to be in good agreement with the experimental results as indicated by correlation coefficient (R2) of 0.9624. Furthermore, statistical tests such as ANOVA table and lack of fit indicated that the model was adequate for representing the experimental data. Ag and Mg co-doped ZnO nanoparticles demonstrated the highest photocatalytic activity in comparison with pure and mono-doped ZnO. Maximum photocatalytic activity of co-doped ZnO nanoparticles was observed for a sample with 3 wt % Ag, 4 wt % Mg calcined at 530°C. [ABSTRACT FROM AUTHOR]

The photooxidative removal of analgesic pharmaceutical compound phenazopyridine (PhP) from aqueous solutions by UV/H2O2 system with a re-circulated photoreactor was investigated. Response surface methodology (RSM) was employed to optimize the effect of operational parameters on the photooxidative removal efficiency. The investigated variables were: the initial PhP and H2O2 concentrations, irradiation time, volume of solution and pH. The analysis of variance (ANOVA) of quadratic model demonstrated that the described model was highly significant. The predicted values of the photooxidative removal efficiency were found to be in a fair agreement with experimental values (R2 = 0.9832, adjusted R2 = 0.9716). The model predicted that the optimal reaction conditions for a maximum removal of PhP (>98%) were: initial PhP concentration less than 23 mg L-1, initial concentration of H2O2 higher than 470 mg L-1, solution volume less than 500 mL, pH close to 2 and irradiation time longer than 6 min. [ABSTRACT FROM AUTHOR]

In this study, a horizontally rotating disc recirculated (HRDR) photoreactor equipped with two UV lamps (6 W) was designed and fabricated for photocatalytic removal of p-nitrophenol (PNP). Photocatalyst (TiO2) nanoparticles were immobilized onto a high-density polyethylene (HDPE) disc, and PNP containing solution was allowed to flow (flow rate of 310 mL min-1) in radial direction along the surface of the rotating disc illuminated with UV light. The efficiency of direct photolysis and photocatalysis and the effect of rotating speed on the removal of PNP were studied in the HRDR photoreactor. It was found that TiO2-P25 nanoparticles are needed for the effective removal of PNP and there was an optimum rotating speed (450 rpm) for the efficient performance of the HRDR photoreactor. Then effects of operational variables on the removal efficiency were optimized using response surface methodology. The results showed that the predicted values of removal efficiency are consistent with experimental results with an R2 of 0.9656. Optimization results showed that maximum removal percent (82.6%) was achieved in the HRDR photoreactor at the optimum operational conditions. Finally, the reusability of the HRDR photoreactor was evaluated and the results showed high reusability and stability without any significant decrease in the photocatalytic removal efficiency. [ABSTRACT FROM AUTHOR]

Hydrothermal method was used to synthesize TiO2 nanotubes (TNTs), which are considered as a novel adsorbent with high surface area and adsorption capacity. Different methods including X-ray diffraction (XRD), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET) analysis were used to investigate and identify synthesized TNTs. The adsorption capacity of TNTs was investigated with regard to removing Basic Violet 2 (BV2) as a model organic pollutant from aqueous solution. The mean outer, inner diameter and thickness of the TNTs were found to be approximately 9, 4 and 2.5 nm, respectively. BET-BJH method was used for measuring specific surface area and pore volume of the TNTs which turned out to be 200.38 m2 g−1 and 0.44 cm3 g−1, respectively. The results of the study indicated synthesized TNTs may be considered as efficient and effective adsorbent for removing BV2 (75.63%) from aqueous solution. The impact of the operational variables, i.e. initial BV2 concentration (2-20 mg L−1), dosage of adsorbent (0.01-0.6 g), and pH (2-8) in relation to the adsorption capacity of BV2 onto TNTs were investigated. The experimental results of the study were meticulously taken into consideration for discussing and analyzing the adsorption isotherms and kinetics. It was found that the collected experimental data regarding the kinetic and isotherm examinations were compatible and well-matched with the pseudo-first order kinetic model and Langmuir isotherm model (R2 = 0.9634). [ABSTRACT FROM AUTHOR]

In this paper, photooxidative removal of p-nitrophenol (PNP) as a model organic pollutant was investigated in the presence of UV/inorganic oxidants system in an annular continuous-flow photoreactor. The aim of this study was to evaluate the photooxidative efficiency of hybrid oxidant system including persulfate (UV/HO/SO) and hydrogen peroxide (HO), under UV-C light irradiation. The effects of operational variables including UV/HO/SO and HO concentrations, the initial PNP concentration, and residence time on the removal efficiency of UV/HO/HO/SO system were studied. It was found that the operational variables affected the removal efficiency of UV/HO/HO/SO system. Operating conditions were optimized using response surface methodology (RSM). Simulation approach showed that the predicted values of removal efficiency are in good agreement with the experimental results with a correlation coefficient ( R ) of 0.95. Optimization results showed that the maximum degree of removal (98%) was achieved by using the UV/HO/HO/SO system under the following operation conditions: concentration of HO = 10 mmol/L, concentration of UV/HO/SO = 10 mmol/L, initial concentration of PNP = 35 mg/L, and residence time = 8 min. The obtained results clearly demonstrated that RSM is one of the useful and cost-effective methods for modeling and optimizing the efficiency of UV/HO/UV/HO/SOsystem. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation of phenazopyridine (PhP) as a model contaminant from pharmaceutical compounds was studied using batch-recirculated photoreactor packed with immobilized TiO-P25 nanoparticles on glass beads. The effects of operational parameters (irradiation time, initial concentration of PhP, volume of solution, and volumetric flow rate) were evaluated by the response surface methodology (RSM). The proposed model of the RSM is a second order mathematical model. According to the results of ANOVA, initial concentration of PhP, volumetric flow rate, irradiation time, volume of solution, mutual effects of initial concentration of PhP × irradiation time, irradiation time × volume of solution and quadratic effects of initial concentration of PhP, and volume of solution are significant model parameters. The optimization process by RSM offers the following optimal conditions: PhP concentration 24 mg L, liquid volumetric flow rate 230 mL min, irradiation time 30 min, and volume of solution 300 mL. Under these conditions, the proposed removal percent of RSM is 90.28% which have good correspondence with experimental removal percent (87.36%). [ABSTRACT FROM AUTHOR]

In this study, ZnO nanoparticles with different Mg contents and calcination temperatures were synthesized by the sol–gel method. The photocatalytic activity of the synthesized nanoparticles was investigated in the photocatalytic degradation of Rhodamine B. The products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX)-mapping, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and Brunauer–Emmett–Teller (BET) techniques. The XRD results showed that the doped nanoparticles had the same crystal structure as the pure ZnO. The EDX and mapping findings indicated the existence of Mg in the doped sample. SEM and TEM analysis showed the spherical shape and uniform-size distribution of the nanoparticles. Based on DRS spectra, the band gap energy value of 2.0 wt% Mg doped ZnO was 3.26 eV, which was larger than the ZnO nanoparticles’ band gap energy. Using BET analysis, the surface areas of ZnO and 2.0 wt% Mg/ZnO were calculated to be 14.9 and 22.5 m2 g−1, respectively. The results of the photocatalytic activity indicated that Mg/ZnO was more active than pure ZnO photocatalyst due to its higher surface area and larger band gap energy. Maximum photocatalytic activity was achieved for Mg/ZnO nanoparticles with 2.0 wt% Mg and at the calcination temperature of 400°C. [ABSTRACT FROM PUBLISHER]

Removal of two triphenylmethane dyes, Acid Fuchsin (AF) and Malachite green (MG), was studied by hybrid advanced oxidation processes of homogeneous (UV/Fe2+/H2O2) and heterogeneous (UV/TiO2−SiO2) photocatalysis. A comparison of various processes for removal of model pollutants was performed. The results showed that the utilizing hybrid photocatalytic processes in the presence of silica leads to rapid removal of pollutants, which may be ascribable to the synergistic influence of produced various radical species. The effects of operational variables were studied on the efficiency of the UV/Fe2+/H2O2/TiO2−SiO2 hybrid process. An artificial neural network (ANN) model was intended to predict the removal efficiency of the UV/Fe2+/H2O2/TiO2−SiO2 hybrid process under different operational conditions. The results indicated that there is a good concurrence between the ANN predicted values and experimental results with a correlation coefficient of 0.9873 and 0.9774 for removal of AF and MG dyes, respectively. The designed neural network model gives a dependable technique for modeling the removal efficiency of the UV/Fe2+/H2O2/TiO2−SiO2 hybrid process. Moreover, the relative significance of each variable was computed based on the input-hidden and hidden-output connection weights of the neural network model. The initial concentration of dyes was the most significant variable in the removal efficiency. [ABSTRACT FROM AUTHOR]

In this study, the photodegradation of cefazolin was investigated in the presence of suspended and immobilized TiO2on a glass plate. The effects of the operational parameters such as the catalyst dosage for the suspended system, the initial pH of the solution, the initial concentration of the cefazolin, and light intensity were examined and compared in both systems. Scanning electron microscopy and atomic force microscopy were used to determine the surface properties of the immobilized catalyst on glass. The favorable conditions obtained for the photodegradation of cefazolin were pH 5, light intensity = 17 W m−2, and [cefazolin]0 = 20 mg L−1in both the systems. Also, in the slurry system, the most suitable catalyst dosage was 400 mg L−1. The kinetic examination, following the pseudo-first-order reaction kinetics, was made based on the Langmuir–Hinshelwood model. [ABSTRACT FROM PUBLISHER]

In this study, removal efficiency of phenazopyridine (PhP) as a model pharmaceutical contaminant was investigated in a batch-recirculated photoreactor packed with immobilized TiO2-P25 nanoparticles on glass beads. Influence of various operational parameters such as irradiation time, initial concentration of PhP, volume of solution, volumetric flow rate, pH and power of light source was investigated. Results indicated that removal percentage increases with the rise of irradiation time, volumetric flow rate and power of light source but decreases with the rise of initial concentration of PhP and volume of solution. Highest removal percentage was obtained in the natural pH of PhP solution (pH= 5.9). Results of mineralization studies also showed a decreasing trend of total organic carbon (TOC) and producing mineralization products such as NO3-, NO 2-and NH 4-.Modeling of the process using artificial neural network showed that the most effective parameters in the degradation of PhP were volume of solution and power of light source. The packed bed photoreactor with TiO2-P25 nanoparticles coated onto glass beads in consecutive repeats have the proper ability for PhP degradation. Therefore, this system can be a promising alternative for the removal of recalcitrant organic pollutants such as PhP from aqueous solutions. [ABSTRACT FROM AUTHOR]

In the present study, Ag–TiO2-P25 nanoparticle was synthesized using photodeposition technique and Mg was impregnated onto the Ag–TiO2-P25 for the preparation of co-doped nanoparticles. The physicochemical properties were characterized by X-ray diffraction (XRD), specific surface area and porosity (Brunauer–Emmett–Teller (BET) and Barret–Joyner–Halender), transmission electron microscopy, diffuse reflectance spectroscopy (DRS), scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy techniques. The BET surface area of the co-doped TiO2-P25 was larger than that of the monometallic catalysts and the XRD data showed anatase and rutile crystalline phases in catalysts, indicating that Ag and Mg co-doping did not influence the crystal patterns of TiO2-P25. Also, the DRS results indicated that the band gap of co-doped photocatalyst was smaller than that of the monometallic and undoped TiO2-P25 and there was a shift in the absorption band toward the visible light region. Additionally, the photocatalytic efficiency of the synthesized catalysts was evaluated by degradation of C.I. Acid Red 27 under visible light irradiation. The results showed that Ag-(1 wt%) and Mg-(0.25 wt%) co-doped TiO2-P25 had the highest photoactivity among all samples under visible light. The optimum calcination temperature and time were 350°C and 1 h, respectively. The results of the total organic carbon analysis indicated 66% mineralization of AR27 after 20 min of irradiation time. [ABSTRACT FROM AUTHOR]

In this paper, the removal efficiency of Color Index Acid Orange 7 (A07) as a model contaminant was investigated in a batchrecirculated photoreactor packed with immobilized titanium dioxide type P25 nanoparticles on glass beads. The effects of different operational parameters such as the initial concentration of A07, the volume of solution, the volumetric flowrate, and the light source power in the photoreactor were investigated. The results indicate that the removal percent increased with the rise in volumetric flowrate and power of the light source, but decreased with the rise of the initial concentration of A07 and the volume of solution. The A07 degradation was followed through total organic carbon, gas chromatography/mass spectroscopy (GC/MS), and mineralization products analysis. The ammonium and sulfate ions were analyzed as mineralization products of nitrogen and sulfur heteroatoms, respectively. The results of GC/MS revealed the production of 1-indanone, 1-phthalanone, and 2-naphthalenol as intermediate products for the removal of A07 in this process. Water Environ. Res., 88, 449 (2016). [ABSTRACT FROM AUTHOR]

In this study, we successfully prepared pure, mono-doped, and Ag, Mg co-doped TiO nanoparticles using the sol-gel method, with titanium tetraisopropoxide as the Ti source. The prepared samples were characterized by X-ray powder diffraction (XRD), specific surface area and porosity (BET and BJH) measurement, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence, and energy dispersive X-ray spectroscopy techniques. The XRD data showed that the prepared nanoparticles had the same crystals structures as the pure TiO. Also, DRS results indicated that the band gap of co-doped photocatalyst was smaller than that of the monometallic and undoped TiO and that there was a shift in the absorption band towards the visible light region. Furthermore, the photocatalytic activity of the prepared catalysts was evaluated by the degradation of C.I. Acid Red 27 in aqueous solution under visible light irradiation. The results showed that Ag (0.08 mol%), Mg (0.2 mol%) co-doped TiO had the highest photoactivity among all samples under visible light. It was concluded that co-doping of the Ag and Mg can significantly improve the photocatalytic activity of the prepared photocatalysts, due to the efficient inhibition of the recombination of photogenerated electron-hole pairs. The optimum calcination temperature and time were 450 °C and 3 h, respectively. [ABSTRACT FROM AUTHOR]

In this study, the nanoparticles of TiO2-P25 in the slurry situation were used for photoreduction of Cr(VI). The experiments were conducted in different operational conditions such as initial concentration of Cr(VI), varying dosages of photocatalyst, and different irradiation times and pHs. Using the response surface methodology, the mathematical equation for estimating the percentage of Cr(VI) photocatalytic removal was obtained. For the first time, the results from this model were utilized for modeling the process by artificial neural networks (ANN). The comparison of the analyzed data obtained from ANN and the experimental data showed that the method was highly efficient in the modeling of process. The relative importance of the parameters affecting the process evaluated by the weights from ANN indicated that pH was the most important factor in photocatalytic reduction of Cr(VI). [ABSTRACT FROM AUTHOR]

Silver-impregnated silicon oxide/titanium oxide nanoparticles (Ag/SiO-TiO) were prepared via impregnation method. X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and UV-Vis diffuse reflectance spectroscopy techniques were used for the characterization of prepared nanoparticles. The effects of synthesis variables such as nanoporous SiO content, Ag content, impregnation pH, and calcination temperature were studied in the photocatalytic activity of prepared nanoparticles in the removal of phenazopyridine as a model drug contaminant. Response surface methodology as a statistical technique was employed for modeling and optimizing synthesis variables. Results showed that the maximum removal efficiency (97.14 %) was achieved for Ag/SiO-TiO nanoparticles at the optimized preparation conditions: SiO content of 34.68 wt%, Ag content of 2.36 wt%, impregnation pH of 5.1, and calcination temperature of 439 °C, whereas at the same conditions, using TiO, SiO-TiO, and Ag-TiO samples lead to 50.14, 60.37, and 71.45 % removal efficiency, respectively. Coupling SiO with large surface area significantly enhanced adsorption of drug molecules, and also impregnation of Ag onto the hybrid system by its ability to trap electrons, provided a synergistic effect in the enhancement of the TiO nanoparticles photocatalytic activity. [ABSTRACT FROM AUTHOR]

This study investigated the optimum conditions in the removal of model contaminant C.I. Acid Orange 7 (AO7) in batch-recirculated photoreactor with immobilized TiO2-P25 nanoparticles. The effect of different operational parameters such as initial concentration of AO7, volume of solution, volumetric flow rate, time of the reaction, and power of light source were studied and optimized by Taguchi method. Sixteen experiments were performed to examine the effect of the parameters on the removal of AO7. To reduce the error, each experiment was repeated three times and the signal/noise (S/N) was calculated. Results indicated that the power of light source was the most effective parameter in comparison to others. Based on the S/N ratio, the optimized conditions for the removal of AO7 in batch-recirculated photoreactor were initial concentration of AO7 (20 mg L−1), volume of solution (500 mL), volumetric flow rate (140 mL min−1), time of reaction (60 min), and power of light source (13 W). [ABSTRACT FROM AUTHOR]

In the present study, nickel oxide nanoparticles synthesized by the sol-gel method were used as an effective adsorbent for the removal of Cr(VI) from aqueous solutions. To do so, the effect of four parameters including the concentration of Cr(VI), the dosage of NiO, contact time, and pH on the removal of Cr(VI) by NiO nanoparticles were studied. In order to examine and describe the optimum conditions for each of the mentioned parameters, Taguchi and response surface methods were used. The results of the experiment using Taguchi and response surface methods indicated the greater effect of the NiO adsorbent parameter in comparison to the other parameters in the adsorption of Cr(VI) by NiO nanoparticles, and showed that the increase in contact time and pH does not affect the removal percentage of Cr(VI) significantly. [ABSTRACT FROM AUTHOR]

In this study, titanium dioxide (TiO) nanoparticles were prepared by the sol-gel method in different synthesis conditions. The effect of synthesis variables (including water:titanium alkoxide molar ratio, reflux temperature, reflux time, gelation pH, and stirring speed) were studied in the removal of Acid Red 27 as a model contaminant from textile industry under UV light irradiation. For the first time, we report modeling of the effects of synthesis variables on the photocatalytic activity of TiO nanoparticles by an artificial neural network (ANN). Five effective synthesis variables were inserted as the input of the network and reaction rate constants ( k) were introduced as the output of the network. The results showed that the predicted data from the designed ANN model were in good agreement with the experimental data, with a correlation coefficient ( R) of 0.9655 and mean square error of 0.00148. The designed artificial neural network provided a reliable method for modeling the photocatalytic activity of TiO nanoparticles prepared under different synthesis conditions. Furthermore, the relative importance of each synthesis variable was calculated based on the connection weights of ANN model. The reflux time and reflux temperature were the most significant variables in the photocatalytic activity of TiO nanoparticles, followed by the water:titanium alkoxide molar ratio and gelation pH. [ABSTRACT FROM AUTHOR]

In this study, the photocatalytic efficiency of anatase-type TiO2 nanoparticles synthesized using the sol--gel low-temperature method, were enhanced by a combined process of copper reduction and surface hydroxyl groups enhancement. UV-- light-assisted photo and NaBH4-assisted chemical reduction methods were used for deposition of copper onto TiO2. The surface hydroxyl groups of TiO2 were enhanced with the assistance of NaOH modification. The prepared catalysts were immobilized on glass plates and used as the fixed-bed systems for the removal of phenazopyridine as a model drug contaminant under visible light irradiation. NaOH-modified Cu/TiO2 nanoparticles demonstrated higher photocatalytic efficiency than that of pure TiO2 due to the extending of the charge carriers lifetime and enhancement of the adsorption capacity of TiO2 toward phenazopyridine. The relationship of structure and performance of prepared nanoparticles has been established by using various techniques, such as XRD, XPS, TEM, EDX, XRF, TGA, DRS and PL. The effects of preparation variables, including copper content, reducing agents rate (NaBH4 concentration and UV light intensity) and NaOH concentration were investigated on the photocatalytic efficiency of NaOH-modified Cu/TiO2 nanoparticles. [ABSTRACT FROM AUTHOR]

In this paper, photooxidative removal of C.I. Basic Red 46 (BR46) as a model organic pollutant was investigated in the presence of UV/inorganic oxidants system. The aim of this study was to evaluate the efficiency of hybrid oxidant system including inorganic oxidant species such as persulfate (), peroxymonosulfate (), periodate (), bromate (), and chlorate () under UV-C light irradiation. The effect of various inorganic oxidants concentration in different reaction times was predicted and optimized in the photooxidation process using response surface methodology. It was found that the concentration of inorganic oxidants significantly affected the removal rate of BR46. Modeling results showed that the predicted values of removal efficiency were found to be in good agreement with the experimental results with a correlation coefficient (R2) of 0.9462. Optimization results showed that maximum removal efficiency (95.51%) was achieved at the optimum oxidants concentration:of 118 mg L−1,of 24 mg L−1,of 1035 mg L−1,of 232 mg L−1andof 267 mg L−1in reaction time of 23 min. Effect of oxidants concentration on the photooxidative removal of BR46 was estimated by the response surface and contour plots. Furthermore, the photooxidative removal efficiency of hybrid oxidant system mode was compared with individual processes. The obtained results clearly demonstrated that experimental design approach was one of the useful and cost-effective methods for modeling and optimizing the efficiency of UV/inorganic oxidants system. Mineralization study showed 84.4% reduction in total organic carbon value after 90 min of process. [ABSTRACT FROM PUBLISHER]

In the present work, a powder mixture of the TiO2and CeO2solid oxides was used for preparation of TiO2/CeO2hybrid nanoparticles. Crystallite size and structure of prepared TiO2/CeO2hybrid nanoparticles were determined by X-ray diffraction and transmission electron microscopy techniques. The effect of operational variables such as catalyst dosage, initial drug concentration, irradiation time, and distance of the solution from UV lamp was predicted and optimized in the photocatalytic removal of phenazopyridine (PhP) using response surface methodology. The results showed that the predicted values of removal efficiency were found to be in good agreement with the experimental results with a correlation coefficient (R2) of 0.9542. The optimum operational conditions were found to be: catalyst dosage of 0.41 g L−1, initial drug concentration of 6.61 mg L−1, irradiation time of 30 min, and distance of the solution from UV lamp of 2 cm. Under the optimized conditions, the maximum removal rate (97.74%) of PhP was achieved. [ABSTRACT FROM PUBLISHER]

In this study, TiO nanoparticles were prepared by the sol-gel method under different pH conditions and the structural properties of TiO nanoparticles were obtained by X-ray diffraction and transmission electron microscopy. The photocatalytic activity of TiO nanoparticles was studied in the removal of C.I. Acid Red 27 (AR27) under UV light. The desired gelation pH for photocatalytic removal of AR27 was obtained at pH 5. At this pH, the predominant crystal phase of TiO is anatase and its crystallite size is smaller than at other gelation pHs. The artificial neural network (ANN) technique was applied to model and predict the photocatalytic activity of TiO nanoparticles prepared at the desired gelation pH. Four effective operational parameters were inserted as the inputs of the network and reaction rate constants ( k) were introduced as the outputs of the network. The results showed that the predicted data from the designed ANN model are in good agreement with the experimental data with a correlation coefficient ( R) of 0.9852 and mean square error of 0.00242. The designed ANN provides a reliable method for modeling the photocatalytic activity of TiO nanoparticles under different operational conditions. Furthermore, the relative importance of each operational parameter was calculated based on the connection weights of the ANN model. The initial dosage of TiO nanoparticles was the most significant parameter in the photocatalytic removal of AR27, followed by the UV-light intensity and initial AR27 concentration. [ABSTRACT FROM AUTHOR]

In this study, Mg/TiO2-UV100 nanoparticles were prepared by the impregnation method. The structural characteristics and properties of the obtained materials were investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and diffuse reflectance spectroscopy (DRS) techniques. XRD patterns of pure and impregnated TiO2-UV100 nanoparticles revealed that all phases were anatase. The results of BET analysis for Mg/TiO2-UV100 nanoparticles indicated a surface area of 171.8 m2 g−1. Maximum distribution pore size is about 2 nm, which is consistent with microporous structure. The particle size obtained from TEM was close to crystallite size calculated from XRD pattern. A comparison of DRS of the Mg/TiO2-UV100 with bare TiO2-UV100 showed a slight red shift. The photocatalytic degradation of C.I. Acid Red 27 (AR27) was investigated in the presence of TiO2-UV100 and Mg/TiO2-UV100 nanoparticles under different conditions. The photocatalytic activity of Mg-impregnated (0.8 mol%) TiO2-UV100 in the removal of AR27 was higher than that of bare TiO2-UV100 nanoparticles. The photocatalytic activity of Mg-impregnated (0.8 mol%) TiO2-UV100 was very sensitive to dopant content, initial concentration of the AR27, catalyst dosage, light intensity, and pH. The results indicated that the use of photocatalytic method in the presence of Mg-impregnated TiO2-UV100 nanoparticles was a good choice for eliminating organic pollutants from aqueous media. [ABSTRACT FROM PUBLISHER]

ZnO- SnO2 nanoparticles were prepared by coprecipitation method; then Mg, with different molar ratios and calcination temperatures, was loaded on the coupled nanoparticles by impregnation method. The synthesized nanoparticles were characterized by X-ray diffraction ( XRD), field emission scanning electron microscopy ( FESEM), energy dispersive X-ray spectroscopy ( EDX), transmission electron microscopy ( TEM), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller ( BET) techniques. Based on XRD results, the ZnO- SnO2 and Mg/ ZnO- SnO2 nanoparticles were made of ZnO and SnO2 nanocrystallites. According to DRS spectra, the band gap energy value of 3.13 and 3.18 eV were obtained for ZnO- SnO2 and Mg/ ZnO- SnO2 nanoparticles, respectively. BET analysis revealed a Type III isotherm with a microporous structure and surface area of 32.051 and 49.065 m2 g−1 for ZnO- SnO2 and Mg/ ZnO- SnO2, respectively. Also, the spherical shape of nanocrystallites was deduced from TEM and FESEM images. The photocatalytic performance of pure ZnO- SnO2 and Mg/ ZnO- SnO2 was analyzed in the photocatalytic removal of methyl orange ( MO). The results indicated that Mg/ ZnO- SnO2 exhibited superior photocatalytic activity to bare ZnO- SnO2 photocatalyst due to high surface area, increased MO adsorption and larger band gap energy. Maximum photocatalytic activity of Mg/ ZnO- SnO2 nanoparticles was obtained with 0.8 mol% Mg and calcination temperature of 350°C. [ABSTRACT FROM AUTHOR]

In this reported work, TiO2 nanoparticles containing anatase-rutile and pure rutile phases were prepared by sol-gel and hydrolysis in acidic solution methods, respectively. Two general procedures, doping during synthesis (DDS) via a hydrolysis method and doping on the provided TiO2 nanoparticles (DOP) that is performed by the impregnation method have been studied by doping copper to these nanoparticles. The photocatalytic activity was evaluated by photodegradation of C.I. Acid Red 27 as a model contaminant. The prepared samples were characterised by X-ray diffraction, atomic absorption flame emission spectroscopy and scanning electron microscopy. It is found that the photosensitised degradation activity can be enhanced by doping an appropriate amount of Cu. Photocatalytic activity results indicated that samples that have been doped by the DDS procedure show higher photocatalytic efficiency than samples doped by the DOP procedure. [ABSTRACT FROM AUTHOR]

Wastewaters contain inorganic anions that affect the removal rate of organic pollutants. The present study aims to optimize the effects of inorganic anions such as NO3-, Cl-, HCO3-, and H2PO4- on the removal rate of an organic pollutant in the presence of immobilized TiO2 nanoparticles using response surface methodology (RSM). C.I. Acid Red 17 (AR17) was used as a model organic pollutant. Thirty experiments were required to study the effects of anions in various concentrations. The results indicate that the addition of NO3- and HCO3- ions intensifies the removal rate of AR17. The results of the analysis of variance (ANOVA) showed a high coefficient of determination value (R² = 0.9866 and Radj.² = 0.9822). The results indicate that RSM is a suitable method for modeling and optimizing the process. The results prove that in the presence of and NO3- and HCO3- ions especially in the combination situation the removal rate of AR17 is enhanced considerably. An important synergy effect was observed in the combination of NO3- and HCO3- ions, so that AR17 removal percent under the optimized RSMconditions was considerably more than the sum of removal percent when these ions are used individually. [ABSTRACT FROM AUTHOR]

In the present study, effects of operational parameters on the electrical energy consumption for photooxidative process (UV/H2O2) for the decolorization of C. I. Acid Red 88 (AR88) have been investigated. In a series of experiments, 20 mg L−1 of AR88 solution were irradiated in the presence of different concentrations of H2O2 (to find out optimum amount of H2O2) by UV light intensity of 30 W m−2 for certain irradiation times. The decolorization of the dye followed pseudo first-order kinetics, and hence, the figure-of-merit electrical energy per order ( EEO) is appropriate for estimating the electrical energy efficiency. The electrical energy consumption was determined during the variation of some parameters such as initial H2O2 concentration, initial dye concentration, UV light intensity, pH, and the gap size of solution. Results showed that electrical energy could be reduced by optimizing operational parameters. [ABSTRACT FROM AUTHOR]

In the present work the performance of immobilized ZnO on a glass plate with the heat attachment method has been described for photoreduction of Cr(VI) to the less harmful Cr(III) at different operational parameters. The photoreduction of Cr(VI) on the surface of the immobilized ZnO catalyst was studied as a function of the pH of solution, initial Cr(VI) concentration and ultraviolet (UV) light intensity. Results indicated that the reduction rate decreases with increasing initial concentration of Cr(VI) and initial pH of solution, whereas it increases with increasing UV light intensity. The photoreduction rate of Cr(VI) on the surface of the immobilized ZnO in the presence of O2 as mobile gas is more than Ar and N2. The reduction process of Cr(VI) by immobilized ZnO also could be done under visible light irradiation. Pseudo first-order kinetics were observed for the photoreduction of Cr(VI) at different operational conditions. With non-linear regression analysis a mathematical kinetics model was developed for the pseudo first-order constant (k ap) as a function of operational parameters. [ABSTRACT FROM PUBLISHER]

In this study, TiO2- and Mg-doped TiO2 nanoparticles with different dopant contents were prepared by sol-gel method. The prepared photocatalysts were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and diffuse reflectance spectroscopy (DRS) techniques. The results of BET analysis indicated a pore diameter of 8 nm and surface area of 48.5 m2 g−1. XRD patterns of pure and doped TiO2 nanoparticles at 450°C revealed that all phases are anatase. The particle size obtained from TEM was less than 20 nm. The band gap energy of Mg-doped TiO2 nanoparticles was lower than that of TiO2. The photocatalytic activity of the pure and doped nanoparticles has been compared in the removal of C.I. Acid Red 27 (AR27). The photocatalytic activity of Mg-doped (0.2 mol%) TiO2 for the degradation of AR27 was higher than that of bare TiO2 nanoparticles. Results of total organic carbon analysis and changes in the AR27 UV-Vis peaks indicated 99% mineralization and extinguishing of all peaks in UV and visible regions is possible with Mg-doped TiO2 nanoparticles. Removal efficiency of AR27 was sensitive to the parameters such as catalyst dose, pollutant concentration and light intensity. [ABSTRACT FROM AUTHOR]

In this work, TiO2 nanoparticles in anatase phase was prepared by sol-gel low temperature method from titanium tetra-isopropoxide (TTIP) as titanium precursor in the presence of acetic acid (AcOH). The effects of synthesis parameters such as AcOH and water ratios, sol formation time, synthesis and calcination temperature on the photocatalytic activity of TiO2 nanoparticles were evaluated. The resulting nanoparticles were characterized by X-ray diffraction, UV-Vis reflectance spectroscopy, transmission electron microscopy and Brunauer-Emmett-Teller techniques. Photocatalytic activity of anatase TiO2 nanoparticles determined in the removal of C. I. Acid Red 27 (AR27) under UV light irradiation. Results indicate that with increasing AcOH/TTIP molar ratio from 1 to 10, sol formation time from 1 to 3 h and synthesis temperature from 0 to 25°C, increases crystallite size of synthesized nanoparticles. It was found that optimal conditions for low temperature preparation of anatase-type TiO2 nanoparticles with high photocatalytic activity were as follows: TTIP:AcOH:water molar ratio 1:1:200, sol formation time 1 h, synthesis temperature 0°C and calcination temperature 450°C. [ABSTRACT FROM AUTHOR]

In this study, to investigate the application of heterogeneous photocatalysis in the removal of organic contaminants from aqueous media a novel tubular continuous-flow photoreactor with supported TiO2-P25 on glass plates was designed and constructed. The photoreactor comprises six quartz tubes and a UV lamp which was placed in the center of the quartz tubes. 4-nitrophenol (4-NP) as a most refractory pollutant was chosen as a probe pollutant to examine the photoreactor efficiency for environmental cleaning applications. Results of experiments show that the removal efficiency of 4-NP in this photoreactor is a function of photoreactor length, gas and liquid flow rates and 4-NP initial concentration. Kinetics analysis indicates that degradation of 4-NP in continuous-mode can be modeled with the Langmuir-Hinshelwood (L-H) model (kL-H = 1.5 mg L-1 min-1, Kads = 0.11 mg-1 L). A design equation was obtained with a combination of L-H modified equation and tubular reactor design equation. This equation can be used for estimation of 4-NP concentration in different photoreactor lengths under various operational parameters. Mineralization study was followed through total organic carbon (TOC) analysis and measurement of nitrite and nitrate as final degradation products. [ABSTRACT FROM AUTHOR]

In this report, TiO2-SiO2 composite nanoparticles were prepared by the thermal hydrolysis method using titanium tetrachloride and tetraethylorthosilicate as TiO2 and SiO2 precursors, respectively. The prepared nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption/desorption and UV-Vis diffuse reflectance spectroscopy (DRS). The results indicated that, in comparison with pure TiO2, TiO2-SiO2 composite nanoparticles had a higher thermal stability, which prevents phase transformation from anatase to rutile. In addition, the TiO2-SiO2 nanoparticles had a higher specific surface area, larger pore volume, greater band gap energy and smaller crystallite size. Thus, the surface area of TiO2-40% SiO2 composite nanoparticles was about 17 times higher than that of pure TiO2 nanoparticles. The photocatalytic activity of TiO2-SiO2 composite nanoparticles in the photodegradation of C.I. Basic Violet 2 was investigated. The photodegradation rate of Basic Violet 2 using TiO2-40% SiO2 nanoparticles calcined at 600°C was much faster than that using pure TiO2 and Degussa P25 TiO2 by 10.9 and 4.3 times, respectively. The higher photoactivity of the TiO2-SiO2 composite nanoparticles was attributed to their higher surface area, larger pore volume, greater band-gap energy and smaller crystallite size compared with pure TiO2. [ABSTRACT FROM AUTHOR]

The photocatalytic activity of silver-doped ZnO was tested by photocatalytic degradation of C.I. Acid Red 88 (AR88) as a model contaminant from monoazo textile dyes. Silver-doped ZnO was prepared by photodeposition (PD) method. Results show that silver-doped ZnO is more efficient than undoped ZnO at photocatalytic degradation of AR88. The PD method parameters such as irradiation time, calcination temperature and silver content of doping were effective on the photoactivity of silver-doped ZnO. Silver content had an optimum value of 0.5% for achieving high photocatalytic activity. In the real wastewater from a textile-dyeing factory color removal with pure and silver-doped ZnO after 18 min of irradiation were 45 and 90%, respectively. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles with different average diameter of particles (8, 18 and 27 nm) and different crystal structure (anatase and rutile) were used for degradation of C.I. Acid Red 88 (AR88) as a model compound. The degree of degradation of AR88 by TiO2 nanoparticles under irradiation of UV-light (254nm) with TiO2-UV100 (8 nm diameter and 100% anatase) is lower than TiO2-Merck (27 nm diameter and 95% anatase). TiO2-P25 with structure of anatase and rutile (80:20) combination shows higher photoactivity than other samples such as TiO2-UV100 and TiO2-Merck. Kinetics of removal of AR88 with all of nanosized-TiO2 particles is pseudo-first-order. The apparent reaction rate constant (kap) for removal of AR88 in the presence of different nanosized-TiO2 particles decreases with increasing of AR88 initial concentration. For TiO2-P25 and TiO2-UV100 a linear relation and for TiO2-Merck a nonlinear relation between kap and light intensity were obtained. [ABSTRACT FROM AUTHOR]

The decolorization and mineralization of Acid Red 27 (AR27), an anionic monoazo dye of acid class, were studied by UV/H2O2 process in laboratory and real samples. Effects of different process parameters such as initial H2O2 and AR27 concentrations, pH and EtOH as an electron scavenger have been studied. H2O2 and UV light have a negligible effect when they were used on their own. The decolorization rate follows pseudo-first order kinetic with respect to the dye concentration. The rate constant of the attack of •OH radicals to the AR27 has been estimated through the adoption of a simplified kinetic model (1.03 × 108 M−1 s−1). This model allows predicting the pseudo-first order rate constant and concentration of AR27 in different illumination times for different initial concentrations of H2O2. Mineralization studies showed, the formation of sulfate ions, the decrease of pH and 85% of COD reduction occur in less than 60 min. In the real wastewater color removal could be achieved after only 75 min, whereas 45% of COD reduction occurs after 105 min of illumination. [ABSTRACT FROM AUTHOR]

A correction to the article "A Comparative Study of Photocatalytic Degradation of the Antibiotic Cefazolin by Suspended and Immobilized TiO2 Nanoparticles," that appeared in the 2015 issue is presented.