Kitirote Wantala, Ph.D.
Khon Kaen University, Chemical Engineering, Faculty Member
- Chemical Engineering, Nanotechnology, Environmental Engineering, Advanced Oxidation Processes, Adsorption and wastewater treatment, Non Thermal Plasma Decontamination Methods, and 19 moreNanoscience, Materials Science, Environmental Studies, Catalysis, Photocatalysis, Adsorption, Kinetics, Arsenic, Cadmium, Kinetic Modeling, Heterogeneous Catalyst, Fenton-like, Box-Behnken, Metal removal, Engineering, Renewable Energy, Environmental Sustainability, Environmental Science, and Materials Science and Engineeringedit
- Dr. Kitirote Wantala received his Ph.D. (Chemical Engineering) from Thammasat University (TU), Thailand in 2010. He s... moreDr. Kitirote Wantala received his Ph.D. (Chemical Engineering) from Thammasat University (TU), Thailand in 2010. He subsequently entered lecturer of Chemical Engineering department, Faculty of Engineering, Khon Kaen University in 2011 and led a group on Environmental Catalysis named "Chemical Kinetics and Applied Catalysis Laboratory, CKCL KKU". He is now an associate professor. Dr. Wantala's current researches focus on Advanced Oxidation Processes (AOPs) such as photocatalysis, Fenton-like, electro-Fenton, Heavy metal adsorption process, Catalysis technology, Environmental catalysis, and Nano-material synthesis. He has published over 35 articles as an author or co-author in peer-reviewed journals.edit
Research Interests:
Research Interests:
Research Interests:
Research Interests:
AbstractThe lead adsorption performances of zero-valent iron coated on diatomite (ZVI-D) were investigated. ZVI-D was prepared by impregnation of diatomite with iron sulfate solution, and followed by reducing with sodium borohydride. The... more
AbstractThe lead adsorption performances of zero-valent iron coated on diatomite (ZVI-D) were investigated. ZVI-D was prepared by impregnation of diatomite with iron sulfate solution, and followed by reducing with sodium borohydride. The zero-valent iron of ZVI-D was confirmed by XPS. The adsorption performances were tested in a batch reactor with an initial lead concentration in the range of 100–1,250 mg/L. It was found that a lead adsorption isotherm could be described by Langmuir equations with a maximum adsorption capacity of 158.73 mg/g at 298 K. The mean adsorption energy (E) of 54.78 kJ/mol was determined by using Dubinin–Radushkevich isotherm. The kinetics of Pb2+ adsorption was fitted with a pseudo-second-order model. From the thermodynamic study, it was found that the adsorption process was endothermic and spontaneous. An adsorption mechanism was proposed by using XPS data. Three steps of the adsorption were suggested, (i) Pb2+ ions were oxidized to Pb0 on ZVI active sites, (ii)ferrous ions reac...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Chemistry and Adsorption
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Adsorption and Zeolite
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Modification of TiO2 is one of the techniques used to enhance its photodegradation efficiency and to make it visible-light-active. In this study, Mo-doped TiO2 nanoparticles were synthesized using a fast sol-gel technique and then coated... more
Modification of TiO2 is one of the techniques used to enhance its photodegradation efficiency and to make it visible-light-active. In this study, Mo-doped TiO2 nanoparticles were synthesized using a fast sol-gel technique and then coated on granular activated carbon (GAC) as both substrate and adsorbent to obtain Mo:TiO2/GAC composite. The fabricated composite was characterized by many techniques such as powder XRD, SEM, EDX, FTIR, and N2 adsorption-desorption analysis. Then, the composite was applied to photodegrade volatile organic compounds (VOCs) under both UV and visible light irradiations. The characterization results showed high crystallinity and purity. Mo:TiO2/GAC composite gave a higher photodegradation efficiency compared with bare TiO2 and bare GAC. Moreover, studying operational parameters showed that the optimum condition for photodegradation efficiency of VOCs was at a flowrate of 1 L min−1, VOCs concentration of 20 ppm, and light intensity of 400 and 600 W m−2 for UV...
Research Interests:
The thermochemical conversion of abundant renewable resources through pyrolytic catalysis cracking (PCC) is one of the most promising technologies for producing green biofuels. In this study, the pyrolysis of palm oil was investigated... more
The thermochemical conversion of abundant renewable resources through pyrolytic catalysis cracking (PCC) is one of the most promising technologies for producing green biofuels. In this study, the pyrolysis of palm oil was investigated over a sustainable CaO-based catalyst derived from waste gypsum. PCC was conducted in a continuous packed-bed reactor under atmospheric pressure without purge gas. The effects of Mg doping and reaction temperature were also examined. A wet ball milling process was used to prepare the well-mixed catalysts and to subsequently form a heterojunction structure between the CaO and MgO particles. CaO was synthesized using the Ca(OH)2 derived from the reaction between gypsum and sodium hydroxide. The pyrolytic oil was separated from the crude oil to remove water and other impurities. The pyrolytic oil was then distilled following ASTM D86, and the three separated products were classified as bio-gasoline, bio-kerosene, and bio-diesel. The highest renewable light fuel volume (bio-gasoline and bio-kerosene) of about 75% (74 %wt.) was obtained at a reaction temperature of 525 °C with 10% MgCO3 content. The percent volume of light fuel increased with increasing reaction temperature. Renewable light fuel production over the Mg-doped CaO-based catalyst was related to both the Mg content and reaction temperature.
Research Interests:
Abstract Results demonstrated in this work presented the synthesis of mesoporous Ce and Fe co-modified SrTiO3 (CexSr1-xFexTi1-xO3) perovskite materials using an innovative chelate complex approach, applying a molar excess of glycerol and... more
Abstract Results demonstrated in this work presented the synthesis of mesoporous Ce and Fe co-modified SrTiO3 (CexSr1-xFexTi1-xO3) perovskite materials using an innovative chelate complex approach, applying a molar excess of glycerol and citric acid monohydrate as the chelating agents. The influence of different Ce and Fe dopant concentrations (0 ≤ x ≤ 0.05) on the characteristics of the SrTiO3 catalysts were systematically investigated using multi-technique. The results showed that controlled Ce and Fe contents significantly altered the physical and chemical properties of the materials. The diffractogram confirmed that all prepared samples crystallized in a typical perovskite structure of SrTiO3 without deviation in the original cubic symmetry in perovskite structure when introduced Ce and Fe in the lattice. Likewise, the microscopy verified the uniformity and particle size reduction of the catalysts with increasing doping contents. In addition, all prepared samples illustrated mesoporosity and BET surface area slightly increased with increasing the doping elements and represented smaller than pure SrTiO3 sample. The Ce atom, replacing some Sr2+ in the lattice, was represented in Ce3+ and Ce4+ valence states mixture. At the same time, Fe atoms, presenting Fe3+ and Fe4+ oxidation states, cannot be incorporated by substituting Ti4+ ions in the SrTiO3 lattice structure, only incorporated with the interstitial site, as confirmed by XPS and XANES measurements. The Ce and Fe dopants improved the absorptivity towards a longer wavelength, resulting in decreasing bandgap energy. Their photocatalytic performance towards beta-lactam antibiotic degradation under visible light irradiation using an LED source was also evaluated. The Ce0.04Sr0.96Fe0.04Ti0.96O3 sample exhibited the best photocatalytic degradation of amoxicillin (67.4%) and demonstrated more activity than the pure SrTiO3 sample about 27 times. In the end, the synergistic effect of Ce and Fe dopants to help enhance the photocatalytic activity and the recycling ability were also detailed.
Research Interests:
The objective of this study was to optimize synthesis conditions for the Cu-K-OMS-2 hydrothermal process. The effects of ageing temperature, ageing time and amount of copper (Cu) dopant were considered via using the Box-Behnken design... more
The objective of this study was to optimize synthesis conditions for the Cu-K-OMS-2 hydrothermal process. The effects of ageing temperature, ageing time and amount of copper (Cu) dopant were considered via using the Box-Behnken design (BBD) method to characterize the conditions for gaseous toluene degradation. In the models studied, the independent variables were ageing temperature (55-145ºC), ageing time (6-18 h) and amount of Cu dopant (2-6% mole). The quadratic model fitted very well with the experimental data (15 runs), which showed a higher value of R2 (0.98) and adjusted R2 (0.95), confirming that the model can explain the results successfully. Ageing temperature was found to be the only significant variable for the Cu-K-OMS-2 transformation phase, with CuO and the bixbyite phase appearing as the highest ageing temperature condition. Furthermore, the effects of ageing temperature, ageing time and amount of Cu dopant on the Cu3+/Cu2+ mole ratio were also investigated. Ageing te...
Research Interests:
The aim of this research was to investigate interactions in the removal of manganese from contaminated water by oxidation through an ozonation process. The manganese oxidation was used to oxidize manganese ions (Mn2+) in solution to... more
The aim of this research was to investigate interactions in the removal of manganese from contaminated water by oxidation through an ozonation process. The manganese oxidation was used to oxidize manganese ions (Mn2+) in solution to manganese dioxide (MnO2) in its brown solid form, in order to reduce levels of manganese ions in the water to below the acceptable limit for drinking water (0.05 mg L-1). In this study, the independent effects such as the initial concentration of manganese (5, 10 and 15 mg L-1), initial pH of solutions (3, 4 and 5) and ozone concentrations (10.970, 21.945 and 32.920 mg L-1) designed Box-Behnken Design (BBD) as a one of the design of experiments were examined foroptimal conditions and including main effects and their interactions. The ozone concentration in the reactor was increased with increasing operating time of an ozone generator and linearly increased at the rate about 2.194 mg O3 L-1 min-1. The experimental results indicated that all factors signif...
Research Interests:
AbstractIn this work, Fe3+ was used to modify TiO2 to give improved performance under UV and visible light irradiation. The catalysts were prepared via a hydrothermal method without further calcination. Box–Behnken design was used to... more
AbstractIn this work, Fe3+ was used to modify TiO2 to give improved performance under UV and visible light irradiation. The catalysts were prepared via a hydrothermal method without further calcination. Box–Behnken design was used to investigate the effects of hydrothermal temperature, hydrothermal time, and Fe content (wt%) on the photocatalytic performance of TiO2. Pollutants such as reactive red 3 (RR3) dye and alachlor were examined. The synthesized catalysts have been characterized by many techniques. Photodegradation of RR3 dye was performed under UV light irradiation whereas photodegradation of alachlor was performed under both UV and visible light irradiation. In RR3 photodegradation, the effect hydrothermal settings for temperature and time were found significant and the highest removal percentages were 92 and 94% for 15 and 30 min UV irradiation, respectively. In alachlor photodegradation, the effect of Fe-doping was found significant under both UV and visible light irradiation. The highest remo...
Research Interests:
Research Interests:
In this study, lanthanum copper oxide was synthesized under hydrothermal techniques and characterized for doxycycline degradation. The catalyst exhibited enhanced photocatalytic doxycycline degradation under visible light owing to its... more
In this study, lanthanum copper oxide was synthesized under hydrothermal techniques and characterized for doxycycline degradation. The catalyst exhibited enhanced photocatalytic doxycycline degradation under visible light owing to its compatible bandgap energy (1.7 eV). The XRD data revealed high crystallinity of the material with no noticeable impurities. Three-dimensional microspheres of varying sizes (average diameter of 2.52 μm) were observed from SEM. EDX confirms the successful synthesis of La2CuO4. The effect of DC concentration, catalyst dosage, and initial pH on the degradation rate of DC was studied methodically. Interestingly, about 85% of doxycycline (10 mg/L) was degraded within 120 min of light-emitting diode irradiation at pH 10. Oxygen vacancies and surface defects were determined through photoluminescence spectra. The recyclability experiments suggested that the catalyst is capable of degrading DC for three consecutive runs. Radical trapping trials suggested that holes (h+), superoxide radicals (●O2−), and hydroxyl radicals (●OH) are involved in the photodegradation of DC. Herein, the novel approach of La2CuO4 synthesis and the efficient visible-light harvesting capability of as-prepared catalyst reveal the potentiality for DC degradation thereby opening a new horizon of research employing La2CuO4 used for various environmental applications.
Research Interests:
The aims of this work were to investigate the characteristics of nanoscale zero valent irons (nZVI) coupled with mesoporous materials (RH-MCM-41) adsorbent and to study the removal mechanisms of Pb (II) from synthetical solutions using... more
The aims of this work were to investigate the characteristics of nanoscale zero valent irons (nZVI) coupled with mesoporous materials (RH-MCM-41) adsorbent and to study the removal mechanisms of Pb (II) from synthetical solutions using full pictorial design batch experiments. Synthetic nZVI coupled with RH MCM-41 as Pb (II) adsorbent were characterized by XRD, TEM, BET and XANES. The results of XANES analyses confirmed the ability of RH-MCM-41 to prevent oxidations of Fe0 to Fe2+ and Fe3+. XANES results also verified the oxidation states of Pb (II). The solution pH was the most significant positive effect in controlling Pb (II) adsorption. The equilibrium and kinetic adsorption isotherms well fitted with the Langmuir isotherm. The pseudo-second order kinetic adsorption indicated that the adsorption process is the rate limiting step for Pb (II) removal. Furthermore, Langmuir-Hinshelwood confirmed the obvious Pb (II) adsorption at the active site of adsorbents. The reduction rate cons...
Research Interests: Chemistry and Adsorption
Abstract Polymer nanocomposites have been exceptionally functional and gaining heightened attention as sustainable materials to address environmental problems. The unique physicochemical properties, electronic compatibility, high... more
Abstract Polymer nanocomposites have been exceptionally functional and gaining heightened attention as sustainable materials to address environmental problems. The unique physicochemical properties, electronic compatibility, high surface-to-volume ratio, conductivity, rapid interfacial interactions, ease of synthesis, low cost, and ease of functionalization accents their usage in the decontamination of water and energy storage. The polymer nanocomposites are innovative for exhibiting the synergistic traits of nanomaterial and polymer of a composite. However, the comprehensive understanding and the real-time applications of these polymer heterojunctions in environmental applications are in infancy. This review presents a crisp introduction about few important polymers in environmental nanotechnology, the interactions at the polymer interfaces, typical synthesis protocols, material characterization, and focused exclusively on their ecological applications like adsorption, pollutant detection, photocatalysis, membranes, energy storage, and disinfection. This review provides the necessary background about the specific application and presents the most recent progress in polymer interfaces to appreciate its intrinsic performance. This review is anticipated to be inclusive, convincing, and handy to the researchers and industrialists who unite to solve many environmental issues globally.
Research Interests:
This work aimed to study the excellent properties of the high-valent copper doped into the framework structure of K-OMS-2 catalyst (Cu-K-OMS-2). The physicochemical properties of Cu-K-OMS-2 materia...
Research Interests:
The photocatalytic reduction of carbon dioxide (CO2) into value-added chemicals is considered to be a green and sustainable technology, and has recently gained considerable research interest. In this work, titanium dioxide (TiO2)... more
The photocatalytic reduction of carbon dioxide (CO2) into value-added chemicals is considered to be a green and sustainable technology, and has recently gained considerable research interest. In this work, titanium dioxide (TiO2) supported Pt, Pd, Ni, and Cu catalysts were synthesized by photodeposition. The formation of various metal species on an anatase TiO2 surface, after ultraviolet (UV) light irradiation, was investigated insightfully by the X-ray absorption near edge structure (XANES) technique. CO2 reduction under UV-light irradiation at an ambient pressure was demonstrated. To gain an insight into the charge recombination rate during reduction, the catalysts were carefully investigated by the intensity modulated photocurrent spectroscopy (IMPS) and photoluminescence spectroscopy (PL). The catalytic behaviors of the catalysts were investigated by density functional theory using the self-consistent Hubbard U-correction (DFT+U) approach. In addition, Mott–Schottky measurement ...
Research Interests:
Abstract The aims of this work were to synthesize Cu and Fe doping on manganese-based octahedral molecular sieves (K-OMS-2) via the in-situ hydrothermal method (Cu-Fe-OMS-2) and impregnation on K-OMS-2 for ex-situ techniques... more
Abstract The aims of this work were to synthesize Cu and Fe doping on manganese-based octahedral molecular sieves (K-OMS-2) via the in-situ hydrothermal method (Cu-Fe-OMS-2) and impregnation on K-OMS-2 for ex-situ techniques (Cu-Fe/OMS-2). The catalytic activities of prepared samples were evaluated through the degradation of reactive red 120 (RR-120) applying a Fenton-like reaction with peroxymonosulfate (PMS). The physicochemical properties of the catalysts were investigated using X-ray diffraction (XRD), N2 adsorption-desorption, Field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) techniques. The effects of catalyst loading, initial pH of the solution and PMS concentration were examined by applying the design of the experiment (DOE) based on the Box-Behnken design (BBD) on RR-120 degradation. Results demonstrated that cryptomelane crystalline phases of the Cu-Fe-OMS-2 and Cu-Fe/OMS-2 catalysts were successfully synthesized, confirmed by XRD measurement. The morphology of the in-situ catalyst represented in rod-like shapes and their size apparently decreased when doped with Cu and Fe metals. On the other hand, the surface morphology of the ex-situ catalyst displayed the aggregation of copper and iron oxides particles on the rod-like of K-OMS-2. The specific surface area of in-situ catalyst showed higher than ex-situ catalyst about 6 times. The oxidation states of Mn, Cu and Fe atoms were analyzed using XPS and XANES techniques. The valence states of the Mn atom in all prepared samples presented Mn3+ and Mn4+, while the Fe atom demonstrated Fe3+ in both modified samples. Simultaneously, the Cu atom in both modified samples illustrated different valence states, ex-situ catalyst (Cu+ and Cu2+) and in-situ catalyst (Cu2+ and Cu3+). The RR-120 removal by Cu-Fe-OMS-2 was more effective than Cu-Fe/OMS-2 in every run order. The significant effects on dye degradation for Cu-Fe-OMS-2 were the initial pH of the solution and catalyst loading. For Cu-Fe/OMS-2, only the catalyst loading effect was significant. The significant interaction term was found only Cu-Fe-OMS-2 catalyst between the initial pH of the solution and PMS concentration. The degradation percentage of the Cu-Fe-OMS-2 catalyst demonstrated higher than the Cu-Fe/OMS-2 catalyst about 5% at pH 4, catalyst loading of 0.85 g/L and PMS of 4.70 mM conditions.
Research Interests:
Abstract The aims of this work were (i) to develop and characterize the cheap and efficient CaO/MgO catalyst with a source of CaO from waste blood clamshell mix with MgO, and (ii) to study the catalyst efficiencies on biofuel production... more
Abstract The aims of this work were (i) to develop and characterize the cheap and efficient CaO/MgO catalyst with a source of CaO from waste blood clamshell mix with MgO, and (ii) to study the catalyst efficiencies on biofuel production via continuous packed-bed reactor under atmospheric pressure without any purge gases. The chemical and physical properties of the catalyst were characterized by many techniques. The results can confirm that the ball-mill technique successfully prepared CaO and MgO catalysts. The specific surface area was increased with the increasing of Mg contents. The surface morphologies of calcined catalysts were obvious in a roughly spherical shape. The results were found that not only the Mg content was a significant effect on product and distilled yields, but also reaction temperature was a significant effect as well. The highest pyrolytic oil, derived from 10 %wt Mg catalyst with reaction temperature at 525 °C, was about 80 %, and it can be distilled almost 100 % following ASTM D86. The pyrolytic oils were purified into three types of biofuel, and then the properties of distilled products were examined. The heating values and kinetic viscosity were on standard values except for acidity. Surprisingly, the acidity was decreased comparing with raw material.
Research Interests:
Research Interests:
Abstract Titanium dioxide photocatalysts co-modified with iron and nitrogen (Fe–N–TiO2) were produced via hydrothermal method using iron(III) nitrate nonahydrate and urea as iron and nitrogen sources, respectively. The effects of... more
Abstract Titanium dioxide photocatalysts co-modified with iron and nitrogen (Fe–N–TiO2) were produced via hydrothermal method using iron(III) nitrate nonahydrate and urea as iron and nitrogen sources, respectively. The effects of different dopant concentrations were investigated. The modified TiO2 catalysts were characterized for phase composition, surface morphology, specific surface area, degree of doping, charge states and bandgap energy combining various techniques. The results showed that controlled iron and nitrogen concentrations significantly altered the physicochemical properties of the catalysts. The photocatalysts displayed the anatase/rutile/brookite crystal phase mixture. The rutile and brookite phase contents increased with increasing iron content. On the other hand, increasing nitrogen content inhibited the formation of rutile and brookite phases and the catalysts displayed predominantly the anatase phase. High iron and low nitrogen contents led to the highest BET surface areas. The surface morphology changed from nanorice to spherical shape with increasing iron content. The bandgap energy of all Fe–N–TiO2 samples was in the range 2.7–3.1 eV, being lower than that of undoped TiO2 and pure anatase phase. Nitrogen was incorporated into the TiO2 lattice on interstitial positions (Ti–O–N). The iron, substituting some Ti4+ in the lattice was presented in Fe2+ and Fe3+ oxidation state, as confirmed by XANES measurements. The photocatalytic degradation of antibiotic ciprofloxacin was performed under visible light using a LED illumination source and nearly 70 % of the antibiotic was removed in 6 h by using the most active sample (2.5 %N–1.5 %Fe). As verified by photoluminescence results, the iron and nitrogen dopants synergistically enhanced the charge separation, since they promoted the formation of the different TiO2 phases.
Research Interests:
Enhanced nitrate reduction of nanoscale zero valent iron (nZVI) by Cu prepared by impregnation method was studied in this work. Using a full factorial design, the performance of nZVI with and without Cu on surface in acidic and neutral... more
Enhanced nitrate reduction of nanoscale zero valent iron (nZVI) by Cu prepared by impregnation method was studied in this work. Using a full factorial design, the performance of nZVI with and without Cu on surface in acidic and neutral conditions was investigated. Static batch reactor was selected in this study to investigate the effects of the independent variables such as catalysts (nZVI with and without Cu), initial pH of solutions (3, 7), and reaction times (10, 30 min). The results found that nitrate removal over Cu-nZVI was greater than that of nZVI by about 37% and 36% at pH 3 and pH 7 for 30 min, respectively. Both catalysts were effective in removing nitrate under acidic conditions (pH 3). Thus, this study concludes that nZVI can enhance the performance by Cu in nitrate removal. Moreover, acidic conditions were more effective than neutral conditions in removing nitrate.
Research Interests:
Research Interests:
Nanoscale zero-valent iron coated on diatomite (nZVI-D) was successfully synthesized as a composite material. It is the combination of nZVI and diatomite which has been proved to be a promising material in arsenite or As(III) removal. The... more
Nanoscale zero-valent iron coated on diatomite (nZVI-D) was successfully synthesized as a composite material. It is the combination of nZVI and diatomite which has been proved to be a promising material in arsenite or As(III) removal. The result showed that 25.5% of As(III) was removed using diatomite only but more than 95% of As(III) was removed using nZVI-D, at the same contact time of 60 min and pH 6. The experimental isotherm data for As(III) adsorption at different initial concentrations were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich equations. Among these three, the equilibrium data fitted well with the Langmuir isotherm. The kinetic adsorption was also studied using the pseudo-first, second-order, and intraparticle diffusion equations. The data were well explained by the pseudo-second-order kinetic model. From the results of kinetic adsorption and the adsorption isotherm, it can be concluded that arsenite adsorption was controlled by the mass transfer ...
Research Interests:
Abstract The aims of this work were to study the effect of Cu–nZVI with and without TiO2 on nitrate reduction and to study the pathway of nitrate reduction utilizing to nitrogen gas. The chemical and physical properties of Cu–nZVI and... more
Abstract The aims of this work were to study the effect of Cu–nZVI with and without TiO2 on nitrate reduction and to study the pathway of nitrate reduction utilizing to nitrogen gas. The chemical and physical properties of Cu–nZVI and Cu–nZVI/TiO2 such as specific surface area, crystalline phase, oxidation state of Cu and Fe and morphology were determined by N2 adsorption–desorption Brunauer–Emmett–Teller (BET) analytical technique, X-ray diffraction (XRD), X-ray Absorption Near Edge Structure (XANES) technique and Transmittance Electron Microscopy (TEM). The full factorial design (FFD) was used in this experiment for the effect of Cu–nZVI with and without TiO2, where the initial solution pH was varied at 4, 5.5, and 7 and initial nitrate concentration was varied at 50, 75, and 100 ppm. Finally, the pathway of nitrate reduction was examined to calculate the nitrogen gas selectivity. The specific area of Cu–nZVI and Cu–nZVI/TiO2 was found to be about 4 and 36 m2/g, respectively. The XRD pattern of Fe0 in Cu–nZVI was found at 45° (2θ), whereas Cu–nZVI/TiO2 cannot be observed. TEM images can confirm the position of the core and the shell of nZVI for Fe0 and ferric oxide. Cu–nZVI/TiO2 proved to have higher activity in nitrogen reduction performance than that without TiO2 and nitrate can be completely degraded in both of solution pH of 4 and 7 in 75 ppm of initial nitrate concentration. It can be highlighted that the nitrogen gas selectivity of Cu–nZVI/TiO2 greater than 82% was found at an initial solution pH of 4 and 7. The main effects of Cu–nZVI with and without TiO2 and the initial nitrate concentration on nitrate reduction were significant. The interaction between solution pH and initial nitrate concentration and the interaction of all effects at a reaction time of 15 min on nitrate reduction were also significant.
Research Interests:
ABSTRACT
Research Interests:
ABSTRACT The synthesis of manganese-based octahedral molecular sieves of the type K-OMS 2 was designed by central composite design (CCD) method. The effect of aging time and temperature were considered for K-OMS 2 synthesis. Consequently,... more
ABSTRACT The synthesis of manganese-based octahedral molecular sieves of the type K-OMS 2 was designed by central composite design (CCD) method. The effect of aging time and temperature were considered for K-OMS 2 synthesis. Consequently, the synthesis was carried out through hydrothermal process without calcination and the obtained K-OMS 2 was tested for benzene oxidation. The physicochemical properties of as-synthesized K-OMS 2 catalysts were characterized by XRD, BET and SEM. The oxidative species of manganese were identified by analysis of the Mn K-edge XANES spectra. CCD results revealed that the crystallization conditions for K-OMS 2 synthesis were dependent on aging temperature and time. The specific surface area of K-OMS 2 was inversely proportional to the aging temperature. The K-OMS 2 sample with aging time of 21 h at aging temperature of 75 °C showed the best catalyst for benzene oxidation. This catalyst was a mixture of Mn2O3 and MnO2 with Mn3 +/Mn4 + ratio of 0.09 as evaluate by XANES technique. It was discovered that the K-edge energy of Mn in each as-synthesized K-OMS 2 samples was 6551.4 eV close to Mn3 + and Mn4 + species. The Mn3 +/Mn4 + ratios were found to have a range of 0.09–0.16. However, a decrease in Mn3 +/Mn4 + ratio and a corresponding decrease in catalytic activity were encountered at high aging time and temperature. Low aging temperature and long aging time could provide active species of manganese oxides for benzene oxidation.
Research Interests:
The aim of this work was focused on the photocatalytic degradation of alachlor from aqueous solution using 10%wt Fe-TiO2, as 0.1%wt of Fe doped into TiO2 structure, immobilized on granular activated carbon (GAC) under black light... more
The aim of this work was focused on the photocatalytic degradation of alachlor from aqueous solution using 10%wt Fe-TiO2, as 0.1%wt of Fe doped into TiO2 structure, immobilized on granular activated carbon (GAC) under black light irradiation. The extended photocatalytic conditions were studied as functions of catalyst loading, number of black light, and initial pH of solution using Response Surface Method (RSM) based on Box-Behnken design (BBD). Characterizations of the photocatalyst by TGA-DTA, and XRD were investigated. Photocatalyst was calcined at 400°C under nitrogen atmosphere. As a Result of calcinations, photocatalyst consisted of only graphite crystallite while the crystallite phases of TiO2 were not observed. The degradation results showed that the photocatalytic process gave the highest percent degradation comparing with adsorption and photolysis processes. The effects of three operating variables which are catalyst loading, number of black light, and initial pH of soluti...
Research Interests:
The reactive red 3 was degraded by catalytic wet oxidation process over Fe-RH-MCM-41 prepared by Direct Hydrothermal Technique (DHT) at Si/Fe molar ratio of 10 using silica from rice husk. The extended reaction conditions were studied as... more
The reactive red 3 was degraded by catalytic wet oxidation process over Fe-RH-MCM-41 prepared by Direct Hydrothermal Technique (DHT) at Si/Fe molar ratio of 10 using silica from rice husk. The extended reaction conditions were studied as a function of reaction temperatures, initial H2O2 concentrations and initial pH of solutions designed by Box-Behnken design (BBD) based on Response Surface Methodology (RSM) to achieve the optimal condition and interaction of independent variables. The characterizations of catalyst were studied by XRD, BET surface area and TEM to explain the morphology of surface and to confirm the hexagonal structure. The results showed the 2theta peak can be indexed to hexagonal lattice that also confirmed by TEM result and surface area about 650 m2/g. All of independent variables showed significant on the degradation of reactive red 3 except for initial H2O2 concentration.
Research Interests:
The aim of this work focused on the preparation of Mn2+ doped on TiO2 by impregnation method for the photocatalytic degradation of Reactive Red-3 dye aqueous solution. Characterizations of the photocatalyst were carried out by using XRD,... more
The aim of this work focused on the preparation of Mn2+ doped on TiO2 by impregnation method for the photocatalytic degradation of Reactive Red-3 dye aqueous solution. Characterizations of the photocatalyst were carried out by using XRD, BET, SEM and UV-DRs. The extended photocatalysis were studied as functions of %wt Mn2+ (0%, 0.05%, 0.1%), pollutant concentration, solution pH and catalyst loading using Response Surface Method (RSM) based on Box-Behnken design. Based on results found that the anatase phase was not affected by Mn2+ added on the surface of TiO2 whereas the rutile phase increased with increasing Mn2+ contents. The band gap energy of Mn2+ doped on TiO2 did not show in red shift but it exhibited higher absorbance than neat TiO2 in visible region. The surface area was insignificantly changed for Mn2+ doped on TiO2. The degradation results were investigated that pollutant concentration, pH of solution and loading of Mn2+ on TiO2 were significant parameters effecting on ph...