scholarly journals Photocatalytic Degradation of Methyl Violet with TiSiW12O40/TiO2

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Shuijin Yang ◽  
Yulin Xu ◽  
Yongkui Huang ◽  
Guohui Zhou ◽  
Zhiyuan Yang ◽  
...  

The photocatalytic degradation of methyl violet using TiSiW12O40/TiO2as a novel eco-friendly catalyst under simulated natural light irradiation was investigated. The physical characterizations were carried out by TG/DTA, FT-IR, XRD, and UV-visible spectra. The effects of the initial methyl violet concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of methyl violet were also examined. The results demonstrated that at optimal condition (initial concentration of methyl violet is 20 mg/L, catalyst dosage is 0.3 g, and the pH is 5.5), the degradation rate of methyl violet is as high as 82.4% after 3 h under simulated natural light irradiation. The reaction of photocatalysis for methyl violet can be expressed as first-order kinetic model.

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Shuijin Yang ◽  
Yongkui Huang ◽  
Yunzhi Wang ◽  
Yun Yang ◽  
Mingbo Xu ◽  
...  

In order to remove aquatic organic dye contaminants by utilizing the inexpensive and inexhaustible solar energy, the Keggin-type H3PW12O40was loaded on the surface of SiO2with the sol-gel method and sensitized by H2O2solution. The photocatalytic degradation of rhodamine B (RhB) by H3PW12O40/SiO2(x) under simulated natural light irradiation was investigated. The effects of the initial RhB concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of RhB were also studied. The results demonstrated that at optimal condition (initial concentration of methyl orange is 10 mg/L, catalyst dosage is 0.8 g, and the pH is 2.5) the degradation rate of RhB is as high as 97.7% after 2 h under simulated natural light irradiation. The reaction of photocatalysis for RhB can be expressed as a first-order kinetic model.


2013 ◽  
Vol 709 ◽  
pp. 70-73
Author(s):  
Guo Bin Duan ◽  
Yong Kui Huang ◽  
Li Yu ◽  
Shui Jin Yang

H3PW6Mo6O40/SiO2 was prepared by sol-gel method, and sensitized by H2O2 solution. The photocatalytic degradation of methyl violet by H3PW6Mo6O40/SiO2 under simulated natural light irradiation was investigated. The results demonstrated that at optimal condition (initial concentration of methyl violet is 10 mg/L, and the pH is 2.5, the dosage of catalyst is 0.5% based on feed stocks), the degradation rate of methyl violet is as high as 88.7 % after 2.5h simulated natural light irradiation. The reaction of photocatalysis for methyl violet can be expressed as first-order kinetic model.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Li Yu ◽  
Yongkui Huang ◽  
Yun Yang ◽  
Yulin Xu ◽  
Guohong Wang ◽  
...  

H4SiW6Mo6O40/SiO2was sensitized by H2O2solution that significantly improved its catalytic activity under simulated natural light. Degradation of basic fuchsin was used as a probe reaction to explore the influencing factors on the photodegradation reaction. The results showed that the optimal conditions were as follows: initial concentration of basic fuchsin 8 mg/L, pH 2.5, catalyst dosage 4 g/L, and light irradiation time 4 h. Under these conditions, the degradation rate of basic fuchsin is 98%. The reaction of photocatalysis for basic fuchsin can be expressed as the first-order kinetic model. After being used continuously for four times, the catalyst kept the inherent photocatalytic activity for degradation of dyes. The photodegradation of malachite green, methyl orange, methylene blue, and rhodamine B were also tested, and the degradation rate of dyes can reach 90%–98%.


2014 ◽  
Vol 665 ◽  
pp. 483-486 ◽  
Author(s):  
Tao Huang ◽  
Yu Lin Xu ◽  
Chong An Lv ◽  
Shui Jin Yang

Cu2O-MoO3 composites has been successfully fabricated by solution-phase reducing method at room temperature. All the powders were characterized by X-rays diffraction (XRD) and scanning electron microscopy (SEM), and explored the catalytic activity for the photocatalytic degradation of methyl orange. The effect of different factors on the degradation was investigated. The best reaction conditions were found out. The results demonstrated that initial concentration of methyl orange is 5 mg/L, the pH is 4, the catalyst dosage is 0.38 g/L and the H2O2 is 1.8 mL, the degradation rate of methyl orange is as high as 95.4% after 30 minutes simulated natural light irradiation.


2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.


2016 ◽  
Vol 14 (1) ◽  
pp. 175-187 ◽  
Author(s):  
Lăcrămioara (Negrilă) Nemeş ◽  
Laura Bulgariu

AbstractMustard waste biomass was tested as a biosorbent for the removal of Pb(II), Zn(II) and Cd(II) from aqueous solution. This strategy may be a sustainable option for the utilization of such wastes. The influence of the most important operating parameters of the biosorption process was analyzed in batch experiments, and optimal conditions were found to include initial solution pH 5.5, 5.0 g biosorbent/L, 2 hours of contact time and high temperature. Kinetics analyses show that the maximum of biosorption was quickly reached and could be described by a pseudo-second order kinetic model. The equilibrium data were well fitted by the Langmuir model, and the highest values of maximum biosorption capacity were obtained with Pb(II), followed by Zn(II) and Cd(II). The thermodynamic parameters of the biosorption process (ΔG, ΔH and ΔS) were also evaluated from isotherms. The results of this study suggest that mustard waste biomass can be used for the removal of heavy metals from aqueous media.


Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.


Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.


2011 ◽  
Vol 8 (s1) ◽  
pp. S19-S26 ◽  
Author(s):  
M. Montazerozohori ◽  
S. Nezami ◽  
S. Mojahedi

Anatase titanium dioxide catalyzed photodegradation of tolonium chloride at various bufferic pH of 2, 7, 9 and 12 in aqueous solution is presented. The effect of some physicochemical parameters such as initial concentration of dye, catalyst amount and reaction time on photocatalytic degradation has been investigated in a photo-reactor cell containing high pressure mercury lamp to obtain the optimum conditions in each bufferic pH at constant temperature. A complete spectrophotometric kinetic study of tolonium chloride under high pressure irradiation at buffer media was performed. The photocatalytic degradation observed rate constants (kobs) were found to be 2.90×10-3, 3.30×10-3, 3.20×10-3and 5.20×10-3min-1for buffer pH of 2-12 respectively. It was found that a pseudo-first-order kinetic model based on Langmuir-Hinshelwood one is usable to photodegradation of this compound at all considered buffer pH. In addition to these, the Langmuir-Hinshelwood rate constants, krfor the titled compound at various pH are reported.


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