Guangtao Wei

Preparation of H3PMo12O40/organobentonite by chemical immobilization method and its catalytic performance in photo-Fenton process

AbstractHomogeneous photo-Fenton process has some significant disadvantages in wastewater treatment. Heterogeneous photo-Fenton process overcomes the disadvantages of homogeneous photo-Fenton process, and shows good prospects in engineering application. In this study, H3PMo12O40/organobentonite was prepared by a chemical immobilization method, and catalytic performance of H3PMo12O40/organobentonite as heterogeneous catalyst in photo-Fenton process was evaluated by adopting methyl orange (MO) dye as a model pollutant. The removal ratio of MO was impacted by reaction time, H2O2 concentration, and initial MO concentration. H3PMo12O40/organobentonite had a wide applicable range of pH and temperature for wastewater treatment. H3PMo12O40/organobentonite had a long-term stability, and retained almost all of its catalytic stability and activity for four recycling times. Characterization results of H3PMo12O40/organobentonite showed that H3PMo12O40 was successfully immobilized on the organobentonite by the chemical...

Preparation and application of acidified/calcined red mud catalyst for catalytic degradation of butyl xanthate in Fenton-like process

Acidified/calcined red mud (ACRM), a novel catalyst used in Fenton-like process, was prepared by acidification and calcination of red mud (RM). Catalyst characterization showed that iron phase of ACRM was mainly α-Fe2O3 and ACRM was a porous material with rough surface and loose structure. Degradation of butyl xanthate in Fenton-like process catalyzed by ACRM was investigated. Butyl xanthate was effectively degraded, and the degradation of butyl xanthate was well fitted by second order kinetic model. ACRM had an excellent long-term stability in a Fenton-like process. The possible mechanisms of hydroxyl radical production and butyl xanthate degradation in a Fenton-like process catalyzed by ACRM were presented.

IMPROVE THE CATALYTIC ACTIVITY OF FEOOH/BENTONITE MATERIAL BY MECHANICAL ACTIVATION

To improve the catalytic activity of FeOOH/bentonite material used in Fenton-like process, the activation of FeOOH/bentonite by mechanical activation was studied. The optimum conditions for activation of FeOOH/bentonite were as follows: filling ratio of grinding medium 30%, “15 mL of D06 balls plus 15 mL of D10 balls” as combination mode of grinding medium, rotation speed of planet carrier 600 rpm, milling time 40 min, and powder-to-ball ratio 0.5:30 (g·mL-1). The mechanical activation was an effective method to improve the catalytic activity of FeOOH/bentonite. Both the lattice distortion and crystal size decrease happened in α-FeOOH and the change of layer structure of bentonite were contributed to the increase of catalytic activity of activated FeOOH/bentonite.

Application of a low-cost bagasse carbon-red mud (BCRM) adsorbent for adsorption of methylene blue cationic dye: adsorption performance, kinetics, isotherm, and thermodynamics

AbstractTo understand adsorption property of bagasse carbon-red mud (BCRM), a low-cost adsorption material prepared from waste solid red mud and bagasse, for disposal of organic dyes in wastewater, the adsorption of methylene blue (MB) from aqueous solution on BCRM has been studied, and the adsorption treatment of real textile wastewater was also investigated. Characterization of BCRM was achieved by scanning electron microscope and nitrogen adsorption–desorption analysis. Effects of adsorption time, BCRM dosage, initial concentration, temperature, and initial pH on the adsorption of MB were explored. From the characterization of adsorbent, it can be seen that the prepared BCRM was a porous material composed of particles with rough surface and loose structure, and an excellent mesoporous material with high specific surface area and good mesopore structure. The adsorption results showed that the data fitted better with pseudo-second-order kinetic model (R2 = 0.9995) than pseudo-second-order kinetic and int...

Photo-Fenton degradation of ethyl xanthate catalyzed by bentonite-supported Fe(II)/phosphotungstic acid under visible light irradiation

In this study, using bentonite-supported Fe(II)/phosphotungstic acid composite (HPW-Fe-Organicbent) prepared by mechanochemical synthesis as heterogeneous catalyst, the photo-Fenton degradation of ethyl xanthate under visible light irradiation was studied in detail. The results showed that the degradation of ethyl xanthate was mainly impacted by H2O2 dosage, catalyst dosage and reaction time. HPW-Fe-Organicbent catalyst had a wide applicable range of pH and kept a high catalytic activity even at high pH in the photo-Fenton degradation of ethyl xanthate. It was found that the degradation of ethyl xanthate in the photo-Fenton process catalyzed by HPW-Fe-Organicbent mainly resulted from the hydroxyl radicals. HPW-Fe-Organicbent had an excellent stability in use, and retained almost all of its catalytic activity for four recycling times. Moreover, the kinetics study showed the degradation of ethyl xanthate, with the initial concentration below 50 mg/L, was well fitted by the pseudo-first-order rate model.

Effect of mechanical activation on catalytic properties of Fe2O3-pillared bentonite for Fenton-like reaction

Abstract A layered composite of Fe2O3-pillared bentonite (Fe-P-Bet), used as a catalyst in a Fenton-like process, was prepared and then its mechanical activation was studied in detail. The optimum conditions for preparation of Fe-P-Bet and the effects of mechanical activation on the catalytic activity of Fe-P-Bet were investigated systematically. The impact of the mechanical activation on the catalytic activity was affected by the filling ratio of the grinding medium, by the combination of different sized milling balls, by the rotation speed of the planet carrier, by the milling time and by the powder-to-ball ratio. Compared with the removal ratio of orange II of 14.5%, catalysed by Fe-P-Bet, the removal ratio catalysed by activated Fe2O3-pillared bentonite (A-Fe-P-Bet) was as high as 93.6%, and A-Fe-P-Bet had the merit of good stability and only a small amount of Fe leaching during the Fenton-like process. The catalysts prepared were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and by the BET method; A-Fe-P-Bet has a small particle size and a rough surface. The lattice distortion and decrease in the crystal size of α-Fe2O3, as well as damage to the layer structure of smectite in the bentonite, were the main reasons for the increase in the catalytic activity of A-Fe-P-Bet. The results indicated that mechanical activation was an easy and effective method for improving the catalytic activity of this bentonite-based layered composite and that A-Fe-P-Bet was a safe, ‘green’, catalyst material for use in Fenton-like oxidation during treatment of wastewater.

Leaching reaction and kinetics of zinc from indium-bearing zinc ferrite under microwave heating

Leaching of zinc from indium-bearing zinc ferrite (IBZF) under microwave heating (MH) has been investigated. The result showed microwave intensified the leaching reaction of IBZF in the MH process. Microwave had a great nonthermal effect on the leaching reaction. The effective collision and the H2SO4 activation under the action of microwave belonged to the nonthermal microwave effect. Particle size of IBZF in the range from 45 to 150 μm almost had no effect on the zinc leaching in the MH process. Leaching temperature and leaching time had important effects on the zinc leaching. Zinc leaching in the MH process obeyed the unreacted shrinking core model very well, and the activation energy was 73.747 kJ/mol. The kinetic equation was

Adsorption of cationic dye from water using thermo-sensitive colloid composed of methylcellulose and sodium alginate

1 - (1 - x)^{1/3} = 8.82 \times 10^8 e^{ - 73.747 \times 10^3 /RT} t