Linye Zhang

Preparation of a Low-Cost Adsorption Material from Red Mud and Bagasse

Preparation of bagasse carbon-red mud (BCRM), a low-cost adsorption material used in wastewater treatment, from red mud and bagasse has been studied. Effects of most important conditions in preparation process on the adsorption capability of BCRM were investigated. The optimal preparation parameters for BCRM were obtained. BCRM had a high surface area and a good mesoporous structure and exhibited an excellent adsorption capacity. The used BCRM could be regenerated via simple calcination at 573 K in air for 1 h. BCRM was an effective, economic, and regenerable material for adsorption of organic contaminants in wastewater.

Study on the Preparation of H3PW12O40–TiO2/Bentonite Composite Material

Preparation of H3PW12O40–TiO2/bentonite, a new photocatalytic composite material used in wastewater treatment, by a sol–gel and intercalation process has been investigated. Effects of most significant parameters in the manufacturing process on the photocatalytic activity of H3PW12O40–TiO2/bentonite were explored. The optimum values of parameters were as follows: calcination temperature was 200°C; mass ratio of TiO2 to bentonite () was 1:1; molar ratio of H3PW12O40 to TiO2 (MHPW/MTiO2) was 0.5:100; and intercalation time was 3 h. H3PW12O40–TiO2/bentonite had good photon absorption performance and high photocatalytic activity. The possible mechanism of enhanced photocatalytic activity of H3PW12O40–TiO2/bentonite in wastewater treatment was proposed.

UV-H2O2 degradation of methyl orange catalysed by H3PW12O40/activated clay.

A catalyst consisting of phosphotungstic acid (H3PW12O40) combined with activated clay was prepared by the impregnation method, and an experiment was carried out to evaluate the catalytic activity of the H3PW12O40/activated clay for the degradation of methyl orange (MO) in the UV–H2O2 process. The degradation ratio of MO can be affected by H2O2 concentration, reaction time, catalyst dosage, pH and temperature. The reaction temperature should be controlled at less than 70 °C, and the catalyst has a wide applicable pH range in the UV–H2O2 process. Hydroxyl radicals were generated in the UV–H2O2 system under the action of H3PW12O40/activated clay, and MO was degraded by hydroxyl radicals. Compared with traditional catalysts used in UV–H2O2 systems, H3PW12O40/activated clay has certain advantages for its practical application.

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.