Kinetics of Reductive Leaching of Low-grade Pyrolusite with Molasses Alcohol Wastewater in H_2SO_4

The kinetics of reductive leaching of manganese from low grade pyrolusite in dilute sulfuric acid in the presence of molasses alcohol wastewater was investigated. The shrinking core model was applied to quantify the effects of reaction parameters on leaching rate. The leaching rate increases with reaction temperature, concentrations of H 2 SO 4 and organic matter in molasses alcohol wastewater increase and ore particle size decreases. The leaching process follows the kinetics of a shrinking core model and the apparent activation energy is 57.5 kJ·mol –1 . The experimental results indicate a reaction order of 0.52 for H2SO4 concentration and 0.90 for chemical oxygen demand (COD) of molasses alcohol wastewater. It is concluded that the reductive leaching of pyrolusite with molasses alcohol wastewater is controlled by the diffusion through the ash/inert layer composed of the associated minerals.

Preparation of InYO_3 catalyst and its application in photodegradation of molasses fermentation wastewater

An InYO 3 photocatalyst was prepared through a precipitation method and used for the degradation of molasses fermentation wastewater. The InYO 3 photocatalyst characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy, surface area and porosimetry. Energy band structures and density of states were achieved using the Cambridge Serial Total Energy package （CASTEP）. The results indicated that the photodegradation of molasses fermentation wastewater was significantly enhanced in the presence of InYO 3 when compared with PbWO 4 . The calcination temperature was found to have a significant effect on the photocatalytic activity of InYO 3 . Specifically, InYO 3 calcined at 700°C had a considerably larger surface area and lower reflectance intensity and showed higher photocatalytic activity. The mathematical simulation results indicated that InYO 3 is a direct band gap semiconductor, and its conduction band is composed of In 5p and Y 4d orbitals, whereas its valence band is composed of O 2p and In 5s orbitals.

Enhanced production of laccase by Coriolus hirsutus using molasses distillery wastewater

The effect of physical parameters of cultivation （load volume, temperature, pH, agitation, inoculum size, and incubation period） in the production of laccase by wood-rotting basidiomycete Coriolus hirsutus were stu- died using diluted molasses distillery wastewater （MDW） as a major composition. Using fractional factorial design, our study first identified load volume, agitation, and inoculum size as statistically significant factors. Optimal preferences and mutual interactions of the factors were then determined by the response surface method, which is based on the center composite design. A quadratic model was used to fit the experimental data. The optimized operational parameters for laccase production were determined to be the following： culture temperature of 25~C, pH 4, load volume of 40 mL diluted MDW in 150 mL flask, agitation rate of 183 r-m in-~, inoculation of 11.5% v/v, and cultivation time of 6 d. The experimental validation under these conditions （the maximum laccase production of 2198.2U.mL-1 was within the confidence interval） subsequently verified the accuracy of the constructed model. Moreover, the removal of chemical oxygen demand and nitrogen of MDW reached 62.85% and 48.00% respectively, and the decolorization ratio under the optimal condition was 41.85%. The enhanced production of laccase by C. hirsutus is a new recovery strategy for MDW.