微波制备柚子皮生物质活性炭及其在偶氮染料吸附中的应用

Use pomelo peel as raw materials and potassium hydroxide as activator to establish a microwave treating preparation method of pomelo peel biomass activated carbon adsorbent. Batch experiments are conducted to study the effect of activator concentration, and radial activation time on the adsorption performance of biomass activated carbon. By establishing the dynamic model of methylene blue adsorption, the adsorption kinetics of biomass activated carbon is studied. The results reveal that under the technological conditions of microwave power of 800 W, the activator concentration of 25%, dipping time of 24 h, activation time of 3.5 min, the biomass activated carbon is optimized with specific surface area of 523.34 m2/g, total pore volume of 0.316 cm3/g and average pore diameter of 4.637 nm, which meets the standard of macro porous activated carbon. The adsorption kinetics was studied by pseudo-first-and pseudo-second-order models, and the adsorption isotherms were studied by Langmuir and Freundlich models. The pseudo-second-order model and Freundlich isotherm were found to fit well the adsorption characteristics of the as-prepared activated carbons, and its adsorption capacity is up to 16.56 -35.95 mg/g. On the basis of these, the pomelo peel activated carbon was used to adsorb azo dye, representative by neutral red and crystal violet, their adsorption capacity were 239.95 mg/g and 456.30 mg/g respectively, adsorption rate both over 90%, has practical application value.