ADSORPTION OF CARMINE ON ETHYLENEDIAMINE MODIFIED PEANUT HUSK FROM AQUEOUS SOLUTION

摘要

A new adsorbent was synthesized from peanut husk, an agricultural by-product, in which epichlorohydrin was used as a cross-linking agent and ethylenediamine as a modification agent. Factors affecting the adsorption behavior of this adsorbent for carmine in aqueous solution, namely, pH value, adsorption time, temperature and initial carmine concentration were evaluated through experiments in a batch system. It was concluded that the maximal adsorption capacity of this adsorbent for carmine was 95.2 mg / g at 303 K, which was improved 17.6 times as much as that of the unmodified peanut husk. The Langmuir isotherm model can provide a better description for the adsorption equilibrium when it was compared with the Freundlich equation under the conditions of the present study. In order to examine the controlling mechanisms of the process, kinetic equations of the mass transfer and chemical reaction, the Largergren first order model, the pseudo-second order model and the intraparticle diffusion model were used to correlate the experimental data. It was found that the intra-particle diffusion is the significant controlling step under the experimental conditions but it was not the unique one and it accompanied with chemical reactions. It showed that the peanut husk modified with ethylenediamine had good performance for removal of azo-dye and can be used as a highly efficient biomass adsorbent to treat dyes-containing wastewater.