| Popis: |
Cornstalk, a cellulosic agricultural waste material, was modified by citric acid to improve the adsorption of rhodamine B (RB) and methylene blue (MB) from aqueous media. Characterization of SEM and FTIR spectra confirmed that the surface morphology of adsorbent changed and carboxylic groups were introduced into the raw cornstalk by chemical modification. The effects of pH, contact time, initial concentration and the amount of dried adsorbent were studied in batch experiments. There was no significant difference in the dye concentration remaining when the pH was increased from 4.0 to 10.0. Several models were used to fit experimental data and the results showed that experimental data fitted the Langmuir model and pseudo-second order model best. Compared with 58.71 and 81.71 mg g-1obtained by CS (raw cornstalk), the maximum adsorption capacities for RB and MB were 203.0 and 245.6 mg g-1by using CCS (cornstalk modified with citric acid), respectively. |
