3.4.4. Recyclability

The repeated adsorption was tested by dynamic adsorption using 25 mL of 20 mg L−<sup>1</sup> Cr(VI) solution as simulated effluent. 100 mL of 2M NaOH was applied as desorption solution and flow through the adsorbent in the column. The adsorbent was rinsed and freeze-dried after desorption for next cycle. The Cr(VI) removal rate of each cycle was shown in Figure 6c. For seven cycles, no obvious performance attenuation was observed. Typically, the Cr(VI) removal rate of adsorbent remained 96.5%, implying its distinguished reusability.
