Abstract:
The current study presents a comprehensive comparison towards the potential of different microalgal-based
materials for the removal of hexavalent chromium (Cr(VI)) from water. Among the tested materials, microalgal
biochar showed the highest removal efficiency (100%) of Cr(VI). The highest monolayer estimated adsorption
capacities were 23.98, 25.19 and 24.27 mg/g at 5, 22 and 35 °C, respectively. Experimental data showed good
compliance with pseudo-second-order kinetic model. The results of continuous column studies showed that the
column removal efficiency increased from 52.33 to 57.58% by increasing the adsorbent dose from 0.125 to
0.200 g. Desorption efficiency of Cr(VI) by 0.1M NaOH was increased from 51.16 to 59.41% by sonication bath
as compared to roller shaker. More than 97% of desorbed Cr(VI) was recovered in less than 10 min by BaCl2. This
study shows that non-living microalga materials are more effective than living cells in the removal and recovery
of Cr(VI) from water.
