Quick Removal of Chromium (VI) Ions from Aqueous Solution by Chitosan and Ferrous Ions

In this paper, we have presented a new method to remove Cr (VI) ions from aqueous solution. Chitosan and ferrous ions were added together to the chromium-contained solution, through two-step pH adjust, 0.5 g·l^-1 chitosan and 2.0 g·l^-1 FeSO₄·7H₂O could reduce Cr (VI) ions from 100 mg·l^-1 to 0.01 mg·l^-1. As compared with chitosan and ferrous alone used to remove Cr (VI), for 100 mg·l^-1 Cr (VI) solution, the maximum of percentage removal of Cr (VI) by chitosan reached 94.08% when the dosage was up to 3.0 g·l^-1, ferrous ions can remove 99.96% Cr (VI) ions when the dosage was up to 3.0 g·l^-1. The experimental results showed that the method of removal Cr (VI) by chitosan cooperated with ferrous ions was of great application prospect due to its high removal rate, quick removal velocity and less sludge volume.