Usage of chitosan on the complexation of heavy metal contents and vertical distribution of Hg(II) and Cr(VI) in different textural artificially contaminated soils

Chitosan has been adopted to remedy artificially contaminated soils with heavy metals of Hg(II) and Cr(VI) in this study. With application of chitosan of different concentrations, results demonstrated that within the first 7 days, available Hg(II) and Cr(VI) contents in three textural artificially contaminated soils of clay, loam and sandy decreased significantly. The contents of heavy metals in these three artificially contaminated soils decreased later than 7 days with the chitosan application. Moreover, the available Hg(II) and Cr(VI) contents in artificially contaminated soil layers of 5 cm significantly reduced than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg⁻¹ DW (dry weight). The available Hg(II) and Cr(VI) contents in loam layers of 5 cm significantly decreased than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg⁻¹ DW. The available Hg(II) and Cr(VI) contents in sandy layers of 5 cm significantly reduced than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg⁻¹ DW. It also decreased after 7 days of chitosan’s application. Results suggested that application of chitosan with 1.15 g kg⁻¹ DW soils of 7 days could improve the remediation of the soil contaminated by Hg(II) and Cr(VI) in the industrial application.