Effect of Some Chitosan-Coated Mineral Amendments on Lead Uptake and Growth Characteristics of Peppermint (Mentha piperita L.)

Soil and plant pollution is a serious problem that has received more attention in recent years due to its impact on human and ecosystem health. Daily consumption of agricultural products is the most important route for human exposure to various pollutants and diseases. In this study, the effect of different types and levels of amendments on the absorption of lead in peppermint plant in greenhouse conditions was investigated. The experiment was performed as a factorial in a completely randomized design. Experimental treatments included 10 types of amendments: nanosilica, microsilica, ferrosilica, magnesium ferrosilicon (with and without chitosan coating), chitosan and bentonite, at five levels (zero, 0.125, 0.25, 5, 1%). The results showed that all the amendments tested had a decreasing effect on the concentration of plant Pb, transfer factors and biological aggregation. Among the amendments, microsilica modifier had the greatest effect on reducing leaf and root Pb and bioaccumulatio factor. On the other hand, chitosan had a greater impact on reducing the transloction factor than other amendments. Also the most effective amendments on vegetative traits were ferrosilicon amendments coated with chitosan, bentonite, chitosan, and microsilica. According to the results, ferrosilica with chitosan coating and microsilica had more effective role in reducing the destructive effects of lead on peppermint.