Phytoremediation Assessment of Mentha crispa L. in Zinc-Contaminated Oxisols: Tolerance and Accumulation Dynamics

This study assessed the phytoremediation potential of Mentha crispa L. grown in Oxisol contaminated with varying zinc concentrations. Mentha crispa was cultivated in soil with Zn levels from 0 to 1920 mg kg^-1. Growth parameters, Zn concentrations in plant parts, bioaccumulation, and translocation factors were measured. The results revealed that Mentha crispa exhibited a high tolerance to elevated Zn levels, accumulating up to 1875 mg kg^-1 in its leaves and 2047 mg kg^-1 in its roots. The bioaccumulation factor ranged from 1.2 to 4.5, and the translocation factor ranged from 1.2 to 2.7, indicating effective Zn uptake and distribution within the plant. The metal extraction rates varied across treatments, with the estimated time for Zn removal ranging from 12 to 34 years. These findings underscore the suitability of Mentha crispa as a candidate for phytoremediation of Zn-contaminated tropical soils, particularly Oxisols, which are characterized by high metal adsorption capacity. Additionally, its ability to produce essential oils enhances its viability for integrated environmental and economic applications.