Water mint (Mentha aquatica L.) belongs to the arsenic tolerant plant species suitable for cultivation

in Central European climate conditions. Therefore, its possible application for remediation of contaminated soil

was investigated in pot and field experiments. Two M. aquatica plants of different origin, i) commercially market-available mint plants, and ii) plants habituated at the arsenic contaminated former mining area in southern

Tuscany (Italy) were tested for their arsenic uptake, transformation, and speciation. The total arsenic concentrations in the experimental soils varied from 21 to 1573 mg As kg-1, the mobile fractions did not exceed 2% of total

soil arsenic. The mint plants originating from the contaminated area were able to remove ~400 µg of arsenic

per pot, whereas the commercial plant removed a significantly lower amount (~300 µg of arsenic per pot). Only

arsenite and arsenate, but no organoarsenic compounds were identified in both stems and leaves. Arsenate was

the predominant arsenic compound and reached up to 80% regardless of the origin of the mint plants. Although

M. aquatica seems to be able to grow in contaminated soils without symptoms of phytotoxicity, its efficiency to

remove arsenic from the soil is limited as can be demonstrated by total elimination of As from individual pots

not exceeding 0.1%. Moreover, the application of plants originating from the contaminated site did not result in

sufficient increase of potential phytoextraction efficiency of M. aquatica. Although not suitable for phytoextraction the M. aquatica plants can be used as vegetation cover of the contaminated soil at the former mining areas