Manganese Uptake By Facultative and Obligate Wetland Plants Under Laboratory Conditions

Abstract

The effect of initial concentrations of manganese on the overall removal efficiency of Mn by wool grass, soft rush, broad leaved cattail and soft stem bulrush plants was investigated under laboratory conditions. The translocation of Mn in the roots, stems, leaves and flowers of each plant species was determined and the fraction of Mn removed by precipitation was calculated. The overall manganese removal efficiencies of the system during the first period were 97.66, 94.09, 98.51 and 98.44 %, 90.94, 95.47, 96.83 and 85.51 % and 92.65, 75.55, 97.56 and 75.55 % which decreased to 82.22, 89.94, 95.26 and 95.85 %, 87.78, 91.85, 90.49 and 84.16 % and 38.88, 61.61, 31.54 and 71.64 % by the end (after 72 days) of the experiment for soft stem bulrush, wool grass, soft rush and cattail in the compartments receiving tolerance concentration, landfill leachate and the control, respectively. The removal of manganese was a function of the initial Mn concentration and the higher the initial concentration the higher the removal efficiency. The results showed the addition of manganese (from wastewater) to the soil by precipitation at average rates of 2.17 and 17.19 mg/kg/day, 2.11 and 15.75 mg/kg/day, 1.71 and 15.86 mg/kg/day and 1.17 and 15.29 mg/kg/day for soft stem bulrush, wool grass, soft rush and cattail in the compartments receiving landfill leachate and tolerance concentration, respectively. The leaves of wool grass, soft rush and cattail accumulated significantly greater concentrations of manganese than the roots with translocation factors > 1 indicating high translocation of Mn from root to shoot for the control, landfill leachate and tolerance concentration, respectively.