Accumulation of mercury in the biomass of selected pleustophytes

Application of phytoremediation process for the purification of the environment, particularly of surface water (running or standing) may be a future alternative to existing standard purification methods, in particular for heavy metal removal. Numerous hyperaccumulators are known which can be used for the purification of water, soil or sediment such as Salvinia or Lemna lemnids, occurring in temperate climates, and thus on the territory of Poland. Ability of mercury accumulation by Salvinia natans and Lemna minor was analyzed. The phytoremediation ability of lemnids was compared depending on their origin - commercial (artificial) cultures and those obtained from the natural environment. Phytoremediation process was carried out for a period of 14 days for the concentration of 0.15 mg Hg/dm3 and 0.2 mg Hg/dm3. It was found that both Salvinia natans and Lemna minor show a significant increase in biomass in the presence of mercury, even up to 76% for Lemna minor and 40% for Salvinia natans. The result of this increase was incorporation a considerable amount of mercury in the tissues of plant. The quantity of mercury in plants biomass was in the range of 41.16-115.28 mg Hg/kg DM, while in the control samples - only 0.2-0.6 mg Hg/kg DM.