Accumulation Of Heavy Metals By Three Wetland Plant Species In Pollution Water

The heavy metal pollution of water have become a serious environmental problem, it's not only harmful to the environment, but also a threat to human health. Phytoremediation of metals is a cost-effective "green" technology based on the use of specially selected metal-accumulatingplants to remove toxic metals from soil and water. The definition , the type of technology and the mechanism of phytoremediation are showing, the factors affecting absorption of heavy metals by water plant are introduced, the advances of phytoremediation in heavy metal contaminated water at home and abroad are reviewed. Meanwhile, the current problems and developing prospect of phytoremediation are elaborated.Pb²⁺,Zn²⁺,Cr(â…¥),Cd²⁺ concentrations in different parts of three wetland plants Scirpus tabernaemontani, Acorus calamus, Phragmites Australis were selected based on previous hydroponic culture researching, while the wetland plants were grown with different concentration of treatment solutions, and so the accumulation of heavy metals on plants to be explored, if the plants are applied to phytoremediation of heavy-metal contamination in pollution water is to be determined.The result showed that heavy metals contents of Phragmites australis, Acorus calamus, Scirpus tabernaemontani increased gradually with the increase of concentration of treatment solutions on the same vegetal part, and varied with the different wetland plants. In same concentration of treatment solution, lead ion concentrations in above-ground parts and under-ground parts of three wetland plants Phragmites Australis, Acorus calamus, Scirpus tabernaemontani were differently, highest in of Acorus calamus.To the same vegetal part of the three plant with different concentration of treatment solutions, the Pb²⁺ concentration at 150.00mg/L are significantly higher than other concentrations. To the same vegetal part of the three plant with different concentration of treatment solutions, the Zn²⁺ concentration of Scirpus tabernaemontani at 1500.00mg/L are significantly higher than other concentrations; the Zn²⁺ concentration on aboveground of Acorus calamus at 1500.00mg/L are significantly higher than other concentrations, the Zn²⁺ concentration on underground of Acorus calamus at 2500.00mg/L are the highest; the Zn²⁺ concentration of Phragmites Australis at 2500.00mg/L are significantly higher than other concentrations. To the same vegetal part of the three plant with different concentration of treatment solutions, the Cr (â…¥) concentration at 320.00mg/L are significantly higher than other concentrations. To the same vegetal part of the three plant with different concentration of treatment solutions especially the aboveground of Scirpus tabernaemontani, the Cd²⁺ concentration at 30.00mg/L are significantly higher than other concentrations, the Cd²⁺ concentration on aboveground of Scirpus tabernaemontani at 30.00mg/L are significantly higher than other concentrations.To the different vegetal part of the same plant with same concentration of treatment solutions, the Pb²⁺ accumulation of the underground parts in Scirpus tabernaemontani and Phragmites Australis are significantly higher than aboveground parts, the Pb²⁺ accumulation of the underground parts in Acorus calamus are significantly lower than aboveground parts. To the different vegetal part of the same plant with same concentration of treatment solutions, the Zn²⁺ accumulation of the underground parts in Scirpus tabernaemontani and Acorus calamus are significantly higher than aboveground parts, the Zn²⁺ accumulation of the underground parts in Phragmites Australis with 0.00mg/L,50.00mg/L,100.00mg/L treatment solutions are significantly lower than aboveground parts, the Zn²⁺ accumulation of the underground parts in Phragmites Australis with 300.00mg/L,800.00mg/L,1500.00mg/L,2500.00mg/L treatment solutions are significantly higher than aboveground parts. To the different vegetal part of the same plant with same concentration of treatment solutions, the Cr (â…¥) accumulation of the underground parts in Scirpus tabernaemontani with 0.00mg/L,20.00mg/L treatment solutions are significantly lower than aboveground parts, the Cr (â…¥) accumulation of the underground parts in Scirpus tabernaemontani with 10.00mg/L,400.00mg/L,80.00mg/L,160.00mg/L,320.00mg/L treatment solutions are significantly higher than aboveground parts; and the Cr (â…¥) accumulation of the underground parts in Acorus calamus with 0.00mg/L,20.00mg/L,160.00mg/L treatment solutions are significantly lower than aboveground parts, the Cr (â…¥) accumulation of the underground parts in Acorus calamus with 10.00mg/L,40.00mg/L,80.00mg/L,320.00mg/L treatment solutions are significantly higher than aboveground parts, the Cr(â…¥) accumulation of the underground parts in Phragmites Australis are significantly higher than aboveground parts. To the different vegetal part of the same plant with same concentration of treatment solutions, the Cd²⁺ accumulation of the underground parts in Scirpus tabernaemontani, Acorus calamus and Phragmites Australis are both significantly higher than aboveground parts.The result indicated that three wetland plants can efficiently absorb heavy metals from the pollution water with different extents, the highest accumulating concentration of Pb²⁺ were 3479.10mg/kg,8800.67 mg/kg and 3487.00 mg/kg in Scirpus tabernaemontani, Acorus calamus, Phragmites Australis; the highest accumulating concentration of Zn²⁺were 20844.17mg/kg,37356.67mg/kg and 20916.67 mg/kg in Scirpus tabernaemontani, Acorus calamus, Phragmites Australis; the highest accumulating concentration of Cr (â…¥) were 12049.17mg/kg,13681.00mg/kg and 4361.00mg/kg in Scirpus tabernaemontani, Acorus calamus,Phragmites Australis; the highest accumulating concentration of Cd²⁺ were 10074.17mg/kg,14759.33 mg/kg and 4620.00 mg/kg in Scirpus tabernaemontani, Acorus calamus. Phragmites Australis. These three wetland plants could apply in industry as phytoremediation species in heavy metal contaminated water especially Acorus calamus.