Studies On Endurance Of Alcea Rosea And Rudbeckia Hirta To Copper Tailings And Its Research On Copper Pollution Environment Restoration

With Cu mine tailings as the culture substrate, and two kinds of ornamental flowers(Althaea rosea and Rudbeckia hirta) as the test materials, the research focuses on the physiological impact of three kinds of organic acids CA, AC and EDTA on two kinds of flowers. At the same time, the research determines physiological indexes including biomass and relative conductivity as well as enzymes including SOD and POD. In addition, it carries out discussion and conclusion of changes in absorption of two kinds of plants of Cu2+ and other metal ions, with the research results as follows:1. Through the experiment with different mixing ratio of garden soil and Cu mine tailings, this paper studies the influence of different content of Cu tailings on physiological index of seedlings of A. rosea and R. hirta. The result shows that the content of chlorophyll of two kinds of plants gradually decreases with the increase in amount of Cu mine tailings. Chl.a and Chl.b of A. rosea decrease by 45.42% and 47.40% respectively under pure Cu treatment compared with the control group, while Chl.a and Chl.b of R. hirta decrease by 18.32% and 47.70% respectively compared with the control group. It shows that under pure Cu treatment, the generation of chlorophyll of two kinds of plants is seriously inhibited. The SOD enzymatic activity within A. rosea increases under 25% garden soil+75% Cu tailings treatment of R. hirta. The POD enzymatic activity of A. rosea gradually decreases with the increase in Cu concentration, while R. hirta first increases and then decreased; under 50% soil+50% Cu tailings treatment, the POD activity of the underground part of R. hirta is 2.3 times that the control group. The conductivity of A. rosea is significantly higher than the control group under pure Cu treatment, while the treatment of R. hirta is lower than the control group. Under high-concentration Cu treatment, the MDA content of R. hirta is lower than that of A. rosea, and the changes of the underground part of R. hirta under T4(pure Cu tailings) treatment are the most obvious, increasing by 33% compared with the content of Pro. The research result shows that two kinds of plants have repair effect on the environment of Cu tailings, and the repair effect of A. rosea on Cu tailings is better than that of R. hirta.2. Through the experiment with different mixing ratio of garden soil and Cu mine tailings, this paper studies the effect of different content of Cu tailings on seedling growth and metal ion accumulation of A. rosea and R. hirta. The result shows that the dry weight and growth amount of A. rosea are affected under 50% soil+50%Cu tailings treatment, reaching the minimum. R. hirta is inhibited obviously under pure Cu tailings treatment, and dry weight of its aboveground part decreases by 44.70% compared with the control group. The Cu amount of underground part of A. rosea and R. hirta under 25% soil+75% Cu tailings treatment reaches the maximum, and high-concentration pure Cu strengthens the absorption of stems of two kinds of plants of Cu under pure Cu treatment, reaching the maximum. For the absorption of heavy metal Cd2+, the content of Cd gradually decreases with the increase in Cu concentration, and R. hirta reaches the minimum under pure Cu treatment. Zn2+ is lower than the control group under treatment of two kinds of plants, while changes in K+, Ca2+ and Na+ are not obvious. It shows that the inhibition effect on the growth of plants becomes stronger with the increase in Cu2+ concentration, and the intoxication of plants is more obvious.3. Through applying three kinds of organic acid with different concentration into the Cu tailings, this paper studies the influence on physiological index of seedlings of A. rosea and R. hirta. The result shows that the content of Chlorophyll a of A. rosea increases slightly compared with the control group under the low-concentration acetic acid treatment, and Chlorophyll is lower than the control group under other treatments. The content of chlorophyll of A. rosea and R. hirta under high-concentration EDTA treatment reaches the minimum. The cell membrane permeability of aboveground of A. rosea reaches the minimum under 1.0 EDTA treatment, decreasing by 36.96% compared with the control group. The cell membrane permeability of R. hirta under 1.0 EDTA treatment decreases, and that of underground part reaches the minimum at such concentration. SOD activity of underground part of A. rosea and R. hirta increases under 1.0EDTA treatment compared with the control group, respectively 1.26 times and 1.96 times that the control group. POD activity of A. rosea decreases under high-concentration EDTA treatment, while that of R. hirta increases, and the underground part of R. hirta increases by 28% compared with the control group, reaching 1883.33U·g-1. The content of MDA of R. hirta with the increase in concentration under CA and EDTA treatment, while that of A. rosea decreases by 23.56% under 1.0 EDTA treatment compared with the control group, which shows that the peroxidation degree of root cells of R. hirta is higher than that of A. rosea. The proline of A. rosea reaches the minimum at low-concentration citric acid, while that of R. hirta does not change obviously. The result shows that citric acid and acetic acid at different concentration inhibit the harm of Cu to seedlings to some extent, whileA. rosea reacts sensitively to interaction of EDTA and Cu stress, and the root of R. hirta is of higher tolerance than that of A. rosea.4. Through applying three kinds of organic acid-citric acid, acetic acid and EDTA at different concentration into Cu tailings, this paper studies the influence on seedling growth and metal ion accumulation of A. rosea and R. hirta. The result shows that the dry weight of A. rosea is higher than the control group, the dry weights of whose aboveground part increases by 67.4% and 139.5% respectively compared with the control group under 0.1CA and 0.1AC treatment, while decreasing obviously under EDTA treatment. The changes in dry weights of R. hirta under the action of acetic acid and citric acid are not obvious, reaching the minimum under 1.0EDTA treatment, and high-concentration EDTA inhibits the growth of seedlings of two kinds of plants. The amounts of Cu in aboveground part of A. rosea and R. hirta reach the maximum under 1.0 EDTA treatment and the content of Cu in A. rosea and R. hirta under 1.0AC treatment increases by 76.3% and 76.5% respectively compared with the control group. The acetic acid promotes the amount of Cu in underground part of two kinds of plants. Three kinds of organic acid do not have obvious effect on absorption of K+ and Pb2+ ion, and 1.0 EDTA promotes the accumulation of Cd2+ in underground part of A. rosea. Although EDTA promotes the accumulation of Cu2+ in two kinds of plants, it affects the growth.