外文翻譯--不同濃度鈾溶液對碎米莎草鈾富集及其生長的影響（原文）

1、 585 Effects of Various Concentration Uranium Solutions on Uranium Accumulation and Growth Parameters of Cyperus iria L. NIE Xiaoqin, DING Dexing, LI Guangyue, GONG Xingzhong, HU Nan, LIU Yulong ( Key Discipline Laborato

2、ry for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China) Abstract: Effects of various concentration uranium solutions on uranium accumulation and

3、 growth parameters of Cyperus iria L. were studied. After exposed to uranium solutions for 30 d, the U concentrations (dry weight) in its roots ranged between 4,158 ±611 mg/kg for 100 mg/L uranium solution and 48,60

4、5 ±1266 mg/kg for 2,500 mg/L uranium solution, the U concentrations in its shoots ranged between 366 ±26 mg/kg for 100 mg/L uranium solution and 8,224 ±856 mg/kg for 2,500 mg/L solution concentration, resp

5、ectively，and these were only 1/5- 1/10 of those in the roots. All the growth parameters except grade of growth inhibition had the similar tendency. They would come to a peak at a U concentration between 100 mg/L and 250

6、mg/L and then steadily decline with a sharp decrease between 500 and 2,500 mg/L U. Keywords: Cyperus iria L.; uranium accumulation; growth parameters; phytoremediation 1 Introduction Uranium has many important uses in nu

7、clear industry and, as a result, uranium ore is subject to intensive mining. However, the mining activities cause the release of U to the environment represents a potential risk of chemical and radiological toxicity to h

8、uman health[1]. In recent years, many researchers have made great efforts to the remediation of uranium contaminated soil and have found that phytoremediation has great potential for the remediation. Phytoremediation is

9、a kind of technology for treating environmental problems by using plant nutrient processes of taking in water and nutrient through roots, transpiring the water and nutrient throughout leaves and metabolizing organic comp

10、ounds, such as oil and pesticides. The plant is capable of absorbing and bioaccumulating toxic heavy metals such as chromium, cadmium, lead, zinc, arsenic and mercury. To successfully manipulate and optimise future phyto

11、extraction technologies, it is argued that a fully combined understanding of soil supply and plant uptake is needed[2]. A key to the success of U phytoextraction is to increase the accessibility of U in soil to plants. H

12、uang[3] indicated that, of the organic acids (acetic acid, citric acid, and malic acid) tested, citric acid was the most effective in enhancing U accumulation in plants, and the results showed that U phytoextraction may

13、provide an environmentally friendly alternative for the clean up of U- contaminated soils. Recently, we studied the uranium accumulation characterisctics of native plants in a uranium mill tailings repository in South Ch

14、ina. We found that Cyperus iria L. accumulated more U than other plant species. In the present work, the growth performancese of Cyperus iria L. in various uranium concentration solutions were investigated. The objective

15、s were to know its tolerance to uranium, its uranium accumulation and translocation characteristics and the effects of various concentration uranium solutions on its growth parameters. 2 Materials and methods 2.1 Nutrien

16、t solution On the basis of the nutrient solution currently used in hydroponic culture (diluted Hoagland‘s solution), a nutrient solution was designed to satisfy both nutritional requirements of plants and uranium speciat

17、ion in solution (pH=6.0): 945 mg/L Ca (NO3)2, 506 mg/L KNO3, 493 mg/L MgSO4, 2.5 mL/L Fe- EDTA (pH=5.5), 4.15 μg/L KI, 31 μg/L H3BO3, 111.5 μg/L MnSO4, 43 μg/L ZnSO4, 1.25 μg/L Na2MoO4, 0.125 μg/L CuSO4 and 0.125 μg/L Co

18、Cl2. Phosphorus source was excluded from the solution to prevent phosphate- uranium complexes from forming by adding certain amount of the uranium standard solution to the nutrient solution, with pH 5.8 adjusted by titra

19、tion of sodium carbonate (10 g/L) and sodium bicarbonate (5 g/L) buffer solutions. Seven solutions with the 587 2.3.3 Calculations and analysis The Water Bioconcentration Coefficient (BC) which reflects the plant capacit

20、y to absorb uranium from the uranium water was defined as: BC root/water= [U concentration in root part of plant, DW (Dry Weight)] / [U concentration in water] BCshoot/water = [U concentration in shoot part of plant, DW

21、] / [U concentration in water] The Translocation Coefficient (TC) used for evaluating the uranium translocation capacity for the shoot part of a plant was defined as: TC shoot/root = [U concentration in shoot part of pl

22、ant, DW] / [U concentration in root part of plant, DW] Tolerance Index = [(Mean biomass of plant species with uranium treatment) / (Mean biomass of control plant species)] × 100 Grade of Growth Inhibition = [(Dry

23、mass of control plants ? Dry mass of U treated plants) / (Dry mass of control plants)] × 100 Results are presented as mean±S.D., the experimental data were subject to an analysis of variance (ANOVA) using the S

24、PSS 16.0 sofewere. 3 Results 3.1 Uptake and bioconcentration and translocation of uranium Experiments were conducted on the uranium uptake by Cyperus iria L., after it was exposed to a modified Hoagland‘s nutrient soluti

25、on for various periods of time. The U concentrations in its roots (DW) ranged between 4,158 ±611 mg/kg for 100 mg/L uranium solution and 48,605 ±1,266 mg/kg for 2,500 mg/L uranium solution, U concentrations in

26、its shoots (DW) ranged between 366 ±26 mg/kg for 100 mg/L uranium solution and 8,224 ±856 mg/kg for 2,500 mg/L uranium solution, and these were only 1/5- 1/10 of those in the roots. At the beginning of the expe

27、riments when the plants were at seedling stage, the roots from the solution with high U concertration contain more U than roots from solution with low U concertration, which is in accordance with the total U of each solu

28、tion and there has significant differences ( p<0.05). As generally observed, the transfer of U from root to shoot is limited[5]. RootU in water(mg/L)100 250 500 750 1000 1500 2000 2500U in plant (mg/kg)010000200003000

29、0400005000060000seedling stage flowering stage seeding stageShootU in water (mg/L)100 250 500 750 1000 1500 2000 2500U in plant (mg/kg)0200040006000800010000seedling stage flowering stage seeding stageEach point represen