Abstract:The large-sized seaweeds are important renewable resources, which can be developed to delicious food and industrial materials. They were used to deal with sewage due to its accumulation of heavy metal. The living seaweeds are sensitive to light and temperature, and its growth was inhibited because of the toxicity of heavy metal. Gracilaria lemaneiformis is large-sized seaweed, which was suit for large-scale cultivation offshore. The uptake and clearance of copper and cadmium by Gracilaria lemaneiformis were investigated using artificial cultivated living Gracilaria lemaneiformis coupled with the low copper and cadmium concentrations in this paper. In order to test the practicability of two-compartment model adapted for accumulation of heavy metal by large-sized seaweeds, the experiment results were analyzed with nonlinear curve fitting. The results showed that the accumulation of heavy metal by Gracilaria lemaneiformis was accordance with two-compartment model, the uptake rate constant (Ku) and clearance rate constant (Kc) were also obtained. The Gracilaria lemaneiformis can accumulate copper and cadmium from waters, the contents of copper and cadmium accumulated in Gracilaria lemaneiformis were increased along with the concentrations of copper and cadmium in waters, and increased with the exposed time. Meanwhile, Gracilaria lemaneiformis can eliminate cadmium and copper strongly, because Gracilaria lemaneiformis accumulate mainly cadmium and copper from water by bio-absorption, which is a two-way process. Gracilaria lemaneiformis can also accumulate cadmium and copper by active transport, and those elements were combined to make into organic metals. The uptake rate constant of copper and cadmium accumulated by Gracilaria lemaneiformis was from 15.4 to 51.1, from 13.9 to 55.7, respectively. The clearance rate constant was from 0.023 to 0.070, from 0.030 to 0.050, respectively. The uptake rate constants decreased with exposure concentrations, while the clearance rate constants were no obviously related exposure concentrations. The bioaccumulation factor of copper and cadmium accumulated by Gracilaria lemaneiformis was from 663 to 1008, from 463 to 1113, respectively; and the biological half-life was 23.1 d, 20.1 d, respectively.
王增焕, 林钦, 李刘冬, 王许诺. 大型海藻对重金属镉、铜的富集动力学研究[J]. 中国环境科学, 2013, 33(1): 154-160.
WANG Zeng-Huan, LIN Qin, LI Liu-Dong, WANG Xu-Nuo. Kinetic study on the bioconcentration of cadmium and copper by large-sized seaweed Gracilaria lemaneiformis. . CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(1): 154-160.