Study on Adsorption and Desorption Characteristics of Cd2+ and Zn2+ on the Surface Sediments of Taihu Lake by Using ICP-MS
FANG Fang1, JI Yu-shan1, BAI Na1, LI Xiang1, LIU Ying1, 2*
1. College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
2. Beijing Engineering Research Center of Food Environment and Public Health, Minzu University of China, Beijing 100081, China
Abstract In our experiment, studies have found that the content of Zn is the highest in the filtered water and surface sediments of Taihu Lake, and Cd has the strongest ecological hazards on surface sediments. Therefore, in this paper, the adsorption and desorption characteristics of Cd2+ and Zn2+ on the surface sediments of Suzhou Bay Bridge East (marked as SES) of Taihu Lake were investigated by using inductively coupled plasma mass spectrometry (ICP-MS) under the optimized experimental conditions. Adsorption kinetics results showed that the adsorption capacity of Cd2+ was similar to that of Zn2+, adsorption was a rapid process within 120 min, and when t≥120 min, the result was the opposite and the adsorption reached to dynamic balance. In addition, the adsorption of Cd2+ and Zn2+ were corresponding to the pseudo-second-order kinetics model. Adsorption thermodynamics experiments showed that the adsorption of Cd2+ on the sediments was in accordance with the Freundlich model, while the adsorption of Zn2+ on the sediments were conformed to the Langmuir model. The assay of desorption kinetics of Cd2+ and Zn2+ in sediments found, both of which were more in accordance with the Elovich equation and belonged to the heterogeneous diffusion. When the pH increased, the desorption of Cd2+ and Zn2+ in the sediments decreased gradually, and tended to stabiliz at pH=9. Combination with the adsorption-desorption characteristics of Cd2+ and Zn2+, the adsorption rates of Cd2+ and Zn2+ were much larger than desorption rates of Cd2+ and Zn2+, which was consistent with the results of our previous studies. This study revealed the mechanism of adsorption and desorption of Cd2+ and Zn2+ on surface sediments of Taihu Lake and the effect of different factors on the adsorption-desorption behavior. It is of great significance to study the distribution of heavy metals and the remediation of polluted water in the solid-liquid interface of Taihu Lake.
[1] Arfania H, Asadzadeh F. Journal of Soils and Sediments, 2015, 15(11): 2311.
[2] Huang Y X, Zhang D F, Li Y H, et al. Fresenius Environmental Bulletin, 2015, 24(9): 2792.
[3] ZUO Hang, CHEN Yi-zhen, CHEN Jian-hua, et al(左 航, 陈艺贞, 陈建华). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2017, 37(3): 902.
[4] Tanaka K, Iwatani H, Sakaguchi A, et al. Journal of Radioanalytical and Nuclear Chemistry, 2014, 301(2): 607.
[5] JIN Xiang-can, MENG Fan-de, JIANG Xia, et al(金相灿, 孟凡德, 姜 霞). Resources and Environment in the Yangtze Basin(长江流域资源与环境), 2006, 15(3): 388.
[6] Wang J, Zhang P, Yang L, et al. Chinese Journal of Chemical Engineering, 2015, 23(9): 1542.
[7] QIAO Dong-mei, PANG Hong-bin, QI Xue-bin, et al(乔冬梅, 庞鸿宾, 齐学斌). Journal of Irrigation and Drainage(灌溉排水学报), 2010, 29(6): 23.
[8] Bhattacharyya K G, Sharma A. Journal of Hazardous Materials, 2004, 113(1): 97.
[9] Qiu R F, Cheng F Q, Wang X M, et al. Desalination and Water Treatment, 2015, 55(1): 142.
[10] LIU Yu-zhen, CHENG Jie-min(刘玉真, 成杰民). Journal of Anhui Agricultural Sciences(安徽农业科学), 2010, 38(3): 1405.
[11] LU Yong-zheng, YAN Bai-xing(路永正, 阎百兴). Research of Environmental Sciences(环境科学研究), 2010, 23(1): 20.
