Institute of Agricultural Resource and Environmental Sciences, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Institute of Environmental Science and Engineering, Yangzhou University, Yangzhou 225009, China.
Int J Environ Res Public Health. 2018 Sep 11;15(9):1982. doi: 10.3390/ijerph15091982.
Batch experiments were conducted to investigate the adsorption characteristics of tetracycline (TC), and the interactive effects of copper (Cu) on the adsorption of TC onto water hyacinth roots. TC removal efficiency by water hyacinth roots was ranging from 58.9% to 84.6%, for virgin TC, 1:1 TC-Cu and 1:2 TC-Cu. The Freundlich isotherm model and the pseudo-second-order kinetic model fitted the adsorption data well. Thermodynamics parameters ⁰ for TC were more negative in the TC plus Cu than the TC-only treatments, indicating the spontaneity of TC adsorption increased with increasing of Cu concentrations. An elevated temperature was associated with increasing adsorption of TC by water hyacinth roots. The additions of Cu(II) significantly increased TC adsorption onto water hyacinth roots within the pH range 4 to 6, because copper formed a strong metal bridge between root surface and TC molecule, facilitating the adsorption of TC by roots. However, Cu(II) hindered TC adsorption onto water hyacinth roots on the whole at pH range from 6⁻10, since the stronger electrostatic repulsion and formation of CuOH⁺ and Cu(OH)₂. Therefore, the interaction between Cu(II) and TC under different environmental conditions should be taken into account to understand the environmental behavior, fate, and ecotoxicity of TC.
进行了批量实验，以研究四环素（TC）的吸附特性，以及铜（Cu）对水葫芦根吸附 TC 的相互作用。对于原始 TC、1:1 TC-Cu 和 1:2 TC-Cu，水葫芦根对 TC 的去除效率在 58.9%至 84.6%之间。Freundlich 等温线模型和拟二级动力学模型很好地拟合了吸附数据。对于 TC 的热力学参数⁰在 TC 加 Cu 处理中比仅 TC 处理更负，表明随着 Cu 浓度的增加，TC 吸附的自发性增加。升高温度与水葫芦根对 TC 的吸附增加有关。在 pH 值为 4 到 6 的范围内，Cu(II)的添加显著增加了 TC 对水葫芦根的吸附，因为铜在根表面和 TC 分子之间形成了强的金属桥，促进了 TC 被根吸附。然而，在 pH 值为 6⁻10 的范围内，Cu(II)总体上阻碍了 TC 对水葫芦根的吸附，因为更强的静电排斥和 CuOH⁺和 Cu(OH)₂的形成。因此，在不同环境条件下，应考虑 Cu(II)和 TC 之间的相互作用，以了解 TC 的环境行为、归宿和生态毒性。
