College of Environment and Ecology, Chongqing University, Chongqing 400045, China; Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
Sci Total Environ. 2020 Jul 10;725:138490. doi: 10.1016/j.scitotenv.2020.138490. Epub 2020 Apr 6.
In this study, an intrinsic kinetics model was proposed to simulate the adsorption process. The kinetics model was established based on the collision theory, where the available adsorption site and residual adsorbate concentration were considered. The model specifically highlights the significance of initial conditions in its equation. The initial reaction condition is expressed by the model parameter ξ, which includes four factors: concentration, volume, adsorbent dosage and adsorption capacity. The applicability of this model was mainly explored with the phosphate adsorption process by layered double hydroxides (LDH). Experimental results indicate that, at a certain initial condition, the intrinsic kinetics rate coefficient exhibits a superior stability, making the adsorption rate become comparable among different materials. On this basis, the kinetics rate coefficients of 60 materials were compared, and the LDH was proved to be advantageous in phosphate removal rate. Additionally, the intrinsic kinetics model was successfully applied to predict the phosphate adsorption kinetics under a wide range of initial conditions. The predicted concentration throughout the entire adsorption process is well consistent with the evolution of experimental data. This model is an effort to advance the kinetics analysis from fitting to comparison and prediction.
在这项研究中，提出了一个本征动力学模型来模拟吸附过程。该动力学模型是基于碰撞理论建立的，其中考虑了可用的吸附位和残留的吸附质浓度。该模型特别强调了方程中初始条件的重要性。初始反应条件由模型参数 ξ 表示，它包含四个因素：浓度、体积、吸附剂用量和吸附容量。该模型的适用性主要通过层状双氢氧化物 (LDH) 对磷酸盐的吸附过程进行了探讨。实验结果表明，在一定的初始条件下，本征动力学速率系数表现出较高的稳定性，使得不同材料之间的吸附速率具有可比性。在此基础上，对 60 种材料的动力学速率系数进行了比较，结果表明 LDH 在磷酸盐去除率方面具有优势。此外，本征动力学模型成功地应用于预测在广泛初始条件下的磷酸盐吸附动力学。整个吸附过程中预测的浓度与实验数据的演变非常吻合。该模型是从拟合到比较和预测推进动力学分析的一次尝试。
