Cheng Ya, Huang Tinglin, Shi Xinxin, Wen Gang, Sun Yuankui
Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
J Environ Sci (China). 2017 Jul;57:402-410. doi: 10.1016/j.jes.2016.11.015. Epub 2016 Dec 29.
Na-rich birnessite (NRB) was synthesized by a simple synthesis method and used as a high-efficiency adsorbent for the removal of ammonium ion (NH) from aqueous solution. In order to demonstrate the adsorption performance of the synthesized material, the effects of contact time, pH, initial ammonium ion concentration, and temperature were investigated. Adsorption kinetics showed that the adsorption behavior followed the pseudo second-order kinetic model. The equilibrium adsorption data were fitted to Langmuir and Freundlich adsorption models and the model parameters were evaluated. The monolayer adsorption capacity of the adsorbent, as obtained from the Langmuir isotherm, was 22.61mg NH-N/g at 283K. Thermodynamic analyses showed that the adsorption was spontaneous and that it was also a physisorption process. Our data revealed that the higher NH adsorption capacity could be primarily attributed to the water absorption process and electrostatic interaction. Particularly, the high surface hydroxyl-content of NRB enables strong interactions with ammonium ion. The results obtained in this study illustrate that the NRB is expected to be an effective and economically viable adsorbent for ammonium ion removal from aqueous system.
通过一种简单的合成方法制备了富钠水钠锰矿（NRB），并将其用作从水溶液中去除铵离子（NH）的高效吸附剂。为了证明合成材料的吸附性能，研究了接触时间、pH值、初始铵离子浓度和温度的影响。吸附动力学表明，吸附行为遵循准二级动力学模型。将平衡吸附数据拟合到Langmuir和Freundlich吸附模型，并评估了模型参数。根据Langmuir等温线，在283K时吸附剂的单层吸附容量为22.61mg NH-N/g。热力学分析表明，吸附是自发的，也是一个物理吸附过程。我们的数据表明，较高的NH吸附容量主要归因于吸水过程和静电相互作用。特别是，NRB的高表面羟基含量使其能够与铵离子发生强烈相互作用。本研究获得的结果表明，NRB有望成为从水体系中去除铵离子的有效且经济可行的吸附剂。
