Hong Changhong, Zhang Weiming, Pan Bingcai, Lv Lu, Han Yongzhong, Zhang Quanxing
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
J Hazard Mater. 2009 Sep 15;168(2-3):1217-22. doi: 10.1016/j.jhazmat.2009.02.161. Epub 2009 Mar 13.
Removal and recovery of aromatic pollutants from water by solid adsorbents have been of considerable concern recently. Relatively limited information is available on desorption kinetics and isotherms aspects. In the present study, batch desorption experiments of loaded 4-nitrophenol on a hyper-cross-linked polymer resin NDA-701, a polymeric adsorbent Amberlite XAD-4 and a granular activated carbon GAC-1 were carried out to study the effects of reaction temperature and pore-size distribution of adsorbents. 4-Nitrophenol desorbed rapidly in the early stages, followed by a much slower release, which was described well by a first-order two-component four-parameter model. The adsorption and desorption equilibrium isotherms were well described by Freundlich equation and the apparent adsorption-desorption hysteresis (hysteresis index) for 4-nitrophenol followed an order as: NDA-701 approximately XAD-4<<GAC-1. Analysis of adsorption-desorption process suggested that higher reaction temperature and larger proportion of macropore of adsorbents favoured desorption kinetic and reduced adsorption-desorption hysteresis. All the results indicated that NDA-701, with a specific bimodal property in macro- and micropore region, had excellent potential as an adsorption material for achieving high removal and recovery of 4-nitrophenol from the contaminated water. These results will also advance the understanding of the adsorption and desorption behavior of hyper-cross-linked polymer resin in the wastewater treatment systems.
近年来，利用固体吸附剂从水中去除和回收芳香族污染物备受关注。关于解吸动力学和等温线方面的信息相对有限。在本研究中，进行了负载4-硝基苯酚在超交联聚合物树脂NDA-701、聚合物吸附剂Amberlite XAD-4和颗粒活性炭GAC-1上的间歇解吸实验，以研究反应温度和吸附剂孔径分布的影响。4-硝基苯酚在早期迅速解吸，随后释放速度慢得多，这可以用一阶双组分四参数模型很好地描述。吸附和解吸平衡等温线可用Freundlich方程很好地描述，4-硝基苯酚的表观吸附-解吸滞后（滞后指数）顺序为：NDA-701≈XAD-4<<GAC-1。吸附-解吸过程分析表明，较高的反应温度和吸附剂中较大比例的大孔有利于解吸动力学并减少吸附-解吸滞后。所有结果表明，在大孔和微孔区域具有特定双峰性质的NDA-701作为从污染水中高效去除和回收4-硝基苯酚的吸附材料具有优异的潜力。这些结果也将增进对超交联聚合物树脂在废水处理系统中吸附和解吸行为的理解。
