Su Qing, Pan Bingcai, Pan Bingjun, Zhang Qingrui, Zhang Weiming, Lv Lu, Wang Xiaoshu, Wu Jun, Zhang Quanxing
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
Sci Total Environ. 2009 Oct 15;407(21):5471-7. doi: 10.1016/j.scitotenv.2009.06.045. Epub 2009 Jul 28.
In the current study, a new hybrid adsorbent HMO-001 was fabricated by impregnating nanosized hydrous manganese dioxide (HMO) onto a porous polystyrene cation exchanger resin (D-001) for enhanced lead removal from aqueous media. D-001 was selected as a support material mainly because of the potential Donnan membrane effect exerted by the immobilized negatively charged sulfonic acid groups bound to the polymeric matrix, which would result in preconcentration and permeation enhancement of lead ions prior to their effective sequestration by the impregnated HMO. HMO-001 was characterized by scanning electron micrograph (SEM), transmission electron micrograph (TEM), and X-ray diffraction (XRD). Lead adsorption onto HMO-001 was dependent upon solution pH due to the ion-exchange nature, and it can be represented by the Freundlich isotherm model and pseudo-first order kinetic model well. The maximum capacity of HMO-001 toward lead ion was about 395 mg/g. As compared to D-001, HMO-001 exhibited highly selective lead retention from waters in the presence of competing Ca(2+), Mg(2+), and Na(+) at much greater levels than the target toxic metal. Fixed-bed column adsorption of a simulated water indicated that lead retention on HMO-001 resulted in a conspicuous decrease of this toxic metal from 1 mg/L to below 0.01 mg/L (the drinking water standard recommended by WHO). The exhausted adsorbent particles are amenable to efficient regeneration by the binary NaAc-HAc solution for repeated use without any significant capacity loss. All the results validated the feasibility of HMO-001 for highly effective removal of lead from contaminated waters.
在当前研究中，通过将纳米级水合二氧化锰（HMO）负载到多孔聚苯乙烯阳离子交换树脂（D - 001）上制备了一种新型混合吸附剂HMO - 001，以增强从水介质中去除铅的能力。选择D - 001作为载体材料主要是因为固定在聚合物基质上的带负电荷的磺酸基团产生的潜在唐南膜效应，这将导致铅离子在被负载的HMO有效螯合之前进行预富集和渗透增强。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）和X射线衍射（XRD）对HMO - 001进行了表征。由于离子交换性质，HMO - 001对铅的吸附取决于溶液pH值，并且可以很好地用Freundlich等温线模型和准一级动力学模型表示。HMO - 001对铅离子的最大吸附容量约为395 mg/g。与D - 001相比，在存在比目标有毒金属含量高得多的竞争性Ca(2 +)、Mg(2 +)和Na(+)的情况下，HMO - 001对水中铅的保留表现出高度选择性。对模拟水进行固定床柱吸附表明，HMO - 001对铅的保留导致这种有毒金属从1 mg/L显著降低至低于0.01 mg/L（世界卫生组织推荐的饮用水标准）。耗尽的吸附剂颗粒可通过二元NaAc - HAc溶液进行有效再生，以便重复使用而不会有任何明显的容量损失。所有结果验证了HMO - 001从受污染水中高效去除铅的可行性。
