[金属离子抑制δ-MnO₂对4-叔辛基苯酚的去除]

Li Fei-Li, Mou Hua-Qian

College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China.

Huan Jing Ke Xue. 2013 Jun;34(6):2232-9.

The effect of metal ions on elimination of 4-t-OP by synthetic delta-MnO2 suspension at pH 4.0 was studied. Experiments indicated that the removal of 4-t-OP by delta-MnO2 achieved 100% at reaction time of 150 min. However, the removal of 4-t-OP by delta-MnO2 was restrained when metal ions were added, and the higher concentration of metal ion was, the stronger the inhibition produced. Additionally, there were apparent differences among the inhibitory effect of the tested metal ions. Firstly, Pb2+ and Mn2+ had the strongest effect at pH 4.0, followed by the transition metal ions, then the alkaline earth ions, while the alkali metal ions had little influence on the removal of 4-t-OP by delta-MnO2. Also comparing the adsorption results of metal ions by delta-MnO2, Pb2+ showed the greatest attraction with delta-MnO2, and among the other metal ions, transition metal ions were adsorbed a little more strongly on delta-MnO2 than alkaline earth metal ions. Consequences showed that the inhibitory effects of metal ions were due to their occupying reactive sites on delta-MnO2 surface, which competed with 4-t-OP. Moreover, the dissimilar suppressions were contributed by the different adsorption capacities, surface structure change of MnO2 and the difference of free metal ion percentage in solution as well as metal ions radii.

研究了金属离子对合成δ-MnO₂悬浮液在pH 4.0时去除4-t-OP的影响。实验表明，δ-MnO₂在150分钟反应时间内对4-t-OP的去除率达到100%。然而，添加金属离子时，δ-MnO₂对4-t-OP的去除受到抑制，且金属离子浓度越高，抑制作用越强。此外，所测试的金属离子的抑制效果存在明显差异。首先，Pb²⁺和Mn²⁺在pH 4.0时的抑制作用最强，其次是过渡金属离子，然后是碱土金属离子，而碱金属离子对δ-MnO₂去除4-t-OP的影响很小。同时比较δ-MnO₂对金属离子的吸附结果，Pb²⁺与δ-MnO₂的吸引力最大，在其他金属离子中，过渡金属离子在δ-MnO₂上的吸附比碱土金属离子稍强。结果表明，金属离子的抑制作用是由于它们占据了δ-MnO₂表面的活性位点，与4-t-OP发生竞争。此外，不同的抑制作用还归因于不同的吸附能力、MnO₂表面结构的变化、溶液中游离金属离子百分比的差异以及金属离子半径的不同。