Chemical Engineering Department, New Mexico State University, PO Box 30001, MSC 3805, 1040 S Horseshoe St, Las Cruces, NM 88003, USA.
J Hazard Mater. 2011 May 15;189(1-2):286-93. doi: 10.1016/j.jhazmat.2011.02.035. Epub 2011 Feb 22.
Adsorption of arsenic (As(5+)) on natural and MnO(2)-modified clinoptilolite-Ca zeolite adsorbents was investigated to explore the feasibility of removing arsenic from groundwater using natural zeolite adsorbents. The natural and MnO(2)-modified clinoptilolite-Ca zeolite adsorbents were characterized with nitrogen adsorption at 77K for pore textural properties, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray fluorescence for morphology, elemental composition and distribution. Batch adsorption equilibrium experiments were conducted to study the effects of pH and initial feed concentration on arsenic removal efficiency. It was found that the amphoteric properties and arsenic removal efficiency of the natural clinoptilolite-Ca zeolite were significantly improved after modification with MnO(2). The MnO(2)-modified zeolite could effectively remove arsenic from water at a wide pH range, and the arsenic removal efficiency that is basically independent of the pH of feed solutions varies slightly with the initial arsenic concentration in the feed solutions. The removal efficiency obtained on the modified zeolite was doubled as compared to that obtained on the unmodified zeolite. The MnO(2)-modified clinoptilolite-Ca zeolite appears to be a promising adsorbent for removing trace arsenic amounts from water.
研究了天然和 MnO2 改性斜发沸石-Ca 沸石吸附剂对砷（As(5+)）的吸附，以探讨利用天然沸石吸附剂从地下水中去除砷的可行性。采用 77K 下氮气吸附法对天然和 MnO2 改性斜发沸石-Ca 沸石吸附剂进行了孔结构性质的表征，采用扫描电子显微镜和能量色散 X 射线能谱及 X 射线荧光分析进行了形貌、元素组成和分布的表征。进行了批式吸附平衡实验，以研究 pH 和初始进料浓度对砷去除效率的影响。结果表明，MnO2 改性后，天然斜发沸石-Ca 沸石的两性性质和砷去除效率显著提高。MnO2 改性沸石可在较宽的 pH 范围内有效去除水中的砷，砷去除效率基本不受进料溶液 pH 的影响，而与进料溶液中初始砷浓度的变化略有不同。与未改性沸石相比，改性沸石的去除效率提高了一倍。MnO2 改性斜发沸石-Ca 沸石似乎是一种很有前途的吸附剂，可用于去除水中痕量的砷。
