锌氧化物改性沸石对腐植酸的吸附机理

Mechanistic Insights into Interaction of Humic Acid with Zinc Oxide Modified Zeolite Adsorbent

将锌氧化物负载在沸石分子筛上制备锌氧化物改性沸石吸附材料。通过XRD、SEM、BET、Zeta电位仪和Raman光谱等分析表征手段研究锌氧化物在沸石中的分散状态和表面带电性。通过动力学和热力学研究,探讨该改性吸附材料对腐植酸的吸附机理;并在相同条件下,与商品活性炭进行腐植酸吸附对比试验。研究结果表明:(1)在21±1℃,锌氧化物改性沸石对腐植酸的最大饱和吸附量达到60 mg/g;(2)锌氧化物改性沸石对腐植酸的吸附符合准二级动力学方程和Freundlich等温吸附模型;(3)锌氧化物改性沸石对腐植酸的吸附性能远高于商品活性炭。

Zinc oxide modified zeolite adsorbent was developed by loading zinc oxide on zeolite. The synthesized materials were characterized by X-Ray diffraction analysis, scanning electron microscopy, Brunauer, Emmett and Teller surface area and pore size distribution, Zeta potential analysis and Raman spectrometry. Kinetics and thermodynamics of humic acid adsorption onto zinc oxide modified zeolite adsorbent were studied and a comparison with humic acid adsorption onto commercial activated carbon under the same condition was made to assess the adsorption mechanisms. Results show that the maximum humic acid adsorption capacity of zinc oxide modified zeolite adsorbent at 21±1℃ is about 60 mg/g, and the pseudo-second-order model and Freundiich isotherm are very suitable for describing the equilibrium of humic acid adsorption onto zinc oxide modified zeolite adsorbent. Furthermore, the adsorption capacity of zinc oxide modified zeolite adsorbent is significantly higher than that of commercial activated carbon.