木质素的氨化改性及其对孔雀石绿的吸附性能研究

Ammoniation Modification of Lignin and Its Adsorption Properties for Malachite Green

关键词:  木质素  氨化改性  曼尼希反应  吸附

Key Words:lignin  ammonization modification  mannich reaction  adsorption

摘要:以木质素和聚乙烯胺（PVAM）为原料，分别采用直接和间接法制备氨化木质素吸附剂，以有效去除水中的孔雀石绿染料。采用多种分析手段对吸附剂进行分析检测，并对其在孔雀石绿溶液吸附中的应用效果及吸附机理进行了研究。结果表明，与直接氨化木质素相比，间接氨化木质素含有较多官能团，可以与更多的孔雀石绿染料分子结合，达到很好的吸附效果。当pH值=5，温度55 ℃，吸附时间100 min，吸附剂添加量1 g/L时，间接法制备的氨化氧化木质素对染料去除效果最佳，去除率可达96.5%，其吸附过程符合准二级动力学模型，吸附行为与Langmuir等温吸附模型相吻合。

Abstract:The ammoniated lignin adsorbent was prepared by direct and indirect methods， respectively， with lignin and polyvinylamine as raw materials to effectively remove malachite green dye from wastewater. Mutiple analytical technigues were used to analyze and detect the adsorbent. The adsorption effect and mechanism in the malachite green solution were analized. The results showed that ammoniated oxidized lignin prepared by indirect method had good adsorption performance for malachite green compared with direct ammoniated lignin due to its more functional groups. When pH value was 5， the temperature was 55 ℃， the adsorption time was 100 min， and the adsorption amount was 1 g/L， the optimal removal rate of dye achieved 96.5%. The adsorption process of malachite green was in accordance with the pseudo-second-order kinetics， and the adsorption behavior was consistent with the Langmuir adsorption isotherms.