摘要
采用丁二酸对稻草进行改性处理,系统研究了不同稻草添加量、pH值、吸附时间和吸附温度条件下,丁二酸改性稻草对水溶液中Th4+的吸附效果。结果表明当吸附剂投加量为0.50g、pH=3.5、反应时间为30min、钍溶液初始浓度为10mg·L-1、温度为65oC时,改性稻草对Th4+的吸附效果最好,去除率可达96%。傅里叶变换红外光谱分析揭示改性后的稻草样品添加了羧基、羟基、酯基的吸收峰。改性稻草的吸附行为符合Freundlich等温吸附模型以及准二级动力学方程,其吸附性能的提高,认为是改性处理暴露了更多的木质素、纤维素内部多孔结构,及增加了木质素、纤维素上的特殊基团。
Background： Agricultural wastes are widely applied in heavy metal wastewater treatment, and became a hot point in this field. Purpose： The aim is to study modified rice straw with significant removal ability of thorium. Methods： The rice straw modified with butanedioic acid was used to remove Th^4＋ from aqueous solution. And its influence factors such as adsorbent dosage, pH, adsorption time and reaction temperature were investigated through dynamic tests. Results： The optimal conditions were found to be 0.50 g of modified rice straw, pH=3.5, 0.5 h of adsorption time and 10 mg·L^-1 of initial thorium concentration at 65℃. Under these conditions, the removal rates reach 96%. Fourier transform infrared spectroscopy （FTIR） analysis shows some new adsorption peaks such as carboxyl, ester and hydroxyl has added to modified rice straw. The adsorption behavior of Th^4＋ could be fitted well by the Freundlich adsorption isotherms and the quasi-second order kinetics equation. Conclusion： Its absorptive property enhancement might attribute to expose more internal porous structure of lignin and cellulose and add special functional groups by the modifying process.
出处
《核技术》
CAS
CSCD
北大核心
2015年第4期16-22,共7页
Nuclear Techniques
基金
国家自然科学基金项目(No.41372364)
羊城学者首席科学家项目(No.12A007S)
广东省放射性核素污染控制与资源化重点实验室建设项目(No.2012A061400023)资助
关键词
钍
丁二酸
改性稻草
吸附作用
Thorium, Butanedioic acid, Modified rice straw, Adsorption
