Adsorption of Uranium onto Modified Rice Straw Grafted with Oxygen-Containing Groups

作者：Zhang, Xiaofeng; Kong, Lingjun; Song, Gang; Chen, Diyun^*

来源：Environmental Engineering Science, 2016, 33(12): 942-950.

DOI：10.1089/ees.2015.0019

• adsorption
• modification
• rice straw
• succinic acid
• uranium

In this work, rice straw was modified by succinic acid to improve its adsorption ability for uranium. Infrared analysis indicated that carboxylic acid groups and ester groups were grafted on rice straw surface. Scanning electron microscope showed that the appearance of rice straw had become thinner, more dispersed, and rolled-up like dead leaves after modification, implying that its structures got looser and its inner pores increased, resulting in its reactive surface area being notably extended. Effects of reaction time, adsorbent dosage, temperature, pH, and initial uranium concentration on adsorption of uranium were also investigated. Results showed that the adsorption efficiency of modified rice straw increased from 55% to 95% at 10mg/L uranium solution, adsorption equilibrium was achieved within 1.5h, and kinetic data could be well described by pseudo-second-order kinetic model. Adsorption isotherms followed the Langmuir and Freundlich models, and maximum adsorption amount of uranium onto the rice straw calculated from Langmuir equation rose from 19.7628 to 24.0385mg/g at 35 degrees C after modification. In addition, infrared analysis depicted that the adsorption of uranium by modified straw mainly depended on the complexation of carboxylic acid groups and ester groups with uranium.

• 出版日期2016-12
• 单位广州大学