Sorption of 2,4-dinitroanisole (DNAN) on lignin

详细信息	查看全文 | 推荐本文 |

• 作者：Rabih Saad^a ; Zorana Radovic-Hrapovic^a ; Behzad Ahvazi^a ; Sonia Thiboutot^b ; Guy Ampleman^b ; Jalal Hawari^a ; ^{jalal.hawari@nrc.ca}
• 关键词：sorption ; DNAN ; lignin ; kinetics ; isotherms
• 刊名：Journal of Environmental Sciences
• 出版年：2012
• 期刊代码：8_10010742
• 类别：env
• 出版时间：May, 2012
• 卷：24
• 期：5
• 页码：808-813
• 文件大小：134 K

摘要

The present study describes the use of two commercially available lignins, namely, alkali and organosolv lignin, for the removal of 2,4-dinitroanisole (DNAN), a chemical widely used by the military and the dye industry, from water. Sorption of DNAN on both lignins reached equilibrium within 10 hr and followed pseudo second-order kinetics with sorption being faster with alkali than with organosolv lignin, i.e. k₂ 10.3 and 0.3 g/(mg路hr), respectively. In a separate study we investigated sorption of DNAN between 10 and 40C and found that the removal of DNAN by organosolv lignin increased from 0.8 to 7.5 mg/g but reduced slightly from 8.5 to 7.6 mg/g in the case of alkali lignin. Sorption isotherms for either alkali or organosolv lignin best fitted Freundlich equation with enthalpy of formation, 螖H⁰ equaled to 14 or 80 kJ/mol. To help understand DNAN sorption mechanisms we characterized the two lignins by elemental analysis, BET nitrogen adsorption-desorption and ³¹P NMR. Variations in elemental compositions between the two lignins indicated that alkali lignin should have more sites (O- and S-containing functionalities) for H-bonding. The BET surface area and calculated total pore volume of alkali lignin were almost 10 times greater than that of organosolv lignin suggesting that alkali lignin should provide more sites for sorption. ³¹P NMR showed that organosolv lignin contains more phenolic -OH groups than alkali lignin, i.e., 70%and 45%, respectively. The variations in the type of OH groups between the two lignins might have affected the strength of H-bonding between DNAN and the type of lignin used.