木质素的化学改性及其对AuCl_4^-的吸附  

Chemical modification of lignin and its adsorption to AuCl_4^-

作　　者：张保平[1,2] 马钟琛 刘运[1,2] 郭美辰[1,2] 杨芳[1,2] 

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081

出　　处：《化工学报》2017年第5期1946-1953,共8页CIESC Journal

基　　金：冶金及资源利用省部共建教育部重点实验室开放基金项目(FMRU201203);第47批教育部留学回国人员科研启动基金项目~~

摘　　要：以稻草为原料,经预处理、酚化、交联、氯化、胺化、季铵化制备了一种新型的化学改性木质素并对其进行了FTIR,SEM,TG-DSC分析,考察了AuCl_4^-初始浓度、吸附时间、盐酸浓度对化学改性木质素吸附AuCl_4^-效果的影响,探讨了吸附过程的机理。结果表明,制备的化学改性木质素表面致密且在217℃以下具有良好的热稳定性和含有大量酚羟基及胺基。当AuCl_4^-初始浓度为8.0 mmol·L^(-1)时吸附容量达到最大,为784.50 mg·g^(-1),在AuCl_4^-初始浓度为1.0 mmol·L^(-1)时吸附达到平衡的时间为600 min,当盐酸浓度为0.5 mol·L^(-1)和AuCl_4^-初始浓度为1.0 mmol·L^(-1)时吸附率为98%。吸附过程遵循准二级动力学模型,吸附等温模型与Langmuir拟合较好。AuCl_4^-被化学改性木质素中的酚羟基以金单质的形态还原出来。The new chemically modified lignin was prepared based on straw by pretreament, phenolation, polycondensation, chloration, amination and quaternarization reaction and was analyzed though FTIR, SEM and TG-DSC. The adsorption effects of the initial concentration of AuC14^-, adsorption time and concentration of hydrochloric acid on AuC14 were investigated. Furthermore, the mechanism of adsorption was explored. The results indicated that chemically modified straw lignin was of excellent thermal stability below 217℃ and had plenty of primary amines and hydroxyls. The maximum adsorption capacity was 784.50 mg · g^-1 when the initial concentration of AuC14 was 8.0 mmol ~ L-1, the equilibrium adsorption time was 600 min when the initial concentration of AuC14 was 1.0 mmol · L^-1 and the adsorption ratio was 98% when the concentration of hydrochloric acid was 0.5 mol · L^-1 and the initial concentration of AuCI4 was 1.0 mmol · L^-1. Equilibrium experiments and kinetics studies fitted well with the Langmuir model and pseudo-second-order model, respectively. Finally, the AuCl4^- was reduced from hydrochloric acid medium in the form of Au（0） by phenolic hydroxyl.

关 键 词：木质素 制备 吸附 AuCl4^- 还原 

分 类 号：TF836[冶金工程—有色金属冶金]