没食子酸接枝吸附剂配位去除水中微量硼的机理  

Mechanism for the Removal of Trace Amount of Boron from Water by Adsorbent Grafted Gallic Acid

作　　者：邵超英[1] 胡晶晶[1] 宫崎義信 竹原公 吉村和久 

机构地区：[1]东华大学化学化工与生物工程学院,上海201620 [2]福冈教育大学化学系,日本福冈8114192 [3]九州大学理学院,日本福冈8128581

出　　处：《东华大学学报（自然科学版）》2015年第1期65-71,共7页Journal of Donghua University(Natural Science)

摘　　要：以11B NMR法研究了溶液中硼酸与没食子酸的配位反应.结果表明,硼酸可与没食子酸反应生成1∶1和1∶2化学计量比的配合物,1∶2配合物主要形成于中性溶液,而碱性环境更利于1∶1配合物的生成.两种配合物的形成常数分别为logβ1=3.79,logβ2=4.10.利用离子交换法制备了没食子酸接枝硼离子选择性吸附剂,并以bath法研究了没食子酸接枝吸附剂对水中硼的去除作用,考察了溶液pH值、硼浓度、吸附时间、温度等因素对硼去除率的影响.吸附试验结果表明,硼酸在没食子酸接枝吸附剂上的吸附行为符合Langmuir、Freundlich方程和准二级速率方程,属自发的单分子层化学吸附过程.没食子酸接枝吸附剂对硼的饱和吸附量为0.39mmol/g.The complexation of boric acid with gallic acid in aqueous solution was examined thoroughly by11 B NMR measurements.It was confirmed that boric acid reacted with gallic acid to form two complexes with 1∶1and 1∶2stoichiometries.The 1∶2complex was mainly distributed in neutral solution,while the 1∶1complex prevailed in a higher pH range.The formation constants for these complexes were evaluated to be logβ1= 3.79 and logβ2= 4.10.A novel boron selective adsorbent grafted gallic acid was prepared by using ion exchange method.Bath experiments were conducted to evaluate the performance of the adsorbent for removal of boron from water,and the effects of pH value and concentration of the boron solution,contact time and bath temperature on the removal efficiency were investigated.The results for the adsorption studies showed that the adsorption process could be well described with Langmuir equation,Freundlich equation and pseudo-second-order rate equation.Boron adsorption on the adsorbent presorbed gallic acid was a spontaneous chemical process with monomolecular layer,and its adsorption capacity was estimated to be about 0.39mmol/g.

关 键 词：没食子酸 吸附剂 硼酸/硼酸盐 去除 机理 

分 类 号：O642[理学—物理化学]