向日葵盘低酯化果胶对水溶液中镉离子的吸附作用  

Study on the Absorption of Cadmium(Il)Ions in Aqueous Solution by Low Methoxy Pectin from Sunflower Heads

作　　者：彭晓夏 高蕊蕊 逯晓青 闫清妮 候秀薇 窦志芳 PENG Xiaoxia;GAO Ruirui;LU Xiaoqing;YAN Qingni;HOU Xiuwei;DOU Zhifang(College of Basic Medical Sciences,Shanxi University of Chinese Medicine,Jinzhong 030619,China)

机构地区：[1]山西中医药大学基础医学院,晋中030619

出　　处：《离子交换与吸附》2023年第2期135-146,共12页Ion Exchange and Adsorption

基　　金：山西省自然科学基金青年项目(202103021223313);山西省高等学校科技创新项目(2019L0716);山西中医药大学科技创新能力培育计划“太行本草”专项资助项目(2022PY-TH-23);山西省高等学校大学生创新创业训练计划项目(20220744);山西省科技创新人才青年团队项目(202204051001028)。

摘　　要：本文研究了向日葵盘中的天然低酯化果胶对水溶液中镉离子(Cd^(2+))的吸附作用,考察了果胶添加量、果胶溶液的pH值、温度、吸附时间、共存离子对Cd^(2+)吸附量和去除率的影响。随果胶添加量的增加,Cd^(2+)的去除率从2.25%逐渐升高至14.60%,而吸附量则先从18.00mg/g增加至20.53mg/g,后逐渐降低至5.84mg/g;随果胶溶液pH值的升高,吸附量和去除率先分别增加至20.70mg/g和15.53%,后逐渐降低;随温度的升高,吸附量和去除率分别增加至20.80mg/g和15.60%后几乎不变;反应10min吸附量和去除率即可达到最大,分别为19.81mg/g和14.75%。此外,溶液中的Ca^(2+)也会影响果胶的吸附作用,当Ca^(2+)与Cd^(2+)的质量比为2时,吸附量和去除率降低了36.70%。确定了向日葵盘果胶吸附Cd^(2+)的最佳条件:当溶液中Cd^(2+)的浓度为8.0mg/L时,添加等体积80mg/L的pH值为8.0的果胶溶液,40℃吸附10min。动力学分析证明吸附过程符合准二级动力学方程,以化学吸附作用为主。而热力学分析则表明果胶对Cd^(2+)的吸附过程是自发的、熵值增加的吸热反应。可见,向日葵盘低酯化果胶能够有效地吸附水溶液中的Cd^(2+),可作为一种安全、高效、环保的生物吸附材料处理含有Cd^(2+)的工业废水,具有良好的应用价值和前景。The absorption of cadmium ions(Cd^(2+))in aqueous solution by the natural low methoxy pectin from sunflower heads was studied.The effects of pectin dosage,pH value of pectin solution,temperature,treatment time and coexisting ions on the adsorption capacity and removal rate of Cd^(2+)were investigated.With the increase of pectin dosage,the removal rate of Cd^(2+)increased from 2.25%to 14.60%,while the adsorption capacity increased from 18.00mg/g to 20.53mg/g,and then decreased to 5.84mg/g.With the increase of pH value of pectin solution,the adsorption capacity and removal firstly increased to 20.70mg/g and 15.53%,and then decreased gradually.With the increase of temperature,the adsorption capacity and removal rate were almost unchanged after increasing to 20.80mg/g and 15.60%,respectively.When the reaction time was 10min,the adsorption capacity and removal rate reached the maximum,which were 19.81mg/g and 14.75%,respectively.In addition,Ca^(2+)in solution also affected the adsorption of pectin,when the mass ratio of Ca^(2+)to Cd^(2+)was 2,the adsorption capacity and removal rate decreased by 36.70%.The optimal conditions for the adsorption of Cd^(2+)by pectin from sunflower heads were determined as follows:when the concentration of Cd^(2+)in solution was 8.0mg/L,the same volume of 80mg/L pectin solution with pH=8.0 was added,and adsorbed at 40℃for 10min.Kinetics analysisshowed that the adsorption process was in accordance with the pseudo-second-order kinetic equation,and was dominated by chemisorption.Thermodynamics analysis showed that the adsorption process of pectin to Cd^(2+)was a spontaneous endothermic reaction with increasing entropy.Therefore,the natural low-methoxyl pectin from sunflowerheads had good heavy metal adsorption in aqueous solution,and could be used as a safe,efficient and environmentally firendly biosorbent material to treat industrial wastewater containing Cd^(2+)to reduce heavy metal pollution,which has good application value and prospect.

关 键 词：向日葵盘 低酯化果胶 重金属 镉离子 吸附作用 

分 类 号：Q539[生物学—生物化学]