摘要
以农林废弃物丝瓜络(LC)为基材,采用电子束辐射接枝法将聚甲基丙烯酸缩水甘油酯(PGMA)接枝到丝瓜络纤维表面,再通过开环反应引入赖氨酸(Lys)和精氨酸(Arg)功能性基团,制备得到2种氨基酸功能化丝瓜络LC-PGMA-Lys、LC-PGMA-Arg,通过FTIR、元素分析、XRD和SEM等方法对其进行了表征,系统研究了初始pH值、吸附时间、吸附温度、Pb(Ⅱ)初始浓度等因素对Pb(Ⅱ)吸附量的影响,并探究了其对Pb(Ⅱ)的吸附行为.结果表明,LC-PG-M A-Lys、LC-PGMA-Arg吸附Pb(Ⅱ)的最佳初始pH值均为6;在初始pH值为6、吸附时间为200 min、吸附温度为35 ℃的最佳条件下,LC-PGMA-Lys对Pb(Ⅱ)的最大吸附量为71.18 mg·g-1;LC-PGMA-Lys对Pb(Ⅱ)的吸附过程符合准二级动力学方程和Freundlich等温吸附模型,表明吸附过程以多分子层吸附、化学吸附为主.
Abstract
Using agricultural and forestry waste loofah as a substrate,we grafted polyglycidyl methacrylate(PGMA)onto the surface of loofah fiber by an electron beam radiation grafting method,introduced functional groups of lysine(Lys)and arginine(Arg)by ring-opening reaction,and prepared two kinds of amino acid-func-tionalized loofah LC-PGMA-Lys and LC-PGMA-Arg.Moreover,we characterized LC-PGMA-Lys and LC-PG-MA-Arg by FTIR,elemental analysis,XRD,and SEM.Furthermore,we systematically studied the effects of ini-tial pH value,adsorption time,adsorption temperature,and initial concentration of Pb(Ⅱ)on the adsorption ca-pacity of Pb(Ⅱ),and investigated the adsorption behavior to Pb(Ⅱ).The results show that the optimum initial pH value of LC-PGMA-Lys and LC-PGMA-Arg for the adsorption of Pb(Ⅱ)is 6.The maximum adsorption ca-pacity of LC-PGMA-Lys for Pb(Ⅱ)is 71.18 mg·g-1 under the optimum conditions as follows:the initial pH value of 6,the adsorption time of 200 min,and the adsorption temperature of 35 ℃.The adsorption process of Pb(Ⅱ)by LC-PGMA-Lys conforms to the pseudo-second-order kinetic equation and Freundlich isothermal adsorption model,indicating that the adsorption process is dominated by multimolecular layers and chemisorption.
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