响应面法优化木质素基选择性吸附树脂的皂化条件

Optimization for saponification of lignin-based selective adsorbent by response surface methodology

采用响应面法研究了膨润土/木质素磺酸钠接枝丙烯酰胺选择性吸附树脂(BLPAM)的皂化实验。以氢氧化钠溶液浓度、皂化温度、皂化时间为影响因素,以Pb^(2+)吸附量、Cu^(2+)吸附量、Pb^(2+)对Cu^(2+)的选择性吸附系数、Pb^(2+)去除率、Cu^(2+)去除率为响应值建立Box-Behnken数学模型,通过响应面分析得到针对各响应值的主次因素和优化皂化条件。采用组合赋权法确定各响应值的权重,获得最终的优化皂化条件。结果表明,BLPAM的优化皂化条件为:氢氧化钠溶液浓度1.45mol/L、皂化温度98℃、皂化时间2.90h,所得皂化BLPAM树脂在二元Pb^(2+)/Cu^(2+)溶液中对Pb^(2+)吸附量为1.772mmol/g,Cu^(2+)吸附量为1.719mmol/g,Pb^(2+)对Cu^(2+)的选择性吸附系数为1.604,Pb^(2+)去除率为96.062%,Cu^(2+)去除率为93.864%。

The saponification hydrolysis of adsorbent composites comprising of bentonite/sodium lignosulfonate graft-polymerized with acrylamide（BLPAM）were investigated by response surface methodology（RSM）.In the process,the concentration of NaOH,saponification temperature and saponification time were used as response variables and the adsorption capacity of lead ions,the adsorption capacity of copper ions,the selective coefficient of lead to copper ions,the removal ratio of lead ions and the removal ratio of copper ions were studied.The Box-Behnken mathematical relational model between response variables and response values was established and the saponification conditions were optimized.Then,combination weighting method was applied to determine the index weights and the optimized saponification conditions considering all response values were obtained.Results have shown that the optimized saponification conditions of BLPAM were as follows：the concentration of sodium hydroxide is 1.45mol/L,the saponification temperature is 98℃,the saponification time is 2.90 h.The adsorption capacities of the saponified BLPAM for Pb^2＋and Cu^2＋in Pb^2＋/Cu^2＋binary solution are 1.772and1.719mmol/g,respectively,the selective coefficient of Pb^2＋to Cu^2＋is 1.604,and the removal ratios of Pb^2＋and Cu^2＋are 96.062% and 93.864%,respectively.