响应面法优化水滑石吸附剂改性工艺

摘要

采用(NH4)2SO4对镁铝水滑石(MgAl-LDH)进行表面改性,制备改性镁铝水滑石吸附剂(ALDH).应用响应面法对改性工艺进行优化,采用Design-Expert 8.0软件,设计3因素3水平的响应面分析方法,得到最优改性工艺参数.在温度60℃,(NH4)2SO4浓度18％和液固比0.15 (mL/mg)的优化条件下改性4h,得到的ALDH对Pb(Ⅱ)吸附率为91.7％,非常接近预测值.%The sorbent (ALDH) was obtained by modifying the Mg-Al hydrotalcite (MgAl-LDH) using (NH4)2SO4 as modifier with surface-modification method.Response surface methodology was applied to optimize the modification process.Design-Expert 8.0 was used to design the experiments with 3 factors including modification temperature,(NH4)2SO4 concentration in the reaction solution and liquid to solid ratio of the solution (NH4)2SO4 to MgAl-LDH,and 3 parameter levels for the response value of the Pb (Ⅱ) removal rate.Under the optimal conditions of 60 ℃,(NH4) 2SO4 concentration 18％ and the ratio of liquid to solid of 0.15 mL/mg for 4 h,the actual Pb (Ⅱ) removal rate of ALDH was 91.7 ％,very close to the predicted value.