甜菜粕的季铵化修饰及其对核固红的吸附特性

Quaternization of Sugar Beet Pulp and Its Adsorption Property to Nuclear Fast Red

为改善甜菜粕作为生物吸附剂的吸附性能,使用季铵盐四丁基溴化铵(TBAB)对甜菜粕(SBP)进行修饰,制得吸附剂季铵盐四丁基溴化铵改性甜菜粕(TBAB-SBP),使用FT-IR、XRD、SEM对TBAB-SBP化学结构和表面形貌进行表征。并探究TBAB-SBP对核固红的吸附性能,分析其动力学、热力学和吸附等温线。结果表明:TBAB能有效负载到SBP表面,增加功能官能团种类和数量。TBAB-SBP对溶液中核固红的静态吸附最佳工艺条件为:溶液pH值2.0,质量浓度100 mg/L的核固红溶液100 mL,吸附剂用量0.6 g、吸附时间180 min、吸附温度25℃,此时的色素清除率为94.44%,与SBP相比,色素清除率上升约12个百分点。TBAB-SBP对核固红的吸附符合Langmuir等温线模型,说明吸附过程为均匀单分子层吸附;吸附过程为自发的放热过程;TBAB-SBP吸附核固红过程符合准二级吸附动力学模型,说明该吸附以化学吸附为主。

In order to improve the adsorption performance of sugar beet pulp as a biosorbent,sugar beet pulp(SBP)was modified with quaternary ammonium salt tetrabutylammonium bromide(TBAB)to obtain the modified adsorbent TBAB-SBP.The adsorption performance of TBAB-SBP on nuclear fast red was explored.Its kinetics and thermodynamics were analyzed,and the chemical structure and surface morphology of TBAB-SBP were characterized by using FT-IR,XRD and SEM.The results showed that TBAB could be effectively loaded on the surface of SBP,and the types and number of functional groups increased.The static adsorption process conditions for nuclear fast red on TBAB-SBP in wastewater were pH value of the solution 2.0,100 mL of nuclear fast red solution with mass concentration of 100 mg/L,amount of adsorbent 0.6 g,treatment time 180 min,adsorption temperature 25℃.Under these conditions,the pigment removal rate of TBAB-SBP was 94.44%,which was about 12%higher than that of SBP;the adsorption equilibrium data conformed to the Langmuir isotherm model;the adsorption process was a spontaneous exothermic process;the TBAB-SBP adsorption nuclear fast red process conformed to the qseudo-second-order equation.