氰乙基球形木质素吸附剂对亚甲基蓝的吸附行为研究

Adsorption Behavior of Methylene Blue on Cyanoethyl Spherical Lignin Adsorbent

中文关键词:  氰乙基球形木质素  亚甲基蓝  吸附  动力学

Key Words:cyanoethyl spherical lignin  methylene blue  adsorption  kinetics

中文摘要:

      利用反相悬浮聚合技术，采取两步升温法制备球形木质素珠体（SLB）；以Fe2+/H2O2为引发体系，在SLB上成功接枝丙烯腈单体，制得氰乙基球形木质素吸附剂（SLBA）。实验探索该吸附剂对亚甲基蓝的吸附行为，考察了SLBA投加量、吸附时间和pH值等因素对吸附的影响，并依据动力学和热力学模型进行分析。结果表明，SLBA对亚甲基蓝的吸附过程符合二级动力学模型；在308 K、pH值为7的溶液中，SLBA吸附约1 h达到平衡，亚甲基蓝去除率达到98%左右，SLBA的饱和吸附容量为87.0 mg/g；吸附过程同时符合Langmuir和Freundlich方程，整个过程是自发的吸热反应过程，并以物理吸附为主。

Abstract:

      The spherical lignin beads，denoted as SLB，were prepared by applying reverse-phase suspension polymerization technique．The cyanoethyl spherical lignin adsorbent，denoted as SLBA，was prepared by grafting acrylonitrile monomer onto lignin beads using Fe2+/H2O2 as initiator. The adsorption behavior of methylene blue solution on SLBA was studied．And the effect of the adsorbent dosage，time and solution pH value on adsorption was investigated. The results concluded that the adsorption kinetics process was conformity with the second kinetics model. SLBA showed excellent adsorption performance for methylene blue at the solution of pH 7,308K for 1 h and the removal rate of methylene blue reached to 98%，its maximum saturated adsorption capacity reached 87.0 mg/g，and the adsorption process was in accordance to the Langmuir and Freundlich equation．Additionally，the whole process belonged to spontaneous and exothermic reaction process，it mainly was physical adsorption by the porous structure．