摘要
以凹凸棒土为主要原料,成功制备了颗粒状凹凸棒土吸附剂。用X射线衍射分析和BET分析对颗粒化样品进行了表征。通过静态吸附实验重点研究了颗粒状凹凸棒土吸附剂吸附水中Ni(Ⅱ)时的影响因素、吸附动力学和吸附等温线。结果表明,颗粒化后,比表面积和孔容积比颗粒化前降低,但凹凸棒土主要衍射峰得以保留。在研究条件下,平衡吸附量随着溶液温度升高而增大,并随着Ni(Ⅱ)初始浓度的增大而变大。颗粒状吸附剂用量增加,平衡吸附量却减少。在p H=2~4时,Ni(Ⅱ)吸附去除率随着p H值的增加而变大,p H值超过4以后去除率基本保持不变。颗粒吸附剂对Ni(Ⅱ)吸附动力学过程符合准二级反应模型,吸附是吸热过程,Freundlich方程可以很好描述不同温度下的等温吸附线。
Granulated adsorbent was successfully prepared with attapulgite as the basic material. Granulated attapulgite was characterized by XRD analysis and BET analysis. The influence factor,kinetic processes and equilibrium isotherms of Ni( Ⅱ) removal by granulated adsorbent were investigated by bath reactor experiments. Results indicated that the main diffraction peaks of attapulgite remained although specific surface area and pore volume decreased after granulation. Equilibrium adsorption capacity increased with the increase of water temperature and initial concentration of Ni( Ⅱ) respectively. Equilibrium adsorption capacity decreased with the dosage increase of granulated adsorbent. The removal ratio of Ni( Ⅱ) increased when p H value increased from 2 ~ 4,while the removal ratio of Ni( Ⅱ) kept stable when p H value was higher than 4. The kinetic processes of Ni( Ⅱ) removal could be described by the pseudo-secondorder kinetic model. The adsorption of Ni( Ⅱ) by granulated adsorbent was an endothermic process. Equilibrium isotherms under different temperature were fitted well by Freundlich model.
出处
《应用化工》
CAS
CSCD
北大核心
2017年第5期935-939,共5页
Applied Chemical Industry
基金
江苏省太湖水污染防治办公室太湖治理科研课题(TH2013307)
住房和城乡建设部科学技术计划项目(2014-K5-032)
江苏省大学生科技创新计划项目(201410298025Z)
关键词
凹凸棒土
镍
颗粒化吸附剂
attapulgite
nickle
granulated adsorbent
