Fe(Ⅲ)负载改性核桃壳对Cu^(2+)吸附研究

Study on Adsorption of Cu^(2+) by Walnut Shell Modified with Fe(Ⅲ)

该研究采用农林废弃物核桃壳以及Fe(Ⅲ)改性的核桃壳作为吸附剂,对模拟废水中的Cu^(2+)进行吸附去除,并且考察了水样初始p H、吸附剂投加量、Cu^(2+)初始浓度、吸附时间等因素对Cu^(2+)吸附效果的影响,确定最佳吸附参数,并进行了吸附动力学和吸附等温线的分析。结果表明:当水样初始p H 5.0、吸附剂投加量0.05g,Cu^(2+)初始质量浓度200mg/L,吸附时间120min,在此条件下50m L水样在180r/min、25℃条件下核桃壳和改性核桃壳对Cu^(2+)的去除率分别达57.6%和93.2%以上,吸附量分别约为120mg/g和195mg/g;采用伪二级动力学方程的拟合结果更为理想,R2均在0.99以上;Langmuir方程可以较好地描述核桃壳和Fe(Ⅲ)改性核桃壳吸附剂对Cu^(2+)的吸附过程,此吸附过程是单分子层的吸附;核桃壳及改性核桃壳对Cu^(2+)的吸附是放热反应。

Using agricultural wasted walnut shell and walnut shell modified with Fe（Ⅲ）as adsorbent,we do adsorp-tion and removal of Cu2＋in simulated wastewater. Then the effects of experimental parameters such as water sampleinitial p H,dosage,Cu2＋initial concentration,contact time were investigated. We ascertain optimal adsorption parame-ters,and analyze adsorption kinetics and adsorption isotherms. The experimental result indicated that the removalrates of Cu2＋were respectively more than 57.6% and 93.2% in 50 m L water samples at the condition of 180 r/min and25℃ under the initial water sample conditions of p H 5.0,dosage of adsorbent 0.05 g,Cu2＋initial mass concentration200mg/L,contact time 120 min. At the same time,adsorption amount was respectively about 120mg/g and 195mg/g.The fitting result is better when we take pseudo-second-order kinetics,the result of R2 are all more than 0.99. Lang-muir equation could be used to describe the adsorption process of Cu2 ＋on walnut shell and walnut shell modifiedwith Fe（Ⅲ）. This adsorption process is the adsorption of singlemolecule layer. The adsorption of walnut shell andmodified walnut shell on Cu2＋is an exothermic reaction.