摘要
采用化学共沉淀法将镍铁氧体(NiFe_(2)O_(4))负载到活性炭,制备出一种磁性吸附剂镍铁氧体@活性炭(NiFe_(2)O_(4)@AC),并将其用于吸附废水中的Cr(Ⅵ).研究了吸附剂吸附Cr(Ⅵ)的影响因素、吸附动力学和吸附等温线.结果表明,在温度为25℃、pH为2、Cr(Ⅵ)初始浓度为150 mg·L^(-1)、活性炭投加量为0.1 g、吸附时间为720 min时,NiFe_(2)O_(4)@AC吸附Cr(Ⅵ)的去除率达到96.92%,吸附量达到72.62 mg·g^(-1).实验数据符合准二级动力学和Langmuir模型,表明其吸附过程是一个单层的化学吸附过程.热力学研究证实,温度升高有利于Cr(Ⅵ)在NiFe_(2)O_(4)@AC上的吸附,该吸附过程是自发和吸热反应.NiFe_(2)O_(4)@AC吸附机制主要是通过络合作用和静电吸引来吸附Cr(Ⅵ),同时,外加磁场可从溶液中分离,具有良好的应用前景.
A magnetic activated carbon adsorbent named NiFe_(2)O_(4)@AC was synthesized by modifying activated carbon with NiFe_(2)O_(4)and used for the adsorption of Cr(Ⅵ)ions from waste water.The influencing factors,adsorption kinetics,and adsorption isotherms of Cr(Ⅵ)adsorption by the adsorbent were investigated.The results showed that the removal rate of Cr(Ⅵ)adsorption by NiFe_(2)O_(4)@AC reached 96.92%,and the adsorption amount reached 72.62 mg·g^(-1)at the adsorption conditions of temperature(298 K),pH 2,Cr(Ⅵ)initial concentration(150 mg·L^(-1)),adsorbent dosage(0.1 g),and contact time(720 min).The experimental data were best described by the proposed secondary kinetics and Langmuir model,indicating that the adsorption process was a monolayer chemisorption process.The increase in temperature favored the adsorption of Cr(Ⅵ)on NiFe_(2)O_(4)@AC because the adsorption process was a spontaneous,heat-absorbing reaction.The adsorption mechanism of NiFe_(2)O_(4)@AC was mainly through complexation and electrostatic attraction to adsorb Cr(Ⅵ);meanwhile,the applied magnetic field could be separated from the solution,which has good application prospects.
作者
张华
李荣华
陈金雄
曾鸿鹄
黄海艺
Asfandyar Shahab
ZHANG Hua;LI Rong-hua;CHEN Jin-xiong;ZENG Hong-hu;HUANG Hai-yi;Asfandyar Shahab(Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin University of Technology,Guilin 541006,China;Guangxi Collaborative Innovation Center of Water Pollution Control and Water Safety Assurance in Karst Areas,Guilin University of Technology,Guilin 541006,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第5期2622-2634,共13页
Environmental Science
基金
广西创新研究团队项目(2018GXNSFGA281001)
广西“八桂学者”岗位专项。
