摘要
以牡蛎壳(OS)为原料制备一种新型牡蛎壳负载壳聚糖(CCOS)吸附剂,并利用电镜扫描(SEM)、红外(FTIR)、X射线衍射(XRD)及热重(TG)分析等方法对吸附剂样品进行表征.同时,研究了吸附剂对活性红152(RR152)的吸附性能,考察了壳聚糖与牡蛎壳质量比、溶液pH值、吸附剂用量、活性红152起始浓度、吸附时间和温度对吸附的影响.结果表明,壳聚糖与牡蛎壳质量比为0.08,pH值为2时,活性红152的去除率达最大值;活性红152的去除率随着吸附剂用量的增加而增大,当吸附剂用量为0.3g时,活性红152的去除率达83.3%.吸附容量也随着起始浓度的增加而增大,并在150min达到吸附平衡.运用3种动力学模型对吸附过程进行拟合,结果表明,吸附过程可以很好地用准二级动力学方程描述.吸附等温线用Langmuir方程的拟合效果优于Freundlich和Tempkin方程,最大吸附容量在298.15、303.15、308.15和318.15K下分别为135.14、142.86、144.92、149.25mg·g-1.在热力学研究中,ΔG0<0、ΔH0>0、ΔS0>0,表明此吸附过程是自发、吸热和熵增加的过程.解吸实验表明,吸附剂用碱液处理再生后,可循环使用4次.
The new adsorbent chitosan-coated oyster shells（CCOS） was prepared by using oyster-shell（OS） as raw materials.The adsorbent was characterized by scanning electron microscope（SEM）,Fourier transform infrared（FTIR） spectra,X-ray diffraction（XRD） and thermogravimetric（TG） analysis.The adsorption behavior for Reactive Red 152（RR 152） was investigated.The effecting factors such as the mass ratio of chitosan/oyster shells,solution pH,adsorbent dosage,initial concentration of RR 152,adsorption time and temperature were studied.The results showed that the removal rate of RR 152 could reach a maximum value when the mass ratio of chitosan/oyster shells was 0.08 and pH was 2.The removal rate of RR 152 would increase proportional to the adsorbent dosage.When the adsorbent dosage was up to 0.3 g,the removal rate would reach 83.3%.The adsorption capacity also increases proportional to the initial concentration,and the adsorption equilibrium was achieved at 150 min.Three kinds of dynamic models were used to simulate adsorption kinetics.The results showed that the adsorption process followed a pseudo-second order equation.The adsorption isotherm could be described very well by Langmuir model rather than Freundlich or Tempkin models.The maximum adsorption capacities of RR 152 under 298.15 K,303.15 K,308.15 K and 318.15 K were found to be 135.14,142.86,144.92 and 149.25 mg · g^-1.In thermodynamic studies,the parameters of ΔG0〈0,ΔH0〉0 and ΔS0〉0 indicated that the adsorption process was spontaneous and endothermic with an increase in entropy.Desorption studies showed that the adsorbent could be recycled for four times after being regenerated by basic solutions.
出处
《环境科学学报》
CAS
CSCD
北大核心
2013年第6期1590-1597,共8页
Acta Scientiae Circumstantiae
基金
福建省自然科学基金项目(No.2012D107)
闽江学院科技启动项目(No.YKQ1005)~~
关键词
牡蛎壳
壳聚糖
吸附
活性红152
oyster shells
chitosan
adsorption
reactive red 152
