Adsorption of Dispersed Red from Aqueous Solution onto Calcined Layered Double Hydroxides
- 作者：Wei HuGuoyun XvLili XvLiang Lv
- 会议时间：2011-06-01
- 关键词：layered double hydroxides ; calcined ; removal ; dispersed red ; dye
- 作者单位：College of Chemical & Materials Engineering, Quzhou University, Zhejiang 324000, China
- 母体文献：2011全国非常规水源利用技术研讨会论文集
- 会议名称：2011全国非常规水源利用技术研讨会
- 会议地点：青岛
- 主办单位：水利部
- 语种：chi
摘要
In this study,calcined layered double hydroxides (CLDH) was used as an adsorbent to remove an anionic dye,dispersed red (DR),from aqueous solution by the batch adsorption technique.Various conditions were evaluated,including CLDH structures,adsorbent dosage,initial dye concentration,and temperature.It was found that the LDHs with an Mg/Al ratio of 3 calcined at 500℃ had the highest capacity to adsorption DR.The adsorption capacity of CLDH decreased with increasing adsorbent dose,but increased with increasing initial DR concentration.The data of sorption isotherms fitted well into the Langmuir equation.Thermodynamic parameters such as △G0,△H0 and △S0 were calculated.The negative values of △G0 indicate the spontaneous nature of adsorption of DR.The positive value of △H0 confirms the endothermic nature of removal process.The positive value of △S0 suggests the increased randomness at the solid/solution interface for the adsorption of DR onto CLDH.The results of two kinetic models fitted the experimental data are shown that the pseudo-first order kinetic model gave a better describe for the adsorption process.The rate constants and activation energy of adsorption were also calculated.The calculated value of Ea was 14.50 kJ/mol,which indicates the adsorption process is controlled by diffusion.