机构地区: 衡阳师范学院资源环境与旅游管理系
出 处: 《湖南科技大学学报(自然科学版)》 2006年第4期92-96,共5页
摘 要: 利用废弃蛋壳合成碳羟基磷灰石(CHAP),对含镉废水进行吸附研究,考查了溶液的pH值、吸附时间和温度对吸附平衡的影响.结果表明:pH=6.00,吸附时间为60min,温度为35℃,CHAP对10~30mg/L的Cd2+的吸附率达到99%,吸附动力学符合拟一级速率方程,理论计算值与实验值吻合很好.常温下CHAP对C d2+的吸附用Langm uir和Freundlish方程进行拟合,相关系数R2分别达到0.975 3和0.995 4,说明吸附反应符合这两种吸附模型.吸附过程的焓变ΔH>0,自由能变ΔG<0,反应容易进行,为自发吸热反应.图8,表4,参8. Cd^2+ adsorption from simulated wastewater was conducted with Carbonate hydroxylapatite (CHAP) which was synthesized by using abandoned eggshell. Factors that might influent the adsorption performance were investigated, such as pH, reaction temperature. The results showed that the removal efficiency of Cd^2+ by CHAP could reach up to 99% when pH is 6, the reaction temperature is 35 ℃, adsorption period is 60 rain, and the initial concentration of Cd^2+ is 10 -30 mg/L. The kinetic equation corresponds to the pseudo first order, and theoretical calculation is well fit to actual experimental data. The adsorption process could be simulated by both Freundlich and Langmuir equation and the R2 respectively achieves 0.975 3 and 0.995 4 at 25 ℃. Conclusion can be made that the adsorption reaction is an easily spontaneous endothermic from A H 〉 0 and A G 〈 0. 8figs.,4tabs., 8refs.