摘要
采用等温吸附法比较了氢氧化钠、氯化钠、硝酸铵、硫酸、磷酸、混合盐和高温改性沸石对含镉废水的吸附效果,并采用Langmuir、Freundlich等温线方程及Lagrange假一级动力学方程、假二级动力学方程、粒内扩散方程对实验数据进行了拟合。结果表明,镉浓度大于10 mg/L时,NaOH改性沸石吸附效果最好,吸附率在99.2%以上;沸石对镉的吸附符合Langmuir方程,属单分子层吸附,最大吸附量Qm=6.456 mg/g;改性沸石对Cd2+的吸附动力学符合假二级动力学方程,以化学吸附为主,有多个控速步骤。
Isothermal adsorption method was used to compare the effects of 7 kinds of modified zeolite＇ s adsorption on cadmium in wastewater,where Langmuir, Freundlich isotherm equation and Lagrange pseudo-first- order kinetics equation, pseudo-second-order kinetics equation and intra-particle diffusion equation were applied to simulate the experimental parameters. The results show that, when the cadmium concentration is more than 10 rag^L, the sodium hydroxide modified zeolite＇ s adsorption result is the best, the adsorption rate is above 99.2%. The adsorption on cadmium meets Langmnir isotherm model, which is a single molecular layer adsorp- tion, the maximum adsorption capacity is 6. 456 mg/g. Modified zeolite＇ s impact on cadmium adsorption fits pseudo-second-order kinetics equation,mainly chemical adsorption. There is more than one control speed steps.
出处
《环境工程学报》
CAS
CSCD
北大核心
2012年第8期2693-2697,共5页
Chinese Journal of Environmental Engineering
基金
国家大学生创新实验计划(101063503)
关键词
改性沸石
镉
吸附
动力学
modified zeolite
cadmium
adsorption
kinetics
