摘要
利用氢氧化钠对天然沸石进行改性,将天然沸石和改性沸石用于吸附去除水中的Cu^(2+),分析了p H、温度、Cu^(2+)初始浓度、吸附时间对Cu^(2+)吸附性能的影响,并对吸附过程的吸附等温模型及吸附动力学进行研究。结果表明,改性沸石对Cu^(2+)的吸附性能明显优于天然沸石,当沸石投加量为10 g/L,Cu^(2+)为200 mg/L,p H为6.67,温度为50℃时,天然沸石和改性沸石对Cu^(2+)的吸附量分别为2.02、2.69 mg/g。Langmuir和Freundlich吸附等温模型均能较好地描述两种沸石对Cu^(2+)的吸附过程。天然沸石对Cu^(2+)的吸附行为更符合准一级动力学方程,而准二级动力学方程对改性沸石的吸附行为拟合度更好。两种沸石对Cu^(2+)的吸附均为非均相吸附,且内扩散过程不是唯一的速控步骤。
Natural zeolites and sodium hydroxide modified zeolites were used to remove Cu^2＋ in aqueous solution. The effects of p H,temperature,Cu^2＋ initial concentration and adsorption time on the Cu^2＋ adsorption capacity of two zeolites were studied. The isotherm and kinetics of adsorption process were also studied. The results showed that modified zeolite had a better adsorption capacity than natural zeolite. When the zeolite dosage was 10 g/L,Cu^2＋ was 200 mg/L,p H was 6. 67,and the temperature was 50 ℃,the Cu^2＋ adsorption capacities of natural zeolites and modified zeolites were 2. 02,2. 69 mg/g,respectively. Both Langmuir and Freundlich isotherm could well fit the Cu^2＋ adsorption process on natural and modified zeolites. Adsorption process of natural zeolite conformed to pseudo-first order kinetic equation,while pseudo-second order kinetic equation was better for fitting the adsorption process of modified zeolites. The adsorption of Cu^2＋ on zeolites was heterogeneous adsorption and intraparticle diffusion was not the only rate-determining step for this adsorption prosess.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2017年第3期314-318,共5页
Environmental Pollution & Control
