摘要
研究了金属离子Pb2+、Cu2+、Cd2+在胡敏酸上的单一吸附和两两组分竞争吸附。结果表明,总体胡敏酸对Cu2+、Pb2+的吸附明显强于Cd2+。Freundlich方程对Pb2+、Cd2+单一金属离子吸附等温线的拟合呈极显著关系,Langmuir方程为胡敏酸吸附Cu2+的最佳拟合方程。Pb2+、Cu2+、Cd2+的两两组分竞争吸附表明,胡敏酸对3种离子均具有"选择性吸附",竞争能力从大到小依次为Pb2+、Cu2+、Cd2+。
The given paper is aimed at presenting our research results on the adsorptive behavior of Cu^2＋ , Pb^2 ＋ and Cd^2 ＋ onto humic acid which is extracted as a result of deposition of alkalidissolving acid. As is known, the power of adsorption of Cu^2＋ by humie acid is stronger than that of Pb^2 ＋ and Cd^2＋ under the same initial concentration. Actually, the adsorption power of the three can be ordered as follows ： Cu^2＋ 〉 Pb^2 ＋ 〉 〉 Cd^2＋ . In addition, significant relationship to the adsorption of Pb^2 ＋ and Cd^2＋ can be found in the equilibrium data of Langmuir, Freundlieh and Temkin isotherms with the Freundlich isotherm fit best for （Pb^2＋ ： R^2 = 0.994 9, Cd^2＋ ： R^2 = 0. 973 6 ）. while Langmuir isotherm should be fit better for Cu^2＋ （R^2 = 0.998 4） than Freundlieh isotherm. But the Temkin isotherm proves not to fit very well. Though pH value is the main factor that may influence the adsorption of Cu^2＋ and Cd^2＋ , the influence of Pb^2 ＋ proves less significant. However, on the whole, it can be said that at low pH value humie acid tends to go against the adsorption of Cu^2＋ , Pb^2＋ and Cd^2 ＋ . But with the increase of pH （pH = 2- 8）, both the adsorption and adsorption rate would also rise in turn. Seen from the infrared spectrum of response, our research results have shown that the linking point among the humic acid and Pb^2＋ and Cd^2 ＋ lies mainly in between phenolic hydroxyl group and earboxyl of aromatic ring. Thus, it can be concluded that humie acid and Cu ＋ in addition to their relation with the phenolic hydroxyl group and carboxyl group, more link can be found between carboxyl and carboxyl of the aromatic ring.
出处
《安全与环境学报》
CAS
CSCD
2008年第6期22-26,共5页
Journal of Safety and Environment
基金
江苏省重点自然科学基金项目(BK2001208)
江苏省高校自然科学基金项目(04KJD610093)
南京市科技发展项目(20012117)
江苏省社会发展项目(BS2007064)
