摘要
活性炭被用于处理水中多种痕量重金属离子和微量有机物。但在一定的条件下活性炭对一些污染物的吸附去除率很低,为了更好的理解和预测活性炭对水中微污染物的吸附行为,本文对活性炭吸附模式和机理方面的研究进行了综述。活性炭比表面积大,微孔结构丰富,其表面含有丰富的含氧官能团(羧基,酚羟基、羰基、内酯基)活性炭对污染物质的吸附受吸附剂的性质、吸附质的性质和溶液性质等因素的影响。对于金属离子Langmu ir和Freund lich模式是活性炭吸附重金属离子的经典经验模式,但表面络合模式能更好的描述变化条件下的吸附现象。活性炭吸附金属离子的主要作用是静电作用和离子交换作用。对于有机物稀溶液条件下的吸附多符合Freund lich模式。给-受电子作用、扩散作用、静电作用是主要的作用机制。pH对金属离子和有机物的吸附有重要的影响,腐植酸对金属离子有吸附竞争作用。
Numerous metal ions and organics can be absorbed by activated carbon. However, for certain compounds, the removal rate is low. To better understand/predict the reactions between activated carbon and micro - pollutants, the isothermal and mechanic information on adsorption reactivity available in literature was reviewed. Activated carbon has exceptionally high surface areas, well - developed internal micro - porosity as well as the presence of wild spectrum of surface functional surface groups （carboxyl, hydroxyl, carbonyl, quinone）. In the case of metal ions, Langmuir and Freundlich isotherms are two classic experiential models, but surface complex formation model can better describe the adsorption under variable conditions. Adsorption of metal ions usually results from Ion exchange and electrostatic attraction and repulsion. In the case of organics, the data for dilute solutions can be best - fitted by the Freundlich isotherm. Electron donor - acceptor interactions, dispersion effect, electrostatic attraction and repulsion are possible interactions between activated carbon and organics, pH has a significant impact on the adsorption of metal ions and organics. Humic acid have competitive effects on metal ions adsorption.
出处
《环境科学与管理》
CAS
2009年第10期88-92,178,共6页
Environmental Science and Management
关键词
活性炭吸附
金属离子
有机物
吸附模式
activated carbon adsorption
metal ions
organics
adsorption mechanisms
