碳纳米管透水混凝土的重金属离子吸附性能

Adsorption properties of heavy metal ions for carbon nanotube reinforced porous concrete

利用多壁碳纳米管(MWCNTs),制备了MWCNTs透水混凝土材料,研究了其对水溶液中二价重金属离子Pb2+、Cd2+以及Cu2+的吸附性能。重金属离子溶液初始浓度为100,400,700及1 000 mg/L,吸附时间为1,2,6,12,24,48及72 h。测试了MWCNTs透水混凝土对Pb2+、Cd2+以及Cu2+吸附量与吸附时间的关系,分析了重金属离子溶液初始浓度对Pb2+、Cd2+以及Cu2+平衡吸附量的影响。研究发现,MWCNTs透水混凝土对Pb2+、Cd2+以及Cu2+离子的吸附量在24 h后达到吸附平衡;随着重金属离子溶液初始浓度的增大,MWCNTs透水混凝土对Pb2+、Cd2+以及Cu2+离子的平衡吸附量明显提高;MWCNTs透水混凝土对重金属离子的吸附能力大小顺序为Pb2+>Cd2+>Cu2+。MWCNTs透水混凝土对重金属离子的吸附等温线与Freundlich模型符合较好,可以采用Freundlich模型描述MWCNTs透水混凝土对重金属离子的吸附等温线。

Multi-walled carbon nanotube(MWCNTs)reinforced porous concrete was prepared.Adsorption properties of some divalent heavy metal ions(Pb2+,Cd2+and Cu2+)for MWCNTs reinforced porous concrete were investigated.The initial concentrations of heavy metal ions were 100,400,700 and 1 000 mg/L.The adsorption times were 1,2,6,12,24,48 and 72 h.Relationship between adsorption time and adsorption quantity was tested.Effect of initial concentrations of heavy metal ions on the equilibrium adsorption quantity of Pb2+,Cd2+and Cu2+was analyzed.It was found that the adsorption quantity of Pb2+,Cd2+and Cu2+for MWCNTs reinforced porous concrete reached the adsorption equilibrium after 24 h.With the increase of the initial concentration of heavy metal ion solution,the equilibrium adsorption quantity of Pb2+,Cd2+and Cu2+for MWCNTs increased obviously.Preference of adsorption onto the MWCNTs reinforced porous concrete can be ordered as Pb2+>Cd2+>Cu2+.The adsorption isotherm of MWCNTs reinforced porous concrete on heavy metal ions is in good agreement with the Freundlich model,which can be used to describe the adsorption isotherm of MWCNTs reinforced porous concrete on heavy metal ions.