Pb(Ⅱ)and Cd(Ⅱ)are common heavy metal ions in water.Their concentration exceeding the standard has great harm to human health and the water environment.Therefore,the removal of Pb(Ⅱ)and Cd(Ⅱ)in water is particularly important.The artificial zeolite material was prepared by mechanical ball milling.The experimental results show that the process of removing Pb(Ⅱ)and Cd(Ⅱ)by artificial zeolite conforms to the Langmuir model.For single adsorption:the adsorption amounts of Pb(Ⅱ)and Cd(Ⅱ)were 503.97 and 460.23 mg/g,respectively,Under the competitive system,when the initial concentration ratios of Pb(Ⅱ)and Cd(Ⅱ)were 1:1,2:1 and 1:2,the adsorption amounts of Pb(Ⅱ)and Cd(Ⅱ)were 468.41,474.71,419.01 mg/g;437.13,365.39,420.31 mg/g.Under the competition system,the selection coefficient of Pb(Ⅱ)is 0.3668-83.3897,Much larger than the selec-tivity coefficient of Cd(Ⅱ),Pb(Ⅱ)is the dominant ion in the binary adsorption system.From the site energy distri-bution,it can be seen that the initial concentration and adsorption amount of Pb(Ⅱ)and Cd(Ⅱ)are negatively correlated with the site energy.In a single system:the Em of Pb(Ⅱ)and Cd(Ⅱ)are 45.50 and 47.58 kJ/mol.Under the competitive system,the average site energy Em and site distribution uniformity of Pb(Ⅱ)and Cd(Ⅱ)are different at different concentration ratios,which are related to the specific adsorption system.
关键词
人造沸石/吸附模型/位点能量分布/竞争吸附
Key words
artificial zeolite/adsorption model/site energy distribution/competitive adsorption
维普
万方数据