牛血清白蛋白对Ni2+与δ-MnO2间吸附平衡的影响

研究了溶液中牛血清白蛋白(BSA)的存在对Ni2 与δ-MnO2衡性质的影响.结果表明, BSA存在时Ni2 在δ-MnO2表面的吸附率'pH曲线仍为典型的"S"形, BSA使Ni2 的吸附突跃向高pH方向移动,影响程度与BSA的加入方式及浓度有关,其大小次序为Ⅳ(先加BSA后加Ni2 ),Ⅲ(N2 和BSA同时加)≈Ⅱ(先加Ni26 后加BSA).BSA存在时Ni2 的等温吸附线很好地遵循Langmuir等温吸附方程, Ni2 的饱和吸附量与BSA的加入方式有关,其大小次序为I(不加BSA)>Ⅱ.m,Ⅳ.升高温度促进Ni2 的吸附.在pH:4.0和pH:7.0条件下, Ni2 在δ-MnO2上的吸附均是不可逆的, BSA对Ni2 的吸附可逆性没有影响.

Influence of BSA on adsorption equilibrium of nickel onto delta-MnO2

The influence of BSA on adsorption equilibrium of Ni2+ onto delta-MnO2 had been investigated using a batch method. It was showed that the adsorption-pH curves of Ni2+ onto delta-MnO2 were "S-shape" at BSA] = 10 mg x L(-1), and the leaping range of adsorption would move to high value of pH in the presence of BSA. The extent of effect had relation to the adding order and the concentration of BSA, and the trend was IV (BSA added first) > III (Ni2+ and BSA added simultaneously) approximately II (Ni2+ added first). The adsorption percentage decreased with increasing BSA concentration at the same value of pH. The Langmuir adsorption model fit the experimental date reasonably in the presence of BSA. The maximum adsorption capacity related to the BSA adding order was I (without BSA) > II approximately III > IV. In addition, the adsorption of Ni2+ onto delta-MnO2 increased with the rise of temperature. It was found that the adsorption was irreversible at pH = 4.0 and pH = 7.0. BSA had no effect on the reversibility of Ni2+ adsorption onto delta-MnO2.