离子强度、pH和腐殖酸浓度对63Ni(Ⅱ)在γ-Al2O3上吸附的影响

摘要

采用静态批式法研究了63Ni(Ⅱ)在γ-Al2 O3上的吸附行为.探讨了震荡时间、pH、离子强度、γ-Al2 O3浓度以及腐殖酸对吸附的影响.实验结果表明:在低pH条件下,离子强度对63Ni(Ⅱ)的吸附影响很大,63Ni(Ⅱ)的吸附主要是离子交换和外层表面络合作用；在高pH条件下,63Ni(Ⅱ)的吸附受pH影响较小,63Ni(Ⅱ)的吸附主要是内层表面络合作用.溶液中的腐殖酸,在低pH条件下促进63Ni(Ⅱ)在γ-Al2 O3上的吸附,而在高pH条件下抑制63Ni(Ⅱ)在γ-Al2 O3上的吸附.%The sorption of 63Ni( II ) on y-Al2O3 was studied by using batch technique. The effect of contact time, pH, ionic strength, y-Al2O3 content and humic acid on the sorption of 63Ni( II ) on y-Al2O3 was investigated under ambient conditions. The results suggest that the sorption of 63Ni( II ) is strongly dependent on ionic strength at low pH values, and independent on it at high pH values. The sorption of 63Ni( II ) at low pH is mainly dominated by ion exchange and/or outer-sphere surface complexation, whereas the sorption of 63Ni( II ) at high pH is mainly dominated by inner-sphere surface complexation. The presence of humic acid enhances 63Ni( II ) sorption to HA-y-Al2O3 hybrids at low pH values, but reduces 63Ni( II ) sorption to HA-r-Al2O3 hybrids at high pH values.