采用静态批式法研究了Ni(Ⅱ)在膨润土上的吸附行为,探讨了震荡时间、pH、离子强度、膨润土浓度以及腐殖酸浓度对吸附的影响。实验结果表明:在低pH条件下,离子强度对Ni(Ⅱ)的吸附影响很大,Ni(Ⅱ)的吸附主要是离子交换和外层表面络和作用;在高pH条件下,Ni(Ⅱ)的吸附受pH影响较小,Ni(Ⅱ)的吸附主要是内层表面络和作用。溶液中的腐殖酸,在低pH条件下促进Ni(Ⅱ)在膨润土上的吸附,而在高pH条件下降低Ni(Ⅱ)在膨润土上的吸附。
The sorption of Ni(Ⅱ) on bentonite was studied by using batch technique.The effects of contact time,pH,ionic strength,bentonite content and humic acid on the sorption of Ni(Ⅱ) on bentonite were investigated.The results suggest that the sorption of Ni(Ⅱ) on bentonite is strongly dependent on ionic strength at low pH,and independent on it at high pH.The sorption of Ni(Ⅱ) at low pH is mainly dominated by ion exchange and/or outer-sphere surface complexation,whereas the sorption of Ni(Ⅱ) at high pH is mainly dominated by inner-sphere surface complexation.The presence of humic acid in the system enhances Ni(Ⅱ) sorption to HA-bentonite hybrids at low pH,but reduces sorption of Ni(Ⅱ) on HA-bentonite hybrids at high pH.