摘要:
研究了菲和吡啶在天然沉积物及粘土矿物(高岭土、蒙脱土)上的吸附行为.结果表明,含有天然有机质的沉积物对菲的吸附最为显著,而高岭土和蒙脱土对菲也能发生一定程度的吸附.菲在3种吸附剂上的吸附行为比较符合线性模型,Kd分别为594.7L·kg-1(沉积物),405.0L·kg-1(高岭土)和286.7L·kg-1(蒙脱土).吡啶在3种吸附剂上吸附的Kd明显低于菲,在沉积物、高岭土和蒙脱土颗粒上分别为1.18,9.03和0.94 L·kg-1.CEC较大的沉积物和蒙脱土上吡啶的吸附量更低,这可能是背景溶液中Na+向此两种吸附剂表面大量聚集所致.总体上溶液pH值对于菲在3种吸附剂上的吸附影响较小,而对于吡啶而言,酸性和碱性条件均较中性条件更有利于其在粘土矿物上的吸附,其在沉积物上的吸附则随溶液pH值的增大而降低.
关键词:
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菲
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吡啶
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吸附
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沉积物
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粘土矿物
Abstract:
Sorption of phenenthrene and pyridine on natural sediment and clay minerals(kaolinite and montmorillo-nite)was studied.On sediment with natural organic matter,phenanthrene sorption was greater than that on the clay minerals.The isotherms on the three sorbents fit well with the linear model,and the Kd values are 594.7L·kg-1(sediment),405.0L·kg-1(kaolinite),and 286.7 L·kg-1(montmorillonite),respectively.Comparing with phenanthrene,the Kd values of pyridine on sediment,kaolinite and montmorillonite are much smaller,which are 1.18,9.03,and 0.94 L·kg-1,respectively.On the sorbents of sediment and montmorillonite with higher CEC,pyridine sorption was lower,which might be due to the congregating of Na+ on the sorbent surface from the background solution.Little effect of pH on the sorption of phenanthrene was observed in this study.Acid or basic condition is more propitious to the sorption of pyridine on the clay minerals.However,on the natural sediment,pyridine sorption decreased with the increasing pH value.
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