表面活性剂对辛基酚在海洋沉积物上吸附行为的影响

Sorption Behaviors of Octylphenol on Marine Sediments in the Presence of Different Surfactants

本文系统地研究人工海水(ASW)中,3种不同类型表面活性剂(十六烷基三甲基溴化铵,CTAB,阳离子表面活性剂;十二烷基苯磺酸钠,SDBS,阴离子表面活性剂;吐温20,Tween20,非离子表面活性剂)存在时辛基酚(OP)在海洋沉积物上的吸附行为。结果表明海洋沉积物中的有机质含量与海洋沉积物吸附OP的能力有着显著的正相关性。在表面活性剂浓度为0～10mg.L-1时,3种表面活性剂对OP在海洋沉积物上的吸附都有促进作用,其促进作用由强到弱顺序依次为:CTAB>Tween20>SDBS。在表面活性剂浓度从0增加到120mg.L-1,相同浓度的OP(4mg.L-1)在海洋沉积物上的吸附行为变化中,CTAB使OP的吸附量增加较快,当CTAB浓度大于40mg.L-1时溶液中未吸附的OP浓度低于检测限;SDBS使OP在海洋沉积物上的吸附量先快速增加、后趋于平稳;Tween20使OP在海洋沉积物上的吸附量先增加后减小,吸附量达到最大值时Tween20的浓度与其临界角束浓度浓度(CMC)相接近。

The sorption behavior of octylphenol（OP） in artificial seawater（ASW） on marine sediments was systematically studied in the presence of three kinds of surfactants（Cetyl trimethyl ammonium bromide,CTAB,cationic surfactant;Sodium dodecylbenzene sulfonate,SDBS,anionic surfactant;Tween20,nonionic surfactant）.The sorption ability of OP on marine sediments had a significant positive relationship with sediment organic carbon content.When the concentration of surfactants was below 10 mg·L-1,all the three surfactants could promote the sorption of OP on marine sediments.At the same concentration（4 mg·L-1）,the promotion effect of three surfactants on the sorption ability of OP on S2 sediment was in the following order： CTABTween20SDBS.With the concentration of CTAB ranged from 0 to 120 mg·L-1,the sorption amount of OP on marine sediments increased quickly and then the residual concentration of OP in sorption solution was below detection limit with CTAB concentration more than 40 mg·L-1.The sorption amount of OP was enhanced first and then remained steady when SDBS concentration increased from 0 to 120 mg·L-1.In presence of Tween20,the sorption amount of OP increased and reached the highest value with about 60 mg·L-1 Tween20 which was close to the CMC of Tween20,then decreased with higher concentration of Tween20.