PDMDAAC改性膨润土对石油类污染物脱附行为的研究

Study of desorption behavior of oily pollutant on PDMDAAC-bentonite

石油类污染是水体环境主要的污染源之一,并且石油是不可再生资源,用吸附法处理含有石油类污染的废水有较好的处理效果。膨润土是一种优良的吸附剂,对其进行改性能提高其吸附石油类污染物的性能。改性膨润土在在含油废水处理方面得到广泛的应用,但其对石油类污染物脱附行为的研究还较少。本实验考察了搅拌时间、搅拌速度、p H、温度和盐度的变化对饱和吸附含油废水的聚二甲基二烯丙基氯化铵(PDMDAAC)改性膨润土脱附行为的影响,并通过正交实验优化了最佳脱附条件:搅拌时间为25 min,搅拌速度为200 r/min,p H为3,温度为35℃,在此条件下,脱附率可达92.05%。在最佳脱附条件下使其再生,并和原土进行了比较,通过脱附动力学研究了其脱附的过程。结果表明,饱和吸附含油废水的PDMDAAC改性膨润土在最优条件下,脱附率可达92.05%,可以用来回收石油;再生得到的改性膨润土用于处理含油废水,去除率在82.84%左右,可以重复使用来处理含油废水;准二级脱附动力学能较好地描述脱附过程。旨在探索改性膨润土的吸附及脱附的规律,为膨润土用于含油废水处理奠定基础。

Petroleum pollution is one of the main pollution sources of water pollution. Petroleum is non-renewable resource and it can usually get good results,using adsorption method,when dealing with wastewater containing petroleum pollution. The bentonite is a kind of excellent adsorbent,and scientists change its properties to improve its adsorption properties of petroleum pollutants. Modified bentonite is widely used in the oil-bearing wastewater treatment,but researches on petroleum pollutant＇s desorption behavior are less. This experiment studied the impact on the desorption behavior of PDMDAAC modified bentonite saturated adsorption of oily wastewater,when changing stirring time,stirring speed,pH,temperature,salinity,and though orthogonal experiment,the desorption conditions were optimized： stirring time of 25 minutes,stirring speed of 200 r/min,pH of 3,temperature of 35℃,under these conditions,the desorption rate up to 92. 05%. We made the modified bentonite regenerated under the optimal desorption conditions,and compared it with the original soil,studied its desorption process though kinetics. The results showed that the desorption rate of PDMDAAC modified bentonite saturated adsorption of oily wastewater could be up to 92. 05% under optimal conditions,which can be used to recover petroleum. When dealing with the oily wastewater using modified bentonite regenerated,the removal rate is about 82. 84%,so it can be used to treat the oily wastewater repeatedly. Quasi-two desorption kinetics can describe the desorption process well. This study was designed to explore the laws of modified bentonite adsorption and desorption,and to lay the foundation for oily wastewater treatment using bentonite.