以柴油污染的海水为对象,研究了吸油草对海水中柴油的吸附、解吸规律,考察了海水盐度、温度和pH三因素对吸附的影响,并根据吸附等温线和吸附热力学的分析探讨了其吸附机理。研究结果表明,吸油草对海水中柴油的吸附及解吸均符合二级反应模式,达到吸附平衡仅需要10~20 min,而达到解吸平衡需要2~3 h,解吸平衡时间是吸附平衡时间的9倍,吸附速率远远大于解吸速率。吸油草对柴油的平衡吸附量和解吸量分别为6.69 g/g和0.325 g/g,释放率约为4.86%。吸附量随盐度的增大、pH的升高、温度的降低而增大。其吸附等温线可用Freundlich式和BET模式描述,属于多分子层吸附;通过热力学分析得知,该吸附属于物理吸附,吸附热约为-12.56 kJ/mol。
The adsorption and desorption of diesel in seawater on spill-sorb and their influencing factors(salinity,pH,temperature)were studied,and the adsorption mechanism was discussed according to adsorption isotherms and adsorption thermodynamics.Results show that the adsorption and desorption of diesel in seawater on spill-sorb fits the second-order reaction model,and the equilibrium period of adsorption and desorption is 10~20 min and 2~3 h,respectively,and the latter is longer than former up to 9 times.The equilibrium adsorption and desorption capacity were 6.69 g/g and 0.325 g/g respectively,and the rate of desorption is 4.86%.The adsorption capacity increases with the increment of salinity and pH of seawater,and decreases when the environmental temperature rises.The adsorption isotherms can be described as Freundlich's and BET equation,and the adsorption of diesel on spill-sorb belongs to physical adsorption according to adsorption thermodynamics study,and the adsorption heat in the process was about-12.56 kJ/mol.