萃取技术分离工业废水中的苯胺

研究以硝基苯为萃取剂,25℃下通过盐析萃取法回收工业废水中苯胺。以静态分批实验考察了废水酸度、初始苯胺浓度、萃取剂与废水比(油水比)、萃取级数、无机盐种类(NaCl,KCl,Na2SO4,CaCl2,K2SO4)和浓度对苯胺萃取率的影响,获得了最佳操作工艺条件。实验结果表明,硝基苯盐析萃取技术可以有效回收废水中苯胺,且高pH和溶剂比有利于苯胺萃取,随着无机盐浓度的增加苯胺回收率增加。在适宜的条件下,通过盐析作用,经过五级萃取苯胺萃取率接近100%。

Separation of aniline from industrial wastewater with extraction technology

Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25℃.The batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance,including acidity of wastewater,initial aniline concentration,ratios of solvent versus wastewater,extraction stages,concentrations and species of inorganic salts,such as NaCl,KCl,Na2SO4,CaCl2 and K2SO4.Thus the optimal operating conditions were given.The experimental results showed that the aniline from wastewater could be effectively seperated with nitrobenzene,high pH values and volume ratios of nitrobenzene/wastewater were more suitable for recovery of aniline,and the recovery of aniline was increased with concentrations of salts.The recovery of aniline reached nearly 100% under appropriate conditions by salting-out effect when five stage extraction was used.