邻仲丁基苯酚萃取回收废水中二甲基甲酰胺

Recovery of dimethylformamide from wastewater by solvent extraction with o-sec-butyl phenol

采用高沸点萃取剂邻仲丁基苯酚萃取回收废水中的二甲基甲酰胺。对质量浓度为100 g/L的模拟废水,在25℃下以邻仲丁基苯酚为萃取剂时分配系数可达6.92,远高于低沸点溶剂氯仿萃取时的分配系数0.91。在相比1∶1(体积比),单级萃取时,萃取率即高达87.54%。3级萃取时,废水中N,N-二甲基甲酰胺(DMF)质量浓度从100 g/L降低至2.44 g/L。在邻仲丁基苯酚中加入稀释剂可改善澄清分层速度。

High boiling-point solvents,o-sec-butyl phenol,was applied to recover dimethylformamide（DMF）from their aqueous solutions by liquid-liquid extraction.The feasibility and conditions of this technology were studied.For the wastewater with DMF mass concentration of 100 g/L,the partition coefficient of o-sec-butyl phenoll at 25 ℃ is 6.92,which is far greater than 0.91 of low point extractant chloroform.DMF extraction rate reaches 87.54% after the first stage extraction at phase ratio 1∶1（volume ratio）.DMF mass concentration in raffinate is decreased from 100 g/L to 2.44 g/L after the third stage extraction.Adding diluent to o-sec-butyl phenol can improve the rate of phase separation.