有机磷阻燃剂生产废水预处理工艺研究

采用液膜萃取—酸析沉降—络合萃取组合工艺对有机磷阻燃剂生产废水进行预处理.最佳工艺条件为:液膜萃取时,液膜油相(表面活性剂与煤油的混合液)与内水相(H2SO4溶液)的体积比2∶1、乳化液膜与废水的体积比1∶8、废水pH 13.0,硫酸体积分数10％、煤油中表面活性剂质量浓度30 g/L、液膜萃取时间 15 min;酸析沉降时,废水pH l.0,酸析沉降时间30 min;络合萃取时,络合萃取剂(烷基叔胺N235与煤油的混合液)中烷基叔胺N235体积分数30％,络合萃取剂与废水的体积比1∶4,废水pH l.0,络合萃取时间30 min.在此最佳处理条件下,废水COD总去除率可达93％,吡啶去除率达99.9％以上,总磷去除率可达97％,BOD5/COD提高至0.32,有利于后续生化处理.

Research on Pre-treatment Process for Wastewater from Organophosphorus Flame Retardant Production

Wastewater from organophosphorus flame retardant production was pre-treated by the combined process of liquid membrane extraction-acid precipitation-complexation extraction.The optimum process conditions are as follows:For liquid membrane extraction,volume ratio of oil phase(mixture of surfactant and kerosene)to internal phase(H2SO4 solution)2∶1,volume ratio of emulsion liquid membrane to wastewater 1∶8,wastewater pH 13.0,volume fraction of H2SO4 solution 10%,mass concentration of surfactant in kerosene 30 g/L,liquid membrane extraction time 15 min;For acid precipitation,wastewater pH 1.0,acid precipitation time 30 min;For complexation extraction,volume fraction of alkyl tertiary amine N235 in complexation extractant(mixture of alkyl tertiary amine N235 and kerosene) 30%,volume ratio of complexation extractant to wastewater 1∶4,wastewater pH 1.0,complexation extraction time 30 min.Under these conditions,the total COD removal rate can reach 93%,the pyridine removal rate can reach above 99.9%,the TP removal rate can reach 97%,and the BOD5 /COD value can increase to 0.32,which is of great advantage to the further bio-treatment.