有机磷阻燃剂生产废水预处理工艺研究

摘要

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 compiexation extraction, volume fraction of alky] 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.%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.