碱减量废水对苯二甲酸回收工艺的影响因素

针对酸析法回收对苯二甲酸(TA)中存在沉淀分离较困难、脱水性能差的问题,对碱减量废水中TA回收工艺影响因素进行了分析探讨,获得的优化回收工艺参数是:酸析pH值3.5～4.0;滴定过程中搅拌速度300 r/min,时间1～2 min;凝过程中搅拌速度60～100 r/min,时间5～10 min;沉降时间10～12 h。在该工艺条件下,粗TA酸析回收率为77%,酸析TA絮体平均粒径11.56μm,碱减量工艺废水COD_(Cr)去除率50.5%。

Factors affecting recovery of terephthalic acid from alkali-peeling wastewater

Parameters affecting recovering of terephthalic acid(TA) from alkali-peeling process wastewater by acidificationsedimentation were studied. The optimal parameters were as follows, pH value 3.5～4.0, stirring 1 ～ 2 minutes at the rate of 300 r/min during acidification, stirring 5 ～ 10 minutes at the rate of 60 ～ 100 r/min during flocculation, sedimentation time 10 ～ 12 h. The recovery rate of TA preform was 77% and the mean particle size of TA floccules was 11.56 μm. Additionally, the removal rate of CODe was 50.5 %.