高浓度酚醛树脂生产废水的预处理

Pretreatment of High-concentration Wastewater in Phenolic Resin Production

采用二次缩合反应预处理高浓度酚醛树脂生产废水。一次反应的最佳工艺条件为:甲醛加入量0.010 0 mL/mL,Ba(OH)2加入量0.005 g/mL,反应时间3 h,反应温度85℃。最佳工艺条件下的一次反应COD去除率为52.9%。二次反应中,当反应温度为80℃、反应时间为3 h、尿素加入量为3 g/L时,二次反应COD去除率最高,为31.5%。COD=85 000 mg/L、ρ(挥发酚)=12 000 mg/L、ρ(甲醛)=6 740 mg/L的废水经两次缩合反应处理后,出水中COD=27 400 mg/L,COD的总去除率为67.8%;ρ(挥发酚)=2 400 mg/L,挥发酚的总去除率达80.0%;ρ(甲醛)=980 mg/L,甲醛的总去除率达84.9%。处理1 t废水还可回收酚醛树脂6.75 kg。

High-concentration wastewater in phenolic resin production was pretreated by the doublecondensation reaction process. Under the optimum conditions for first condensation reaction of formaldehyde dosage 0.010 0 mL/mL,Ba（OH）2 dosage 0.005 g/mL,reaction time 3 h and reaction temperature 85 ℃,the COD removal rate of first condensation reaction is 52.9%. Under the optimum conditions for secondary condensation reaction of reaction temperature 80 ℃,reaction time 3 h and urea dosage 3 g/L,the COD removal rate of secondary condensation reaction is 31.5%. After the wastewater with 85 000 mg/L of COD,12 000 mg/L of ρ（volatile phenol）,6 740 mg/L of ρ（formaldehyde） was treated by the double-condensation reaction process,the effluent COD is 27 400 mg/L with 67.8% of total COD removal rate,ρ（volatile phenol） is 2 400 mg/L with 80.0% of total volatile phenol removal rate,ρ（formaldehyde） is 980 mg/L with 84.9% of total formaldehyde removal rate. 6.75 kg phenolic resin can be recovered from 1 t wastewater.