高浓度酚醛树脂生产废水的预处理

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。

Pretreatment of High-concentration Wastewater in Phenolic Resin Production

High-concentration wastewater in phenolic resin production was pretreated by the double-condensation 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.