螯合沉淀组合高级氧化降解鞣酸铅废水研究

Combination of Chelate Precipitation and Advanced Oxidation for Treating Tannic Acid Lead Wastewater

针对鞣酸铅废水的酸性大、可生化降解性低、组分复杂的现状,采用螯合物理沉淀法和高级氧化法组合工艺处理该废水.系统地研究了螯合沉淀过程pH值,Fenton氧化过程pH、n(H2O2):n(Fe2+)比、H2O2投加量以及超声强化等因素对CODCr去除率的影响.结果表明:螯合沉淀过程去除了95.1%的铅离子和50.1%的CODCr;Fenton氧化过程CODCr去除率为82.6%,最佳操作条件为pH值为3,n(H2O2):n(Fe2+)比为12,H2O2投加量3 mL/L.超声波可以强化Fenton氧化效果,使废水中残留CODCr值降到57mg/L,并探讨了超声波强化Fenton降解鞣酸的可能途径.

The tannic acid lead wastewater were acidic,low biochemical degradation and complex compo-nents.Based on the existing circumstance,the combined process,chelate physical precipitation and ad-vanced oxidation,were used for treating tannic acid wastewater.The effect of pH was studied in chelate precipitation process.The effects of pH,n（H2O2）：n（Fe^2＋）ratio,H2O2 dosage and ultrasonic enhance-ment on the CODCr removal were systematically investigated in the Fenton reaction proess.The results show that 95.1% lead ion and 50.1% CODCr can be removed in chelation precipitation process.The CODCr removal rate is 82.6% in the Fenton reaction process.The optimum reaction conditions are that the pH value is 3,n（H2O2）：n（Fe^2＋ ）ratio is 12 and H 2O2 dosage is 3 mL/L.Ultrasound can enhance the the effect of Fenton oxidation and make CODCr drop to 57 mg/L in wastewater.The possible degra-dation pathway of tannic acid by ultrasonic enhancement Fenton was discussed.