黄铁矿烧渣催化H_2O_2氧化废水中难降解污染物

Fenton-like oxidation of refractory organic contaminants in wastewater using pyrite cinder at neutral pH

传统Fenton氧化是以Fe2+离子为催化剂进行催化H2O2氧化,以含铁矿物为催化剂的非均相类Fenton反应最近受到重视。以酸性红B染料、苯酚等污染物以及实际工业废水为处理对象,研究了黄铁矿烧渣为催化剂的非均相类Fenton反应。考察了催化剂、H2O2投加量、初始pH、反应时间、催化剂回收重复利用等因素的影响和优化。在烧渣投加量为10g.L-1,双氧水投加量为20ml.L-1,体系pH在1～11范围内,反应6h后,酸性红B染料、苯酚的去除率接近100%,工业废水处理后脱色效果明显,而且BOD5/COD比值能大幅提高。研究表明:黄铁矿烧渣对催化H2O2氧化具有很强的催化活性,是有效的类Fenton反应催化剂,而且相比于单一含铁矿物具有更好的催化性能,反应受pH影响很小,解决了传统Fenton反应需要调节pH的难题。催化剂易于沉淀分离,能回收重复利用。

Traditional Fenton oxidation process uses ferrous iron（Fe2＋）as catalyst.Fenton-like reactions using iron minerals as heterogeneous catalysts has caught attention recently.However,Fenton-like reaction using pyrite cinder as catalyst was not reported in early research.The catalytic activity of pyrite cinder for pollutants oxidation was evaluated by using Acid Red B,phenol and industrial wastewater as model organic contaminants.The effect of catalyst and H2O2 dosage,initial pH,reaction time,reusability of catalyst on the oxidation was investigated.When the concentration of pyrite cinder and H2O2 dosage were 10 g·L-1 and 20 ml·L-1respectively,the removal efficiencies of Acid Red B and phenol were almost 100% in a broad range of pH value from 1 to 11.Obvious decolorization of industrial wastewater was observed within 6 h,and the ratio of BOD5/COD increased greatly.The results indicated that unlike traditional Fenton reagent,the reaction of pyrite cinder with H2O2 could effectively catalyze the oxidation of organic contaminants at circumneutral pH.This process avoids the initial acidification.In addition,pyrite cinder exhibited higher activity than other pure iron oxide minerals.The catalyst could be easily recovered by sedimentation or filtration for further use.