中文摘要：

印染废水的脱色是重要的处理难题。以6种偶氮染料模拟废水和实际印染废水为目标污染物,研究了亚铁羟基化合物（ferrous hydroxy complex,FHC）还原预处理印染废水的效果和机理。通过亚铁结构形态、初始pH、FHC投加量、Fe/OH-摩尔比等因素对FHC还原转化染料的影响研究,综合评价了FHC对多种偶氮染料的反应性能。实验结果表明FHC具有较高的还原活性,投加89.6 mg.L-1的FHC,可以去除90%以上的偶氮染料。亚铁结构形态对还原脱色有很大影响,溶解态亚铁基本不能还原偶氮染料,结构态亚铁FHC和绿锈都具有较高的还原活性,而FHC的还原能力强于绿锈。亚铁与羟基摩尔比对FHC对染料脱色产生较大影响,而且FHC还原偶氮染料受pH的影响很大,但其适宜的pH范围较广,为4~10。FHC还原预处理实际印染废水表明,在亚铁投加量为120 mg.L-1时,脱色效果显著,废水的CODCr去除率可以达到49%,废水的可生化性明显提高,BOD5/CODCr从0.32提高到0.62。FHC同时具有较强的混凝吸附作用和还原作用,为印染废水脱色和提高可生化性提供了新的工艺技术。

英文摘要：

Decolorization of printing dyeing industry wastewater is a big challenge for wastewater treatment.In this study,ferrous hydroxy complex（FHC）was used to treat six types of simulation and industrial pollutant samples containing azo dye,and its reductive pretreatment mechanism and efficiency were studied.Influencing factors including morphology of ferrous iron,initial pH of wastewater,dosage of FHC,and molar ratio of Fe/OH-on the reductive transformation were also studied to examine FHC reactivity towards various azo dyes.The results show that the FHC is of higher reductive reactivity.More than 90% of azo dyes could be removed when the dosage of FHC was 89.6 mg·L-1.The structure morphology of FHC has great influence on its reductive decolorization.Although both FHC and green rust are of high reduction reactivity,dissolved ferrous iron can not practically react with azo dyes.These results indicated that the structure and morphology of ferrous iron play an important role in decolorization of azo dyes.The decolorization performance is much higher for FHC than that for green rust.The molar ratio of ferrous iron to hydroxyl in FHC can impact its reactivity.The pH value has great influence on reduction of azo dyes by FHC,however,there is 4—10 of pH wide range in which high efficiency of dyes removal can be reached.Experiments for treating textile industrial wastewater showed that the removal of CODCr was up to 49% and the BOD5/CODCr ratio increased from 0.32 to 0.62,as well as obvious decolorization was observed when dosage of ferrous iron was 120 mg·L-1,all these indicated that the biodegradability of wastewater was improved significantly.Owing to FHC strong coagulation and reduction ability,it should be of potential for decolorization and biodegradability of textile wastewater.