多羟基亚铁络合物还原转化活性黑5的实验

Reductive Transformation of Reactive Black 5 by Ferrous Hydroxy Complex

摘要:

通过调控反应条件,制备了高活性的亚铁羟基络合物(FHC),以活性黑5(RB5)为目标污染物研究了FHC还原转化偶氮染料的反应性能.探讨了FHC对RB5还原脱色的影响因素,包括亚铁结构形态、FHC的投加量、初始pH值、溶解氧等,结果表明结构态亚铁具有很强还原反应活性,亚铁投加量89.6 mg?L-1,染料初始质量浓度为100 mg?L-1,反应10 min后RB5去除率达80%以上.pH对亚铁的还原性能产生重要影响,最适宜的pH值范围为8～10.实验证明,FHC的还原作用是导致染料脱色的最主要机理,并非是传统的混凝沉淀作用,染料结构中的显色基团偶氮键还原转化为胺基,苯胺类化合物是主要还原产物,该研究对于亚铁促进染料脱色,提高废水生化性能提供了新的机理解释,为该技术工艺的发展提供了理论基础.

Abstract:

In this study,high activity ferrous hydroxy complex (FHC) was prepared by controlling the special reaction conditions,and reductive transformation of azo dyes was investigated by employing reactive black 5 as model pollutant.The influencing factors of reduction decolorization of reactive black (RB5) by FHC,including ferrous morphology,dosage of FHC,pH,dissolved oxygen and so on were studied.The results show that the structural state of ferrous iron has a strong reductive activity,when the dosage of ferrous iron is 89.6 mg?L-1 and initial concentration of dye is 100 mg?L-1 ,80% of RB5 disappears within 10 min; pH has an important effect on the reduction of ferrous iron with optimum pH value range of 8 to 10.The experiment studies demonstrate that reductive reaction with FHC is the most important mechanism resulting in decolorization of azo dye,rather than traditional coagulation.The chromogenic groups of azo in the dye structure become the amino groups,so the aniline compounds are the main final products.The research suggests a new mechanism on the promotion of dye decolorization by ferrous iron,improving biodegradability of wastewater,which lays a theoretical basis for the technology development