Degradation Characteristics And Intermediateculture Of Efficient Decolorization Community

Dyes are widely used in textile printing and dyeing, paper printing, leathermanufacturing, etc. Containing dyes wastewater have became one of the mainsources of water pollutions. It not only affects the beauty of the water environment,but also endanger the survival of water organisms. Some dyes have been consideredbodycarcinogenic and mutagenic hazards. Therefore, containing dyes wastewatermust be properly handle.Decolorization strains were isolated from the laboratory acclimated sludge, andefficient decolorization communities were obtained by mixed. The degradationcharacteristics of efficient decolorization communities for malachite green andreactive red dye were studied. The possible decolorization and degradation pathwayof dyes by the efficient decolorization communities was investigated. The methodof high density cultureing efficient decolorization communities and expanddecolorization experiments was explored.Seven strains of better decolorization capability were isolated，and identified asBacillus sp., Klebsiella sp., Escherichia sp., Acinetobacte sp., Enterobactersp.and Yersinia sp.. Two efficient decolorization communities M-C and M-H wasobtained. The maximum concentration of malachite green and reactive red byefficient decolorization communities (M-C and M-H) were150mg/L and100mg/L,respectively. The suitable decolorization mediums were glucose1.0g/L, KH2PO42.65g/L and Na2HPO44.26g/L, and the optimal decolorization conditions weretemperature30℃~37℃, neutral or alkaline and anaerobic or Anoxic conditions.Six different single dyes could be decolorized by efficient decolorizationcommunities，and the decoloring rate of mixed dyes（malachite green and reactivered）was over90%.The decolorization process of malachite green dye by efficient decolorizationcommunity M-H was biodegradation，and could be divided into four stages: notdecolorization stage, bleaching stage, biodegradation stage and completiondegradation stage. the possible degradation pathway was that the malachite greenwas hydroxylated to malachite green carbinol at first, and then decomposed intodi-benzyl methane and N,N-dimethylaniline through stepwise demethylation processes, and further degradation at last.Dyes could be directly decolorized by decolorization community that had beenhigh-density cultured, and decoloring rates of malachite green and reactive redwere96.07%and85.95%, respectively. The high-density culturing communitycould repeatedly decolorized dyes, and could keep decoloring characteristics. Theremoval rates of COD and chroma to60mg/L active red dye wastewater were about75%and90%in a reactor, respectively.The dye decoloring microbial resources have been riched by this study, and thestudy provide theory basis for dye wastewater biological decoloring. At the sametime, it has important theoretical significance and practical significance forimproving dye wastewater biochemical system efficiency and saving cost, etc.