| In this paper, we studied one individual plant azo dye degradation bacterium. The research content involved:selection and identification of the azo dye degradation bacterium; research on the azo dye degradation bacterium’s degrading bacteria degradation characteristics; With sodium alginate as the carrier of immobilized technology and its degradation characteristics research.In recent years, microbial degradation and decoloring have been studied more widely, and there are many reports about biodegradable dye microbial, the microorganisms including bacteria, fungi and algae. Based on the previous studies, we studied this kind of microbial further. Through the enrichment training, we isolated a kind of new strains Y3from a ditch,which is500metres away from a dye factory in Haicheng Liaoning. It can effectively degradation azo dyes. After screening, separation, physiological, biochemical, PCR amplification and16S rDNA appraisal,it was identified as Klebsiella bacteria genera (Klebsiella sp). We concluded that in anaerobic conditions, the strains can effectively degrade azo dyes.Through the degradation characteristics test, we analysised the strains degradation characteristics. Through the experiment, we discovered that it can effectively degradation methyl red under the conditions of pH range in4-9, the temperature of25℃-50℃,salt concentration1%-4%. When the concentration of methyl red is100mg/L-800mg/L, the strains of the degradation rate has remained at95%. When the concentration of Congo red is100mg/L-800mg/L, the strains of the degradation rate also maintain over85%. In10hours, the bacteria can degrade several dyes effectively,such as Congo red, Methyl red, Chromium black T, Orange I and methyl orange.The decomposition rate were90.5%,93.5%,37.6%,97.8%and10.2%. In45hours, the degradation rate of chromium black T is more than60%, the degradation rate of methyl orangemore is more than90%. This shows that the strains can effectively degradation azo dyes, and it is possible to use it in the actual application of the developmental.At the same time, we made a preliminary study about the immobilized azo dye degradation bacterium dual nitrogen removal performance of the dyes. The reason why we do the study is that how to effectively deal with azo dye wastewater has always been a difficult problem. In recent years, many scholars has studied new methods widely to degrade the azo dyes, but so few people research the immobilized microorganism cells methods to degradation azo dye. Our study results show that, compared with the free bacteria, immobilized bacteria has the following advantages:first, for most of the azo dyes, immobilized azo dyes degrading bacteria have the ability of continuous decoloring. Immobilized bacteria can effectively degradate continuous dosing azo dyes, and degradation rate remained stable. Its effect is better than the free bacteria’s.Second, immobilized azo dye degradation bacterium can resistant to the outer environment,such as high or low temperature and ph. At5-10℃, the degradation rate still can maintain at more than50%. Under the conditions of pH range in3-12,immobilized azo dye degradation bacterium can still degradate dual nitrogen dyes. Third, the immobilized azo dyes degradation bacterium has tolerance to salt concentrationto. When salinity is5%,the degradation rate can maintain around90%. When the salt concentration exceed6%, immobilized bacteria can still effectively degradate azo dye. Fourth, the immobilized azo dyes degradation bacterium also effectively degradate azo dye in high concentrationscan. When Congo red’s concentration reaches1000mg/L,the degradation rate remains above70%. The results showed that, immobilized means it can make the azo dyes degradation bacterium tolorate bad environment. And make it possible to ues it as the main azo dye degradation bacterium to manage industrial environment. |
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