Isolation Of Swine Wastewater Decolorizing Strains And Study On Decolorization Mechanism

In this paper,through screene the highefficient decolorizing bacteria,for solve the problems caused by the color of swine wastewater,and study the decolorization mechanism,aimed to provide the basis for the application of mixed bacterial flora in the treatment of swine wastewater.First,screening and cultivating the decolorize strain and measuring the decolorization ability.Thenoptimizing the condition of bacteria decolorization of swine wastewater,and in the optimal decolorization conditions,using UV Vis spectroscopy,adsorption test,decolorization enzyme activity determination,FTIR,XPS,fluorescence quantitative analysis,preliminary exploration of pig farms water color formation regular,analysis of the decolorization mechanism.The main results are as followed:(1)From swine wastewater,dye wastewater and pond water sieve four strains,and were identified as Enterococcus faecalis,Lactococcus garvieae,Meyerozyma guilliermondii,Asticcacaulis sp..At the same time,four strains of bacteria were mixed to form a highly efficient decolorization bacteria group,the decolorization rate as high as 43.39 ±1.46%.(2)In this study,the decolorization conditions of swine wastewater were optimized.The results show that the bacteria in the p H was 6,37?,aerobic,10% inoculation conditions,glucose as the carbon source and sodium nitrate as thenitrogen source.Under this condition,reached the maximum decolorization rate in the fourth day,was 70.03±0.05%,andfound that the decolorization rate increased with the amount of bacteria in the optimization process,at the same time can degrade the COD andincrease the phosphorus removal rate in wastewater,but no effect on ammonia nitrogen degradation.(3)A preliminary study on the mechanism of decolorization of swine wastewater by bacteria: after the UV visible spectrum scanning,it was found that the decolorization of swine wastewater by microbial community by the biological adsorption and biodegradation,but mainly by biodegradation;The decolorization rate of inactivated bacteria was increased with the extension of time,and the highest was reached at 25.33±1.42%in fourth days;The processof degradation were secretethree main decolorization enzyme activity,such aslaccase(Lac),manganese peroxidase(MnP),does not depend on manganese peroxidase(MIP),the enzyme activity of manganese peroxidase was highest,and in fourth days can be as high as 99±5.57U/L,and laccase activity was the lowest,15.67±2.08 U /L.The swine wastewater decolorization were measured by Fourier transform infrared spectroscopy,the analysis found that carbonyl in wastewater disappeared,and through the XPS verification of the oxygen content of the oxygen in the form of the formation of carbonyl oxygen and carboxyl oxygen disappear,most of the conversion of carbon oxygen single oxygen.This shows that the carbonyl is the main chromophores of swine wastewater,the auxochromic group may as hydroxyl,amino and carbon oxygen bond,and the existence of carbon oxygen bond of oxygen and carbon carbon double bond formation of ?electron conjugated system,which can't further remove the color of swine wastewater.By quantitative analysis,Lactococcus garvieaeplays a major role in the decolorization process.In summary,the flora of swine wastewater has good decolorizing effect,under the optimized decolorization conditions,found on the decolorizing bacteria group of swine wastewater by biological degradation,and the main chromophores secretion in swine wastewater decolorization enzyme degradation of carbonyl.The results provide a reference for solving the problem of decolorization of swine wastewater by using mixed bacteria.