The Screening And Studying Removal Of Nitrogenous Pollutants Of Denitrifying Bacteria From The Sea

NH4+-N and NO2--N are two kinds of main pollutants that containing nitrogen in breedmarine lives. It has a negative impact on the water quality and has strong toxicity to aquaticanimal，even cause animal death and cause huge loss. Therefore, how to effectively removenitrogen pollutants, especially reducing ammonia nitrogen and nitrite nitrogen, is one of thekey problems faced in aquaculture.Biological nitrogen removal has been paid wide attentionin a variety of method of denitrification, which has the advantages of low cost, low sideeffect, many advantages of aquaculture animal harmless.Heterotrophic denitrifying bacteria has advantages of fast growth, low dissolved oxygenconcentrations, can endure acid environment, low cost and heterotrophic microorganisms bothnitrification and denitrification ability.Therefore, an important role in biological nitrogenremoval process is more and more widely recognized, has a broad application prospect inaquaculture.In this paper, taking the sea of Changli, to obtain good denitrification effect ofmicroorganisms by screening culture medium, the growth of the microorganism underdifferent conditions, the biological nitrogen removal ability and solid-state fermentationcondition optimization, fermentation products obtained were plant breeding experiment.Theresults are as follows:1Obtained a strain of denitrifying bacteria by screening, and further study of the initial pHvalue, temperature, C/N effect on the bacterial growth.The microbial growth conditions were:pH7.5, temperature35℃, C/N7:1, properly dissolved oxygen conditions.2Preliminary study on the microbial degradation of nitrite, ammonia nitrogen condition, theoptimum pH value about7.5, in the range of25~40℃have good degradation effect, at atemperature of30~35℃within the degradation rate of nitrite reached more than94%, theammonia nitrogen degradation rate of more than78%. The bacteria for C/N7:1.3Through orthogonal test, single factor test and key factors on species, culture medium,inoculation ratio, water content of culture medium, fermentation temperature, fermentationtime and other factors of a series of screening,the best fermentation conditions: corn flour andwheat bran4:6,5:5,6:4, inoculum10%, fermentation time5d, moisture content of60%,fermentation temperature35℃. 4On the solid state fermentation denitrifying bacteria can significantly reduce the breedingpool of ammonium nitrogen and nitrite nitrogen, adding amount of0.5kg/mus of surface.