Efficient Breeding Of Microbial Flocculant And Its Application

Sewage water quality degradation of the increasingly complex and more difficult to substances in the emergence of the traditional water treatment agent has been difficult to meet the requirements of modern sewage treatment. Flocculant in sewage treatment in the application of the relationship juice at home and abroad,mainly in the flocculating activity of microbial screening work. Flocculant for sewage treatment in the processing cost is relatively high,resulting flocculant is difficult to achieve a wide range of industrial applications,reduce their costs of dealing with less.This article as a starting point, the sewage treatment plant by activated sludge separation,selection of efficient strains of microbial flocculant activity,and reduce the production cost of microbial flocculants experimental study carried out.From Shenyang City,north of activated sludge sewage treatment plant separated by 96 breeding microorganisms,which has the flocculating activity of a 30 micro-organisms,Then by expanding cultivation methods kaolin flocculation test,get the best flocculating activity of a strain JB-5,Obtained by UV mutagenesis of strain JB-5 mutant strain JB-5B,it's in the flocculation of kaolin suspension to reach the highest rate of 95.7%. By Gram staining,electron microscopy,and their physiological and biochemical characteristics,derived strains JB-5B JB-5B for the Gram-negative bacteria,both for short rod,oxidase test was negative,starch hydrolysis into the negative,that starch hydrolysis is not strong;Methyl red test positive staining, indicating that glucose fermentation capacity of strong acid. Flocculant for by anthrone test , biuret test and ninhydrin test shows that the resulting strains contain polysaccharide and protein flocculant macromolecules.Flocculation to Kaolin suspension as the object , JB-5B producing flocculant for optimization of culture conditions, strain JB-5B of the best conditions for flocculant production:glucose 40 g/L,KNO₃ 1g/L,K₂HPO₄ 5g/L,KH₂PO₄ 2g/L,MgSO₄ 0.1g/L,NaCl 0.1g/L,carbon/nitrogen ratio of 50,carbon concentration of 45g/L, initial pH 8.0,culture temperature 30℃,vaccination volume of 3mL,160r/min shaking culture 30h. Under these conditions,the highest flocculating rate of up to 95.7%.The application of the above test conditions for flocculant,carrier Kaolin suspension of the effects of flocculation, pH values were discussed,Ca2 solution dosage,the amount of bacterial suspension dosage effect on the flocculation,and the orthogonal test. Strain derived from the fermentation broth of 4g/L of kaolin suspension was the best flocculation conditions: pH value of 8,add 1%Ca²⁺ solution dosage of 3.5mL,the amount of dosage of bacilli 3mL,in the conditions Kaolin suspension under its flocculation rate of 95.7%. And obtained the factors on the flocculation strain JB-5B production capacity in decreasing order:pH value>CaCl₂ solution was added to the amount of>JB-5B dosage of bacilli. In addition,the experiment investigated the microbial flocculant effect on sewage treatment,the use of JB-5B producing flocculant treatment of domestic sewage,the best treatment conditions in the JB-5B strain flocculant flocculation of sewage have significant effect. Among them,the flocculant on color,turbidity,SS The effect is very obvious that the best amount of broth added, the removal rate reached 86.8%,85.8% and 88.5%. Of COD and BOD also have some effect,in the best amount of broth added,the removal efficiency reached 51.6% and 52.4%.