Screening The High-Efficiency Flocculation Bacteria In Swine Wastewater And Its Practical Effect Experiment

With the development of economic and society,the livestock and poultry industry is also developing rapidly.The waste of livestock also become a serious issue to the environment.In the treatment of livestock wastewater,flocculants have always played an important role.As a substitute for traditional flocculants,bioflocculants have unparalleled advantages over other kinds of flocculants.In view of the increasing use of flocculants in the treatment of pig farm wastewater,and the development direction of biological flocculants as the future flocculants Therefore,this laboratory hopes to screen the pig farm wastewater for effective bioflocculants in order to obtain a biological flocculant suitable for treating farm wastewater.This study mainly obtained the following results:(1)Two high-efficiency flocculation strains A1 and A3 were screened.After biochemical identification and 16 sr DNA identification comparison,A1 was identified as Raoultella sp.and A3 was Pseudomonas sp.It was named Raoultella sp.A1 and Pseudomonas sp.A3.(2)The single-factor experiment method was used to analyze the optimal fermentation carbon source of Raoultella sp.A1 was glucose,the optimal nitrogen source was urea,the optimal culture temperature was 25-30?,the initial p H of the culture medium was controlled between 6-7 and 5g./L kaolin test,the optimal flocculation conditions are p H=8,flocculant added 2%(v/v),coagulant added 2.5%(v/v);Pseudomonas sp.A3 optimal fermentation carbon source is Glucose,the best nitrogen source is urea,the best culture temperature is 30 ?,the initial p H of the medium is 7,in the 5g/L kaolin test,the best flocculation conditions are p H=8,flocculant added 3%(v/ v).Add coagulant 2.5%(v/v).(3)The flocculent active substances of the two strains are both exuded into the fermentation broth rather than the bacteria itself.the flocculated active material has good thermal stability and can resist the conditions of 121? and 20 min,while the flocculating activity is hardly affected.(4)The pig farm wastewater test proves that the modified biological flocculant has a good removal effect on COD and total phosphorus in the farm wastewater,but the treatment effect is slightly insufficient for ammonia nitrogen.(5)The combination test shows that the strain is more suitable as a seed strain fermented by the bioflocculant rather than an improved strain of activated sludge.Any change in the proportion of its presence in the flora may lead to the competitive inhibition of the flora and thus reduce the pollution of the flora to pollutants Processing effect.This study screened Two high-efficiency flocculation strains A1 and A3,and through practical verification,it was confirmed that it can get better treatment effects on COD and total phosphorus in the pig farm wastewater.This research expands the resource base of strains produced by bioflocculants,and accumulates the foundation for the subsequent research work of bioflocculant fermentation production.