Screening Of Phosphorus Microorganisms And Optimum Immobilization Technology

The high-efficiency phosphorus removing bacteria,S21,which is obtained from natural lake water,is used as research materials.The fermentation medium formula and fermentation conditions of strain S21 were studied by single factor test.Mean while through orthogonal test we further optimized the detailed fermentation conditions of S21.Under the optimum medium conditions,the growth curve of strain S21 was determined every two hours by turbid metric method.The mixed carrier of polyvinyl alcohol(PVA)and sodium alginate(SA)has the characteristics of high strength,high permeability,good biocompatibility and strong stability.In order to determine the optimal combination ratio of polyvinyl alcohol(PVA)and sodium alginate(SA),polyvinyl alcohol(PVA)and alginate(SA)were used.Sodium(SA)was mixed in different proportions to form immobilized microorganism pellets,and their physical properties and phosphorus reduction ability were explored.Simulated experiments on phosphorus reduction of wastewater after immobilization of microorganisms were carried out.The results are as follows:1.21 strains of high-efficiency phosphorus-removing bacteria were obtained from natural lake water and were applied to the re-screening of phosphorus-rich wastewater.The results showed that strain S3,S9,S 19 and S21 had a better effect on phosphorus reduction,and that the strain S 3,S 9,S 19 and S 21 were more effective.Strain S21 had the most stable effect of phosphorus reduction.The strain S21 was identified as Bacillus licheniformis.By means of morphological characteristics,routine physiological and biochemical characteristics and sequence analysis of 16 SRNA gene.2.The results of single factor test and orthogonal test showed that the optimum medium ratio was 0.5% sucrose,0.7% soybean cake powder,0.2% KCl and pH 7.The results of symbiosis test showed that the strain could promote the growth of aquatic algae to a certain extent.3.It can be seen from the results of the growth curve that the colony growth reaches a stable stage at 18 h,which is the best time to harvest bacteria or primary metabolites in industry.4.The results of immobilization showed that when 10% polyvinyl alcohol and 0.5% sodium alginate were used to immobilize phosphorus removing bacteria,the mixed colloid had the best effect on pelletizing,mechanical strength,transmissibility and phosphorus reduction.The dephosphorization resin,new phosphorus removing material and active carbon have certain phosphorus removing ability.When they are used as part of immobilized pellets,the results show that when activated carbon is added to the immobilized pellets,the new-type phosphorus-removing materials,respectively,can be used as phosphorus-removing materials.The mechanical strength,mass transfer performance and phosphorus reduction efficiency of immobilized beads were increased when phosphorus removal resin was used,and the effect of phosphorus removal was the best when 10%PVA 0.5%SA 0.5% phosphorus removal resin was combined with phosphorus removing microorganism.After 72 hours,the phosphorus removal rate reached more than 75.00%.5.The simulated experiment results showed that the phosphorus removal rate was over 70.00% after 60 h.When pH was 7,temperature was 25 ?,rotational speed was 160 r / min and the effect of immobilization was the best.