Study On Screening Of Highly Degradation Bacteria With High Efficiency And The Degradation Characteristics About 17?-ethynylestradiol And Norfloxacin

In recent years, environmental pollution has abstracted more and more attention. Especially, water pollution generated by 17a-ethynylestradiol and norfloxacin is increasing year by year. Although many scientists have performed hard work on the degradation of pollutants by physical or chemical methods,17a-ethynylestradiol and norfloxacin could not completely removed. In this work, two strains with the capacity of degrading 17a-ethynylestradiol and norfloxacin respectively were isolated from activated sludge wastewater from a factory in shandong. In addition, the degradation characteristics of these two strains were also explored.For strain QL212, the following parameters were mainly explored:(1) By high performance liquid chromatography and ultraviolet spectrophotometric method, the degradation characteristics of ethinylestradiol of QL212 was demonstrated. Through 16S rDNA sequencing, QL212 was identified as Pseudomonas genus, and renamed as Pseudomonas sp. QL212.(2) The impact of various environmental factors on the growth of QL212 and the ethinylestradiol degradation characteristics were investigated, and the optimal culture conditions were:temperature of 30?, medium initial pH of 7, fermentation period for 7 days,20% inoculated quantity, speed of table is 150 r/min. At the optimal culture conditions, 80.3%of 17a-ethynylestradiol was consumed after 168 h when 30 mg/L was supplemented at the initial of incubation; when the initial concentration of 17a-ethynylestradiol increased to 100 mg/L, only 47.2% of 17?-ethynylestradiol was degraded after 168 h incubation.(3) The growth trend of QL212 with different initial concentrations of 17a-ethynylestradiol was demonstrated and the kinetic model for bacterial growth was established using the Logistic equation. The maximum growth rate of QL212 was 0.011/h, R2 were above 0.9, and the kinetic equation for the growth rate of strain QL212 was: Y=0.0192Ln (x)-0.0358.For strain QL, the following strategies were carried out to determine the degradation efficiency:(1) By ultraviolet spectrophotometric method, the degradation characteristics of norfloxacin was explored. After 16S rDNA sequencing, QL was identified as Microbacterium genus and renamed Microbacterium sp. QL.(2) The impact of various environmental factors on the growth of QL and the norfloxacin degradation characteristics were investigated. The optimal culture conditions were: temperature of 30?, medium initial pH of 7, fermentation period for 9 days,20% inoculated quantity, speed of table is 150 r/min. At the optimal culture conditions,45.6% of norfloxacin was consumed after 216 h when 100 mg/L was supplemented at the initial of incubation.(3) In order to know the effect of the concentration of norfloxacin on the QL about growth and degradation, under different initial concentration of norfloxacin QL growth trends were detected, and bacterial growth kinetics model constructed using a logistic equation. The maximum growth rate of QL was 0.078/h, R2 are above 0.9, and the kinetic equation for the growth rate of strain (QL212) was Y=0.0171Ln(x)-0.0287.Overall, in this study, QL212 and QL with degration capacity of ethinylestradiol and norfloxacin respectively were isolated. Through the optimization of culture conditions, the degradation effect was further improved, and the growth and degradation kinetics were also explored. The results of this research could be application in urban sewage or pharmaceutical wastewater treatment to removing estradiol or norfloxacin by activated sludge, To minimize the amount of them into the environment, reducing the degree of environmental pollution and the harm to human.