Screening High Effective Oil Degradation Strain And Application On Oily Wastewater Treatment

Oily wastewater is a kind of high concentration organic wastewater, in recent years,more and more oily wastewater were discharged, seriously affect the water source of people slives, pollution of the environment,and harmful people′s healthy. Therefore, treatment for oilywastewater has attracted widespread attention in recent year. In most cases, Physcial andchemical methods are widely used. However, these two methods always produce secondarypollution, and can t completely degrade the wastoil. On countary, biological method candigest the used grease effectively and safly. End-products are CO2,H2O and other metabolites,and withoutout any secondary pollution.In order to get the Oily wastewater and soil, the canteen sewer was collected in Lzjtucampus. The meterials were treated by enrichment, domestication and screening. The oildegradation rate of different strains was tested one by one. The optimal condition wasconferred by orthogonal test. Then the screened strains were encapsulated by PVA.All resultswere showed as follows:(1) Nine strains were separated by enrichment, domestication and effective screening,then five strains with higher degradation ability of oil are identified by ultravioletspectrophotometer, named Y-1,Y-5,C-1,C-3and C-4. According to the cell taxonomy,morphplogy, physiological, biochemical index, and molecular biology identification. Theresults show that, Y-1and Y-5blong to the Candida.berkhout, C-1,C-3and C-4blong to theBacillus.(2) Under the soybean salad oil as sole carbon source conditions, environmental factors(temperature, the initial determination of pH value, initial soybean oil concentration, saltconcentration) effect on bacterial growth. The results showed that: When under the conditionsof35℃, inoculation amount is5%, strains of Y-1,C-1and C-3best initial pH is6.5-5, Y-5and C-4best initial pH value is7, salt concentration in culture medium is1.2%, the initialconcentration of soybean oil for2g/L, all strains have the best degradative ability for culturing48h.The different degradative value are showed as follow: the cultivation of48h all the strainsfor the degradation of oil rate maximum, respectively is: Y-1(83.3%), Y-5(79.8%), C-1(86.6%), C-3(82.3%), C-4(80.1%).(3) In order to improve the degradative rate, multiple strains are always better than thesingle. Therefore, in the study show that: The best proportion of strain is Y-1: Y-5: C-1: C-3:C-4=3:3:5:2:4, with the orthogonal experiment method to determine the best proportion of thebacterial strain. Under the degraded condition, composite degradation of oil rate as high as96.3%. (4) The five strains screened were immobilized by microencapsulation, the optimumstrain embedding was determined as follow:①Y-1: embedding quantity is6%, theconcentration of PVA is4%, the cross-linking time is24h, microcapsule diameter is3.0mm.②Y-5: embedding quantity is2%, the concentration of PVA is5%, the cross-linking time is16h, microcapsule diameter is3mm.③C-1:embedding quantity is6%, the concentration ofPVA is5%, the cross-linking time is8h, microcapsule diameter is3mm.④C-3: embeddingquantity is6%, PVA the concentration of6%, the cross-linking time is16h, microcapsulediameter is2.5mm,⑤C-4: the embedding capacity is4%, PVA concentration is4%,crosslinking time is16h, microcapsule diameter is3.5mm.