Characterizistics And Application Of An Oil-degrading Rhodococcus Rubber For Oily Wastewater Treatment

A strong adaptability and high efficient degradation crude oil strain JC-106 was isolated from the oil-contaminated soil sample, by using rising oil concentration gradient method. The strain JC-106 was preliminarily identified as Rhodococcus rubber by morphological, physiological biochemical characteristics and 16 S rDNA sequence analysis.The cultural conditions of temperature, initial pH and NaCl concentration for strain JC-106 were studied with single factor experiment. The strain JC-106 grew well under the conditions of the temperature ranging from 15℃ to 40℃, the initial pH ranging from 6.0 to 8.0 and the NaCl concentration ranging from 0% to 4%. The optimum temperature, initial pH and NaCl concentration for strain JC-106 respectively were 35℃, 8.0, 1%. According to the experimental design principle of Box-Benhnken center combination and combining with single factor experimental results, the growth conditions for strain were carried out with orthogonal experiment. When analyzed with variance and response surface, the optimal growth conditions for strain JC-106: temperature, initial pH and NaCl concentration were 39.855, 7.979, 1.237% respectively and the response value(OD600nm) was 0.211. The OD600 nm was 0.213, by verifying experiment, which proved the authenticity of experiment.The degradation rate of crude oil was determined by using weight method. When the strain JC-106 was cultured at 35℃ and 15℃ for 15 days, the degradation rates of oil crude were respectively 58.18% and 41.61%. The degradation rates of alkane components in crude oil were determined by using GC-MS. When the strain JC-106 was cultured for 15 days, the degradation rates of alkanes, phytane and Pristane respectively were 98.16%, 54.60%, 85.46% at 35℃ and 96.13%, 48.61%, 86.83% at 15℃. The strain JC-106 grew well in broth containing different organic substrates as sole carbon source, such as dodecane, tetracosane, n-octane, catechol, anthracene and naphthalene.The treatment effect of activated sludge and strain JC-106 in the oily wastewater of high concentration was studied by using the batch activated sludge method, which the activated sludge treatment equipment of SBR was designed independently. The average removal rates of COD, NH4+-N, TP were respectively measured to be 96.49 %、96.88 % and 99.15 %. The oil removal rate was measured to be as high as 92.43 % in the experimental group containing the oil-degrading bacterium JC-106,only a low oil removal rate of 53.80 % was found in the control group.