Study On The Treatment Of Oily Sludge With Oily Degrading Strains

During oil exploitation and processing, a great quantity of oily sludge were produced. But the sludge was discharged into environment without any treatment. It was harm to the environment and humanity’s healthy. Now engineer and technicians are trying their bset to solute the problem.Oily sludge is a waste, it is also a usable resource. Microbiological remediation technology has been brought to treat the oil sludge. The degrading strains were screened from oily sludge and waste water, and a mixed strain was formed. Forther more, the physiology and biochemical property were studied, and the degrading ability were evaluated. Then the treatment processs was discussed, the detail results were showed below:(1)Ten strains were screened and separated out from oil sludge. The strains were inoculated in liquid medium with oil as the unique carbon source. After15days’training at36℃, the oil content of the medium was measured to evaluate the capacity of oil degradation. The degradation rate of different strains was different, it was from1.8to56.0%. Two strains named as YC-1and YC-3were obtained, their degradation rate were more than40%. Both strains are identified Bacillus sp.based on its morphological and physiolgical characteristics.(2) A mixd strain named as YC-13was constructed from YC-1and YC-3mixed with the same concentration. There is a co-coordinated response betreen strain YC-1and YC-3. Mixed strain YC-13has degradationg rate55.1%.The influence of operation parameters such as temperature, pH value and the salt concentration on the degradation effectiveness was studied: When the salt concentration is6%,the degradting rate of YC-1,YC-3and YC-13were52.1%,51.2%and58.5%; At30℃, the degradationg rate of YC-1,YC-3and YC-13were reach or near70%and at40℃,their were46.1%,32.8%and69.5%; pH value is6and7, the degradationg rate of YC-1and YC-3were69.1%and43.7%, pH value is from5to7, the degradationg rate of YC-13was from50%to70%. In all, the best suitable temperature of YC-1and YC-3is30℃while YC-13is40℃; pH value is from5to7and the salt concentration is6%. YC-13showes great stability against temperature, pH and mineralization.Therefore, it can be applied in much environment.(3)The oily sludge was treated with microbial composting, and the oil removal rate was used to evaluate the treat effect of different bacterias, inoculation amount, culture medium and composting time. The results showed that the oil removal rate of strain YC-1and YC-13in55days were44.15%and55.11%. The oil removal rate of strain YC-1using soil conditioner was43.38%, which was better than soil and buckwheat husk of22.95%. However, strain YC-3showed a different effect, the oil removal rate using soil and buckwheat husk was34.80%, which was higher than soil of24.90%.