Microbial remediation and optimization of oil polluted wetlands at Dalian Bay in China.
OBJECTIVE
The wetland at Dalian Bay in the Northeast of China has been polluted by oil severely. The effect of various microbes and operation parameters on the bioremediation of oil-polluted wetlands at Dalian Bay was investigated and reported previously. In the study, other operation conditions related to the status of medium were investigated via statistical experimental design and analysis and a necessary information is involved to use micro-technology in the application.


METHODS
The method used involved the direct inoculation of selected bacteria, which were capable of degrading oil. The operation conditions were further optimized and evaluated by gravimetrical assay.


RESULTS
The optimal pH and temperature for the studied bacteria to degrade the existing oil pollutants were established as pH 8.0 and 27 degrees C. The mixed of various bacteria showed better results in terms of oil degradation than any single one. Among the selected four factors, disturbance, oxidant, nutrients, and biosurfactant, the former two contributed more impacts on the oil degradation in the early stage of process, while the latter two became the limiting factors in the late stage. Three sets of optimal conditions were obtained for each individual stage, but no one was suitable for the overall process.


CONCLUSIONS
The study demonstrated the technical feasibility of using direct inoculation into the contaminated soil samples to remove oil pollutants. It suggested that the operation conditions should be monitored and adjusted during the different stages of bio-reactions in the process to achieve the best result of oil degradation.
Huang
Lei-Chang
LC
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
Ye
Shu-Hong
SH
Zhang
Yu
Y
Li
Yao Olive
YO
Wang
Xiang-Rong
XR
Ding
Dewen
D
D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002681:China; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010578:Petroleum / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000737:chemistry* / Q000378:metabolism*; D013696:Temperature
D010578:Petroleum; D012987:Soil; D012989:Soil Pollutants