Distribution Of Petroleum Hydrocarbons In Aquatic Environment And The Isolation And Degradation Characteristics Of Petroleum Degrading Bacteria From The Water-source Reaches Of Chaohu Lake

Based on the petroleum pollutants as the main subject of this research, focusing on the distributions of the petroleum hydrocarbons and tetraethyl lead in the water-source reaches in Chaohu Lake from January2010to March2011. On this background, isolating the petroleum-degrading bacteria and doing the laboratory pollution water and soil degradation simulating experiments, to provide the scientific basis data and support for the bioremediation technology of the petroleum contaminant area.Studies showed that the petroleum pollution in the east Chaohu Lake was serious from January2010to March2011, the mean content was between0.0338mg/L to2.5089mg/L, and in May2010the content reached the highest. The mean content of petroleum in Zhegao estuary was much higher than in the little Zhegao estuary and the Shuangqiao estuary. The mean content of tetraethyl lead was between0.00019mg/L and0.00185mg/L, beyond the pollution concentration range. From March to September in2010, the concentration was higher than other months. The mean content of tetraethyl lead in Zhegao estuary was much higher than in the little Zhegao estuary and the Shuangqiao estuary.We isolate the petroleum degrading bacteria M1, M5and M8from the petroleum contaminated soil and water from Chaohu Lake. By biochemical identification and identification of16S rDNA experiment, the three strains were identified Gram-negative, the stain Ml was identified as Pesudomonas sp. and M5was identified Pesudomonas aeruginosa and M8as serratia.By dynamics study and the study of temperature, initial pH value, content of NaCl, carbon and nitrogen sources and other single factor analysis, researching the impacts of the environmental conditions on the degrading bacteria. The results showed that strains Ml and M8grew and degraded petroleum well respectively under the conditions of35℃,1%concentration of NaCl and the ammonium sulfate nitrogen source. M1strain grew well in the initial pH7.0and dextrin as carbon source, however degrading the petroleum pollutions better in the initial pH8.0condition. M8strain grew well in the initial pH8.0and maltose as carbon source, however degrading the petroleum pollutions better in the initial pH7.0condition. Strain M5grew and degraded petroleum well respectively under the conditions of35℃,5%concentration of NaCl and the sodium nitrate nitrogen source. M5strain grew well in the initial pH8.0and fructose as carbon source, however degrading the petroleum pollutions better in the initial pH7.0condition.On screening for petroleum hydrocarbon strains of water pollution degradation simulation experiment, analyze the efficiency of the petroleum degrading bacteria on the polluted water. The M5group and the mixed group of the treatment without exogenous pollutants had the same degrading efficiency after30-day treatment and the degrading efficiency reached72%nearby. The treatment with2.5mL oil/L water had the highest degrading efficiency than other treatments. With the input of M5strain for thirty days, the oil pollutant in water removal rate reached89%. However the oil removal rate reached only56%after the30-day treatment with10.0mL oil/L water with input of mixed bacteria.On the observation of cyanobacteria color changes in the simulation experiment of petroleum hydrocarbon strains of polluted Chaohu algae water. There were no significant differences between the treatments of no bacteria group, M5group and the mixed group. In the sixth day of the treatment, the cyanobacteria in no bacteria group were still green but not as bright as original sample. Cyanobacteria in M5and the mixed group presented yellow. With the depth of treatment, cyanobacteria in the three treatment groups all turned deep yellow. Cyanobacteria turned into filamentous suspending in the water.In the simulation experiment of polluted Chaohu algae water, the algae water without exogenous petroleum pollutants had the removal of pollutants4%in contrast with24%removal rate in water group. M5and the mixed group had the same degradation trend and the petroleum removal rate reached75%after30days. The treatment with2.5mL oil/L water had the highest degrading efficiency than other treatments after30-day experiment. The algae water group had the highest removal rate nearly89%. The oil removal rate reached only48%after the30-day treatment with10.0mL oil/L water with input of mixed bacteria.On screening for petroleum hydrocarbon strains of soil pollution degradation simulation experiment, analyze the efficiency of the petroleum degrading bacteria on the polluted soil. The non sterilization soil group with M5reached the highest pollutants removal rate51%after the30-day treatment, and the mixed bacteria group reached43%. The sterilization soil group with mixed bacteria group reached the higher removal efficiency74%contrast with61%in the M5group.