| Oily sludge (sludge for short) is oily solid waste generated in oil exploration, transportation, refining and oily wastewater treatment process. The sludge contains saturated hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) etc. Improper disposal of sludge will absolutely lead to the accumulation of these pollutants in the soil, causing changes of soil structure and nature, and changes in microbial communities, decreasing the activity of the destruction of vegetation and ecological variation, threatening the safety of agricultural production. Especially the PAHs not only affect the normal function of the soil, reduce the environmental quality of the soil, but also threaten human health through the food chain to humans. Therefore, sludge is included in the national list of hazardous waste, and its emissions are strictly limited. For the sludge contaminated soil, this study focus on bioremediation technology, in order to provide strong technical support for remediation of sludge contamination soil.The main results were summarized as follows:For the16kinds of PAHs controlled by U.S. Environmental Protection Agency, this paper compared the two methods of HPLC and GC-MS, the result shows:the GC-MS method is more appropriate, A method(GC-MS-SIM) of determining16polycyclic aromatic hydrocarbons (PAHs) in oily sludge contaminated soil samples and other complex matrices using gas chromatograph-mass spectrometry was developed. In order to meet the requirements of laboratory analysis, elimination of background interference and improvement of the reliability of the data, detailed sample preparation and instrumental analysis have been examined, together with quality assurance and quality control (QA/QC) of the method. Results indicated good correlation coefficient and low method of detection limits (MDLs) with recovery rates and relative standard deviation. These suggested this method highly applicable in analyzing soil samples contaminated by PAHs.As sample preparation techniques, solid phase extraction have been more widely used in the laboratory. This laboratory has now completed the production of semi-volatile organic compounds auto-purification equipment.For this equipment, this paper carried out the optimization of the parameters, determined the performance of the instrument, and summarized the advantages and disadvantages and prepared instructions for use finally, to prepare putting this instrument into use for large-scale production.A pot experiment was conducted to investigate the effect of bioremediation for plant, this study used the high tolerance of tall fescue, for microorganism, plant growth promoting bacteria D5A and surfactant producing bacteria screened by this lab were collected. The results indicate: significant promoting effect of S-B and D5A addition on oil and total PAHs dissipation from soils was observed. The removal rates of oil are84.6%and73.2%respectively. Plus, the removal rates of total PAHs are60.0%and57.3%, By a significant analysis, the above mentioned removal rates were significantly higher than that of plants inoculated control treatment and separate planting plants processed. And then the biomass of bacteria processed and separate plants were also measured, relations of the different treatments were: tall fescue+SB> tall fescue+D5A> tall fescue.Because of the significant promoting effect of S-B and D5A, some biotechnologies such as microbial culture, solo carbon utilization tests (Biolog), luminous bacteria bio-toxic method and PCR-DGGE were applied to study the changes in microbial ecology of oily sludge contaminated soil. The results showed that the numbers of cultivable bacteria had significant different between the S-B, D5A treatments and the control treatment. Community level physiological profile through Biolog sole carbon source utilization tests were used to investigate the effect of S-B and D5A on the soil microbial diversity. The diversity index such as McIntosh index Gini index and McIntosh evenness increased in the S-B and D5A treatment. The above results indicated that the S-B and D5A treatments increased the microbial diversity of the soil. Besides, the acute bio-toxicity test by luminous bacteria method showed that the relationship of different treatments of the DCM/DMSO extract from the soil were:tall fescue+SB<tall fescue+D5A<tall fescue<CK. Plus, PCR-DGGE results showed that:the bacteria (D5A, S-B) enhanced treatments changed the community structure of the dominant bacteria in the soil and enhanced the bacterial diversity. |
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