| In this dissertation, taking Atrazine as a model pollutant, its analytical method, degrading-bacteria enrichment and isolation, characterization of its biodegradation and bioremediation of Atrazine contaminated water and soil by isolates were studied systematically. The main items as following:1.Author introduced the use situation, pollution, mobility in environment, degradation and metabolism, ecological toxicological characteristics and pollutant management of Atrazine, which has been applied extensively in the world and recently in China, and present the issues that would be investigated.2.The extraction and analysis method of Atrazine in liquid media were set up. The residual Atrazine in culture media was extracted with an equal volume of trichloromethane, and then determined by GC-14C with FID(Fire Ion Detector ) . GC-FID is simple sensitive methods for Atrazine with detection limit of 1.948xlO'10g and recovery of 96.06 ?1.70% ~ 105.75 ?2.45% under different added concentration: 1.04, 5.21, 10.41, 52.10 and 104.1 mg i/1, witch could meet the requirement for analysis of Atrazine residue.3.The Atrazine degrading-bacteria were isolated by direct way and selective enrichment from soil exposed to herbicides spills and wastewater of pesticides production. 52 bacteria strains were isolated in all, only 12 strains of witch can degrade Atrazine in culture media. But the three isolates ,HW-23, HB-3, HB-5, were differentiated by observing clearing zones on indicator agar plates containing 1000mg·L-1 Atrazine, witch shows these three isolates can live on and degrade lOOOmg ·L-1 Atrazine. So these three isolates were selectedto make further study.4. The characterization of Atrazine metabolism by three isolates were studied. The result suggested: the biodegradation of Atrazine is proportional to the growth of bacteria; the culture temperature and pH had great effects on the biodegradation of Atrazine and bacterial growth in coordination. The optimal conditions for three isolates' growth and Atrazine biodegradation as following: culture temperature 20℃-35℃; pH 6.0-9.0. Others, these three isolates has great endurance on high concentration of Atrazine, witch can live on and degrade 1000mg ·L-1 Atrazine.5. The additional readily biodegradable C (sucrose) and N (mineral nitrogen NH4NO3 and (NH4)2SO4) in culture medium can activate the three isolates' growth obviously; but have little effects on then- ability to degrade Atrazine, witch demonstrates that the three isolates' ability to degrade Atrazine will not be inhibited by available C and N of environment. On the other hand, Cells grown in medium without additional C and N sources degraded Atrazine ,but the cell numbers had a little increase, witch shows the three isolates can utilize carbon and nitrogen from Atrazine under the condition without additional C and N sources.6.The ability of the three isolates to degrade other s-triazine herbicides was studied. The result demonstrates that the three isolates also can degrade Prometryn and Cyanazine in the same culture conditions as Atrazine degradation.7. The evaluation of the three isolates to clean-up contaminated water and soil with Atrazine , and even the wastewater of pesticide production was studied. In river water, whether it was sterilized or unsterilized, 100mg ·L-1 Atrazine was eliminated 99% within 3 days; in soil, 20mg·kg-1 Atrazine was eliminated over 80% in sterilized soil and over 88.9% in unsterilized soil within one week, but the biodegradation rate of Atrazine was over 90% in both soils within three weeks; In wastewater of pesticides production, whether it was sterilized or not, 100mg·L-1 Atrazine was eliminated 99% within 5 days.The data of studies suggests that the three isolates can be used for bioremediation of contaminated water and soil with Atrazine, and even clean-up of wastewater of Atrazine production in the future.8.Author studied Atrazine degradation in free-cells supernatants of culture medium, pieces of cell wall and crude cell extracts. The resu...
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