Effects Of Fertilizer Application On Atrazine Degradation And Detoxification By Degrading Strain HB-5

In this dissertation, methods was developed for the residue analysis of atrazine in soil, an atrazine-degrading strain HB-5 was used as a bacteria for biodegradation. Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation and eco-toxicity test; then, relationship between atrazine degradation rate and soil available nitrogen, available phosphorus were discussed. The results could be summarized as follows:1. The physical-chemical characteristics, general situations of application, present pollution situation, ecological toxicological characteristics and bioremediation of atrazine, which had been applied extensively all over the world and in China recently, were introduced, a comprehensive overview of the system effects of the conditions for microbial degradation of pesticides, and accordingly the issues that would be investigated was presented by the author.2,The methods based on using high-performance liquid chromatography (HPLC) with reversed-phase C18 column, and gradient UV detection. The column was maintained at 25℃with a mobile phase flow rate of 0.8mL·min-1.The mobile phase consisted of methanol-water(70:30,v/v).Atrazine was detected at 222nm.The retention time of atrazine was 6.69 min.The detection of LOD and LOQ for atrazine were found to be 0.5 ng and 0.05μg·g-1。3.On the basis of atrazine-degrading strain HB-5, Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation. Adding to the soil a certain concentration of atrazine, after soil were added a certain amount of nitrogen single, phosphorus single and nitrogen phosphorus together, sampling at 0,1,3,5,7,10,14d. After sampling, Soil samples were extracted and purified, atrazine residues levels were determined by HPLC, obtained N and P on degradation of atrazine law in soil.The results show that, The treatment of application of atrazine-degrading strain HB-5 degraded atrazine faster than the non-application of atrazine-degrading strain HB-5. After separately or together application, nitrogenous and phosphorous fertilizers could significantly accelerate atrazine degradation, the order of atrazine degradation was ANP> AP>AN>A; 5 days later, no statistically significant differences were found between treatments(p>0.05), reached more than 95%. Therefore, nitrogen and phosphorus fertilizer used could promote atrazine-degrading strain HB-5 on degrading atrazine in the soil, all these results could be keystone of atrazine pollution remediation in contaminated soil in the future.4. While studied the efficient atrazine-degrading strain HB-5 degradated atrazine in soil, through use of the method of micronucleus test of vicia faba root tip cells to explore the change of the ecological toxicity in the process of degradation of atrazine by atrazine-degrading strain HB-5.The soil of eco-toxicity test results indicated that the eco-toxicity significantly reduced with the degradation of atrazine by HB-5, and the eco-toxicity on treatments of soil with atrazine-degrading strain HB-5 were all below the treatments without strain HB-5. In dealing with the same time, the eco-toxicity on treatments of soil with fertilizer were all below the treatments without fertilizer; On day 5, the order of eco-toxicity was ANP< AP