The Detection Of Escherichia Coli In The Soil Of Chicken Farm And The Selection Of Chemical Disinfectant

With the rapid development of animal husbandry industry, the soil contamination problem caused by farms and slaughterhouses has aroused people's attention. The physical and chemical characteristic of soil would be changed once it contaminated. Not only the normal function of soil is influenced, the groundwater will be polluted by the transmission of Pathogenic microorganisms in soil. People's health will be threatened by drinking or using this unsanitary water. So far, there has not been adequate study on the effective and environmental friendly disinfectants which can be used extensively in soil. At present the control and remediation of soil contamination is still a challenge confronted people.The soil samples collected between 2009 and 2010 from the chicken farm in different areas of Hubei Province were detected and the contamination circumstances were evaluated in this study. The amount of total bacteria, coliform group and Escherichia coli in soil were detected. The result suggests that the amount of total bacteria is higher than that of coliform group, which is higher than Escherichia coli. The chicken farm soil was highly contaminated at spring and autumn seasons while less contaminated at summer and winter seasons. The distribution of pathogens and contamination circumstances can be a reference to the subsequent control and remediation measures.A strain of Escherichia coli was isolated and identified from the soil sample collected from a chicken farm in Hubei Hanchuan, which was used in the following study on efficacy of different chemical disinfectants. The results of quantitative suspension test of Glutaraldehyde as a disinfectant show that 0.01% concentration action for 30 min or 0.02% concentration action for 5 min to Escherichia coli has a killing rate at 100%. The results of Glutaraldehyde soil carrier disinfection test demonstrated that 0.01% concentration function 30 min or 0.02% concentration function 10min for Escherichia coli has a 100% killing rate, which revealed a favorable killing effect. The results of quantitative suspension test of chlorine dioxide as a disinfectant showed that the activity of Escherichia coli was full eliminated by 25 mg/L chlorine dioxide function for 10 min. The results of chlorine dioxide soil carrier disinfection test demonstrated that 300 mg/L concentration function 30 min or 400 mg/L concentration function 10 min for Escherichia coli can achieve a 100% killing rate, which revealed a favorable Bactericidal effect.