Reduction Effect of Typical Enteric Pathogens in Sludge by Dissolved Ozone Flotation System
The production of wastewater activated sludge(WAS),an inevitable by-product of biological wastewater treat-ment,continues to increase.WAS carries a large number of pathogenic bacteria and toxic and harmful pollutants,which will inevitably cause serious pollution to the environment if not properly treated.Results of the study on pathogen removal by ozone air flotation showed that the ozone dose increased from 0 mg/g SS to 2.0 mg/g SS,the total E.coli flora inactivation rate increased from 0.02 lg to 1.86 lg,the fecal E.coli flora inactivation rate increased from 0.03 lg to 2.01 lg,and the fecal E.coli flora content in the residual sludge could meet the Category B criteria established by the US EPA after treatment with an ozone dose of 1.5 mg/g SS.While the 2.0 mg/g SS ozone dose had an overall inactivation ratio of norovirus to adenovirus of 1.42 lg and 1.69 lg,as calculated by quantifying its health risk,its disease burden was 2.61×10-7 and 3.62×10-8,all reaching the standard values of 10-6 recommended by the World Health Organization.Ozone air flotation can effectively remove the pathogens present in the remaining sludge and reduce the health risk for disposal by subsequent treatment,which provides a technical and theoretical reference for sludge sanitary utilization.
万方数据
维普
