The influencing factors of water treatment with ozone
Reduce the ability of purifier drinking water Ozone has a high sterilization efficiency when used in drinking water disinfection, but it often need a large amount of ozone dosage and a longer contacting time in the application of sewage disinfection. The main reason is that there are more pollutants such as COD, NO2-N, chroma and suspended matter in sewage, which will reduce the consume ozone and reduce sterilization ability of ozone. Therefore, the sewage need be pretreated before ozone disinfection, in order to make the effect of ozone disinfection become more economical and effective. The contacting way of ozone and sewage and water flow also can affect the dosage and disinfection effect of ozone.
1 water quality
The main factors which impact ozone disinfection are mainly including COD, NO2-N, suspended solids and chroma in the water.
2 ozone dosage and residual ozone
The residual ozone as chlorine plays an important role in the disinfection. When we disinfect for drinking water the residual ozone concentration should be 0.4mg/L. At this time the Escherichia bacteria in drinking water can meet standards of water quality. When disinfecting for sewage, ozone residue can only exist in a very short time. Except for a small amount of free ozone, the residual ozone is also included in the ozone removal, and the oxidation of ozone and other oxidants. When the water quality is good, the more the free ozone content is, the better the disinfection effect is.
3 contacting time
The contacting time of ozone disinfection is very short. But this process is also affected by the water quality. It was found that the residence time after contacting with ozone contact, disinfection effect will continue. In the original residence time within 10min, there also be some disinfection. After ozone 30min, the ozone will not in disinfect continuously.
4 contacting way
The contacting way between ozone and sewage also could have an impact on the effect of disinfection. Such as the use of bubble method, the smaller bubble dispersion is, the higher the utilization rate of ozone is, and the better disinfection effect is. The bubble size depends on the pore size of diffusion, pressure and surface tension of water. Water vapor mixing effect of Mechanical mixer, reverse screw fixed mixer and venture injector have a very good effect on water vapor mixing, which can be used for ozone disinfection of sewage.