In order to measure the bactericides performance of the bactericide, the bactericidal rate is mainly used as an indicator. At present, there are two methods for calculating the sterilization rate: one is the number of starting bacteria before the addition of the bactericides - the number of viable bacteria at a certain time plus the number of starting bacteria before the bactericides; and the other is the blank at a certain time. Number of bacteria - number of viable cells at the same time at a certain time
The former uses the number of starting bacteria before sterilization as the base, and is suitable for use in dynamic simulation and industrial production. The latter takes the number of bacteria in the blank at the same time as the base, taking into account the influence of external factors on the growth and reproduction of bacteria, so it is suitable for comprehensive evaluation of bactericides in the laboratory, which is more reasonable. It can be seen from the above two formulas that the amount of starting bacteria directly affects the calculation results. Therefore, the amount of starting bacteria in the experiment should generally be controlled within the order of 105-107. In general industrial circulating water treatment, it is required to maintain the sterilization rate above 90%.
Second, another indicator for evaluating the bactericides performance of the biocide is the minimum inhibitory concentration. For the bactericides of industrial circulating water, the bactericides is required to have a bacteriostatic effect under low dose conditions, and the general concentration should not exceed 00 mg/L.
Finally, the evaluation of the biocidal ability of a bactericides should also consider its sterilization rate, efficacy period and whether it is easy to produce drug resistance. Practice has found that microorganisms can develop resistance to general bactericides, and the effect of using the same bactericides continuously for a long period of time is not very good. Therefore, different types of bactericides or compound bactericides should be added at intervals.www.china-zhufengchem.com