Polarographic free chlorine concentration measuring method and its measuring apparatus

摘要

An object of the present invention is to provide a polarographic free chlorine measuring method and its measuring apparatus capable of removing trichloramine by aeration and measuring a true free chlorine concentration in real time even in a low water temperature period. SOLUTION: With respect to sterilized treated water obtained by injecting free chlorine for at least sterilization into raw water containing ammonia nitrogen, the free chlorine concentration of the sterilized treated water is measured to control the injection amount of the free chlorine. It is a polarographic type free chlorine concentration measuring device 1, characterized in that the free chlorine concentration is measured after the aeration treatment is performed on the measurement treated water 5 in which a part of the sterilizing treated water is diverted and the trichloramine is removed. I assume. [Selected figure] Figure 1