What is residual chlorine and the standard content of residual chlorine

Residual chlorine means that after chlorine is put into water, in addition to consuming part of the chlorine by the action of bacteria, microorganisms, organic substances, and inorganic substances in the water, there is still a part of chlorine remaining, which is called residual chlorine. Residual chlorine can be divided into compound residual chlorine (referring to the compound of chlorine and ammonia in water, there are three kinds of NH 2 Cl, NHCl2 and NHCl3, NHCl2 is more stable and has a good bactericidal effect), also called combined residual chlorine; free residual chlorine (refers to OC 1 +, HOC 1, Cl 2, etc. in water, which have fast sterilization speed and strong bactericidal power, but disappear quickly), also called free residual chlorine. Residual chlorine is the sum of combined residual chlorine and free residual chlorine. Residual chlorine in tap water effluent refers to free residual chlorine to test bacteria in tap water, and the result cannot be obtained immediately, but the number of bacteria in tap water is inversely proportional to the amount of residual chlorine, so the determination of residual chlorine in tap water can be used as a measure Effects on water disinfection and signs of recontamination of tap water. It is especially necessary for the situation where the pipe network is long, there are dead water ends and the equipment is outdated. Therefore, residual chlorine is an important indicator to ensure the continuous sterilization ability of chlorine and prevent external pollution. Whether it is in domestic life or industrial application, as long as tap water is drawn, the detection of residual chlorine is necessary. Since residual chlorine is a basic indicator of tap water, its detection method is relatively complete, and a complete detection method is provided in GB5750-2006. At the same time, since residual chlorine detection is a basic water quality indicator of tap water, it is of great significance. A variety of detection tools are also provided, including instruments, kits, test strips, etc. Users can choose different products according to actual needs and measurement ranges.