The so-called microbial risk of drinking water quality refers to the risk of outbreak of water-borne infectious diseases caused by pathogenic microorganisms in drinking water, which seriously endanger human health and directly threaten human survival. The pathogenic microorganisms transmitted through drinking water mainly include bacteria, viruses, protozoa and intestinal worms. At the end of the 19th century, people realized that cholera, typhoid fever, dysentery and other infectious diseases that seriously endanger life were transmitted by pathogenic microorganisms through drinking water.
This is the first time in human history that water quality has been linked to health. Since the 1970s. New pathogenic microorganisms are constantly found in drinking water, such as micro-like viruses, toxigenic Escherichia coli (including 0-157 E. coli), Giardia, Cryptogamy, Legionella pneumophila, etc. With the development of human activities and the advancement of science and technology, the types and numbers of pathogenic microorganisms in drinking water have been continuously discovered and understood.
Over the past 10 years, dozens of bacteria have been detected in the pipe network that maintains a certain amount of residual chlorine, among which, except for a few iron bacteria and sulfur bacteria, the main ones are heterotrophic bacteria that use organic matter as the nutrient matrix. The main reasons for the increase of E. coli and other heterotrophic bacteria in the pipe network water than the factory water are as follows: ① The organic matter (especially AOC and BDOC) in the factory water is a necessary condition for the growth and reproduction of bacteria and other microorganisms in the pipe network. ②Self-repair of unkilled bacteria and other microorganisms after chlorine disinfection and exogenous bacteria entering pipelines are the internal reasons for the growth and reproduction of bacteria and other microorganisms in the pipe network.
③ The rough surface of the pipe network wall, boundary layer effect, suspended and colloidal deposits, pipe scale, etc. provide a base for the growth and reproduction of bacteria and other microorganisms. ④Pipe network water temperature, water residence time and residual chlorine in the pipe network often increase Aoc, BDoC and other operating conditions, which are external factors that affect the growth and reproduction of bacteria and other microorganisms in the pipe network. Therefore, researchers at home and abroad have proposed the concept of biological stability of drinking water, and the concentration of Aoc and BDOC (mainly Aoc) in drinking water is used as the evaluation index of biological stability of drinking water.
The higher the AoC or BDOC in drinking water, the worse the biological stability of the water quality, and the greater the microbial risk of the water quality. Poolking is the best swimming pool equipment manufacturer and supplier in China. Poolking exists to provide the highest quality swimming pool equipment while offering competitive pricing..