Domestic Hot Water Silver Ion Disinfection Technology Research

Secondary water supply system of city, as urban water supply system of the terminal, is the lifeline of people. Domestic hot water is the important part of secondary water supply water system. At present, the unsatisfactory quality lead to the nonstandard hot water quality in our country. Even it is exist that the legionella pollution problem in domestic hot water system, caused by the social attention gradually.This topic investigate and analyze the difference between hot water and tap water through the real domestic hot water system, points out that the hot water biological stability, then established the simulated pilot-scale pipeline system research effect of silver ions on legionella disinfection, and silver ion disinfection technology of living hot water system.The test results of silver ions to the life of hot water legionella and conventional inactivated bacteria show that the inactivation rate up to99.92%in1cfu/mL of legionella and0.10mg/L concentration of silver ion after210min inactivated, according with the provision of WHO that the number of legionella which test from water is less than1cfu. It is showed a significant effect of the inactivation of silver ions in the test system of Legionella. The inactivation rate of the total bacterial count reached to97.86%and average inactivation rate of heterotrophic bacteria was85.71%after180min inactivation within the range of0.05-0.07mg/L concentration of silver ion. Content to the drinking water health standards "(GB5749-2006) standard in our country. It is showed that silver ions was included with wide range effects of bacteria inactivation, and the effect is significant.Most researchers consider that the assimilation of assimilable organic carbon (AOC) is a better characterization of biological stability of drinking water, also take the bacterial growth potential of the primary pipe network water AOC as evaluation indexes. This topic choose a university domestic hot water system sampling to test, the results show that AOC value between50-100cfu/mL in one water samples, the other two is between100-250cfu/mL, it may impact on microbial proliferation in hot water.It is point out that the biological stability problems which exist in domestic hot water.The management of living hot water system and the maintenance of hot water system are impact to water quality health safety significanlyt. At present it is not yet set up legionella bacteria killing and the safty guaranteeing measures in living hot water system in our country. It is need to establish safety management system of living hot water system. Combining to disinfection technology of legionella, maintenance and management regulations and emergency measures of legionella outbreak,management will complete Water quality monitoring method of living hot water system and 《Living hot water water quality standards》gradually.