Objectives To understand the contamination of legionella pneumophila thermophilic bacteria in the cooling water of central air conditioning systems in Jinshan District, and to discuss the effective prevention and control measures.
Methods Sixteen central air conditioning systems with open type cooling towers in Jinshan District were selected. Cooling water samples were collected once in each month of May to October in 2012 to make cultivation and identification of legionella pneumophila.
Results The detected rate for legionella pneumophila in the cooling water was 26.2%, and the serotype was dominated by LP1 type, which accounted for 68.2%.The contamination of legionella pneumophila in cooling water was more serious in July, August and September, and the detected rates were 43.8%, 37.5%, and 50%, respectively. Under the treatment of not doing any disinfection, doing regular artificial disinfection or mechanically continuous adding disinfectants in cooling water, the detected rates of legionella pneumophila in cooling water were 58.3%, 26.7% and 0%, respectively.
Conclusions There was a certain degree of legionella pneumophila contamination in the cooling water of central air conditioning systems in Jinshan District. The way of periodic disinfection could not solve the problem of legionella pneumophila contamination. It is suggested to take a measure of continuously adding disinfectants in the cooling water of central air conditioning systems to prevent and control the breeding of Legionella pneumophila.
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