Isolation and inactivation of chlorine resistant bacteria in water treatment plants
The tolerance experiment of two disinfectants was tested by isolating four strains of chlorine-resistant bacteria from the treated water of three water treatment plants in a northern city.The results showed that,in terms of the removal rate of chlorine-resistant bacteria,sodium hypo-chlorite was more efficient than chloramine disinfection.Sodium hypochlorite can achieved disinfec-tion effect in about 30 min,while chloramines need longer time.The disinfection effect of chlora-mine was slightly better than the result of sodium hypochlorite for 4 strains of chlorine-resistant bacteria which selected under the water environment of 0.7 mg/L sodium hypochlorite for a long time.No.1 Sphingomonas sp.and No.4 Bacillus toyonensis had strong tolerance to both disin-fectants.The removal rate of No.1 Sphingomonas sp.Under the influence of all experimental con-centrations of two different disinfectants could not inactive 2 lg(99％).Chloramine could inactive 1.9 lg of No4.Bacillus toyonensis,sodium hypochlorite had almost no effect on it.No.2 Bacillus licheniformis and No.3 Pseudomonas mendocina were less resistant to the both disinfectants.No.2 Bacillus licheniformis could be basically removed under the influence of high experimental con-centrations.No.3 Pseudomonas mendocina could be inactivated 3.6 lg by high concentration of chloramine.It was recommended that the water treatment plants should intermittent increased the concentration of sodium hypochlorite or switch to chloramine disinfectant to prevent the enrichment and reproduction of chlorine-resistant bacteria.
Water treatment plantsChlorine-resistant bacteriaSphingomonas sp.Pseudo-monas sp.Bacillus sp.Disinfectant resistance
万方数据
维普
