Chlorine resistance by some bacteria that isolating from distribution Systems of drinking water

Abstract

This study was done to detect the effect of different concentrations of chlorine on some bacterial species that isolated from drinking water distributions Systems , that included aerobic plate count (APC) which founding in water ,in addition to three isolates of bacteria (E.coli , Ps. Aeruginosa and Bacillus sp.) depending on prevalence ,the frequency of their isolating was more in drinking water patterns . The concentration 3 mg/l of chlorine was enough to kill 97.35% from Aerobic plate count after only two hours . and killed all bacteria of E.coli after half hour in (2 ,2.5 ,3) mg/L. Ps.aeruginosa was completed killing it in (2.5 ,3) mg/L after 2 hour . while there wasn ,t complete killing on Bacillus sp. in use all studying concentrations during the different peroids and killed 75.18 % of its in 3 mg/L after 2 hour