HIGH CHLORINATION EFFECTS ON DRINKING WATER BIOFILMS AND DEPOSITS FORMED ON PLASTIC PLUMBING MATERIALS

摘要

Accidental or intentional contaminations by microorganisms of drinking water distribution systems impair water services for the safe use of water. These events occur more or less frequently as a result of (i) negative pressures on the network and intrusion of undesirable bugs through leaks,1 (ii) natural disasters associated with urban flooding, (iii) default in treatment or distribution with a risk of epidemic situations,2 (iv) back-contaminations of point-of-use systems which may become points of nosocomial contamination in specific environments like hospital emergency services (e.g., contamination by Pseudomonas or Escherichia coli),3'5 (v) unexpected bloom of microorganisms of sanitary interest (e.g., Legionella), or (vi) intentional contamination in the framework of terroristic activities. Such contaminations determine a crisis situation, which affects or is likely to affect a water utility or its provided services, and involve more than the usual means of operation and/or organizational structures to deal with it. Indeed, cleaning and effective disinfection of the water systems is required. The issue is thorny as undesirable biological contaminants will be found not only in the water bulk but also associated with pipe walls.