Evaluation of the disinfection potential of low chlorine concentrations in tap water using immobilised Enterococcus Faecium in a continuous flow device

• Published in: Water science and technology Vol. 35; no. 11-12; pp. 77 - 80
• Main Authors: Wiedenmann, A., Braun, M., Botzenhart, K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York NY Elsevier Ltd 01.01.1997; Oxford Pergamon Press; IWA Publishing
• Subjects: Applied sciences; Bacteria; Chlorination; Chlorine; Continuous flow; CT-values; Disinfection; distribution system; Drinking water; Drinking water and swimming-pool water. Desalination; Evaluation; Exact sciences and technology; faecal streptococci; Kinetics; Pollution; Reduction; Water distribution systems; Water purification; Water treatment and pollution; Drinking water; distribution system; disinfection; faecal streptococci; CT-values; chlorine; Continuous process; Drinking water treatment; Streptococcaceae; Enterococcus faecium; Chlorination; Bacteria; Micrococcales; Disinfection; Experimental study
• ISBN: 9780080433004; 0080433006
• ISSN: 0273-1223; 1996-9732
• DOI: 10.1016/S0273-1223(97)00238-2

A simple continuous flow device in which bacteria were immobilised on membrane filters and flushed with tap water with free chlorine residuals of 0.05, 0.1, 0.2 and 0.4mg/L at pH 7.7 and 10°C, has been used for disinfection experiments with faecal streptococci. A 99.99% reduction of Enterococcus faeciam was observed between 3.4–5.2mm (0.05mg/L), between 2.8–4.1mm (0.1mg/L), between 1.7–3.1mm (0.2mg/L) and between 0.8–2.1mm (0.4mg/L). CT-products covered a range of 0.17 (0.05mg/L, lower limit) up to 0.85mg/L/min (0.4mg/L, upper limit). The test system is suggested as a more reliable alternative to batch experiments when the disinfection potential of low chlorine concentrations acting for several minutes has to be evaluated. The system cannot be used to demonstrate exact reduction kinetics but it allows the calculation of CT values and the evaluation of the disinfection potential of chlorinated water at any point of a distribution system where initial chlorine concentrations may have already remarkably declined.