Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/87489
Title: Effect of chloramine concentration on biofilm maintenance on pipe surfaces exposed to nutrient-limited drinking water
Authors: Park, S.-K. 
Kim, Y.-K.
Keywords: Biofilm
GAC
HPC
Low-nutrient water
Monochloramine residual
Physiological substrate utilisation profile
Issue Date: Jul-2008
Source: Park, S.-K.,Kim, Y.-K. (2008-07). Effect of chloramine concentration on biofilm maintenance on pipe surfaces exposed to nutrient-limited drinking water. Water SA 34 (3) : 373-380. ScholarBank@NUS Repository.
Abstract: This study addresses the effect of specific monochloramine concentration on biofilm density and bacterial functional potential in nutrient-limited water. The efficacy of monochloramine residual maintenance on biofilm density was studied at a range of 0.5 to 2.0 mg/ℓ, using a 3:1 (w/w) dosing ratio of chlorine to ammonia, with the provision of low-nutrient water (0.18 mg/ℓ as total organic carbon, 0.055 mg/ℓ as biodegradable dissolved organic carbon, and 10.5 μg/ℓ as assimilable organic carbon) using a granular activated carbon (GAC) filter. Biofilm density was monitored using biofilm bacteria counts and analysis of the physiological substrate utilisation profiles in Biolog gram-negative (GN) micro-plates. The monochloramine residuals were maintained stable in the low-nutrient water pipes, which contributed to the inhibition of biofilm density. Increasing the monochloramine residual from 0.5 to 2.0 mg/ℓ suppressed the total cells and heterotrophic plate count (HPC) bacteria in the biofilms by about 1 and 2 log units, respectively. The biofilm HPC densities were more sensitive to monochloramine residual, and the reduction in biofilm HPC densities expressed as log CFU/cm2 showed an exponential relationship with the increase in monochloramine residual. The Biolog micro-plate-based community-level assay showed that the biofilm communities occurring at 3 levels of chloramination were distinguished by the differences in their substrate utilisation potentials. The functional/metabolic potential of the biofilm community's ability to utilise specific substrates was much lower at higher monochloramine concentration. Results suggest that the maintenance of a consistently high-level monochloramine residual in the low-nutrient water system led not only to a reduction in biofilm density on pipe surfaces but also depressed potential functional/metabolic ability of the biofilm community.
Source Title: Water SA
URI: http://scholarbank.nus.edu.sg/handle/10635/87489
ISSN: 03784738
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

60
checked on Apr 20, 2018

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.