scholarly journals Disinfection efficacy of chlorine and peracetic acid alone or in combination against Aspergillus spp. and Candida albicans in drinking water

2011 ◽  
Vol 10 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Maurizio Sisti ◽  
Giorgio Brandi ◽  
Mauro De Santi ◽  
Laura Rinaldi ◽  
Giuditta F. Schiavano
Keyword(s):  
Drinking Water ◽  
Candida Albicans ◽  
Peracetic Acid ◽  
Contact Time ◽  
Distribution Systems ◽  
Water Distribution ◽  
Synergistic Effects ◽  
Water Disinfection ◽  
Experimental Conditions ◽  
Complete Inactivation

The aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid in drinking water against various pathogenic Aspergillus spp. and Candida albicans strains. A. nidulans exhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a complete inactivation. Under the same experimental conditions, peracetic acid was even less fungicidal. In this case, A. niger proved to be the most resistant species (50 ppm for 60 min for complete inactivation). All Aspergillus spp. were insensitive to 10 ppm even with extended exposure (>5 h). The combination of chlorine and peracetic acid against Aspergillus spp. did not show synergistic effects except in the case of A. flavus. Complete growth inhibition of C. albicans was observed after about 3 h contact time with 0.2 ppm. C. albicans was less sensitive to peracetic acid. Hence the concentrations of chlorine that are usually present in drinking water distribution systems are ineffective against several Aspergillus spp. and peracetic acid cannot be considered an alternative to chlorine for disinfecting drinking water. The combination of the two biocides is not very effective in eliminating filamentous fungi at the concentrations permitted for drinking water disinfection.

Biofouling: an historic and contemporary review of its causes, consequences and control in drinking water distribution systems

Biofilms ◽  
2005 ◽  
Vol 2 (3) ◽  
pp. 197-227 ◽  
Author(s):  
R. T. Bachmann ◽  
R. G. J. Edyvean
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Distribution Systems ◽  
Water Distribution ◽  
Bacterial Load ◽  
Microbial Control ◽  
Water Distribution Systems ◽  
Water Disinfection ◽  
Pipe Material ◽  
Pipe Materials

Biofouling in water distribution systems has, arguably, affected our lives for more than 3500 years. It may be defined as the undesirable accumulation of biotic matter on a surface, which can cause odour and taste problems, the deterioration of pipe materials and fittings and result in the discoloration of water. Early efforts to combat these problems included the use of sedimentation tanks, disinfection by silver ionization and cleaning of the distribution network. At the turn of the nineteenth century, rapid sand filtration and water disinfection became widely used and helped to reduce the organic and bacterial load in drinking water. A better understanding of the role and causes of biofouling in water distribution systems resulted in various legislations, which in turn have been a driving factor for improving or developing new water treatment methods, pipe materials, analytical techniques, etc. However, increasing requirements on water quality in the late twentieth century made water treatment and specific anti-corrosion and/or microbial control regimens insufficient as a means of solving the transportation problem owing to the heterogeneity of pipe materials and contamination from outside the distribution system. Furthermore, as drinking water passes through the mains it undergoes a series of quality changes owing to interactions with the pipe walls, bacteria and the sediment phase.This review emphasizes the extent to which biofouling depends on interactions between microorganisms and (1) nutrients, (2) environmental conditions (temperature), (3) physicochemical processes (sedimentation, corrosion, disinfection) and (4) pipe material. A good knowledge of these complex interactions is necessary for implementing a successful biofouling control strategy.

The assessment of biofilm community composition on plumbing materials in filtered and unfiltered water distribution systems

2003 ◽  
Vol 3 (1-2) ◽  
pp. 187-191
Author(s):  
M.M. Critchley ◽  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Drinking Water ◽  
Fatty Acid ◽  
Community Composition ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Polymer Materials ◽  
Fatty Acid Profiles ◽  
Water Supplies ◽  
Drinking Water Distribution Systems

Biofilms have been extensively characterised within drinking water distribution systems. However, the significance of materials on biofilm species diversity is not established. This study investigated the community composition of biofilms on plumbing materials receiving filtered and unfiltered water supplies. Biofilms were extracted from polybutylene, polyethylene, cross-linked polyethylene, unplasticised polyvinyl chloride and copper tubes in sampling rigs receiving Murray-Onkaparinga water before or after filtration. Biofilms were extracted and analysed for fatty acid composition using the FAME™ methodology. There were differences in the fatty acid profiles of biofilms and the respective water supplies, indicating differences in the attached and planktonic communities. The results also showed significant differences in the fatty acid profiles of biofilms on the polymer materials compared to copper, suggesting variations in biofilm populations on the different materials. The potential for materials to select for microbial populations has significant implications for the ecology of drinking water biofilms.

scholarly journals Identification of Aminoglycoside Resistance Genes From Bacteria Isolated From Selected Municipal Drinking Water Distribution Systems in Southwestern Nigeria

2020 ◽  
Vol 41 (S1) ◽  
pp. s255-s255
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Southwestern Nigeria ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Background: Multidrug-resistant bacteria can lead to treatment failure, resulting in infectious diseases being transferred through nonpotable water. Aminoglycosides are an important class of antibiotics that are abused in Nigeria. Few studies have investigated aminoglycoside-modifying genes (AMGs) that are likely responsible for resistance in Nigeria bacteria isolates. Therefore, we aimed to characterize AMGs from isolates in drinking water distribution systems (DWDS) in southwestern Nigeria. Methods: Multidrug-resistant bacteria (n = 181) that had been previously characterized by 16S rDNA sequencing and that were positive for resistance to at least 1 aminoglycoside antibiotic were selected from 6 treated and untreated water distribution systems. Strains were PCR genotyped for 3 AMGs: aph(3)c, ant(3)b and aph(6)-1dd. Results: Of 181 MDR bacteria tested, 69 (38.12%) were positive for at least 1 of the AMGs. The most common was ant(3)c (27.6%), followed by aph(3")c (18.23%). Both aph(3)c and ant(3")b were found in 7.73% of tested isolates, ant(3)b was most commonly found in Alcaligenes spp (50%). Furthermore, aph(3")c was most commonly detected in Proteus spp (50%). Other genera positive for AMGs included Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter, and Serratia. Conclusions: High occurrence of ant(3)c and aph(3)c among these bacteria call for urgent attention among public health workers because these genes can be easily disseminated to consumers if present on mobile genetic elements like plasmids, integrons, and transposons.Funding: NoneDisclosures: None

Characterization of chemical composition and bacterial community of corrosion scales in different drinking water distribution systems

2017 ◽  
Vol 3 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Haibo Wang ◽  
Chun Hu ◽  
Lang Yin ◽  
Sujia Zhang ◽  
Lizhong Liu
Keyword(s):  
Drinking Water ◽  
Chemical Composition ◽  
Distribution Systems ◽  
Water Distribution ◽  
Iron Release ◽  
Drinking Water Distribution Systems ◽  
Biochemical Function ◽  
Drinking Water Distribution ◽  
Corrosion Scales

There is a relationship between biochemical function and chemical composition of corrosion scales, and Fe3O4formation reduced iron release.

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