Effect of GAC pre-treatment and disinfectant on microbial community structure and opportunistic pathogen occurrence

Wang, Hong; Pryor, Marsha; Edwards, Marc; Falkinham, Joseph O.; Pruden, Amy

doi:10.1016/j.watres.2013.06.052

Cited by 76 publications

(61 citation statements)

References 60 publications

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“…from nutrient (like C) competition, production of inhibitory compounds (e.g., antibiotics, bacteriocins), or predation and parasitism (e.g., bacteriophage, protozoa, invertebrates) (Hibbing et al, 2010;Vital et al, 2012;Wang et al, 2013). However, we also observed a protagonistic effect for P. aeruginosa, as also shown elsewhere for both E. coli and Klebsiella pneumonia (Moreira et al, 1994;Kerr et al, 1999).…”

Section: Indigenous Microbial Communitysupporting

confidence: 85%

Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet

Nguyen

Allemann

Ziemba

et al. 2017

Front. Environ. Sci.

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Highlight• Bacterial growth in fecally-contaminated water is highly variable and dependent on several factors. • Regrowth occurs after chlorination (low doses, no residual).• Indigenous microbial communities variably impact bacterial growth.• A combination of treatments can both inactivate and inhibit growth.The Blue Diversion AUTARKY Toilet is a urine-diverting toilet with on-site treatment. The toilet is being developed to provide a safe and affordable sanitation technology for people who lack access to sewer-based sanitation. Water used for personal hygiene, hand washing, and flushing to rinse urine-and feces-collection bowls is treated, stored, and recycled for reuse to reduce reliance on external water supplies. The system provides an opportunity to investigate hygiene of water for reuse following treatment. Treatment in the toilet includes a Biologically Activated Membrane Bioreactor (BAMBi) followed by a secondary treatment technology. To identify effective secondary treatment, three options, including granular activated carbon (GAC) only, GAC+chlorine (sodium hypochlorite), and GAC+electrolysis are considered based on the bacterial inactivation and growth inhibition efficiency. Four different hygiene-relevant bacteria are tested: Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Salmonella typhimurium. Our evaluation demonstrates that-despite treatment of water with the BAMBi-E. coli, P. aeruginosa, and S. typhimurium have the potential to grow during storage in the absence of microbial competition. Including the indigenous microbial community influences bacterial growth in different ways: E. coli growth decreases but P. aeruginosa growth increases relative to no competition. The addition of the secondary treatment options considerably improves water quality. A column of GAC after the BAMBi reduces E. coli growth potential by 2 log 10 , likely due to the reduction of carbon sources. Additional treatments including chlorination and electrolysis provide further safety margins, with Nguyen et al. Pathogens in Water for Reuse more than 5 log 10 inactivation of E. coli. However, reactivation and/or regrowth of E. coli and P. aeruginosa occurs under in the absence of residual disinfectant. Treatment including the BAMBi, GAC, and electrolysis appear to be promising technologies to control bacterial growth during storage in water intended for reuse.

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Section: Indigenous Microbial Communitysupporting

confidence: 85%

Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet

Nguyen

Allemann

Ziemba

et al. 2017

Front. Environ. Sci.

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“…Therefore, it is necessary to establish the microbial diversity of microorganisms in the incoming water, and accordingly select the best biocides (10,11). The effectiveness of biocides is tested under laboratory conditions as well as in dental offi ce (12,13). Tuttlebee and his team tested two peroxide-based biocides and found that Sanosil was more suitable for repeated DUWL decontamination (14).…”

Section: Introductionmentioning

confidence: 99%

Legionella spp. in dental unit waterlines

Jurásková¹,

Sedlackova²,

Janska³

et al. 2017

BLL

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OBJECTIVE: To determine the current presence of Legionella spp. in the output water of dental unit waterlines (DUWLs) and examine its mitigation by disinfection at the Institute of Dentistry and Oral Sciences, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc. MATERIAL AND METHODS: The fi rst stage of our survey involved collecting samples of DUWL output water from 50 dental chair units (DCUs), and 2 samples of the incoming potable water. In October 2015, a one-time disinfection (1 % Stabimed) of DUWLs was conducted. This was followed by collecting 10 control samples (survey stage 2). RESULTS: From the total of 50 samples (survey stage 1), 18 samples (36.0 %) tested positive for Legionella spp. Following the disinfection, nine of the ten samples no longer showed any presence of Legionella. CONCLUSION: Based on culture results, the one-time disinfection (1 % Stabimed) was effective. We are unable to comment on the duration of positive effect of disinfection on the occurrence of Legionella spp. in the outlet water. It was a one-time survey (Tab. 2, Ref. 32). Text in PDF www.elis.sk. KEY WORDS: Legionella spp., water of dental unit waterlines, disinfection.

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“…Likewise, Legionella, which was identified in raw water, persisted within the filter, albeit at a relatively low abundance (0.02%). Legionella is an intracellular pathogen, which has been reported to be a natural colonizer of GAC (Wang et al 2013), and which can persist through water treatment systems within amoebae, such as Acanthamoeba (Thomas et al 2008). This has also been demonstrated for species of Mycobacterium, which in our study increased from about 0.15% in raw water to around 0.3% in the filter (Table 1).…”

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confidence: 99%

“…This has also been demonstrated for species of Mycobacterium, which in our study increased from about 0.15% in raw water to around 0.3% in the filter (Table 1). Like Legionella, species of Mycobacterium are natural colonizers of BAC (Wang et al 2013), can survive within amoebae (Thomas et al 2008), and have been identified as a prevalent microbe in both experimental and treatment plant filters and distribution systems (Dailloux et al 2003;Revetta et al 2013;Revetta et al 2016;Stanish et al 2016;Thomas et al 2008;Wang et al 2013). Species of Mycobacterium are of particular concern for drinking water safety, given that they are the causal agent of human and animal van Hannen, E.J., Zwart, G., van Agterveld, M.P., Gons, H.J., Ebert, J., and Laanbroek, H.J.…”

mentioning

confidence: 99%

From source to filter: changes in bacterial community composition during potable water treatment

2017

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Rural communities rely on surface water reservoirs for potable water. Effective removal of chemical contaminants and bacterial pathogens from these reservoirs requires an understanding of the bacterial community diversity that is present. In this study, we carried out a 16S rRNAbased profiling approach to describe the bacterial consortia in the raw surface water entering the water treatment plants of two rural communities. Our results show that source water is dominated by the Proteobacteria, Bacteroidetes, and Cyanobacteria with some evidence of seasonal effects altering the predominant groups at each location. A subsequent community analysis of sections through a biological carbon filter in the water treatment plant revealed a significant increase in the proportion of Proteobacteria, Acidobacteria, Planctomycetes, and Nitrospirae relative to raw water. Also, very few enteric coliforms were identified in either the source water or within the filter, although the abundance of Mycobacterium was high, and was found throughout the filter along with Aeromonas, Legionella, and Pseudomonas. This study provides valuable insight into bacterial community composition within drinking water treatment facilities, and the importance of implementing appropriate disinfection practices to ensure safe potable water for rural communities.

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Effect of GAC pre-treatment and disinfectant on microbial community structure and opportunistic pathogen occurrence

Cited by 76 publications

References 60 publications

Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet

Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet

Legionella spp. in dental unit waterlines

From source to filter: changes in bacterial community composition during potable water treatment

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