Total organic halogen (TOX) species formation at different locations in drinking water distribution systems

2020 ◽  
Vol 6 (9) ◽  
pp. 2542-2552
Author(s):  
Daekyun Kim ◽  
Amer Kanan ◽  
Naushita Sharma ◽  
Paul Westerhoff ◽  
Tanju Karanfil

TOCl, TOBr and TOI concentrations were quantified quarterly at 11 US drinking water treatment plants and distribution systems.

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Patrick J. McNamara

ABSTRACT Patrick J. McNamara works in the field of environmental engineering. In this mSphere of Influence article, he reflects on how the papers “Bacterial community structure in the drinking water microbiome is governed by filtration processes” (A. J. Pinto, C. Xi, and L. Raskin, Environ Sci Technol 46:8851–8859, 2012, https://doi.org/10.1021/es302042t) and “Differential resistance of drinking water bacterial populations to monochloramine disinfection” (T. Chiao, T. M. Clancy, A. Pinto, C. Xi, and L. Raskin, Environ Sci Technol 48:4038–4047, 2014, https://doi.org/10.1021/es4055725) by Lutgarde Raskin and colleagues made an impact on him by providing a foundation for the study of microbial ecology in engineering drinking water treatment plants and drinking water distribution systems.


2017 ◽  
Vol 15 (2) ◽  
pp. 218-227 ◽  
Author(s):  
Huirong Lin ◽  
Xuan Zhu ◽  
Yuxin Wang ◽  
Xin Yu

Human health and biological safety problems resulting from urban drinking water pipe network biofilms pollution have attracted wide concern. Despite the inclusion of residual chlorine in drinking water distribution systems supplies, the bacterium is a recalcitrant human pathogen capable of forming biofilms on pipe walls and causing health risks. Typical drinking water bacterial biofilms and their response to different concentrations of chlorination was monitored. The results showed that the four bacteria all formed single biofilms susceptible to sodium hypochlorite. After 30 min disinfection, biomass and cultivability decreased with increasing concentration of disinfectant but then increased in high disinfectant doses. PMA-qPCR results indicated that it resulted in little cellular damage. Flow cytometry analysis showed that with increasing doses of disinfectant, the numbers of clusters increased and the sizes of clusters decreased. Under high disinfectant treatment, EPS was depleted by disinfectant and about 0.5–1 mg/L of residual chlorine seemed to be appropriate for drinking water treatment. This research provides an insight into the EPS protection to biofilms. Resistance of biofilms against high levels of chlorine has implications for the delivery of drinking water.


2020 ◽  
Vol 41 (S1) ◽  
pp. s255-s255
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi

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


2017 ◽  
Vol 3 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Haibo Wang ◽  
Chun Hu ◽  
Lang Yin ◽  
Sujia Zhang ◽  
Lizhong Liu

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


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