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Author (up) Anastasi, E.M.; Wohlsen, T.D.; Stratton, H.M.; Katouli, M. file  url
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  Title Survival of Escherichia coli in two sewage treatment plants using UV irradiation and chlorination for disinfection Type Journal Article
  Year 2013 Publication Water Research Abbreviated Journal Water Res  
  Volume 47 Issue 17 Pages 6670-6679  
  Keywords  
  Abstract We investigated the survival of Escherichia coli in two STPs utilising UV irradiation (STP-A) or chlorination (STP-B) for disinfection. In all, 370 E. coli strains isolated from raw influent sewage (IS), secondary treated effluent (STE) and effluent after the disinfection processes of both STPs were typed using a high resolution biochemical fingerprinting method and were grouped into common (C-) and single (S-) biochemical phenotypes (BPTs). In STP-A, 83 BPTs comprising 123 isolates were found in IS and STE, of which 7 BPTs survived UV irradiation. Isolates tested from the same sites of STP-B (n = 220) comprised 122 BPTs, however, only two BPTs were found post-chlorination. A representative isolate from each BPT from both STPs was tested for the presence of 11 virulence genes (VGs) associated with uropathogenic (UPEC) or intestinal pathogenic (IPEC) E. coli strains. Strains surviving UV irradiation were distributed among seven phylogenetic groups with five BPTs carrying VGs associated with either UPEC (4 BPTs) or IPEC (1 BPT). In contrast, E. coli strains found in STP-B carried no VGs. Strains from both STPs were resistant to up to 12 out of the 21 antibiotics tested but there was no significant difference between the numbers of antibiotics to which surviving strains were resistant to in these STPs. Our data suggests that some E. coli strains have a better ability to survive STPs utilising chlorination and UV irradiation for disinfection. However, strains that survive UV irradiation are more diverse and may carry more VGs than those surviving SPTs using chlorination.

Subject Headings: Biodegradation, Environmental/radiation effects; *Disinfection; Drug Resistance, Microbial/radiation effects; Escherichia coli/genetics/pathogenicity/physiology/*radiation effects; *Halogenation/radiation effects; Microbial Viability/*radiation effects; Sewage/*microbiology; *Ultraviolet Rays; Virulence/genetics/radiation effects; *Water Purification; Chlorination; Disinfection; Escherichia coli; Sewage treatment plant; UV irradiation

Keywords: Survival of Escherichia coli in two sewage treatment plants using UV irradiation and chlorination for disinfection
 
  Call Number Serial 2815  
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Author (up) Brooks, J.P.; Adeli, A.; McLaughlin, M.R. file  url
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  Title Microbial ecology, bacterial pathogens, and antibiotic resistant genes in swine manure wastewater as influenced by three swine management systems Type Journal Article
  Year 2014 Publication Water Research Abbreviated Journal Water Res  
  Volume 57 Issue Pages 96-103  
  Keywords Animal Husbandry/*methods; Animals; Anti-Bacterial Agents/pharmacology; Bacteria/drug effects/*genetics/*isolation & purification; Bacterial Proteins/genetics/metabolism; Drug Resistance, Bacterial/*genetics; Manure/*microbiology; Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/isolation & purification; *Microbiota; RNA, Ribosomal, 16S/genetics/metabolism; Real-Time Polymerase Chain Reaction; Southeastern United States; Sus scrofa; Waste Water/*microbiology; Antibiotic resistance; Campylobacter; Confined animal feeding operation (CAFO); Lagoon wastewater; Salmonella; Swine; Microbiome  
  Abstract The environmental influence of farm management in concentrated animal feeding operations (CAFO) can yield vast changes to the microbial biota and ecological structure of both the pig and waste manure lagoon wastewater. While some of these changes may not be negative, it is possible that CAFOs can enrich antibiotic resistant bacteria or pathogens based on farm type, thereby influencing the impact imparted by the land application of its respective wastewater. The purpose of this study was to measure the microbial constituents of swine-sow, -nursery, and -finisher farm manure lagoon wastewater and determine the changes induced by farm management. A total of 37 farms were visited in the Mid-South USA and analyzed for the genes 16S rRNA, spaQ (Salmonella spp.), Camp-16S (Campylobacter spp.), tetA, tetB, ermF, ermA, mecA, and intI using quantitative PCR. Additionally, 16S rRNA sequence libraries were created. Overall, it appeared that finisher farms were significantly different from nursery and sow farms in nearly all genes measured and in 16S rRNA clone libraries. Nearly all antibiotic resistance genes were detected in all farms. Interestingly, the mecA resistance gene (e.g. methicillin resistant Staphylococcus aureus) was below detection limits on most farms, and decreased as the pigs aged. Finisher farms generally had fewer antibiotic resistance genes, which corroborated previous phenotypic data; additionally, finisher farms produced a less diverse 16S rRNA sequence library. Comparisons of Camp-16S and spaQ GU (genomic unit) values to previous culture data demonstrated ratios from 10 to 10,000:1 depending on farm type, indicating viable but not cultivatable bacteria were dominant. The current study indicated that swine farm management schemes positively and negatively affect microbial and antibiotic resistant populations in CAFO wastewater which has future “downstream” implications from both an environmental and public health perspective.  
  Call Number Serial 1943  
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Author (up) Hua, G.; Salo, M.W.; Schmit, C.G.; Hay, C.H. file  url
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  Title Nitrate and phosphate removal from agricultural subsurface drainage using laboratory woodchip bioreactors and recycled steel byproduct filters Type Journal Article
  Year 2016 Publication Water Research Abbreviated Journal Water Res  
  Volume 102 Issue Pages 180-189  
  Keywords Bioreactors; Denitrification; *Nitrates; Phosphates; *Steel; Nitrate; Nutrient removal; Phosphate; Steel byproducts; Subsurface drainage; Woodchips bioreactors  
  Abstract Woodchip bioreactors have been increasingly used as an edge-of-field treatment technology to reduce the nitrate loadings to surface waters from agricultural subsurface drainage. Recent studies have shown that subsurface drainage can also contribute substantially to the loss of phosphate from agricultural soils. The objective of this study was to investigate nitrate and phosphate removal in subsurface drainage using laboratory woodchip bioreactors and recycled steel byproduct filters. The woodchip bioreactor demonstrated average nitrate removal efficiencies of 53.5-100% and removal rates of 10.1-21.6 g N/m(3)/d for an influent concentration of 20 mg N/L and hydraulic retention times (HRTs) of 6-24 h. When the influent nitrate concentration increased to 50 mg N/L, the bioreactor nitrate removal efficiency and rate averaged 75% and 18.9 g N/m(3)/d at an HRT of 24 h. Nitrate removal by the woodchips followed zero-order kinetics with rate constants of 1.42-1.80 mg N/L/h when nitrate was non-limiting. The steel byproduct filter effectively removed phosphate in the bioreactor effluent and the total phosphate adsorption capacity was 3.70 mg P/g under continuous flow conditions. Nitrite accumulation occurred in the woodchip bioreactor and the effluent nitrite concentrations increased with decreasing HRTs and increasing influent nitrate concentrations. The steel byproduct filter efficiently reduced the level of nitrite in the bioreactor effluent. Overall, the results of this study suggest that woodchip denitrification followed by steel byproduct filtration is an effective treatment technology for nitrate and phosphate removal in subsurface drainage.  
  Call Number Serial 1764  
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