Investigation of potential surrogate organisms and public health risk in UV irradiated secondary effluent

2003 ◽  
Vol 47 (9) ◽  
pp. 37-43 ◽  
Author(s):  
D. Simpson ◽  
J. Jacangelo ◽  
P. Loughran ◽  
C. McIlroy

Watercare's Mangere Wastewater Treatment Plant in Auckland, New Zealand treats sewage from a population equivalent of approximately 1,000,000. The treatment plant is currently undergoing a major upgrade, and as a part of this upgrade the largest UV disinfection plant in the world (at the time of award of the contract) is being constructed. Pilot scale investigations were undertaken at a purpose built facility. The pilot plant employed secondary treatment, sand filtration, UV disinfection and a number of low pressure membrane systems. Investigations at the facility focussed on attempting to identify relationships between potential surrogate indicator organisms (including enterococci, faecal coliforms, Clostridium perfringens spores and F-specific bacteriophage) and pathogenic organisms (including culturable human enteric viruses, bacterial pathogens and parasites). The aim of the study was to identify a suitable indicator organism and an associated effluent concentration that would ensure that an acceptable level of public health risk was maintained in the environment. The results showed that no suitable surrogate indicator organism could be found. However the results did indicate that a two tiered operating strategy, based on the concentration of enteroviruses present in raw sewage and an appropriate UV dose, would ensure that an acceptable level of public health risk was maintained in the environment.

2008 ◽  
Vol 137 (6) ◽  
pp. 803-809 ◽  
Author(s):  
K. TAKUMI ◽  
P. H. C. LINA ◽  
W. H. M. VAN DER POEL ◽  
J. A. KRAMPS ◽  
J. W. B. VAN DER GIESSEN

SUMMARYWe present the frequency and the nature of contact incidents of the Serotine bat,Eptesicus serotinus, with humans and with companion animals (specifically cats and dogs), in The Netherlands between 2000 and 2005. Out of 17 bats in bite contact with humans, five tested positive for European bat lyssavirus (EBLV) type 1a. Cats had the most numerous contacts with bats (49 times) but a relatively low number of these bats were EBLV positive (six times). We estimated that the average incidence of human bat rabies infection might be between once per year and once per 700 years, depending mainly on the number of infectious viral particles in bat saliva. The risk of bat rabies is higher between April and October, and in the northern half of the country. This is the first study in Europe describing the risk of human bat rabies after bat contact incidents.


2014 ◽  
Vol 3 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Mohamed M.A. Zeinhom ◽  
Gihan K. Abdel-Latef

PLoS ONE ◽  
2007 ◽  
Vol 2 (3) ◽  
pp. e309 ◽  
Author(s):  
Timothy J. Welch ◽  
W. Florian Fricke ◽  
Patrick F. McDermott ◽  
David G. White ◽  
Marie-Laure Rosso ◽  
...  

2011 ◽  
Vol 64 (12) ◽  
pp. 2352-2361 ◽  
Author(s):  
A. Luczkiewicz ◽  
K. Jankowska ◽  
R. Bray ◽  
E. Kulbat ◽  
B. Quant ◽  
...  

The main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus spp.). The susceptibility of fecal indicators to antimicrobial agents important in human therapy was examined. Resistance to nitrofurantoin and erythromycin was common among enterococci and followed by resistance to fluoroquinolones and tetracycline. Resistance to high-level aminoglycosides and glycopeptides was also observed. E. coli isolates were most frequently resistant to penicillins and tetracycline. The extended-spectrum beta-lactamase-producing E. coli was detected once, after ozonation. Substantial attention should be paid to the E. coli and enterococci resistant to three or more chemical classes of antimicrobials (MAR), which in general constituted up to 15 and 49% of the tested isolates, respectively. Although the applied methods were effective in elimination of fecal indicators (removal efficiency up to 99.99%), special attention has to be paid to the application of sufficient disinfection and operation conditions to avoid selection of antimicrobial resistant bacteria.


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