Document Detail

Evaluation of activated sludge treatment and the efficiency of the disinfection of Giardia species cysts and Cryptosporidium oocysts by UV at a sludge treatment plant in Campinas, south-east Brazil.
MedLine Citation:
PMID:  17037138     Owner:  NLM     Status:  MEDLINE    
Among many waterborne diseases the giardiasis and cryptosporidiosis are of particular public health interest, because Giardia cysts and Cryptosporidium oocysts can persist for long periods in the environment, and both pathogenic protozoa have been implicated as the cause of many outbreaks of gastroenteritis in the last 25 years. In order to evaluate the efficiency of cysts and oocysts' removal by the activated sludge process, and by UV reactor in inactivating cysts and oocysts in one wastewater treatment plant (WWTP) of Campinas, three sampling points were selected for study: (1) influent, (2) treated effluent without UV disinfection and (3) treated effluent with UV disinfection. Giardia spp. cysts prevailed with higher density in the three different sample types. Cryptosporidium spp. oocysts were observed in only two samples of influent and just one sample of treated sewage with UV disinfection. In the animal infectivity assay for Giardia spp, one mouse of the UV treated group revealed trophozoites in intestinal scrapings. The results of the present study indicate that treatment by activated sludge process delivered a reduction of 98.9% of cysts and 99.7% of oocysts and UV disinfection was not completely efficient regarding the inactivation of Giardia cysts in the case of the WWTP studied.
R Cantusio Neto; L U Santos; J U Santos; R M B Franco
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Publication Detail:
Type:  Evaluation Studies; Journal Article    
Journal Detail:
Title:  Water science and technology : a journal of the International Association on Water Pollution Research     Volume:  54     ISSN:  0273-1223     ISO Abbreviation:  Water Sci. Technol.     Publication Date:  2006  
Date Detail:
Created Date:  2006-10-12     Completed Date:  2006-12-19     Revised Date:  2008-02-05    
Medline Journal Info:
Nlm Unique ID:  9879497     Medline TA:  Water Sci Technol     Country:  England    
Other Details:
Languages:  eng     Pagination:  89-94     Citation Subset:  IM    
Laboratory of Protozoology, Dept of Parasitology, University of Campinas (UNICAMP), Campinas, SP, Brazil.
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MeSH Terms
Cryptosporidium / isolation & purification,  radiation effects*
Giardia / isolation & purification,  radiation effects*
Mice, Inbred BALB C
Oocysts / radiation effects*
Sewage / parasitology*
Reg. No./Substance:
Erratum In:
Water Sci Technol. 2007;56(12):151
Note: Santos, J U [corrected to Santos, L U]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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