Use of coliphages to evaluate water treatment processes and determine faecal contamination origin of source waters (original) (raw)
Related papers
Viral Removal by Wastewater Treatment: Monitoring of Indicators and Pathogens
Food and Environmental Virology, 2009
The discharge of treated civil wastewater into natural waters or their reuse in industry and agriculture involves virological risks for the exposed population. Although European and Italian regulations do not require routine viral analysis of treated wastewater, a better understanding of viral contamination and resistance to treatments is needed to assess and control such risks. To this end, a wastewater treatment plant was monitored by analysing the sewage at the plant entry and exit points in order to quantify the initial presence and eventual reduction of adenovirus, Torque Teno virus, Hepatitis A virus, rotavirus, enterovirus, norovirus genogroups I and II, somatic coliphages, Escherichia coli and enterococci. The results reveal that treated water may still contain infectious human viruses and thereby represent a potential health hazard. No significant correlations were found between bacterial indicators and the viruses considered, confirming their inadequacy for virological risk assessment, while the best indicators for virus inactivation in recycled waters seem to be adenovirus, followed by somatic coliphages.
Water
Monitoring the quality of water is a requisite to prevent outbreaks related to waterborne diseases, predominantly caused by pathogens like enteric viruses, usually transmitted via the fecal-oral route. This study aimed to survey a group of enteric viruses (Enterovirus, Norovirus genogroups I and II, and hepatitis A virus) in two surface water sources of drinking water, also intending to evaluate the extent of their elimination in the two water treatment plants (WTPs) involved in drinking water production. Correlations between these viruses and fecal indicator bacteria (FIB) were also evaluated. Positive samples for viral RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR) and quantified, in genomic copies per liter (gc/L) of sampled water. Viral RNAs were detected in 14 out of 27 samples of surface water, and 21 out of 36 samples of drinking water, NoV II having been the most frequently detected in both (0–78.6 gc/L and 0–12.5 gc/L, respectively). Both WTP...
Efficiency of Traditional Water Treatment Plant and Compact Units in Removing Viruses
International Journal of Applied Sciences and Biotechnology, 2015
The fecal bacteria have been taken as the gold standard for water industry. However, the spread of viral gastroenteritis due to drinking water have given a momentum to a recent push by microbiologists to consider viruses as important pollution indicator as fecal bacteria. Therefore, we designed a study to evaluate the efficiency of two types of water purification systems: the traditional water treatment plant and two types compact units. Both systems produced drinking waters free of bacteria, chemical contaminants and mostly viruses free. However, recent advances in molecular biology techniques, such as RT-PCR have detected Rotaviruses in chlorinated drinking waters resulted from all systems. The frequency of Rotaviruses since October 2010 till September 2012 in Shark El-Mansoura WTP in drinking water samples was 12.5% similar to raw water. While the compact unit at Depo Awam (American design) the frequency of Rotavirus was 16.6% in both raw and drinking water samples. On the othe...
Waterborne Viral Pathogens: Detection, Control and Monitoring of Water Quality for Human Consumption
VIRUS Reviews & Research, 2013
The viral contamination of water for human consumption is a common cause of diseases outbreaks, therefore, a matter of great relevance for public health, especially in developing countries. In most countries, legislation recommends the study of coliforms to indicate the potability of water, however, this is not correlated with the presence of virus. The present review sought to characterize the epidemiological importance of waterborne viral diseases and the limitations of laboratorial detection and elimination of these pathogens. Besides, the state of art of virus as a tool to assess the quality of the water, as well as, the use of a single virus as the indicator of environmental contamination by virus itself are presented. Reports have demonstrated that some viruses are resistant to conventional water treatment process. Changes in water treatment policy should be achieved, and, should involve viral detection and resistance to physical and chemical agents, amongst other methods. However, we have to bear in mind that the decrease of waterborne infectious diseases is greatly dependent upon the improvement of sanitation, water treatment, together with preventive measures. All those measures together could ensure appropriate conditions for the promotion of human health and the reduction of environmental impacts.
The viral contamination of water for human consumption is a common cause of diseases outbreaks, therefore, a matter of great relevance for public health, especially in developing countries. In most countries, legislation recommends the study of coliforms to indicate the potability of water, however, this is not correlated with the presence of virus. The present review sought to characterize the epidemiological importance of waterborne viral diseases and the limitations of laboratorial detection and elimination of these pathogens. Besides, the state of art of virus as a tool to assess the quality of the water, as well as, the use of a single virus as the indicator of environmental contamination by virus itself are presented. Reports have demonstrated that some viruses are resistant to conventional water treatment process. Changes in water treatment policy should be achieved, and, should involve viral detection and resistance to physical and chemical agents, amongst other methods. How...
Detection of enteric viruses in treated drinking water
Applied and Environmental Microbiology, 1984
The occurrence of viruses in conventionally treated drinking water derived from a heavily polluted source was evaluated by collecting and analyzing 38 large-volume (65- to 756-liter) samples of water from a 9 m3/s (205 X 10(6) gallons [776 X 10(6) liters] per day) water treatment plant. Samples of raw, clarified, filtered, and chlorinated finished water were concentrated by using the filter adsorption-elution technique. Of 23 samples of finished water, 19 (83%) contained viruses. None of the nine finished water samples collected during the dry season contained detectable total coliform bacteria. Seven of nine finished water samples collected during the dry season met turbidity, total coliform bacteria, and total residual chlorine standards. Of these, four contained virus. During the dry season the percent removals were 25 to 93% for enteric viruses, 89 to 100% for bacteria, and 81% for turbidity. During the rainy season the percent removals were 0 to 43% for enteric viruses, 80 to 9...
Study of the viral removal efficiency in a urban wastewater treatment plant
Water Science and Technology, 2008
Municipal and agricultural wastewater contain a variety of microorganisms and in particular enteric viruses. For the reuse of this treated wastewater it is important to ensure the efficiency of purification treatments and disinfection practices, that have often been insufficient to lower the viral load below the risk level. For this reason, for the routine analysis of recycled waters, the research into pathogenic viruses (e.g. HAV) and classical bacterial parameters (E. coli, enterococci and Salmonella) has to be associated with specific viral indicators such as somatic coliphages, adenovirus and TTV. The results of environmental monitoring, carried out in a wastewater treatment plant, showed the presence of adenovirus DNA in 100% of collected samples and TTV DNA in 95% (19/20) of raw sewage and in 85%
Acta Hydrochimica Et Hydrobiologica, 2001
Measures devised for guaranteeing the supply of epidemiologically and hygienically sound drinking water are generally based on observations made during epidemics and the follow-up scientific studies. Despite the high level standards that have been attained in the treatment of drinking water, the drinking water-derived outbreaks still keep cropping up even in the industrialized countries. The outbreaks of the parasites Giardia lamblia and Cryptosporidium parvum, and the recent outbreak in Canada caused by Toxoplasma gondii, again focused our attention to the possible infection risk posed by pathogens in drinking water. The circumstances of the cryptosporidia outbreak in Milwaukee in 1993 can be considered as typical for such outbreaks in which parasites have caused human disease. There are generally two ways of avoiding the transmittance of pathogens by drinking water: (i) use of uncontaminated groundwater, or (ii) treatment of the potentially contaminated one. All surface waters have to be considered potentially contaminated, while the purity of the groundwater depends on the local conditions. Routine disinfection of drinking water should be used to minimize the residual risk posed by pathogens. For purification of fecally contaminated water it is utterly inadequate. Testing of water for pathogens followed by more extensive decontamination measures in the case of positive findings appears to be of little value.