Virus removal from water by a portable water treatment device (original) (raw)
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Water Research, 1997
Abstraet-A point-of-use (POU) water treatment system (WTS), comprised of a pressed activated carbon block filter followed by an ultraviolet (UV) light reactor, was evaluated for microbial disinfection efficacy following the general guidelines of the United States Environmental Protection Agency Guide Standard and Protocol for Testing Microbiological Water Purifiers. The POU WTS was challenged against bacterial, viral and protozoan waterborne pathogens including Vibrio cholerae, Shigella dysenteriae serotype 2, Escherichia coli 0157:H7, Salmonella typhi, hepatitis A virus strain HM 175, poliovirus type i strain Lsc2ab, simian rotavirus SAIl, Cryptosporidium parvum oocysts, Giardia lamblia cysts and coliphage MS2. The POU WTS was tested for the removal/inactivation of each challenge organism in separate 16-to 20-day test periods under various conditions of water quality, at the system's maximum recommended flow rate and at 70% of the lamps normal UV intensity. For each organism tested, microbial challenges were conducted over the course of the test period at 0, 50, 100 and 150% of the system manufacturer's rated water treatment capacity. Each microbial challenge consisted of 30 L of influent water containing approximately 105 bacterial cfu/mL, 104 viral pfu/mL or 103 protozoan cysts/mL. Influent and effluent water samples were taken during the challenges and assayed for the particular pathogen and the percent reduction calculated. Effluent water samples were also taken and assayed for the possible presence of the pathogens following two 60-h stagnation periods. The POU WTS was found to effectively remove and/or inactivate greater than 99.9999% of the bacterial pathogens, greater than 99.99% of the viruses and greater than 99.9% of the protozoan cysts and oocysts tested to 150% of the water treatment capacity of the POU WTS. These findings suggest that a properly designed and operated POU WTS may be a practical approach to removing microbiological waterborne pathogens from drinking water.
Applied and Environmental Microbiology, 2009
The U.S. Environmental Protection Agency's information collection rule requires the use of 1MDS electropositive filters for concentrating enteric viruses from water, but unfortunately, these filters are not costeffective for routine viral monitoring. In this study, an inexpensive electropositive cartridge filter, the Nano-Ceram filter, was evaluated for its ability to concentrate enteroviruses and noroviruses from large volumes of water. Seeded viruses were concentrated using the adsorption-elution procedure. The mean percent retention of seeded polioviruses by NanoCeram filters was 84%. To optimize the elution procedure, six protocols, each comprising two successive elutions with various lengths of filter immersion, were evaluated. The highest virus recovery (77%) was obtained by immersing the filters in beef extract for 1 minute during the first elution and for 15 min during the second elution. The recovery efficiencies of poliovirus, coxsackievirus B5, and echovirus 7 from 100-liter samples of seeded tap water were 54%, 27%, and 32%, respectively. There was no significant difference in virus recovery from tap water with a pH range of 6 to 9.5 and a water flow rate range of 5.5 liters/min to 20 liters/min. Finally, poliovirus and Norwalk virus recoveries by NanoCeram filters were compared to those by 1MDS filters, using tap water and Ohio River water. Poliovirus and Norwalk virus recoveries by NanoCeram filters from tap and river water were similar to or higher than those by the 1MDS filters. These data suggest that NanoCeram filters can be used as an inexpensive alternative to 1MDS filters for routine viral monitoring of water.
Water Treatment Challenges towards Viruses Removal
Open Access Library Journal, 2020
In spite of the considerable development registered in microbiology, humankind remains incapable to dominate scientifically and technologically the large microbial world. This is well established and illustrated, unfortunately, in the present Coronavirus disease (COVID-19) pandemic. This work aims to contribute to highlighting the world of pathogenic microorganisms, especially viruses, and their removal from potable water. Identical to the manner by which chemical contaminants are handled in the environment, the particular properties that control transport and demobilization of enveloped viruses in solutions, on surfaces, and in the air must be understood. Besides, the fashion by which ecological parameters form likely virus transmission and mutation mechanisms should be comprehended. Since water treatment constitutes a secure barrier against drinking water infection, the main stages in the water treatment plant dealing with pathogens removal such as disinfection have to be enhanced with more efficient techniques such as advanced oxidations processes. In the field of eliminating pathogens, some research trends are suggested especially those founded on thermal destruction and solar irradiation due to their high performance and low costs.
On the Other Side of Viruses in the Background of Water Disinfection
Open Access Library Journal, 2020
At COVID-19 time, as surface water and urban wastewater will constantly carry microbial pathogens, pathogens should be eliminated at least to degrees that do not have an effect on public health. Among the pathogen groups observed in water, viruses constitute the biggest danger since they frequently appear in much bigger levels and possess much greater infectivity than bacteria and parasitic protozoa. This work highlights the viruses especially in terms of composition and behavior in ecosystems and discusses the main disinfec-tion techniques, especially thermal demobilization, chlorination and ozona-tion, and their involved mechanisms. Precise estimates of viral demobilization and log removal throughout water treatment techniques stay crucial for evaluating danger to human health, developing regulations, and informing engineering design of full-scale treatment plants. Practical demobilization details developed at bench-scale for human pathogens like norovirus and COVID-19 will be vital. The more we study the composition of viruses and their fate in ecosystems, and the more we try the techniques for their disposal in water treatment plants, the more we realize that it is difficult to get rid of them using a single treatment method. Employing advanced water treatment trains (such as coagulation, reverse osmosis, ultrafiltration, advanced oxidation) was proposed to guarantee removals of viruses to differing degrees of regulatory control following the degrees of human subjection and related health hazards.
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...
Integrating Virus Monitoring Strategies for Safe Non-Potable Water Reuse
Water
Wastewater reclamation and reuse have the potential to supplement water supplies, offering resiliency in times of drought and helping to meet increased water demands associated with population growth. Non-potable water reuse represents the largest potential reuse market. Yet, economic constraints for new water reuse infrastructure and safety concerns due to microbial water quality, especially viral pathogen exposure, limit the widespread implementation of water reuse. Cost-effective, real-time methods to measure or indicate the viral quality of recycled water would do much to instill greater confidence in the practice. This manuscript discusses advancements in monitoring and modeling viral health risks in the context of water reuse. First, we describe current wastewater reclamation processes and treatment technologies with an emphasis on virus removal. Second, we review technologies for the measurement of viruses, both culture- and molecular-based, along with their advantages and di...
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.
Efficacy of a solar still in destroying virus and indicator bacteria in water for human consumption
Natural water distillation can destroy and/or inactivate microorganisms that are sensitive to heat and ultraviolet radiation (UV). This method is currently used to provide fresh water in ships and in the desalination of brackish water. For the development of this research, a pilot-scale solar still was built and installed in the southern region of Brazil, in order to assess its efficiency in water disinfection, which was based on the most probable number (MPN) of total coliforms and Escherichia coli, in addition to the DNA copy number of human adenovirus type 5 (HAdV-5) in raw, undistilled samples and in treated distilled water. Results showed that the distillation process removed 100% of total coliform and Escherichia coli and 4.5 log (99.997%) of HAdV-5, which meets the microbiological standards for drinking water according to national Brazilian regulations, as well as USEPA and HEALTH CANADA requirements.
Journal of Water and Health, 2014
Municipal water disinfection systems in some areas are not always able to meet water consumer needs, such as ensuring distributed water quality, because household water management can be a contributing factor in water re-contamination. This fact is related to the storage options that are common in places where water is scarce or is distributed over limited time periods. The aim of this study is to assess the removal capacity of a multiple-barrier water disinfection device for protozoa, bacteria, and viruses. Water samples were taken from households in Mexico City and spiked with a known amount of protozoa (Giardia cyst, Cryptosporidium oocyst), bacteria (Escherichia coli), and viruses (rotavirus, adenovirus, F-specific ribonucleic acid (FRNA) coliphage). Each inoculated sample was processed through a multiplebarrier device. The efficiency of the multiple-barrier device to remove E. coli was close to 100%, and more than 87% of Cryptosporidium oocysts and more than 98% of Giardia cysts were removed. Close to 100% of coliphages were removed, 99.6% of the adenovirus was removed, and the rotavirus was almost totally removed. An effect of site by zone was detected; this observation is important because the water characteristics could indicate the efficiency of the multiple-barrier disinfection device.