Category Archives: POU/POE Treatment

Arsenic Removal by Table Top Water Pitcher Filters

Barnaby R, Liefeld A, Jackson BP, Hampton TH, Stanton, BA. Effectiveness of table top water pitcher filters to remove arsenic from drinking water. Environmental research. 2017 Jul 15;158:610-615. doi: 10.1016/j.envres.2017.07.018.

Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As3+ and As5+, from 1000μg/L to < 3μg/L, well below the MCL. Moreover, the amount of total dissolved solids or competing ions did not affect the ability of the ZeroWater® filter to remove arsenic below the MCL. Thus, the ZeroWater® pitcher filter is a cost effective and short-term solution to remove arsenic from drinking water and its use reduces plastic waste associated with bottled water.

Point of Use Filters for Waterborne Pathogen Removal

Totaro M, Valentini P, Casini B, Miccoli M, Costa AL, Baggiani A. Experimental comparison of point-of-use filters for drinking water ultrafiltration. J Hosp Infect. 2016 Dec 1. pii: S0195-6701(16)30543-6. doi: 10.1016/j.jhin.2016.11.017.

BACKGROUND: Waterborne pathogens such as Pseudomonas spp. and Legionella spp. may persist in hospital water networks despite chemical disinfection. Point-of-use filtration represents a physical control measure that can be applied in high-risk areas to contain the exposure to such pathogens. New technologies have enabled an extension of filters’ lifetimes and have made available faucet hollow-fibre filters for water ultrafiltration.

AIM: To compare point-of-use filters applied to cold water within their period of validity.

METHODS: Faucet hollow-fibre filters (filter A), shower hollow-fibre filters (filter B) and faucet membrane filters (filter C) were contaminated in two different sets of tests with standard bacterial strains (Pseudomonas aeruginosa DSM 939 and Brevundimonas diminuta ATCC 19146) and installed at points-of-use. Every day, from each faucet, 100 L of water was flushed. Before and after flushing, 250 mL of water was collected and analysed for microbiology.

FINDINGS: There was a high capacity of microbial retention from filter C; filter B released only low Brevundimonas spp. counts; filter A showed poor retention of both micro-organisms.

CONCLUSION: Hollow-fibre filters did not show good micro-organism retention. All point-of-use filters require an appropriate maintenance of structural parameters to ensure their efficiency.

Comparison of 4-Point of Use Water Filters

Pérez-Vidal A, Diaz-Gómez J, Castellanos-Rozo J, Usaquen-Perilla OL. Long-term evaluation of the performance of four point-of-use water filters. Water Research. 2016 Apr 12;98:176-182. doi: 10.1016/j.watres.2016.04.016.

Despite technological advances water supply quality and poor access to safe water remain a major problem in developing countries, especially in rural areas. Point-of-use (POU) water treatment has been shown to be a viable option to produce safe drinking water quality. The aim of this study was to evaluate, under laboratory conditions over 14 months, the performance of four household filtration systems: membrane filter (MF), one-candle ceramic filter (1CCF), two-candle ceramic filter (2CCF) and pot ceramic filter (PCF). The evaluation was made using spiked water having the required concentrations of turbidity, Escherichiacoli and Total Dissolved Solids (TDS). The results show that all systems have high removal efficiencies for turbidity (98-99%), and E. coli 4-5 Log Reduction Value (LRV). The poorest efficiency was for TDS (9-18%). The MF and the CCF displayed no significant difference in efficiencies for these parameters. The PCF had less significant differences for turbidity removal than the other systems. The average filtration rate for all systems decreased during the operation time. The CPF showed the major potential to be used in rural communities mainly for its low operational level and maintenance requirements as well as its local craftsmanship. It was observed that the efficiency of the systems is highly sensitive to cleaning and maintenance activities and therefore, the system sustainability will depend considerably on the training and education of the potential users.

Evaluation of a Handheld UV Disinfection Unit

Timmermann LF, Ritter K, Hillebrandt D, Küpper T. Drinking water treatment with ultraviolet light for travelers – Evaluation of a mobile lightweight systemTravel Medicine and Infectious Disease. 2015 Nov 6. pii: S1477-8939(15)00174-X. doi: 10.1016/j.tmaid.2015.10.005.

BACKGROUND: The SteriPEN® is a handheld device for disinfecting water with ultraviolet (UV) radiation. The manufacturer claims a reduction of at least 99.9% of bacteria, viruses, and protozoa. The present study intends to verify the general effectiveness of the device. Furthermore, the influence of bottle geometry and water movement is examined and the issue of user safety with regard to UV-C radiation is addressed.

METHODS: The device was applied on water containing a known number of microorganisms (Escherichia coli, Staphylococcus aureus, and the spore of Geobacillusstearothermophilus) and the survival rate was examined. Three different types of bottles commonly used among travelers served as test containers. All tests were conducted with and without agitating the water during irradiation. Furthermore, a spectral analysis was performed on the light of the device.

RESULTS: The SteriPEN® reached a mean reduction of more than 99.99% of bacteria and 99.57% of the spores when applied correctly. However, the results of the trials without agitating the water only yielded a 94.98% germ reduction. The device’s maximal radiation intensity lies at 254 nm which is the wavelength most efficient in inactivating bacteria. The UV-C fraction is filtered out completely by common bottle materials. However, when applied in larger containers a portion of the UV-C rays exits the water surface.

CONCLUSIONS: If applied according to the instructions the device manages a satisfactory inactivation of bacteria. However, it bears the danger of user errors relevant to health. Therefore, education on the risks of incorrect application should be included in the travel medical consultation. Also there are still aspects that need to be subject to further independent research.

POU Reverse Osmosis Units Require Careful, On-Going Maintenance

Sacchetti R, De Luca G, Guberti E, Zanetti F. Quality of Drinking Water Treated at Point of Use in Residential Healthcare Facilities for the Elderly. International Journal of Environmental Research and Public Health. 2015 Sep 9;12(9):11163-77. doi: 10.3390/ijerph120911163.

Municipal tap water is increasingly treated at the point of use (POU) to improve the acceptability and palatability of its taste. The aim of this study was to assess the bacteriologic and nutritional characteristics of tap water treated at the point of use in residential healthcare facilities for the elderly. Two types of POU devices were used: microfiltered water dispensers (MWDs) and reverse-osmosis water dispensers (ROWDs). All samples of water entering the devices and leaving them were tested for the bacteriological parameters set by Italian regulations for drinking water and for opportunistic pathogens associated with various infections in healthcare settings; in addition, the degree of mineralization of the water was assessed. The results revealed widespread bacterial contamination in the POU treatment devices, particularly from potentially pathogenic species. As expected, the use of ROWDs led to a decrease in the saline content of the water. In conclusion, the use of POU treatment in healthcare facilities for the elderly can be considered advisable only if the devices are constantly and carefully maintained.

Coliphage as Human-Virus Surrogates

Gerba CP, Abd-Elmaksoud S, Newick H, El-Esnawy NA, Barakat A, Ghanem H. Assessment of Coliphage Surrogates for Testing Drinking Water Treatment Devices. Food and Environmental Virology. 2014 Nov 16.

Test protocols have been developed by the United States Environmental Protection Agency (USEPA) and the World Health Organization (WHO) to test water treatment devices/systems that are used at the individual and home levels to ensure the removal of waterborne viruses. The goal of this study was to assess if coliphage surrogates could be used in this testing in place of the currently required use of animal or human enteric viruses. Five different coliphages (MS-2, PRD1, ΦX-174, Qβ, and fr) were compared to the removal of poliovirus type 1 (LSc-2ab) by eight different water treatment devices/systems using a general case and a challenge case (high organic load, dissolved solids, and turbidity) test water as defined by the USEPA. The performance of the units was rated as a pass/fail based on a 4 log removal/inactivation of the viruses. In all cases, a failure or a pass of the units/system for poliovirus also corresponded to a pass/fail by all of the coliphages. In summary, in using pass/fail criteria as recommended under USEPA guidelines for testing water treatment device/systems, the use of coliphages should be considered as an alternative to reduce cost and time of testing such devices/systems.

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Exposure to Silver Released From Modified Activated Carbon

Garboś S, Swiecicka D. Human exposure to silver released from silver-modified activated carbon applied in the new type of jug filter systems. Roczniki Państwowego Zakładu Higieny. 2013;64(1):31-6.

BACKGROUND: A water filtered by jug filter system (JFS) can be applied for the preparation of food products, as well as it can be directly consumed as drinking water. In the European Union, in both above-mentioned cases the quality of water filtered using JFSs has to fulfill the requirements listed in Directive 98/83/EC. However, Directive 98/83/EC sets no parametric value for silver, JFSs are not regulated under this legislative act and additionally, silver-modified activated carbon (applied in such systems) has not been approved by European Food Safety Authority (EFSA). Therefore, the exposure to this metal should be assessed for all JFSs containing filtration cartridges with silver-modified activated carbon, present on the retail market.

OBJECTIVE: A comprehensive study was conducted in order to examine the effect ofJFSs (consisted of filtration oval-cartridges of the new type with silver-modified activated carbon) on the quality of filtered water regarding the released amounts of silver. Silver migration from such type of cartridges has not been examined before. The aim of work was the assessment of exposure to silver released into filtered water from silver-modified activated carbon applied in such types of FSs.

MATERIAL AND METHODS: Silver migration from six brands of JFSs (A-F) was investigated according to British Standard BS 8427:2004 using a validated inductively coupled plasma mass spectrometry method.

RESULTS: The average daily silver concentrations in the composite samples collected on six measurement days for A, B, C, D, E and F JFSs were in the ranges of: 3.95-18.1 microg/l, 4.6-21.7 microg/l, 0.41-8.7 microLg/l, 6.9-10.9 microg/l, 3.3-17.1 microg/1 and 10.1-20.8 pg/1l, respectively. The established grand mean concentrations of released silver from all six oval cartridges were in the range of 2.7-14.3 jg/1. The estimated Hazard Quotient (HQ) indices were in the range of 0.015-0.082

CONCLUSIONS:. The estimated HQ indices were significantly lower than 1 and therefore no long-term risk for human health could be expected. All the investigated JFSs of the new type meet previously established provisional migration limit for silver from such systems–25 microg/L.