Journal of High Institute of Public Health (Dec 2008)
Assessment of Bacteriological Quality of Drinking Water in some Household Water Filter Systems in Benghazi City
Abstract
Water is very important to human beings. Although human life can exist for many days without food, the absence of water for only a few days has fatal consequences. A wide variety of commercial water treatment systems are available for application to treat very small quantities, such as for individual homes or taps. These can treat virtually any water quality problem. It is important to have a good understanding of the specific water quality problems before selecting water treatment system. It is also important that products be tested and approved by a qualified independent certification organization to have confidence that the device will indeed perform as the vendor claims. The present study aimed to assess the bacteriological quality of drinking water in some household water filter systems inBenghazi city. The study was carried out on a total of 600 water samples (300 tap water samples and 300 filter water devices samples). All water samples were examined for enumeration of viable heterotrophic bacteria by pour plate method and enumeration of total coliforms (TC) by both the multiple tube fermentation (MTF) and membrane filtration (MF) methods and for thermotolerant coliforms (TTC), Fecal streptococci (FS), and Pseudomonas aeruginosa (P. aeruginosa) by the MF method. According to Libyan guidelines, out of 600 examined drinking water samples 76.8% were acceptable. The highest percentage of acceptable samples was revealed from reverse osmosis (RO) system (90.7%), followed by charcoal filter (83.3%), tap water distribution system (DS) (82.3%), and only 54.7% from tap water tanks. It was concluded from this study that filtered water samples were found to be superior to tap water samples as regards their bacteriological aspects. In addition, P. aeruginosa was considered as an excellent indicator for the efficiency of the water filters.
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