Filtration as a sample concentration method of water samples - Research Paper Example

Filtration as a Sample Concentration Method of Water Samples Affiliation Water is an important part of life.Environmental microbiologists have had to assess the quality of water for purposes of safety and health preservation. The paper is divided into three sections. The introduction touches on the overall aspects and principles of filtration as a concentration method. The body exclusively covers the types of microorganisms that are tested during water quality assessment such as coliforms with the filtration method been used in the respective studies. It also looks at the different types of filtrations; ultrafiltration, membrane filter, and new filtration types like the biofilm filtration as presented in studies. In conclusion, the paper finds that filtration is vastly used in the concentration of environmental water samples for water quality testing. Filtration as a Sample Concentration Method of Water Samples Introduction Water is an essential constituent of life. In fact, human beings cannot do without water. Water is a biological, physical, and chemical component that bears a huge influence on life as it is known on Earth. Hence, researchers from diverse fields have sought to come up with ways to manipulate water in order to achieve certain aims that are beneficial to life. However, in the process of the day-to-day activities, human beings have polluted water by dumping waste into it. In addition, varying microorganisms that are harmful to human health tend to exist in contaminated water. These microorganisms are the reason why microbiologists spend a huge part of their time, resources, and knowledge into devising ways through which contaminated water can be purified and declared fit for human consumption. The main aim being to protect the health of human beings. Thus, microbiologists have developed various techniques that are utilized to recuperate microorganisms from water samples. One such method is filtration. In environmental microbiology, filtration is used as a sample concentration method to recover microorganisms. It is duly applied in water quality analysis. Hence, the paper seeks to describe what researchers have found in regard to filtration as a sample concentration method for water quality analysis. In the testing of the quality of water, numerous microorganisms that are of interest to microbiologists exist. However, testing of the quality of water is affected by the low quantity levels of each type of microorganism present in the water. Hence, that is why filtration is an important water sample concentration method. Utilizing filtration uses the principle that microorganisms are treated as particles. Therefore, through the use of a physical barrier, particles, in this case microorganisms, of a certain size and mass cannot pass through the physical barrier. However, particles or microorganisms of a smaller size pass through the barrier. Nevertheless, the filtration barrier is relative; hence, the sizes can be increased or decreased as per the research. According to Douterelo, et al. (2014, p. 137) the principle of filtration as a concentration technique in the analysis of the quality of water is dependent. It is dependent on the functioning of microorganisms as if they are particles, which cannot bend. However, if they are capable of bending when pressure is applied, then the possibility of the microorganisms to go through the pores, which in essence may be regarded as minute that their real size at normal pressure and temperature. To gaining a better understanding of how filtration is used as a sample concentration method, ultrafiltration and membrane filtration are examined. However, due to the limitation of research concerning the application of ultrafiltration in environmental microbiology concerning water quality evaluation, a bigger emphasis shall be given to membrane filtration. According to Koster, et al., (2001, p. 240), ultrafiltration is a technique that makes use of membranes. The membranes are specialized, such as those of Tween 80 and Sodium polysulphate, all of them at a concentration of 0.01% (Mitchell & Gu, 2010, p. 72). Pressure has to be applied on the water sample for the technique to work. Hence, during ultrafiltration, particles, or microorganisms for this matter, with a diameter of 0.02 µm or greater do not move through the specific membrane (Koster, et al., 2001, p. 241). The researchers assert that phages and viruses do not pass through because they have a bigger diameter, which means they are retained. In addition, they note of several filter systems that are used. They include sheet membranes and spiral wound. For the sheet membranes, water is run against them with the assistance of a pump. Doing so boosts the filtration, hinders obstruction, and leads to a near 100% recovery yield. For ultrafiltration, it is specified that it give a big recovery. Extremities associated with the pH do not destroy microorganisms such as phages and viruses. In addition, there is little adsorption to the membranes by phages and viruses. Nevertheless, the ultrafiltration membranes are easily obstructed, which implies that the amount of water samples that can be concentrated is limited (Koster, et al., 2001, p. 241). An example where ultrafiltration has been utilized is the in the study done by Ahmed, Hodgers, Sidhu, and Toze (2012). In this study, the water samples were concentrated using a hollow-fiber ultrafiltration technique (Hodgers, Sidhu, and Toze, 2012, p. 220). The technique had filters termed as Hemoflow (Hodgers, Sidhu, and Toze, 2012, p. 220). As per the given procedure, the concentration of water samples using this ultrafiltration method employed a peristaltic pump-to-pump water and a filter cartridge for water retrieval (Hodgers, Sidhu, and Toze, 2012, p. 220). The concentration of these water samples was conducted to roughly 100 ml (Hodgers, Sidhu, and Toze, 2012, p. 220). The membrane filter technique is widely used in environmental microbiology to analyze various types of microorganisms. Bordner, Winter, and Scarpino (2007, p. 161) summarize membrane filtration as follows. It is the passage of the water sample through pressure that is positive. The water sample goes through a pore of 0.45 µm pore. The diameter of the filter is 142 mm. It is placed in a system unit that uses pressure. Once filtration has been conducted. The membrane filter is segmented aseptically into varying segments, which are then put into enrichment media (Bordner, Winter, and Scarpino, 2007, p. 161). The membrane filtration technique of has been used in numerous researches to concentrate water samples in order to assess specific microorganisms. One such research is that conducted by HSU and Williams (1982). In this research, the researchers opine that the membrane filter technique is widely used and accepted in the evaluation of water treatment. In specific, they indicate that the federal Safe Drinking Water Act Regulations do commend the method. They also state that the filtration method is used in water testing quality to check for coliform quantity. In a research by Cabral (2010, p. 3658), it is stated that water is fundamental to life. The study looks at water contamination by animal or human fecal matter. The research notes that many bacterial agents can be found in contaminated water. The study evaluates different kinds of these bacterial agents. Of importance to this paper are the coliforms, which are described a non-spore forming rods, gram-negative, and as lactose fermenters. The research indicates that studies conducted on water samples collected from the environment positive results are obtained for Enterobacter, Klebsiella, Citrobacter, and Escherichia (Cabral 2010, p. 3680). Nevertheless, it is asserted that these coliforms are not a determination of fecal contamination. However, while testing for fecal coliforms, it is indicated that filtration through the membrane is carried out during testing. Thus, the technique is said to be quite sensitive and is done for water samples that are minimally contaminated (Cabral 2010, p. 3681). Maheux, et al. (2014, p. 4074) note that coliforms have been used as water quality indicators since the start of the Twentieth century. The researchers note that if total coliforms are present in water, then it means that the water system is compromised. As a result, environmental microbiologists use their testing to assess the quality of water. The study made use of membrane filtration as per the guidance of the research previously undertaken by Maheux et al. (Maheux, et al., 2014, p. 4083). In the outlined procedure, Millipore filters are used (Maheux, et al., 2014, p. 4075). Two other studies that used filtration to concentrate water samples collected for the evaluation of the water quality are those by Tissier, Denis, Hartemann, and Gassilloud (2012) and Maheux, et al. (2013). In the latter, membrane filtration has been used as the concentration technique for the water samples. The type of filters utilized were the GN-6 membranes (Maheux, et al., 2013, p. 7657). In the former, the researchers collected 20 L of groundwater. They applied micro-filters in the concentration of the groundwater samples. The types used were flat disc, charge-enhanced diatomaceous cellulose, cellulose ester, and an electropositive flat filter (Tissier, Denis, Hartemann, and Gassilloud, 2012, p. 840). In addition to the two water sample concentration methods, using filtration, to test for the quality of water, new filtration techniques have been developed. Wendt, et al. (2015, p. 765) opine that a filtration system has to sustain enough microbial lessening levels for long durations and process huge water volumes. As per the study, the new filtration methods were described as bio-filter systems. Hence, it can be concluded that filtration is one of the most widely used water concentration methods in water quality treatment. The studies given have shown how widespread filtration is in environmental microbiology. Furthermore, research shows that novel filtration methods can be developed for the purposes of water treatment. References Ahmed, W., Hodgers, L., Sidhu, J. P., & Toze, S. (2012). Fecal Indicators and Zoonotic Pathogens in Household Drinking Water Taps Fed from Rainwater Tanks in Southeast Queensland, Australia. Applied and Environmental Microbiology, 78(1), 219-226. Bordner, R., Winter, J. A., & Scarpino, P. (Eds.). (2007). Microbiological Methods for Monitoring the Environment : Water and Wastes. Virginia: Environmental Protection Agency, Office of Research and Development, Environmental Monitoring and Support Laboratory. Cabral, J. P. (2010). Water Microbiology. Bacterial Pathogens and Water. International Journal of Environmental Research and Public Health, 7(10), 3657-3703. Douterelo, I., Boxall, J. B., Deines, P., sEKAR, r., fISH, k. e., & bIGGS, C. A. (2014). Methodological approaches for studying the microbial ecology of drinking water distribution systems. Water Research, 65, 134-156. HSU, S. C., & Williams, T. J. (1982). Evaluation of Factors Affecting the Membrane Filter Technique for Testing Drinking Water. Applied and Environmental Microbiology, 44(2), 453-460. Koster, W., Egli, T., Ashbolt, N., Botzenhart, K., Burlion, N., Endo, T., . . . Rust, A. (2001). ANALYTICAL METHODS FOR MICROBIOLOGICAL WATER QUALITY TESTING. World Health Orgabization. Maheux, A. F., Berube, E., Boudreau, D. K., Villeger, R., Cantin, P., Boissinot, M., . . . Bergeron, M. G. (2013). Abilities of the mCP Agar Method and CRENAME Alpha Toxin-Specific Real-Time PCR Assay To Detect Clostridium perfringens Spores in Drinking Water. Applied and Environmental Microbiology, 79(24), 7654-7661. Maheux, A. F., Boudreau, D. K., Bisson, M., Dion-Dupont, V., Bouchard, S., Nkuranga, M., . . . Rodriguez, M. J. (2014). Molecular Method for Detection of Total Coliforms in Drinking Water Samples. Applied and Environmental Microbiology, 80(14), 4074-4084. Mitchell, R., & Gu, J. (Eds.). (2010). Environmental Microbiology. Hoboken: John Wiley & Sons. Tissier, A., Denis, M., Hartemann, P., & Gassilloud, B. (2012). Development of a Rapid and Sensitive Method Combining a Cellulose Ester Microfilter and a Real-Time Quantitative PCR Assay To Detect Campylobacter jejuni and Campylobacter coli in 20 Liters of Drinking Water or Low-Turbidity Waters. Applied and Environmental Microbiology, 78(3), 839-845. Wendt, C., Ives, R., Hoyt, A. L., Conrad, K. E., Longstaff, S., Kuennen, R. W., & Rose, J. B. (2015). Microbial Removals by a Novel Biofilter Water Treatment System. The American Journal of Tropical Medicine and Hygiene, 92(4), 765-772. Read More