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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
In the United States, the number of water treatment plants increased from eighty-three in 1850 to over 4000 in 1900. The first use of chlorine to disinfect a public water supply in the U.S. was in Jersey City in 1908 and was quickly followed by installations in other cities. Water treatment developed primarily as a means of making water potable. The major techniques used in large-scale water purification continue to be coagulation and sedimentation (usually with lime and soda ash), filtration to remove suspended microparticulates, and chlorination to disinfect the water.
Fungi and Water
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Tap water or municipal water comes from lakes, rivers, underground stream, large wells, or reservoirs. Water is then processed, disinfected, and purified at treatment plants. The kind of treatment applied by a public water system varies with source type and quality. Public drinking water systems use various methods of water treatment to provide safe drinking water for their communities. Today, the four steps in water treatment used by community water systems (mainly surface water treatment) include: coagulation and flocculation; sedimentation; filtration; and disinfection (175–176).
Ecology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
The UV inactivation of the phage MS2 was enhanced by aqueous silver (Butkus et al. 2004, 2005; Kim et al. 2008). The synergistic effect of the UV irradiation with peracetic acid and H2O2 treatment against the phage MS2, as well as bacterial indicators, was demonstrated by Koivunen and Heinonen-Tanski (2005). The results of the UV295 nm/H2O2 advanced oxidation process led to the conclusion that the disinfection due to the presence of OH radicals was very small compared to the damage from the UV irradiation, although for the MS2 and the DNA coliphages T4 and T7 tested, there might be some oxidative enhancements that could assist disinfection efficacy (Mamane et al. 2007). The phage MS2 was used by the advanced UV/H2O2 oxidation study that compared efficiency of low-pressure and medium-pressure UV lamps for the treatment of natural waters containing micropollutants (IJpelaar et al. 2010). Then, sequential application of the UV as a primary disinfectant with and without H2O2 addition followed by free chlorine as secondary disinfectant was studied with the phage MS2 and B. subtilis spores as indicators (Cho et al. 2011). It was concluded that the efficiency of UV/free chlorine sequential disinfection processes, which were widely employed in drinking water treatment, could be significantly enhanced by adding H2O2 in the primary step and hence converting the UV process to an advanced oxidation process.
Perception of proposed preliminary food-based dietary guidelines for Lake Victoria region of Kenya: findings from a qualitative study among adult community members
Published in South African Journal of Clinical Nutrition, 2023
EC Korir, PJ Tuitoek, D Marais
The ‘whole cereal grains’, translated to mean ‘locally milled flour’ was described as ‘heavy’, having ‘more energy’ with enhanced ‘satiety’. The high fibre content in the locally milled flour is likely to increase bulk in meals, delay digestion, give a feeling of fullness for a longer time and thus delay the onset of hunger pangs. Alongside the locally milled flour, traditional foods such as cassava and bananas were described as ‘natural’, ‘harvested directly from the farm’ ‘without chemicals’. Similarly, the use of water treatment chemicals was associated with harm. The ‘naturalness’ characteristic of food has been noted as important in people’s perceptions of healthy eating.19 Although the participants linked the dietary shifts to emerging diseases including diabetes, the consumption of traditional foods was viewed as a diabetic diet and not a healthy eating choice. It may be necessary to incorporate simple explanations of benefits accrued from adherence to the FBDGs when developing educational materials for the community.
Nanogel-based coating as an alternative strategy for biofilm control in drinking water distribution systems
Published in Biofouling, 2023
Olga Sójka, Damla Keskin, Henny C. van der Mei, Patrick van Rijn, Maria Cristina Gagliano
Globally, the biofilm control approach in DWDS often involves disinfection strategies via chlorination and chloramination (Al Abri et al. 2019; Li et al. 2021). However, chlorine is incapable of complete inhibition of biofilm growth, affecting only the periphery of the EPS matrix, and does not target microorganisms within the biofilm (Liu et al. 2016). Chlorine has limited penetration within the biofilm matrix due to its reaction with organic and inorganic compounds (Schwering et al. 2013); this reaction with organics also produces harmful disinfection by-products, which are suspected human carcinogens (Le Roux et al. 2017). Water companies that resigned from chlorination, focus on limiting the organic matter and nutrients essential for bacterial growth through improved water treatment (Park et al. 2021). Nevertheless, it has been reported that oligotrophic bacteria are still found to accumulate and form biofilms even when little to no molecules, neither organic nor inorganic, are present in the water stream (Kulakov et al. 2002). Common cleaning practices, such as periodic pipe flushing with increased water velocity, also do not completely remove the biofilm since they were found to mobilize and remove only loose biofilm clusters (Douterelo et al. 2013).
Monitoring of 2,4-dichlorophenoxyacetic acid concentration in Karun River and effluents of water treatment plants
Published in Toxin Reviews, 2022
Naghmeh Orooji, Afshin Takdastan, Reza Jalilzadeh Yengejeh, Sahand Jorfi, Amir Hossein Davami
The first samples were taken from the raw water in the inlet of the treatment plants before the cropping season to determine 2,4-D concentration. Several samples were also taken from the operational and process units of the treatment plants and then analyzed. All samples were taken and stored under the Standard Methods for the Examination of Water and Wastewater (APHA 2017). Before sampling, all sampling containers were washed with detergent and twice distilled water. Then, the containers were completely washed with methanol and acetonitrile. Finally, the washed containers were heated in an oven at 400 °C for 2 h (Acero et al.2008). The solution pH of the samples was reduced to 2 at the sampling site using hydrochloric acid. S2 presents a summary of common operations and processes used in the studied water treatment plants.