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1
Matsumoto, Takahiro, Ichiro Tatsuno e Tadao Hasegawa. "Instantaneous Water Purification by Deep Ultraviolet Light in Water Waveguide: Escherichia Coli Bacteria Disinfection". Water 11, n. 5 (9 maggio 2019): 968. http://dx.doi.org/10.3390/w11050968.
Testo completoAbstract (sommario):
The necessity of small water purification equipment has been increasing in recent years as a result of frequent natural disasters. Ultraviolet (UV) radiation treatment is an effective method for the disinfection of bacterial contaminants in water. As an emerging technology, disinfection by deep-ultraviolet light-emitting diodes (DUV-LEDs) is promising. Few studies have used the point-source characteristics of LEDs and have instead replaced mercury vapor lamps with LEDs. Here, we demonstrate the instantaneous purification of contaminated water by combining the point source characteristics of DUV-LEDs with a water waveguide (WW). The principle is based on the WW region acting as an effective DUV disinfector, whereby a high UV dose in a confined WW region can be applied to bacterial contaminants in a short period of time (around one second). We demonstrate the effect of this DUV-LED WW disinfection technique by showing the results of 3-log disinfection levels of water contaminated with Escherichia coli bacteria after a short treatment time. We believe that the combination of the point-source nature of DUV-LED emission, the water-waveguide effect, and a small photovoltaic cell paves the way toward environmentally friendly and emergency preparedness portable water purification equipment that instantaneously supplies clean water just before drinking.
2
Gibbons, J., e S. Laha. "Water purification systems: a comparative analysis based on the occurrence of disinfection by-products". Environmental Pollution 106, n. 3 (settembre 1999): 425–28. http://dx.doi.org/10.1016/s0269-7491(99)00097-4.
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STRUTYNSKA, Lesya. "EVALUATION OF ECONOMIC EFFICIENCY OF INNOVATIVE WATER TREATMENT TECHNOLOGIES OF SWIMMING POOLS AND WATER PARKS". Herald of Khmelnytskyi National University. Economic sciences 308, n. 4 (28 luglio 2022): 202–9. http://dx.doi.org/10.31891/2307-5740-2022-308-4-32.
Testo completoAbstract (sommario):
Typical processes of water purification and water treatment of water park pools are considered. The method of economic estimation of efficiency of their application is offered. The methodology is based on the introduction of a number of indicators of the quality of the water treatment process of calculating the coefficient of “efficiency criterion” of water treatment of swimming pools. The purpose of this study was to develop an innovative technology of electrolytic-cavitation water treatment for swimming pools and water parks and to create a method of comparative evaluation of the effectiveness of modern water treatment technologies. A new technological scheme of electrolytic-cavitation water purification of public water bodies is proposed. A mathematical dependence has been created, which allows to objectively assess the effectiveness of various methods of water treatment and purification using the proposed indicator called “efficiency criterion” It is established that the proposed method of electrolytic-cavitation water purification has the highest values of efficiency from the considered water purification processes. This method is based on an organic combination of the advantages of such physical methods as electrolytic and cavitation disinfection of organic and biological water pollutants. The degree of purification and disinfection provided by him reaches 97-98%.
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Schmidt, Wido, Ute Böhme, Frank Sacher e Heinz-Jürgen Brauch. "Minimization Of Disinfection By-Products Formation In Water Purification Process Using Chlorine Dioxide — Case Studies". Ozone: Science & Engineering 22, n. 2 (gennaio 2000): 215–26. http://dx.doi.org/10.1080/01919510008547222.
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Reshnyak, Valerii I., Aleksandr I. Kaliaush e Ksenia V. Reshnyak. "DEVELOPMENT OF BALLAST WATER PURIFICATION AND DISINFECTION TECHNOLOGY". Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 14, n. 3 (2 settembre 2022): 365–73. http://dx.doi.org/10.21821/2309-5180-2022-14-3-365-373.
Testo completoAbstract (sommario):
The technology of purification and disinfection of ballast water developed by the authors is presented in the paper. Based on the results of a systematic analysis of the problem and on research experience in this field, it has been shown that the quality of ballast water discharged overboard after its use as ballast is determined by such basic factors as purification technology and design features of treatment devices, as well as conditions for operations with ballast water. The technology of ballast water purification as a complex of operations for purification, treatment and disinfection is determined by environmental requirements for the quality of purified and discharged overboard water, as well as the properties of the initial ballast water. The analysis of modern environmental requirements for the discharge of ballast water is given. It is shown that these requirements establish the level of permissible bacteriological danger of the discharged ballast water, taking into account the dispersed characteristics of the bacteriologically dangerous substance. These requirements determine the composition of operations that should be included in the technology of purification and disinfection of ballast water. Based on the results of the analysis of environmental requirements for the quality of purified ballast water, which determine the required water quality, a number of technological solutions collectively representing the technology of water purification and disinfection are proposed and justified. As disinfection, the use of ozone as an effective oxidizer is proposed. The use of sedimentation is proposed to regulate the content of dispersed particles of pollutants. Technological solutions also take into account the need for operations with a large amount of ballast water, as well as high reception and discharge capacity. It is proposed to carry out the disinfection process in small volumes of sediment, which is a concentrated mass of bacteriological substance obtained during preliminary coagulation and sedimentation, for which ship ballast tanks can be used. The proposed technology can be applied both in ship installations and in offshore environmental protection equipment - floating or coastal, for example, port facilities.
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Matsumoto, Takahiro, Tsuyoshi Hoshiai, Ichiro Tatsuno e Tadao Hasegawa. "Action Spectra of Bacteria and Purification of Pollutant Water at Faucets Using a Water Waveguide Method". Water 14, n. 9 (26 aprile 2022): 1394. http://dx.doi.org/10.3390/w14091394.
Testo completoAbstract (sommario):
Ultraviolet (UV) radiation treatment is an effective method for purifying pollutant water contaminated with bacteria and/or chemicals. As an emerging technology, purification by deep ultraviolet light-emitting diodes (DUV-LEDs) is promising. Few studies have used the point-source characteristics of LEDs and have instead replaced mercury vapor lamps with LEDs. Here, we show our recent progress in the instantaneous purification of contaminated water by combining the point-source characteristics of DUV-LEDs with a water waveguide (WW). Before the demonstration, we determined the efficacy of disinfection as a function of irradiation wavelength (action spectra) by constructing a wavelength tunable DUV light source. We found that, as a function of irradiation wavelength, there is a strong correlation between the dose-based inactivation rate constants and deoxyribonucleic acid (DNA) absorbance. Based on this correlation, the emission wavelength of 265 nm was determined as the most effective wavelength for disinfecting water contaminated with bacteria. Instantaneous 2-log disinfection levels of water contaminated with Escherichia coli O1 or Pseudomonas aeruginosa were demonstrated by using the DUV-LED WW method. We also discuss how far-UVC radiation shorter than 230 nm, which has recently been attracting attention and is known as a safe and effective disinfection wavelength for the human body, cannot give a higher-dose-based inactivation rate constant compared to that of 265 nm irradiation due to the larger absorption coefficient of water with a wavelength shorter than 230 nm.
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Zhang, Shuo, e Ruhua Wang. "Study on the change of organic matter along the Processes of Drinking Water Plant". E3S Web of Conferences 118 (2019): 03023. http://dx.doi.org/10.1051/e3sconf/201911803023.
Testo completoAbstract (sommario):
According to contaminated raw water and drinking water purification processes, volatile/semi-volatile organic compounds in water are determined by GC-MS. The changes of the organic along the process and water quality from unsafe to safe process were revealed. The results show that there are odorous substances such as heptanal in raw water, which are not detected after the filtration. The composition of volatile organic compounds changes a lot after the ozone activated carbon process, thus anthropogenic pollutants are no longer detected such as 5-ethyl-5-(3-hydroxy isopentyl)-barbituric acid. However, biological metabolites that are not present in raw water such as cedrenol appear. Except disinfection by-products after disinfection, there are a variety of halogenated compounds as 1-1-dichlorocyclobutane and 1-chloro-3, 3-dimethyl-butane. Some hydrocarbons and alcohols in the finished water have little impact on drinking water safety.
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Iannelli, R., S. Ripari, B. Casini, A. Buzzigoli, G. Privitera, M. Verani e A. Carducci. "Feasibility assessment of surface water disinfection by ultrafiltration". Water Supply 14, n. 4 (30 gennaio 2014): 522–31. http://dx.doi.org/10.2166/ws.2014.003.
Testo completoAbstract (sommario):
Ultrafiltration (UF) has been presented as an alternative to chemical disinfection to obtain safe drinking water, for its ability to remove microbiological contamination. Hollow-fiber UF membranes are designed as an effective barrier to microorganisms, for their high manufacturing integrity and for the ‘potting’ method adopted to seal fibers to the feeding/extraction manifold. While the main advantage over chemical disinfection is the drastic reduction of disinfection-by-product (DBP) formation, some chemicals are still required to control fouling and related sanitary risks. This study aims at an up-to-date assessment of UF use for surface water disinfection by compact, minimally-attended, automated plants. A 3.5 m3/h automated UF pilot-plant was run for 8 months for drinking quality purification of surface water from Pescia stream. Standard drinking water parameters, as well as specific microbiological parameters (Legionella, Mycobacterium, Adenovirus, coliphage) and DBP formation were monitored. Final results highlighted that the plant could reach a good removal of bacteria and a significant reduction of viruses. However, the adopted operation/maintenance policies had a strong impact on energy and water consumption, efficacy of bacterium/virus barrier and DBP formation. Hence, an accurate and competent operation, as well as the assistance of chemical disinfection, are still required for safe drinking water production.
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Deng, Daosheng, Wassim Aouad, William A. Braff, Sven Schlumpberger, Matthew E. Suss e Martin Z. Bazant. "Water purification by shock electrodialysis: Deionization, filtration, separation, and disinfection". Desalination 357 (febbraio 2015): 77–83. http://dx.doi.org/10.1016/j.desal.2014.11.011.
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Jung, Y. J., B. S. Oh, J. W. Kang, M. A. Page, M. J. Phillips e B. J. Mariñas. "Control of disinfection and halogenated disinfection byproducts by the electrochemical process". Water Science and Technology 55, n. 12 (1 giugno 2007): 213–19. http://dx.doi.org/10.2166/wst.2007.409.
Testo completoAbstract (sommario):
The aim of this study was to investigate some aspects of the performance of electrochemical process as an alternative disinfection strategy, while minimising DBPs, for water purification. The study of electrochemical processes has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals (•OH), were also generated. The formation of mixed oxidants increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Using several microorganisms, such as E. coli and MS2 bacteriophage, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radicals, was investigated for enhancement of the inactivation rate. Additionally, the formation and reduction of DBPs was studied by monitoring the concentration of haloacetic acids (HAAs) during the process.
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Suh, In-Yong, Dong-Min Lee e Sang-Woo Kim. "Self-Powered Water Disinfection System Acheving a Novel Oxidation-Assisted Electroporation Mechansim with Rotational Triboelectric Nanogenerator". ECS Meeting Abstracts MA2022-02, n. 36 (9 ottobre 2022): 1298. http://dx.doi.org/10.1149/ma2022-02361298mtgabs.
Testo completoAbstract (sommario):
In world, one of three people lack reliable access to clean water and water-borne diseases resulting from pathogenic microbescontaminated water remain a great threat to public health. Disinfection is an effective drinking water purification method; however, the most commonly used water disinfection method, chlorination, is limited by carcinogenic disinfection byproducts formation. Alternative methods such as ultraviolet (UV) radiation and membrane filtration suffer from drawbacks such as pathogen regrowth, low throughput, and intensive energy/chemical consumption. In addition, the methods have a limited disinfecting capacity and may be inadequate during a crisis like in cases of a severe epidemic outbreak, such as coronavirus disease 2019. Here, we report a rapid, self-powered water disinfection system for both bacterial and viral inactivation based on a novel oxidation-assisted electroporation mechanism powered by a supercoiling-mediated rotational TENG (S-TENG) that converts the periodic hand stretching/releasing into high-speed rotation. Owing to a rational design of the S-TENG that yields an ultrafast rotation (≈7500 rpm), we successfully overcame the insufficient output limitations of TENG caused by the low-frequency stimuli ambient energy harvesting. The S-TENG with sufficient voltage and current output can generate an NW-enhanced localized electric field and oxidative species simultaneously, and therefore achieving high disinfection efficiency. More than 99.9999% of bacteria and viruses were inactivated at a high flux of 15 m3 h–1 m–2. Our work presented an efficient enlarged demonstrator wherein 1 L of natural water can flow through the whole system within 1 min solely driven by gravity, and achieve complete disinfection, confirming the feasibility of this method for water disinfection in areas with an inadequate power supply. Figure 1
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Reshnyak, Valeriy Ivanovich, Alexander Ivanovich Kalyaush e Dmitry Igorevich Rochev. "Technology of purifying and disinfecting ballast water". Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2021, n. 1 (26 febbraio 2021): 32–38. http://dx.doi.org/10.24143/2073-1574-2021-1-32-38.
Testo completoAbstract (sommario):
The paper considers the problem of transferring microorganisms with ballast water used in the ship operation. It is noted that the search for a solution to the above problem takes a significant amount of time and requires developing special purifying equipment for disinfecting ballast water. Currently, there are various plants ensuring the decreased number of microorganisms in the process of disinfection. There has been proposed a new technology for ballast water treatment and decontamination that involves depositing microorganisms, removing them from the total volume of ballast water followed by ozone treatment. Actually, the volume of water containing sediment and decontaminated with ozone is significantly less than the total volume of ballast water and makes up about 3-5% of it. Microorganisms depositing takes place due to coagulation and sedimentation. The diagram of the ballast water purification and disinfection technology has been presented. The basic circuit of the ballast water disinfection plant includes a ship's ballast tank, receiving pipeline, reagent tank, metering pump, coagulant, collector, bulkhead, contact column, ozone generator, dehydration device and ultraviolet lamps. The operating conditions of the ship plants have space and time limits. The above technological solutions infer carrying out some operations (coagulation, sedimentation) and disinfection by using the ultraviolet lamps inside the ballast tanks for saving space. The proposed technology can be applied both on board a ship and in the floating or onshore environmental protection equipment, for example, in the port facilities.
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Stoeva, Donka, Hafize Fidan e Stanislava Tasheva. "Cavitation water treatment with GE USM cleaner device". BIO Web of Conferences 45 (2022): 03002. http://dx.doi.org/10.1051/bioconf/20224503002.
Testo completoAbstract (sommario):
Cavitation treatment of surface and natural waters is a method for their microbiological purification. The aim of the present paper was to investigate the possibilities for the disinfection of natural waters by cavitation treatment with a Ge USM Cleaner device. A full factorial experiment of type 22 was performed. The factors influencing the water purification process were studied. Based on the obtained experimental results, the activation energy, the thermal effect due to the disinfection of the water and the rate constant of the process were calculated. The thermodynamic parameters of the transition state -Gibbs energy, enthalpy and entropy were also calculated. The analysis of the experimental results proveеd the effectiveness of the method used for natural water treatment.
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Pchelnikov, Igor V., Alexey I. Vergunov e Arkady Y. Cherkesov. "Production Tests of the Don Water Purification and Disinfection Technology". Materials Science Forum 1052 (3 febbraio 2022): 454–61. http://dx.doi.org/10.4028/p-0a724x.
Testo completoAbstract (sommario):
One of the promising ways to reduce the content of organic pollutants in natural waters is the use of biological processes in combination with sorption on powdered activated carbon followed by membrane filtration and, as the final stage, disinfection of the obtained permeate by direct electrolysis. The paper presents the results of the efficiency of purification of the Don water, which underwent physicochemical treatment from halogen-organic contaminants in a biosorption-membrane reactor and the dependencies characterizing the disinfection of water by direct electrolysis in a flow-through membraneless electrolyzer. The studies were carried out using powdered active carbon, hollow fiber, and flat plate membranes. An oxide iridium-ruthenium titanium anode (OIRTA) was used as electrodes in a flow-through electrolyzer. As a result of processing the experimental results, the efficiency of removing not only the turbidity and color of water, but also organic substances, which cause high permanganate oxidizability and COD, has been established. The results of experimental studies have shown a high efficiency of purification and disinfection of natural water to the requirements of SanPiN. The efficiency of COD reduction was on average 41.2%, color - 57.3%, permanganate oxidizability - 33.3%.
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Koval, Iryna. "Synergistic Effect of Ultrasound Cavitation and Gas in the Water Disinfection". Chemistry & Chemical Technology 15, n. 4 (25 novembre 2021): 575–82. http://dx.doi.org/10.23939/chcht15.04.575.
Testo completoAbstract (sommario):
The paper considers water purification processes from Bacillus bacteria type under the conditions of gases bubbling only (argon, helium, oxygen, and carbon dioxide), cavitation and combined action of gas and cavitation. The synergistic effect was found under conditions of simultaneous action of gas and cavitation (kd(gas/US ) >kd(gas) + kd(US) almost double) and it was shown that kd(gas/US) >kd(gas) by almost an order of magnitude. Relative series of effective destruction of microbial cells was established: Ar/US > О2/US >Не/US > СО2/US. Destruction degree of the cells reaches 70 %at the short-term Ar/US exposure (~8 min), which is 7 times more active than cavitation action and 13.5 times more than bubbling of Aralone.
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Torres, Patricia, Camilo Hernán Cruz Vélez, Magally González, Héctor Mario Gutiérrez, Luz Edith Barba, Juan Carlos Escobar e Luis Germán Delgado. "Pentachlorophenol reduction in raw Cauca river water through activated carbon adsorption in water purification". Ingeniería e Investigación 28, n. 3 (1 settembre 2008): 92–95. http://dx.doi.org/10.15446/ing.investig.v28n3.15126.
Testo completoAbstract (sommario):
Reducing chemical risk in raw water from the River Cauca (caused by the presence of pentachlorophenol and organic matter (real color, UV254 absorbance)) was evaluated at bench scale by using three treatment sequences: adsorption with powdered activated coal (PAC); adsorption – coagulation; and, adsorption – disinfection – coagulation. The results showed that although PAC is appropriate for pentachlorophenol removal, and its use together with the coagulant (aluminium sulphate) significantly improved phenolic compound and organic matter removal (promoting enhanced coagulation), the most efficient treatment sequence was adsorption – disinfection - coagulation, achieving minor pentachlorophenol levels than detection (1.56 μg/l) and WHO limits (9μg/l) due to the effect of chloride on PAC.
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Darabee, Sonia, Mohammad Hamdan, Hadi Daghari e Salman Ajib. "Enrichment of the Usage of Solar Purification of Water by Employing Hybrid Nanofluid Mixtures". Energies 15, n. 16 (18 agosto 2022): 5983. http://dx.doi.org/10.3390/en15165983.
Testo completoAbstract (sommario):
In terms of human needs, water has traditionally been regarded as the most significant bioresource. However, there are still limitations on the quality and mobility of drinking water. Renewable energy technologies are at the forefront of research to bridge the gap between conventional fuels and renewable energy systems. Currently, the main objective is to speed up the solar water disinfection process of contaminated water when hybrid nanofluid mixtures are added. Five hybrid nanofluid mixtures containing different amounts of aluminum oxide (Al2O3) and Titanium oxide (TiO2) nanoparticles were used in this study, focusing on how they affected the solar disinfection of polluted water. Five hybrid nanofluid mixtures of different volumes and volume concentrations were used for this purpose; each one was introduced into a contaminated water-contained glass container with a volume of 500 mL. Additionally, a sixth container, used exclusively for comparison, was filled with tainted water. All containers were installed next to each other and exposed to solar radiation for simultaneous measures under identical metrological conditions. During the experimental time, and after exposure to sun radiation for one, two, and three hours, samples were taken from each bottle. to gauge the toll of Total coliforms and E. coli by using the IDEXX setup. It was found that adding a hybrid nanofluid mixture of any composition speeds up the disinfection process. Additionally, it was found that the optimal concentration of the hybrid nanofluid mixture to cut down the Total Coliform was with a volume concentration of 250 mL of Al2O3 and 250 mL of TiO2, while that to cut down the E. coli count was 400 mL of Al2O3 and 100 mL of TiO2. Finally, it may be concluded that among all hybrid mixtures used, the hybrid nanofluid with a volume concentration of 250 mL of Al2O3 and 250 mL of TiO2 is the most efficient in the solar water disinfection process.
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Toui, Syuji. "The Oxidation of Manganese and Disinfection By Ozonation in Water Purification Processing". Ozone: Science & Engineering 13, n. 6 (dicembre 1991): 623–37. http://dx.doi.org/10.1080/01919512.1991.10555706.
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Krutau, A. V., M. M. Dechko e M. A. Boika. "Optimization of Wastewater Treatment Process on Energy Costs at Truck and Tractor Washing Posts". Science & Technique 18, n. 5 (14 ottobre 2019): 436–42. http://dx.doi.org/10.21122/2227-1031-2019-18-5-436-442.
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The paper considers a process pertaining to purification of oily effluents while using electrocoagulation, electro-flotation and an electromagnetic hydro-cyclone, implemented with the help of a laboratory unit (Patent of the Republic of Belarus for the invention No 21229). The investigations have been carried out with the purpose to optimize specific energy consumption for the process of cleaning fuel and lubricants effluents. The following investigation methods have been applied – a literature review, a comparative analysis, an experiment execution, a mathematical modeling. Content of oil products in wastewater before and after treatment has been evaluated in the analytical laboratory of the Belarusian State Agrarian Technical University in accordance with standard methods. Purification of the oily effluents has been made with the help of a laboratory unit while using electroflotocoagulation method with removal of floated sludge in an electromagnetic hydrocyclone. This cleaning method makes it possible to increase a degree of water disinfection, provides a closed water supply, rational use of water resources, reduction of harmful effects of pollutants on the environment. An experimental design technique has been worked out and a three-level Box – Behnken design has been implemented in the paper. The problem concerning optimization of the purification process on energy costs has been solved without worsening the required concentration indices of petroleum products in water after treatment . Mathematical models have been obtained and optimal purification modes have been determined at the lowest specific energy costs and with sufficiently high degree of purification. Significance of regression coefficients has been estimated by Student criterion. It has been established that while using the proposed unit it is possible to obtain a degree of wastewater purification at automotive equipment washing stations with its performance G = 0.7 l/s, current density j = 150 A/m2. The degree of purification, determined by ratio of pollutant concentrations before and after purification, is up to 99.9 %. The results can be used in implementation of microprocessor control of cleaning mode while taking an initial concentration of pollution, unit capability, current density of an electroflotocoagulator as control action factors.
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Mizgirev, Dmitriy S., e Nikolay M. Guryanov. "ANALYSIS OF TECHNICAL SOLUTIONS FOR SHIP POTABLE WATER SYSTEMS". Russian Journal of Water Transport, n. 63 (1 giugno 2020): 77–89. http://dx.doi.org/10.37890/jwt.vi63.79.
Testo completoAbstract (sommario):
The article provides an overview and analysis of all main types of potable water systems currently used on inland and mixed navigation vessels: without potable water treatment; with elements of potable water disinfection and conditioning; with complete purification and disinfection of potable water. The operation principles of potable water systems of all types and designs are considered in detail, all the advantages and disadvantages of these systems are noted. Special attention is paid to stations for preparing potable water by using UV lamps, which essentially differ in the technological process from most of the stations used, and provide guaranteed high-quality disinfection of potable water, which allows to choose the most promising station type and outline a plan for further work on creating new and improving existing stations.
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Koval, Iryna. "Water disinfection under the helium influence". Technology audit and production reserves 4, n. 3(60) (30 giugno 2021): 6–8. http://dx.doi.org/10.15587/2706-5448.2021.235933.
Testo completoAbstract (sommario):
The object of research is the process of water disinfection at the influence of gas from bacteria of a particular genus with different amounts per unit volume of water. Due to the annual increase in the amount of pollutants in natural waters, new opportunities to improve microbiological indicators of water quality are being explored. There are many different ways to disinfect it, both physical and chemical. However, no single method has been found to purify aqueous media from microorganisms that would ensure their effective destruction. It is proposed to study the activity of specific microorganisms during the bubbling of inert gas through the aqueous medium. The microorganisms studied were rod-shaped sporogenic cells of Bacillus cereus bacteria type. The test gas was inert helium. The study used continuous gas bubbling throughout the process, which allowed to mix microbial water efficiently and prevent the formation of stagnant zones in the reaction medium. In particular, active gas mixing facilitates its access to each cell. The gas supply rate corresponded to 0.2 cm3/s, and its flow rate was 0.7 dm3 for one hour of bubbling through microbial water. The duration of the entire research process was 7200 s. The constant temperature of the microbial water (T=288±1 K) was maintained during the experiment by cooling the glass reactor with running water. An in-depth method of culturing bacterial cells was used. A decrease in the number of microorganisms was observed throughout the helium supply process, despite the different initial amounts in the water. The highest destruction degree of bacillus (77.06 %) was obtained at the lowest studied concentration in water (NM01=3.4·104 CFU/cm3). This is due to the fact that less microbial load provides better conditions for access of helium to the cell and their effective destruction. The proposed method of water purification allowed to achieve a sufficiently high degree of water disinfection from sporogenic rod-shaped bacteria after the action of helium alone. In particular, it has been experimentally proven that the efficiency of the water disinfection process depends on the concentration of microorganisms per unit volume of water. Due to the treatment of contaminated water with gas, it is possible to obtain high rates of its purification and the application of this method for practical purposes in water treatment technology.
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Zhuravlev, Igor. "Sorption Membranes and Filter for Water Purification and Disinfection in Outdoor Conditions". Colloids and Interfaces 3, n. 1 (11 marzo 2019): 35. http://dx.doi.org/10.3390/colloids3010035.
Testo completoAbstract (sommario):
The aim of this article was to develop a simple, cheap, light, highly efficient sorption membrane and filtering device for the purification of naturally polluted water with application in outdoor conditions. Sorption membranes have been prepared from cellulose pulp using paper and pulp technology. The sorbents were introduced into paper pulp as a filler (as activated carbon) or were chemically grafted to cellulose fibers. The absorption ability of such membranes assembled in a filter device has been investigated. The removal of weighted small mechanical particles, microorganisms, dissolved organic contaminants and colloids, and the undesirable ion impurities by the filter was investigated. Using a 10 × 10 cm filter, purification and disinfection of 18 liters of natural polluted water from a lake was done. Purification of dirty water occurs with gravity from a tank (bucket).
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Deryabkina, L. A., B. I. Marchenko, N. K. Plugotarenko e A. I. Yukhno. "Assessing efficiency of pre-ammonization aimed at reducing carcinogenic risks caused by trihalomethanes in drinking water". Health Risk Analysis, n. 3 (settembre 2020): 70–77. http://dx.doi.org/10.21668/health.risk/2020.3.08.
Testo completoAbstract (sommario):
In most Russian regions there is still a pressing issue related to providing population with high quality and safe drinking water. Up to now, chlorination has been the primary technique applied to disinfect drinking water as it is highly efficient, reliable, and relatively cheap. However, when chlorine is used to disinfect natural water that contains organic pollutants, it results in risks of by-products occurrence. These products are trihalomethanes, epigenetic carcinogenesis promoters that cause elevated carcinogenic risks under oral, inhalation, and subcutaneous exposure. Our research goal was to hygienically assess efficiency of pre-ammonization applied in water treatment procedures in order to prevent occurrence of carcinogenic organic chlorine compounds during chlorination and to minimize carcinogenic risks. We determined trihalomethanes and residual chlorine contents in model samples of natural water taken from a surface water source after chlorination with different doses of chlorine. We examined 52 pair parallel samples that had undergone pre-ammonization with ammonia sulfate and control ones. Trihalomethanes concentrations were determined in model water samples with gas-liquid chromatography. Basing on the results obtained via experiments on laboratory chlorination of river water, we determined quantitative characteristics and built regression models showing dependence between concentrations of organic chlorine compounds occurring due to chlorination (chloroform, dichlorobrommethane, dibromchloromethane) and chlorine doses and preammonization parameters. It was established that pre-ammonization was the most efficient in terms of preventing trihalomethanes occurrence under such disinfection modes when contents of residual active chlorine didn’t exceed recommended levels (0.8–1.2 mg/L). Basic ways to minimize carcinogenic risks caused by trihalomethanes are systemic control over their contents in drinking water during social and hygienic monitoring procedures; preliminary ammonization of water taken from surface water sources; prevention of unjustified hyper-chlorination; preliminary deep purification of initial water; disinfection with ultrasound radiation instead of preliminary chlorination; etc.
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Deryabkina, L. A., B. I. Marchenko, N. K. Plugotarenko e A. I. Yukhno. "Assessing efficiency of pre-ammonization aimed at reducing carcinogenic risks caused by trihalomethanes in drinking water". Health Risk Analysis, n. 3 (settembre 2020): 70–77. http://dx.doi.org/10.21668/health.risk/2020.3.08.eng.
Testo completoAbstract (sommario):
In most Russian regions there is still a pressing issue related to providing population with high quality and safe drinking water. Up to now, chlorination has been the primary technique applied to disinfect drinking water as it is highly efficient, reliable, and relatively cheap. However, when chlorine is used to disinfect natural water that contains organic pollutants, it results in risks of by-products occurrence. These products are trihalomethanes, epigenetic carcinogenesis promoters that cause elevated carcinogenic risks under oral, inhalation, and subcutaneous exposure. Our research goal was to hygienically assess efficiency of pre-ammonization applied in water treatment procedures in order to prevent occurrence of carcinogenic organic chlorine compounds during chlorination and to minimize carcinogenic risks. We determined trihalomethanes and residual chlorine contents in model samples of natural water taken from a surface water source after chlorination with different doses of chlorine. We examined 52 pair parallel samples that had undergone pre-ammonization with ammonia sulfate and control ones. Trihalomethanes concentrations were determined in model water samples with gas-liquid chromatography. Basing on the results obtained via experiments on laboratory chlorination of river water, we determined quantitative characteristics and built regression models showing dependence between concentrations of organic chlorine compounds occurring due to chlorination (chloroform, dichlorobrommethane, dibromchloromethane) and chlorine doses and preammonization parameters. It was established that pre-ammonization was the most efficient in terms of preventing trihalomethanes occurrence under such disinfection modes when contents of residual active chlorine didn’t exceed recommended levels (0.8–1.2 mg/L). Basic ways to minimize carcinogenic risks caused by trihalomethanes are systemic control over their contents in drinking water during social and hygienic monitoring procedures; preliminary ammonization of water taken from surface water sources; prevention of unjustified hyper-chlorination; preliminary deep purification of initial water; disinfection with ultrasound radiation instead of preliminary chlorination; etc.
25
Greene, D. J., C. N. Haas e B. Farouk. "Numerical simulation of chlorine disinfection processes". Water Supply 2, n. 3 (1 luglio 2002): 167–73. http://dx.doi.org/10.2166/ws.2002.0099.
Testo completoAbstract (sommario):
The efficacy of disinfection processes in water purification systems is governed by several key factors including reactor hydraulics, disinfectant chemistry and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics (CFD) model to predict flow structure, mass transport and chlorine decay in a continuous flow pilot scale reactor. These predictions were compared with experimental measurements for model validation. The current research demonstrates that inlet configurations can significantly impact reactor hydrodynamics.
26
Malczewska, Beata. "Evaluation of effectiveness of natural organic compounds removal from water in hybrid processes". Journal of Water and Land Development 30, n. 1 (1 settembre 2016): 81–85. http://dx.doi.org/10.1515/jwld-2016-0024.
Testo completoAbstract (sommario):
Abstract Natural organic matter (Natural Organic Matter – NOM) represents a mixture of diverse chemical structure and different properties. The humic substances constitute an important component of NOM, and they are responsible for water color and taste, also they can contribute to the formation of disinfection by-products (DBP). Therefore, removal of NOM is considered to be one of the important technological operations during water treatment. The present study evaluate the effectiveness of NOM removal from water by one of the hybrid process and the results showed that the use of this process allows to improve the efficiency of water purification and also reduces the intensity of blocking membranes. Batch adsorption tests of heated aluminum oxide particles (HAOPs) showed that the NOM removal efficiency has been between 86 to 77% at a dose 5 and 10 mg·dm−3, respectively for both tested natural water.
27
Knežević, Nemanja, e Srboljub Nikolić. "Water quality monitoring after floods". Odrzivi razvoj 3, n. 1 (2021): 47–61. http://dx.doi.org/10.5937/odrraz2101047k.
Testo completoAbstract (sommario):
Safe drinking water is one of the most important conditions for a healthy life. However, in case of disasters and emergencies, the water is often contaminated with various impurities of physical, chemical and/or biological origin. These contaminations can lead to a number of health problems, including various infectious diseases. For that reason, it is important to act preventively, and to perform appropriate treatment and water purification in a timely and urgent manner, depending on the type of pollution. In order to determine the type of pollution and perform the appropriate water treatment, the precondition is arranging certain chemical analyzes and monitoring of water quality through quality parameters. Since our time and economic resources are limited in the first moments of the accident, it is not possible to monitor all the parameters, so we monitor the most important: pH value, amount of residual chlorine, color, turbidity and the presence of pathogens. However, even when the type of pollution is determined, it is sometimes not possible to do centralized water purification immediately. Therefore, it is important to know the methods that can independently, and with the help of some handy tools, be applied in our household (eg. disinfection by boiling water or using some of the chemicals for disinfection; sedimentation, etc.). Using these methods, at least a physiological minimum can be provided for family members in the first moments after the accident, until a centralized purification is performed.
28
Benjamin, Earl, Aron Reznik, Ellis Benjamin, Saroj K. Pramanik, Louise Sowers e Arthur L. Williams. "Mathematical models for Enterococcus faecalis recovery after microwave water disinfection". Journal of Water and Health 7, n. 4 (1 luglio 2009): 699–706. http://dx.doi.org/10.2166/wh.2009.132.
Testo completoAbstract (sommario):
Microwave water disinfection is a rapid purification technique which can give billions of people access to clean drinking water. However, better understanding of bacterial recovery after microwave heating over time is necessary to determine parameters such as delayed bacterial growth rates and maximum bacterial yields. Mathematical models for Enterococcus faecalis recovery after microwave treatment in optimum growth conditions were developed for times up to 5 minutes using an optical absorbance method. Microwave times below 3 minutes (2,450 MHz, 130 W) showed that bacterial recovery maintained a time-dependent sigmoidal form which included a maximum value. At microwave times greater than three minutes, bacterial recovery, with a time-dependent exponential form, significantly decreased and did not reach the maximum value within the interval of observance (0–8 hours). No bacterial growth was found after 6 minutes of microwave treatment. The prepared mathematical models were produced by transforming the given variables to the logistic or exponential functions. We found that time-dependent maximum growth rates and lag times could be approximated with second order polynomial functions. The determined models can be used as a template to illustrate bacterial survival during water purification using microwave irradiation, in both commercial and industrial processes.
29
Kitazawa, H. "Keeping residual chlorine and decreasing unpleasant odor caused by disinfection of tap water". Water Supply 6, n. 2 (1 marzo 2006): 193–99. http://dx.doi.org/10.2166/ws.2006.069.
Testo completoAbstract (sommario):
Keeping residual chlorine at a certain level in tap water is effective not only in improving sanitary conditions but also in suppressing the regrowth of microorganisms and preventing the formation of biofilms on the internal surface of distribution pipelines. However, in our recent survey about customer satisfaction, over 50% of the customers were not satisfied with tap water for drinking. One of the main reasons for the dissatisfaction was the odor or taste caused by the disinfection process. We therefore investigated the behavior of residual chlorine in the water distribution network by estimating the chlorine decay coefficients, and discussed measures to decrease the unpleasant odor while maintaining the effect of disinfection. The effective measures are shortening of retention time, replacement of aged pipes, corrosion control of distribution and service pipes, removal of organic substances in water, additional chlorination at water-supply stations, and improvement in water supply facilities with receiving tanks. By adopting these measures, and setting the target value of residual chlorine at representative water taps, we successfully controlled residual chlorine at the outlets of purification plants or water-supply stations by application of the decay coefficient of chlorine in each water distribution system.
30
Naumova, Olga Valerievna, Elena Vladimirovna Spiridonova e Danila Sergeevich Katkov. "Device for water treatment and water purification". Agrarian Scientific Journal, n. 4 (20 aprile 2022): 89–91. http://dx.doi.org/10.28983/asj.y2022i4pp89-91.
Testo completoAbstract (sommario):
The article is devoted to the problems of water purification and organization of water treatment for engineering systems. Well-known methods of water treatment, such as mechanical, electrophysical, chemical, are not always able to ensure the quality of water in heat supply systems. Modern trends in the development of industry are aimed at the modernization of technological equipment in terms of the implementation of new progressive technologies. For the efficient operation of water heaters and to reduce heat losses in the heating and water supply system of the building, it is necessary to minimize scale deposits on the inner surface of the pipes. The article describes the principle of operation of an energy-combined liquid treatment device that can intensify the process of activation, disinfection and water purification. It is possible to improve the water quality by using a combined system that includes the effect of a high-voltage discharge pulse, cavitation and a magnetic field. Exposure to the liquid by a discharge pulse leads to the death of pathogenic microorganisms, as well as to ensure the emancipation of impurity ingredients. During magnetic treatment, the calcium, silicon and magnesium ions dissolved in water lose their ability to salt formation, and the impurities in the water are present in a suspended state. The magnetic field combines the suspensions contained in the water, the process of coagulation of impurity inclusions is observed, which after processing do not settle on the surfaces of pipelines, heat exchangers and other equipment. It is worth noting the high efficiency in cleaning and filtering various particles of polluting impurities, despite the fact that in most cases these impurities consist of completely non-magnetic materials. The use of the proposed method is of great interest in obtaining water of a high degree of purification for the chemical, microbiological and electronic industries.
31
Naumova, Olga Valerievna, Elena Vladimirovna Spiridonova e Danila Sergeevich Katkov. "Device for water treatment and water purification". Agrarian Scientific Journal, n. 4 (20 aprile 2022): 89–91. http://dx.doi.org/10.28983/asj.y2022i4pp89-91.
Testo completoAbstract (sommario):
The article is devoted to the problems of water purification and organization of water treatment for engineering systems. Well-known methods of water treatment, such as mechanical, electrophysical, chemical, are not always able to ensure the quality of water in heat supply systems. Modern trends in the development of industry are aimed at the modernization of technological equipment in terms of the implementation of new progressive technologies. For the efficient operation of water heaters and to reduce heat losses in the heating and water supply system of the building, it is necessary to minimize scale deposits on the inner surface of the pipes. The article describes the principle of operation of an energy-combined liquid treatment device that can intensify the process of activation, disinfection and water purification. It is possible to improve the water quality by using a combined system that includes the effect of a high-voltage discharge pulse, cavitation and a magnetic field. Exposure to the liquid by a discharge pulse leads to the death of pathogenic microorganisms, as well as to ensure the emancipation of impurity ingredients. During magnetic treatment, the calcium, silicon and magnesium ions dissolved in water lose their ability to salt formation, and the impurities in the water are present in a suspended state. The magnetic field combines the suspensions contained in the water, the process of coagulation of impurity inclusions is observed, which after processing do not settle on the surfaces of pipelines, heat exchangers and other equipment. It is worth noting the high efficiency in cleaning and filtering various particles of polluting impurities, despite the fact that in most cases these impurities consist of completely non-magnetic materials. The use of the proposed method is of great interest in obtaining water of a high degree of purification for the chemical, microbiological and electronic industries.
32
Hillebrand, Theodor, Yannik Auth, David Horch, Maike Taddiken e Konstantin Tscherkaschin. "SCIPIO—Scientific Purification Indicator". Proceedings 2, n. 13 (6 dicembre 2018): 960. http://dx.doi.org/10.3390/proceedings2130960.
Testo completoAbstract (sommario):
This paper presents a new way of dealing with drinkable water shortness all over the world. The developed devices’ functionality is based on the well-known and established SODIS (SOlar DISinfection) method. The whole device, Scipio—Scientific Purification Indicator, is designed in a way, that it is self-powered by solar cells and can be placed inside a bottle in order to provide best measurements. The device is capable of communicate via Bluetooth with other devices. Thus, an observation or control of the correct application of the SODIS method can be established. The paradigm shift we offer in terms of development aid not to simply help the people but to empower them to care for themselves. It is a very important that everyone can purify their own drinking water without the need of subsequent supplies.
33
Ehdaie, Beeta, Yi-Hsuan Su, Nathan S. Swami e James A. Smith. "Protozoa and Virus Disinfection by Silver- and Copper-Embedded Ceramic Tablets for Water Purification". Journal of Environmental Engineering 146, n. 4 (aprile 2020): 04020015. http://dx.doi.org/10.1061/(asce)ee.1943-7870.0001664.
Testo completo
34
Tkachenko, I. S., S. N. Tkachenko e V. V. Lunin. "The principles of ‘green chemistry’ using the example of design and operation of an underground water treatment station at a Moscow food processing enterprise for purification out of compounds of iron and the utilization of byproducts". Water Practice and Technology 10, n. 1 (1 marzo 2015): 36–42. http://dx.doi.org/10.2166/wpt.2015.005.
Testo completoAbstract (sommario):
This paper deals with the technology of ozonation together with sorption on activated carbons (AC) and its compliance with 12 principles of green chemistry. The report also provides an illustrative example of a drinking water treatment station with a capacity of 160 m3/h which purifies underground water from ions of iron by using ozone sorption technology and 12 principles of green chemistry. R&D, design, construction, and maintenance of the station are described. Our company LLC NVF ‘TIMIS’ was the first to propose an environmentally friendly method of disposal of residual products after purification of water by using them as components in the catalyst decomposition of ozone. The research work at Lomonosov Moscow State University has shown that ozonation with AC sorption technology reduces the concentration of total iron from 1.28 to 0.03 mg/L, reduces color grade and turbidity, provides disinfection and deodorization of water, and oxidizes organic and ions of iron more effectively than the oxidation of water by air or oxygen. This technology has successfully purified more than 8,000,000 m3 of underground water for the last 8 years.
35
Nikolaeva, Arina V., Natalya A. Zhitova, Pavel А. Agafonov, Sergey A. Polovkov, Lidia А. Norina e Mikhail A. Troshin. "Analysis of the efficiency of stage-by-stage treatment of rainwater and industrial wastewater during the operation of oil pipelines and petroleum products’ pipelines". SCIENCE & TECHNOLOGIES OIL AND OIL PRODUCTS PIPELINE TRANSPORTATION 10, n. 4 (31 agosto 2020): 412–26. http://dx.doi.org/10.28999/2541-9595-2020-10-4-412-426.
Testo completoAbstract (sommario):
Treatment of rainwater industrial wastewater during the operation of oil pipelines and petroleum products’ pipelines is a complex technological process that involves water purification from dissolved and emulsified oil products, oil, suspended solids and other polluting components. Organizations of the Transneft system have implemented a highly efficient technology for treatment of oily effluents, which makes it possible to reduce the level of pollutants to standard values. In order to assess the efficiency of the treatment facilities, an industrial, environmental and analytical control has been organized, which is carried out at all stages of the wastewater treatment and disinfection (after each block of equipment). Also, in order to optimize the performance of this procedure, a specialized program has been developed that allows for an operational analysis of the control results, as well as a comparative analysis of data (values of pollutant concentrations and treatment efficiency) at each stage of the process. According to the measurement results, the average indicators of the concentration of pollutants at all stages of purification are calculated for the observation period. According to these indicators, graphs of their compliance with regulatory requirements and comparison graphs with the typical scheme are plotted, and based on the results obtained, a conclusion is drawn about the efficiency of the treatment facilities for the selected observation period and based on the annual results.
36
Joó, Szilvia, e Rita Földényi. "Removal of dissolved organic matter (DOM) from water with activated carbon and effective microorganisms". Water Supply 12, n. 1 (1 febbraio 2012): 65–71. http://dx.doi.org/10.2166/ws.2011.119.
Testo completoAbstract (sommario):
Humic substances (HS) cause problems in water purification because of disinfection by-product (DBP) formation during chlorination. The efficiency of activated carbon (AC) adsorption as a method in drinking water treatment has been investigated in removing HS at different pH values (pH = 5; 6; 7; 8) in static equilibrium experiments. The degradation of HS was studied with an EM (effective microorganisms) bacteria community, and solutions of fulvic acid, sodium humate furthermore extracts of sandy soil were investigated. EM products are widely used but their effect on HS has not been investigated before. The combination of EM and AC methods in the case of fulvic acid resulted in higher performance than any of these methods alone. Humic substances were analyzed using a UV–VIS spectrophotometer and by total organic carbon (TOC) measurements. The carbon/nitrogen ratio was also determined, which enabled conclusions to be made for the nutrient supply. According to these results the degradation was efficient, especially in fulvic acid solutions.
37
Geldreich, Edwin. "Control of Microorganisms of Public Health Concern in Water". Journal of the IEST 29, n. 2 (1 marzo 1986): 34–37. http://dx.doi.org/10.17764/jiet.1.29.2.8273n444t436513k.
Testo completoAbstract (sommario):
The concept of microbial barriers in water supply and wastewater treatment involves a variety of processes other than disinfection. Many of these treatment processes have evolved from the enhancement of some factors associated with natural self-purification (sedimentation, aeration, nutrient limitations, water pH, etc.). Utilizing the multiple barrier concept in treatment of wastes before discharge to receiving waters and the further refinement possible by natural self-purification processes in the stream are beneficial in optimizing the quality of this raw water resource prior to further processing into drinking water supplies. A flow diagram based on typical percent removals in various treatment processes illustrates how water contaminated with fecal wastes can be improved in quality to protect downstream users from microbial hazards.
38
Lebedev, N. M., V. A. Grachev, O. V. Plyamina, O. Yu Lebedev, D. S. Lukichyova, V. A. Doilnitsyn, A. A. Akatov e L. V. Leonov. "Testing Combined Application of Ultraviolet and Ultrasonic Disinfection of Wastewater". Ecology and Industry of Russia 23, n. 7 (19 luglio 2019): 26–30. http://dx.doi.org/10.18412/1816-0395-2019-7-26-30.
Testo completoAbstract (sommario):
The article presents the results of an industrial test of a new technique for wastewater disinfection that combines ultrasonic and ultraviolet methods at the final stage of water purification in order to destroy pathogenic microorganisms, and thereby prevent the spread of infectious diseases. The new method was developed and patented by the authors; it has been tested at one of the most advanced water utilities in Russia, SUE “Vodokanal of St. Petersburg”. The combined ultraviolet and ultrasonic wastewater treatment proved to be effective.
39
Rodda, N., B. Bateman e R. Kfir. "Removal of Salmonella Typhi, Shigella Dysenteriae, Vibrio Cholerae and Rotavirus from Water Using a Water Treatment Tablet". Water Science and Technology 27, n. 3-4 (1 febbraio 1993): 347–50. http://dx.doi.org/10.2166/wst.1993.0373.
Testo completoAbstract (sommario):
Chlor-floc tablets are intended for purification of small quantities of water for individual use by combined flocculation and disinfection. Removal of Escherichia coll E25, various viruses and Giardia cysts from polluted water by Chlor-floc has been previously demonstrated. This study evaluated the efficiency of removal of Salmonella typhi, Shigella dysenteriae, Vibrio cholerae and rotavirus from simulated hard water of high organic content and colour. All four pathogenic microorganisms were successfully removed within the recommended treatment time. Log removals of 7-8 log were achieved for bacterial pathogens, and a removal of 6.5 log was obtained for rotavirus.
40
Zhang, Yue, Xinhua Zhao, Xinbo Zhang e Sen Peng. "A review of different drinking water treatments for natural organic matter removal". Water Supply 15, n. 3 (23 gennaio 2015): 442–55. http://dx.doi.org/10.2166/ws.2015.011.
Testo completoAbstract (sommario):
In the past decades, natural organic matter (NOM), which is a complex heterogeneous mixture of organic materials that are commonly present in all surface, ground and soil waters, has had an adverse effect on drinking water treatment. The existence of NOM results in many problems in drinking water treatment processes, and the properties and amount of NOM can significantly affect the efficiency of these processes. NOM not only influences the water quality with respect to taste, color and odor problems, but it also reacts with disinfectants, increasing the amount of disinfection by-products. NOM can be removed from drinking water via several treatment processes, but different drinking water treatment processes have diverse influences on NOM removal and the safety of the drinking water. Several treatment options, including coagulation, adsorption, oxidation, membrane and biological treatment, have been widely used in drinking water purification processes. Therefore, it is of great importance to be able to study the influence of different treatment processes on NOM in raw waters. The present review focuses on the methods, including coagulation, adsorption, oxidation, membrane, biological treatment processes and the combination of different treatment processes, which are used for removing NOM from drinking water.
41
J P, Malavika, e Shobana C. "Fabrication of potable and eco-friendly solar disinfection (sodis) unit and its performance analysis". Kongunadu Research Journal 8, n. 1 (4 giugno 2021): 41–50. http://dx.doi.org/10.26524/krj.2021.7.
Testo completoAbstract (sommario):
Solar disinfection (SODIS) is a technique, which involves utilization of solar energy to make safe drinking water from biologically contaminated water. In the conventional SODIS method, the PET bottles are filled with polluted water and exposed to the sunlight for a certain period depending upon the local weather conditions. However much more effective disinfection system is needed to overcome the problems of inefficient utilization of available solar energy and the health risk posed by treating the water using chemicals during the purification process. Hence, the present work aims in designing a portable solar disinfection unit that can efficiently use solar energy by manually adjusting the unit according to sunlight availability. Along with it, incorporation of the additional eco-friendly unit with water purifying plants Vetiveria zizanioides (Vetiver) and Hemidesmus indicus (Nannari) is done to achieve high efficiency in producing potable water from biologically contaminated water. The contaminated water samples treated in the solar disinfection unit and eco-friendly water purifying unit are analyzed for the presence of total coliforms and E-coli by using the Most probable Number method and P/A analysis, respectively. A reduction in 99.74% of total coliform count and absence of E-coli was observed in the treated water samples. The physicochemical analysis was carried out to ensure the suitability of treated water for consumption and the results revealed a notable reduction in the parameters, and all the parameters came under the permissible range of IS drinking water characteristics. The designed system can be used to disinfect the contaminated water sample most efficiently, thereby making the water suitable for consumption.
42
Ding, Yajie, Chong Zhang, Guoqiang Cai, Ke Xu, Jindan Wu, Jinhuan Zheng e Jiping Wang. "A facile preparation of cotton fabric containing hybrid poly(sodium methacrylate)/silver nanoparticles for oil removal and water disinfection". Textile Research Journal 89, n. 23-24 (13 maggio 2019): 5096–107. http://dx.doi.org/10.1177/0040517519849470.
Testo completoAbstract (sommario):
Water scarcity and pollution has become one of the most serious problems in the world. Generally, both oils and microorganisms exist in polluted water, hence multi-functional materials for the removal of diverse substances from water are desired. We reported a facile method for preparing cotton fabric possessing hybrid poly(sodium methacrylate) (pNaMAA)/silver nanoparticles (AgNPs) for oil/water separation and water disinfection. A crosslinked pNaMAA layer was generated on the cotton surface by ultraviolet-initiated polymerization. By replacing Na+in pNaMAA molecules, Ag+was incorporated into the fabric and then was reduced to AgNPs in situ by photo-thermal reduction. Due to the high underwater oleophobicity and bactericidal effect of the pNaMAA/AgNP hybrid layer, the gravity-driven oil/water separation efficiency of the prepared fabric was higher than 99% and the bacteria killing ratio achieved nearly 100%. Furthermore, AgNPs exhibited relatively good fastness during application. Combining their excellent oil removal and water disinfection effectiveness, these textile-based materials provide a promising future in the field of point-of-use water purification.
43
Matoh, Lev, Boštjan Žener e Boštjan Genorio. "Green Synthesis of Immobilized CuO Photocatalyst for Disinfection of Water". Sustainability 14, n. 17 (25 agosto 2022): 10581. http://dx.doi.org/10.3390/su141710581.
Testo completoAbstract (sommario):
A green method for depositing a CuO layer with good adhesion and a large surface area on a support of activated alumina (Al2O3) was evaluated. The relatively simple method consists of adsorption of a copper salt on the surface of Al2O3, formation of Cu(OH)2, and subsequent decomposition of the hydroxide to CuO. The XRD confirmed that the deposited photocatalyst crystalized at low temperatures (80 °C). Furthermore, BET measurements show a surface area of about 90 m2/g. The large surface area is the result of the speed of the conversion and decomposition reactions. The photokilling properties of the prepared photocatalyst were evaluated using E. coli cells and the leaching of copper ions was determined using ICP-MS. The photocatalytic efficiency was also evaluated by the degradation of an organic azo dye. The prepared photocatalyst shows good activity in the purification and disinfection of treated water. The described method is economical, fast, and can be considered green, since the only byproducts are water and NaCl.
44
Bischoff, A., J. H. Fan, P. Cornel, M. Wagner e L. M. Ma. "Disinfection of treated wastewater as an essential purification step for safe urban reuse: a comparative pilot study of UV- and ClO2-disinfection systems for urban reuse applications in China". Journal of Water Reuse and Desalination 3, n. 3 (7 marzo 2013): 325–35. http://dx.doi.org/10.2166/wrd.2013.087.
Testo completoAbstract (sommario):
Disinfection of wastewater is vital in addressing the potential health risks of urban water reuse. To compare the applicability of wastewater disinfection methods other than chlorine, identical pilot plants that used ultraviolet (UV) irradiation and chlorine dioxide (ClO2) dosing were installed at municipal wastewater treatment plants in Shanghai, China and Darmstadt, Germany. The investigation included public health and environmental aspects associated with the two disinfection methods. The results of the pilot-scale studies suggest that, in order to comply with Chinese water quality standards for urban water reuse, it is advisable to have a tertiary treatment before wastewater disinfection. Both methods were able to achieve a 4 log10 reduction in both total coliforms and Escherichia coli (E. coli). There was no evidence for regrowth of E. coli. However, after an initial 3 log10 reduction, HPC increased within 48 h by more than 10-fold after UV irradiation as well as after low doses of ClO2. An increase in acute toxicity was detected after dosing with ClO2 but not after UV irradiation.
45
Libecki, B. "The effectiveness of humic acid coagulation with the use of cationic polyacrylamides". Water Science and Technology 61, n. 6 (1 marzo 2010): 1555–60. http://dx.doi.org/10.2166/wst.2010.663.
Testo completoAbstract (sommario):
The chemical coagulation process is a popular method for eliminating the precursors of disinfection by-products. This study presents the results of a laboratory experiment which investigates the use of cationic polyacrylamide copolymers (CPAMs) as primary coagulants in the purification of solutions containing humic acids (HA). A number of polymers with various molecular weight and charge density were tested. The optimal doses were determined by colloidal titration. The effectiveness of coagulation-flocculation was determined by jar test method. The post-coagulation suspension was separated by filtration through cellulose filter paper. The experiment showed that charge neutralization destabilizes organic colloidal particles. An inversely proportional relationship was observed between the optimal dose and polymer charge density. The effectiveness of UV254 reduction (52–81%) and colour removal (51–88%) was determined by the effectiveness of filtration in removing post-coagulation turbidity, as well as by the type of applied polymer. The results of the study suggest that the use of CPAMs with high charge density and low molecular weight enables effective removal of humic acids from water in the coagulation and filtration process.
46
Libecki, B. "The effectiveness of humic acids coagulation with the use of cationic polyacrylamides". Water Science and Technology 63, n. 9 (1 maggio 2011): 1944–49. http://dx.doi.org/10.2166/wst.2011.194.
Testo completoAbstract (sommario):
The chemical coagulation process is a popular method for eliminating the precursors of disinfection by-products. This study presents the results of a laboratory experiment which investigates the use of cationic polyacrylamide copolymers (CPAMs) as primary coagulants in the purification of solutions containing humic acids (HA). A number of polymers with various molecular weight and charge density were tested. The optimal doses were determined by colloidal titration. The effectiveness of coagulation-flocculation was determined by jar test method. The post-coagulation suspension was separated by filtration through cellulose filter paper. The experiment showed that charge neutralization destabilizes organic colloidal particles. An inversely proportional relationship was observed between the optimal dose and polymer charge density. The effectiveness of UV254 reduction (52–81%) and colour removal (51–88%) was determined by the effectiveness of filtration in removing post-coagulation turbidity, as well as by the type of applied polymer. The results of the study suggest that the use of CPAMs with high charge density and low molecular weight enables effective removal of humic acids from water in the coagulation and filtration process.
47
Friedlander, Lonia R., Neha Puri, Martin A. A. Schoonen e A. Wali Karzai. "The effect of pyrite on Escherichia coli in water: proof-of-concept for the elimination of waterborne bacteria by reactive minerals". Journal of Water and Health 13, n. 1 (9 giugno 2014): 42–53. http://dx.doi.org/10.2166/wh.2014.013.
Testo completoAbstract (sommario):
We present proof-of-concept results for the elimination of waterborne bacteria by reactive minerals. We exposed Escherichia coli MG1655 suspended in water to the reactive mineral pyrite (FeS2) at room temperature and ambient light. This slurry eliminates 99.9% of bacteria in fewer than 4 hours. We also exposed Escherichia coli to pyrite leachate (supernatant liquid from slurry after 24 hours), which eliminates 99.99% of bacteria over the same time-scale. Unlike SOlar water DISinfection (SODIS), our results do not depend on the presence of ultraviolet (UV) light. We confirmed this by testing proposed SODIS additive and known photo-catalyst anatase (TiO2) for antibacterial properties and found that, in contrast to pyrite, it does not eliminate E. coli under our experimental conditions. Previous investigations of naturally antibiotic minerals have focused on the medical applications of antibiotic clays, and thus have not been conducted under experimental conditions resembling those found in water purification. In our examination of the relevant literature, we have not found previously reported evidence for the use of reactive minerals in water sanitization. The results from this proof-of-concept experiment may have important implications for future directions in household water purification research.
48
Matseluk, Ye M., D. V. Charnyy, V. D. Levytska e S. V. Marysyk. "New technological solutions for water treatment systems in modern conditions". Міжвідомчий тематичний науковий збірник "Меліорація і водне господарство", n. 2 (23 dicembre 2021): 201–9. http://dx.doi.org/10.31073/mivg202102-303.
Testo completoAbstract (sommario):
The current state of water quality formation in surface water bodies, which serve as sources of drinking water supply in the Dnieper river basin, was considered. The water treatment technologies currently used in Ukraine, were analyzed. The inconsistency of these technologies with the current water quality in these sources of water supply was established, as these technologies are not quite suitable for the purification of water with a significant organic component of any genesis. It was found that one of the main factors that influences the quality of water in water bodies in the warm period is phytoplankton, especially during their "flowering. The factors accompanying this phenomenon were shown, the development trends and their influence on the operating water treatment systems were analyzed. It was considered the feasibility of using reagents with the effect of oxidation of the organic component of the source water, in particular chlorine dioxide, the use of which is effective in disinfection of chlorine-resistant microbiota and phenols oxidations. Moreover, in the conditions of the expected increase in the concentration of mycocystins, chlorine dioxide can be, by analogy with ozone, a fairly effective oxidant of these toxins with a prolonged disinfection effect.
The potential development areas of water treatment systems by intensifying bio-physico-chemical processes on the basis of the existing typical capacitive and package units of water treatment plants are given. The perspective areas of scientific and technological developments for substantiation of effective solutions on modernization of existing water treatment facilities were established in these conditions, namely it is reasonable to consider only those solutions, which provide effective purification of water with high concentration of phytoplankton without comprehensive or radical change of water treatment technology. That is, these approaches should make maximum use of existing treatment facilities, either by their reconstruction, or with the use of new reagents, or a combination of both.
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Danil de Namor, A. F. "Water purification: from ancient civilization to the XXI Century". Water Supply 7, n. 1 (1 marzo 2007): 33–39. http://dx.doi.org/10.2166/ws.2007.004.
Testo completoAbstract (sommario):
Ancient civilization valued the vital role of water in human life. As reflected in the literature, environmental awareness led to early water treatments and these are briefly described in this paper. Thus the period prior to 500 BC to 1000 AD saw the use of naturally occurring materials for water purification, the building of aqueducts, and the introduction of the distillation process. This was followed by a dormant period of five centuries in which hardly any progress was made in water purification methodology. From the 17th to the 19th century, progress was made on filtration processes and the introduction of the microscope. In addition chemical methods for water disinfection by the use of chlorine and ozone were reported. These methods and their combination progressed significantly through the 20th century. However the problems associated with chemical contamination of ground water, from which, drinking water is mainly generated remained practically ignored for about five decades. It was in the late seventies that this was brought to light. Since then technologies for groundwater purification started to emerge but a lot remains to be done in this area of research. The crucial role of suitable analytical tools for any technological development which aim to remove toxic pollutants from water is acknowledged. Thus the need of re-visiting old methodology making use of the advantages resulting from the availability of advanced analytical techniques and the possibility of enriching naturally occurring materials by the introduction of supramolecular receptors for water decontamination purposes are emphasized.
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Johan, Erni, Verónica Américo António Fernando, Salma Sadia, Satoshi Mitsunobu, Soichiro Hirai e Naoto Matsue. "A new tool for disinfecting household drinking water for rural residents: protonated mordenite-embedded sheet". Journal of Water, Sanitation and Hygiene for Development 12, n. 3 (21 febbraio 2022): 271–77. http://dx.doi.org/10.2166/washdev.2022.202.
Testo completoAbstract (sommario):
Abstract Many rural residents in developing countries drink water contaminated with feces due to inadequate purification, causing many diarrheal deaths, most of them infants. We have fabricated a protonated (H+-retaining) mordenite-embedded non-woven fabric sheet (H-MES) as a new tool for disinfecting drinking water at home. Proton retention amount was 1.2 mmol per gram of mordenite, 75% of its cation-exchange capacity. The H-MES released protons through cation exchange with cations in aqueous solutions, lowering the pH of the solutions to below 4. This low pH led to disinfecting 100 mL of 100-fold diluted TSB solutions containing an Escherichia coli species (DH5α). For example, an initial viable count of around 5,000 CFU mL−1 decreased to 14 CFU mL−1 after 24 h shaking at 25 °C with added H-MES containing 0.2 g protonated mordenite; 3.8×107 CFU mL−1 without the H-MES. Adding a nitric acid solution showed a similar effect, but using chemical reagents at home might lead to unexpected accidents. Adding and removing the H-MES to and from household waterpots by hand is easy. Besides the H-MES, similar sheets embedded with bactericides and bacterial adsorbents could be a simple water-disinfection tool for rural residents.