scholarly journals Investigations on Temperature Effects and Germ Recovery for Solar Water Disinfection (SODIS)

2017 ◽  
Vol 4 (4) ◽  
pp. 430-435
Author(s):  
Michael Sift ◽  
Sophia Wagner ◽  
Martin Hessling
Keyword(s):  
Drinking Water ◽  
Isotonic Saline ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
Real Surface ◽  
Large Delay ◽  
Uva Irradiation ◽  
Solar Water Disinfection ◽  
Saline Solutions ◽  
Uva Radiation

In many developing countries no infrastructure for providing people with microbiological safe drinking water exists. This demands for decentralized water disinfection that is inexpensive and requires no consumables. The casualties are often recommended the application of SODIS for drinking water treatment. There are numerous scientific studies on this disinfection method, which however are still leaving questions on the mode of functioning which is often reduced to the effect caused by the UV part of the solar radiation and there is almost no discussion in the literature what happens to the disinfected water after the SODIS treatment.In this paper disinfection experiments with Escherichia coli in isotonic saline solutions and real surface water are performed for a set of realistic conditions for UVA irradiation and for heating but separated from each other. The results confirm that SODIS is based on the combined effect of UVA radiation and increased temperature. Further experiments lead to the recommendation that once disinfected water should be consumed without a large delay, otherwise the germ concentration rises again.Int J Appl Sci Biotechnol, Vol 4(4): 430-435

DISINFEKSI UNTUK PROSES PENGOLAHAN AIR MINUM

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Nusa Idaman Said
Keyword(s):  
Drinking Water ◽  
Water Purification ◽  
Distribution System ◽  
Residual Effect ◽  
Drinking Water Treatment ◽  
Disinfection Byproducts ◽  
Water Disinfection ◽  
Pathogenic Microorganisms ◽  
Microbiological Contamination ◽  
Disinfection Process

Water disinfection means the removal, deactivation or killing of pathogenic microorganisms. Microorganisms are destroyed or deactivated, resulting in termination of growth and reproduction. When microorganisms are not removed from drinking water, drinking water usage will cause people to fall ill. Chemical inactivation of microbiological contamination in natural or untreated water is usually one of the final steps to reduce pathogenic microorganisms in drinking water. Combinations of water purification steps (oxidation, coagulation, settling, disinfection, and filtration) cause (drinking) water to be safe after production. As an extra measure many countries apply a second disinfection step at the end of the water purification process, in order to protect the water from microbiological contamination in the water distribution system. Usually one uses a different kind of disinfectant from the one earlier in the process, during this disinfection process. The secondary disinfection makes sure that bacteria will not multiply in the water during distribution. This paper describes several technique of disinfection process for drinking water treatment. Disinfection can be attained by means of physical or chemical disinfectants. The agents also remove organic contaminants from water, which serve as nutrients or shelters for microorganisms. Disinfectants should not only kill microorganisms. Disinfectants must also have a residual effect, which means that they remain active in the water after disinfection. For chemical disinfection of water the following disinfectants can be used such as Chlorine (Cl2),  Hypo chlorite (OCl-), Chloramines, Chlorine dioxide (ClO2), Ozone (O3), Hydrogen peroxide etch. For physical disinfection of water the following disinfectants can be used is Ultraviolet light (UV). Every technique has its specific advantages and and disadvantages its own application area sucs as environmentally friendly, disinfection byproducts, effectivity, investment, operational costs etc. Kata Kunci : Disinfeksi, bakteria, virus, air minum, khlor, hip khlorit, khloramine, khlor dioksida, ozon, UV.

Progress on Drinking Water Treatment with Chlorine Dioxide

2013 ◽  
Vol 848 ◽  
pp. 255-258 ◽  
Author(s):  
Yu Zhong Guo ◽  
Yan Zhen Yu ◽  
Ming Li ◽  
Guang Yong Yan
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Chlorine Dioxide ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
Water Quality Standards ◽  
Water Pretreatment ◽  
Detection Technology ◽  
Filter Water ◽  
By Products

By the reason of strong responses activity and oxidation ability, Chlorine dioxide as oxidant and disinfectant has been applied to peroxidation and disinfection more and more widely.In this paper, it give an account of the preparation of chlorine dioxide, as oxidants to raw water pretreatment, used in filter water disinfection ,the detection technology of chlorine dioxide and disinfection by-products, the water quality standards formulated by domestic and overseas chlorine dioxide in using chlorine dioxide, and summarized progress on drinking water treatment with chlorine dioxide .

scholarly journals Insights into Solar Disinfection Enhancements for Drinking Water Treatment Applications

2021 ◽  
Vol 13 (19) ◽  
pp. 10570
Author(s):  
Abdassalam A. Azamzam ◽  
Mohd Rafatullah ◽  
Esam Bashir Yahya ◽  
Mardiana Idayu Ahmad ◽  
Japareng Lalung ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
World Health ◽  
Solar Disinfection ◽  
Physical Chemical ◽  
Main Challenge ◽  
Pre Treatment ◽  
Health Organization

Poor access to drinking water, sanitation, and hygiene has always been a major concern and a main challenge facing humanity even in the current century. A third of the global population lacks access to microbiologically safe drinking water, especially in rural and poor areas that lack proper treatment facilities. Solar water disinfection (SODIS) is widely proven by the World Health Organization as an accepted method for inactivating waterborne pathogens. A significant number of studies have recently been conducted regarding its effectiveness and how to overcome its limitations, by using water pretreatment steps either by physical, chemical, and biological factors or the integration of photocatalysis in SODIS processes. This review covers the role of solar disinfection in water treatment applications, going through different water treatment approaches including physical, chemical, and biological, and discusses the inactivation mechanisms of water pathogens including bacteria, viruses, and even protozoa and fungi. The review also addresses the latest advances in different pre-treatment modifications to enhance the treatment performance of the SODIS process in addition to the main limitations and challenges.

Seasonal Variation in Drinking Water Disinfection By-products in Gharbia Governorate, Egypt

2021 ◽  
Vol 1 (2) ◽  
pp. 11-14
Author(s):  
Rafat Moustafa ◽  
Ali M. Hassan ◽  
Hamdi A. Hammad ◽  
Ali M. Abdullah
Keyword(s):  
Drinking Water ◽  
Continuous Monitoring ◽  
Drinking Water Treatment ◽  
International Standards ◽  
Water Disinfection ◽  
Dichloroacetic Acid ◽  
Mean Values ◽  
Drinking Water Disinfection ◽  
Congenital Disabilities ◽  
By Products

Chlorine is the most common disinfectant used in drinking water treatment because it is cheap and has an efficient germicidal ability. However, chlorine and organic matter reacting trihalomethanes (THMs) are suspected carcinogens. The major groups of disinfection by-products (DBPs) are THMs, haloacetic acids (HAAs), haloacetonitriles (HANs), and halogenated ketones (HKs). Exposure to these by-products increases the risk of cancers, abortion, low birth weight, and congenital disabilities. The wastewater contents of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), as the source of total organic carbon (TOC) compounds, are oxidized by chlorine to produce DBPs. This study aimed to monitor the seasonal levels of THMs in Egypt compared with international standards using capillary gas chromatography. Results revealed that THMs mean values vary between 9.26 to 35.86 μg/l, while dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) mean values vary between 3.82 to 17.74 μg/l and 4.41 to 13.25 μg/l, respectively. The maximum THM and TCAA values were observed during the summer, probably due to high temperatures. While the maximum DCAA values were observed during the autumn due to the high levels of raw water TOC. In conclusion, continuous monitoring of THM and its species is highly recommended, taking into consideration how climate can influence THMs formation.

Solution and Condensed Phase Characterization

1997 ◽  
Author(s):  
Roger A. Minear ◽  
Mark A. Nanny
Keyword(s):  
Drinking Water ◽  
Natural Waters ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
Water And Wastewater Treatment ◽  
Aquatic Chemistry ◽  
Aluminum Speciation ◽  
Drinking Waters ◽  
Geochemical Significance ◽  
Aqueous Aluminum

Improvements in nuclear magnetic resonance (NMR) instrumentation, magnetic field strength, pulse sequences, and computer technology and software have increased the range of applications and specific elements available for study by NMR. The five chapters in this Part clearly indicate the benefits of these advances, especially regarding studies of aquatic, environmental significance. Each of the studies focuses on environmentally significant issues. For example, chlorination is widely used to disinfect drinking waters, a method that can produce undesirable disinfection by-products. This was first recognized in 1974 with the discovery of trihalomethanes in most finished drinking waters where hypochlorite was used for disinfection. Chapter 7 examines the chlorination of alanine and relates it to the chlorination reactions of acetaldehyde and ammonia, a topic of importance with respect to drinking water disinfection. Aluminum is also widely used in drinking water treatment, and understanding its hydrolysis chemistry and complexation behavior is of great importance to aquatic chemistry. In addition, the aquatic chemistry of aluminum is important because acid rain can release soluble aluminum ions from clay into soil water, possibly damaging terrestrial plant life. Aluminum may eventually reach and accumulate in hydrological systems where it can be toxic to aquatic life. Chapters 8 and 9 focus on 27Al NMR in defining aqueous aluminum speciation in a mildly acidic solution or in the presence of complexing organic compounds. Furthermore, aluminum is of environmental and geochemical significance since it is an integral component of clays, another ubiquitous constituent of natural waters (surface and ground). Interaction between clays, cations, and internal water molecules can be significant in understanding the fate and transport of chemicals through the environment. Since colloidal suspensions of clay materials frequently represent challenges to water and wastewater treatment, understanding of physical and chemical processes are of tantamount importance to the environmental scientist and engineer. Chapter 10 explores cation behavior in clay matrices by using “uncommon” nuclei such as 7Li, 23Na, and 133Cs as probes. This is unique in that many NMR studies of complexation in clay have focused primarily upon the nuclei 27A1 and 29Si.

Rural Drinking Water Disinfection Technology and Research Progress of Application

2015 ◽  
Vol 737 ◽  
pp. 672-676
Author(s):  
Ran An ◽  
Ming Da Liu ◽  
Jun Xing Li ◽  
Xiao Wei Liu ◽  
Dan Yang
Keyword(s):  
Drinking Water ◽  
Rural Areas ◽  
Drinking Water Treatment ◽  
Water Disinfection ◽  
Research Progress ◽  
Ultraviolet Disinfection ◽  
Management Level ◽  
Disinfection Process ◽  
Drinking Water Disinfection ◽  
Ozone Disinfection

With the living standards improvement of rural residents, people pay more attention to the safety of drinking water in China. As the final step in drinking water treatment, disinfection technology has received much attention. At present, drinking water disinfection process is mainly involved in chlorine disinfection, chlorine dioxide disinfection, chloramine disinfection, disinfection of potassium permanganate, ozone disinfection and ultraviolet disinfection. However, due to limitations in rural economic conditions and management level, only ozone disinfection and ultraviolet disinfection are suitable for rural areas in China. This paper described some of the application problems and limitations in drinking water disinfection process, as well as the select principle in rural areas. The principle, research status, trends and issues in application of ozone and ultraviolet disinfection technology were emphatically introduced. Finally, the development of drinking water disinfection technologies was discussed.

scholarly journals TiO2:Cex onto Al Clays for Photocatalytic Solar Water Disinfection

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
C. Belver ◽  
S. Ponce ◽  
E. Carpio ◽  
G. Salazar ◽  
P. García ◽  
...  
Keyword(s):  
Energy Source ◽  
Drinking Water ◽  
Visible Region ◽  
Layered Silicate ◽  
Water Disinfection ◽  
Reaction Parameters ◽  
Absorption Properties ◽  
Solar Water Disinfection ◽  
Anatase Nanoparticles ◽  
Silicate Layers

A novel methodology was employed to prepare new nanocomposites with photocatalytic properties based on Ce-doped TiO2 nanoparticles arranged over a layered silicate. The catalysts were porous materials formed by exfoliated silicate layers surrounded by anatase nanoparticles. In this way, the anatase was doped by different amounts of Ce, yielding to catalysts with light absorption properties on the visible region. The photocatalytic behavior was tested for different reactions: adsorption and photocatalysis, showing outstanding and promising results for the removal of bacteria by using solar light as an energy source. The influence of the physicochemical properties of the catalyst and the reaction parameters will be studied in detail to manage new catalysts for the disinfection of drinking water.

scholarly journals Solar Water Disinfection to Produce Safe Drinking Water: A Review of Parameters, Enhancements, and Modelling Approaches to Make SODIS Faster and Safer

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3431
Author(s):  
Ángela García-Gil ◽  
Rafael A. García-Muñoz ◽  
Kevin G. McGuigan ◽  
Javier Marugán
Keyword(s):  
Drinking Water ◽  
Kinetic Models ◽  
Critical Role ◽  
Water Disinfection ◽  
Safe Drinking Water ◽  
Reactor Material ◽  
Solar Water ◽  
Solar Water Disinfection ◽  
The Impact ◽  
Modelling Approaches

Solar water disinfection (SODIS) is one the cheapest and most suitable treatments to produce safe drinking water at the household level in resource-poor settings. This review introduces the main parameters that influence the SODIS process and how new enhancements and modelling approaches can overcome some of the current drawbacks that limit its widespread adoption. Increasing the container volume can decrease the recontamination risk caused by handling several 2 L bottles. Using container materials other than polyethylene terephthalate (PET) significantly increases the efficiency of inactivation of viruses and protozoa. In addition, an overestimation of the solar exposure time is usually recommended since the process success is often influenced by many factors beyond the control of the SODIS-user. The development of accurate kinetic models is crucial for ensuring the production of safe drinking water. This work attempts to review the relevant knowledge about the impact of the SODIS variables and the techniques used to develop kinetic models described in the literature. In addition to the type and concentration of pathogens in the untreated water, an ideal kinetic model should consider all critical factors affecting the efficiency of the process, such as intensity, spectral distribution of the solar radiation, container-wall transmission spectra, ageing of the SODIS reactor material, and chemical composition of the water, since the substances in the water can play a critical role as radiation attenuators and/or sensitisers triggering the inactivation process.

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