scholarly journals Nanomaterials Based Drinking Water Purification: Comparative Study with a Conventional Water Purification Process

2018 ◽  
Vol 63 (1) ◽  
pp. 96-112 ◽  
Author(s):  
Barış Şimşek ◽  
İnci Sevgili ◽  
Özge Bildi Ceran ◽  
Haluk Korucu ◽  
Osman Nuri Şara

One of the ways of fully securing the presence of fresh water is water treatment process. Nanomaterials and nanotechnology offers an innovative solution for water treatment. In this study, physical, chemical and microbiological improvement rates of raw water were analyzed after filtration with graphene oxide. Graphene oxide's water treatment performance; silver nanoparticles, silver nanoparticles & graphene oxide composites that are commonly used in water treatment were compared with a traditional treatment method. When compared to the traditional method, there were improvements of 50 %, 40.7 %, 86.8 % and 45.5 % for color, TIC, TOC and hardness properties, respectively in water treatment by GO-based filtration with solid liquid ratio of 0.7 % (v/v). In water treatment with GO-Ag based filtration, 39.8 %, 69.8 %, 10.3 % and 28.6 % of improvements were obtained for TIC, TOC, hardness and LSI value compared to the conventional method. Both GO at 0.7 % (v/v) solid-liquid ratio and GO-Ag nanocomposites were successful in the number of total viable microorganisms and inhibiting microorganisms such as Escherichia coli fecal (gaita-infected), Salmonella typhi, Enterococcus faecalis, Pseudomona aeruginosa and Staphylococcus aureus. Among the studied parameters GO-Ag nanocomposites found to be the most suitable for drinking water treatment.

2012 ◽  
Vol 65 (6) ◽  
pp. 983-988 ◽  
Author(s):  
M. Poberžnik ◽  
A. Leis ◽  
A. Lobnik

CO2 gas with a special isotopic signature (δ13C = −35.2‰ vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water–supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of δ13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO2 gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method's overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage.


2018 ◽  
Vol 62 (4) ◽  
pp. 141-147
Author(s):  
T. Prošek ◽  
V. Šefl

Abstract Main factors affecting the corrosivity of water in water treatment plants and water towers and other storage facilities, observed types of corrosion degradation of stainless steel and the effect of manufacturing and surface treatment on their corrosion resistance are discussed. A list of stainless steel grades currently used in the field of treatment, transport and storage of drinking water is given together with some other suitable ones. Based on literature resources, optimal stainless steel grades are recommended as a function of water composition and treatment method.


2020 ◽  
Vol 1 (1) ◽  
pp. 10-19
Author(s):  
Emmy C. Kerich

Access to safe and clean drinking water is a major challenge to the people living around Ahero Irrigation Scheme (AIS). Water sources in the area are constantly and increasingly polluted by agrochemical like pesticides from rice farming. 2, 4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide extensively used in AIS. The neurotoxic, immunosuppressive, cytotoxic and hepatoxic effects of (2,4-D) have been well documented. Residues of (2,4-D) have been documented in ponds, rivers, lakes and irrigation canals. Therefore this study surveyed agrochemicals used in AIS, the drinking water source for the residents and finally water treatment option for the obtained water in the year 2013. The study established that (52.8%) of the farmers used hand-weeding and 20.8% of them use (2,4-D) for the weeds control. Results indicated that the most preferred water source was lined improved well (47.2%) followed by irrigation canal (22.2%), the least preferred was rain water with (2.8%). The most used method of water treatment was chlorination (45.8%). Spearman’s coefficient of correlation ( ) revealed that there was positive correlation between the two variables ( =0.145, 72, p=0.224>0.05). As  is positive, it implies that the type of treatment given to water depend on its source of the water. Despite the use of chlorinate with almost half of the residents, some of them (22.2%) do not treat their water at all, which may pose a risk of getting water related diseases. Furthermore, despite a proportional number of residents obtaining their water from irrigation canal, all of them do not have appropriate method/s for treating water contaminated with organic pollutants such as herbicides. There is a need to promote water appropriate drinking water treatment method/s in the study area to prevent water related diseases at the family level. Doi: 10.28991/HEF-2020-01-01-02 Full Text: PDF


Author(s):  
Gomes CEP ◽  
Oliveira HA ◽  
Azevedo AC ◽  
Rubio J

In drinking water treatment plants, chemical reagents are employed to aggregate and remove suspended particles. However, not all reagents are eco-friendly and exists concerns over environmental, economic, and health issues. This study shows features of the sustainability of commercial coagulants/flocculants and presents experimental research on floc characterization and settling of dispersed solids with a combination of Ferric Chloride (FeCl3 ) and gelatinized starch. Bench studies were conducted using kaolin suspensions and results were validated with raw water collected from a river (Rio dos Sinos, Brazil). Flocculation indexes, floc structure, and residual turbidities were compared with Polyaluminum Chloride (PAC), as a reference. All techniques showed that the combination of FeCl3 and starch formed well-structured, larger, and more settleable flocs than those produced with PAC. Superficial loadings, in a continuous separation tank (2 to 4 m.h-1) were studied with and without lamellae. Best results were obtained with 15 mg.L-1 Fe3+ and 10 mg.L-1 starch, with a velocity gradient, G, of 60 s-1 in the slow mixing and with 60° inclined lamellae spaced 1.3 cm apart. Best conditions were applied to the clarification of the raw water and again, due to the rapid settling of flocs with FeCl3 and starch, better results were obtained compared to PAC. A turbidity reduction of 94% and a residual value of 2.5 NTU with superficial loadings of 3 m.h-1 were obtained. Results were discussed in terms of interfacial and operating parameters and a promising potential for the combination of FeCl3 with starch for solid/liquid separation was envisaged.


Author(s):  
Samuel Dorevitch ◽  
Kendall Anderson ◽  
Abhilasha Shrestha ◽  
Dorothy Wright ◽  
Aloyce Odhiambo ◽  
...  

Ozonation is widely used in high-income countries for water disinfection in centralized treatment facilities. New microplasma technology has reduced the energy requirements for ozone generation dramatically, such that a 15-watt solar panel is sufficient to produce small quantities of ozone. This technology has not been used previously for point-of-use drinking water treatment. We conducted a series of assessments of this technology, both in the laboratory and in homes of residents of a village in western Kenya, to estimate system efficacy and to determine if the solar-powered point-of-use water ozonation system appears safe and acceptable to end-users. In the laboratory, two hours of point-of-use ozonation reduced E. coli in 120 L of wastewater by a mean (standard deviation) of 2.3 (0.84) log-orders of magnitude and F+ coliphage by 1.54 (0.72). Based on laboratory efficacy, 10 families in Western Kenya used the system to treat 20 L of household stored water for two hours on a daily basis for eight weeks. Household stored water E. coli concentrations of >1000 most probable number (MPN)/100 mL were reduced by 1.56 (0.96) log removal value (LRV). No participants experienced symptoms of respiratory or mucous membrane irritation. Focus group research indicated that families who used the system for eight weeks had very favorable perceptions of the system, in part because it allowed them to charge mobile phones. Drinking water ozonation using microplasma technology may be a sustainable point-of-use treatment method, although system optimization and evaluations in other settings would be needed.


2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Nusa Idaman Said

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.


2015 ◽  
Vol 14 (6) ◽  
pp. 1347-1354 ◽  
Author(s):  
Florica Manea ◽  
Anamaria Baciu ◽  
Aniela Pop ◽  
Katalin Bodor ◽  
Ilie Vlaicu

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