Academic literature on the topic 'Ultraviolet irradiation for potable water'
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Journal articles on the topic "Ultraviolet irradiation for potable water"
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Cutler, Timothy D., and Jeffrey J. Zimmerman. "Ultraviolet irradiation and the mechanisms underlying its inactivation of infectious agents." Animal Health Research Reviews 12, no. 1 (June 2011): 15–23. http://dx.doi.org/10.1017/s1466252311000016.
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AbstractWe review the principles of ultraviolet (UV) irradiation, the inactivation of infectious agents by UV, and current applications for the control of microorganisms. In particular, wavelengths between 200 and 280 nm (germicidal UV) affect the double-bond stability of adjacent carbon atoms in molecules including pyrimidines, purines and flavin. Thus, UV inactivation of microorganisms results from the formation of dimers in RNA (uracil and cytosine) and DNA (thymine and cytosine). The classic application of UV irradiation is the inactivation of microorganisms in biological safety cabinets. In the food-processing industry, germicidal UV irradiation has shown potential for the surface disinfection of fresh-cut fruit and vegetables. UV treatment of water (potable and wastewater) is increasingly common because the process is effective against a wide range of microorganisms, overdose is not possible, chemical residues or by-products are avoided, and water quality is unaffected. UV has been used to reduce the concentration of airborne microorganisms in limited studies, but the technology will require further development if it is to gain wider application. For bioaerosols, the primary technical challenge is delivery of sufficient UV irradiation to large volumes of air, but the absence of UV inactivation constants for airborne pathogens under a range of environmental conditions (temperature, relative humidity) further compounds the problem.
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Abdul-Halim, Nadiya, and Kenneth R. Davey. "A Friday 13th risk assessment of failure of ultraviolet irradiation for potable water in turbulent flow." Food Control 50 (April 2015): 770–77. http://dx.doi.org/10.1016/j.foodcont.2014.10.036.
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Soliman, Amany, Azza El-Adawy, Amany A. Abd El-Aal, Marwa A. Elmallawany, Reham K. Nahnoush, Asmaa R. Abd Eiaghni, Mohamed Sherif Negm, and Amira Mohsen. "Usefulness of Sunlight and Artificial UV Radiation Versus Chlorine for the Inactivation of Cryptosporidium Oocysts: An in Vivo Animal Study." Open Access Macedonian Journal of Medical Sciences 6, no. 6 (June 10, 2018): 975–81. http://dx.doi.org/10.3889/oamjms.2018.180.
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BACKGROUND: Cryptosporidium is an important waterborne protozoan.AIM: The aim of this study was to investigate the effect of sunlight being the natural source of UV and artificial UV irradiation on Cryptosporidium oocysts versus the effect of chlorination, being the traditional method of water disinfection and to provide an insight into the viability and degree of infectivity of Cryptosporidium oocysts, using an animal model.METHODS: An experimental study including 300 neonatal mice was carried out to investigate the effect of artificial ultraviolet (UV) irradiation and sunlight being the natural source of UV irradiation versus chlorine, the traditionally used water disinfectant on the infectivity of Cryptosporidium oocysts present in water. For each item, nine different exposure times were investigated. Parasitological assessment (Modified Ziehl Neelsen stained stool smears) and histopathological assessment of the excised segments of the small intestine (stained by both Haematoxylin & Eosin and ZN stain) of mice were used to verify the inactivation of oocysts.RESULTS: Cryptosporidium oocysts failed to induce any noticeable infection after 4 hours of artificial UV exposure that provided a UV dose of 10mJ/cm2 and after an 8 hours exposure to sunlight, whereas they showed resistance to disinfection by chlorine.CONCLUSION: The results of the study demonstrate the important role of an 8 hours sunlight exposure of potable water in plastic bottles in achieving complete inactivation of any contaminating Cryptosporidium oocysts, thus offering an applicable, economical and convenient method for the control of cryptosporidiosis especially in developing countries.
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Kalisvaart, Ben F. "Photobiological effects of polychromatic medium pressure UV lamps." Water Science and Technology 43, no. 4 (February 1, 2001): 191–97. http://dx.doi.org/10.2166/wst.2001.0219.
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Ultraviolet (UV) light has become widely accepted for the disinfection of potable water, process water and wastewater as an alternative to chlorination. To avoid the failure of a UV disinfection system due to the recovery of micro-organisms, certain additional wavelengths in the UV area are emitted by newly developed UV lamps. To reduce the chance of microbial recovery after ultraviolet irradiation, damage must be inflicted in as many areas of the micro-organism as possible. The effective killing of micro-organisms by improved polychromatic medium pressure UV lamps is due to their exceptionally high UV energy output at specific wavelengths across a broad section of the UV spectrum. The combination of these properties results in several different lethal effects in small and large micro-organisms. Important biological molecules other than DNA are likely to be damaged, which helps to prevent the recovery of irradiated micro-organisms. Absorption line spectra of absorbing nucleotide bases, DNA and other biological molecules, including proteins and enzymes, show how effective UV light can be. Recent findings on the biological effects of short wavelengths on Bacillus subtilis, Cryptosporidium parvum and Escherichia coli confirm the effect of short wavelengths. Practical comparisons with conventional low pressure UV lamps at equal UV dosages show better killing rates from polychromatic medium pressure lamps, without formation of disinfection byproducts (DBPs).
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Abdul-Halim, Nadiya, and Kenneth R. Davey. "A risk model for Escherichia coli survival in a sequential sand-filter (SF) and turbulent flow annular-reactor with ultraviolet irradiation (UV) for potable water production." Chemical Engineering Science 243 (November 2021): 116736. http://dx.doi.org/10.1016/j.ces.2021.116736.
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Wolfe, Roy L. "Ultraviolet disinfection of potable water." Environmental Science & Technology 24, no. 6 (June 1990): 768–73. http://dx.doi.org/10.1021/es00076a001.
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Uddin Sikder, Md Kabir. "ULTRAVIOLET DISINFECTION OF POTABLE WATER IN RAINWATER HARVESTING SYSTEMS." International Journal of Engineering Applied Sciences and Technology 04, no. 11 (April 30, 2020): 557–63. http://dx.doi.org/10.33564/ijeast.2020.v04i11.098.
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Christianto, Victor. "Extended experiment on potable water irradiated with low-intensity laser pen and Solfeggio scale frequencies." Journal of Cosmology, Filaments and Astrobiology 2, no. 1 (2022): 11–15. http://dx.doi.org/10.54216/jcfa.020102.
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In previous article, we reported initial findings based on small experiment on potential use of salt-water as cheap source of renewable battery with various kind of metals as anode and cathode. The purpose of these experiments is to find out which combination of anode and cathode is capable to generate the best performance in terms of electric voltage. Following those previous reports, this writer also conducted several tests to see effect of low-intensity laser irradiation on potable water. While the first series of our experiment clearly indicated possible laser cooling effect of low intensity laser irradiation of potable water and salt water, the following extended experiment on low intensity laser irradiation shows a rather mixed result. In a series of initial experiment, laser irradiation with laser pen gave lower electric potential (down to several minus milli Volt to the Voltmeter reading), but later on after more than 180 sec of irradiation, it shows increased positive milli Volt of electric potential of the system. In this experiment, we found that combination of low-intensity laser irradiation and Solfeggio scale frequencies applied to potable water shows dim result.
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Blatchley, E. R., N. Dumoutier, T. N. Halaby, Y. Levi, and J. M. Laîne. "Bacterial responses to ultraviolet irradiation." Water Science and Technology 43, no. 10 (May 1, 2001): 179–86. http://dx.doi.org/10.2166/wst.2001.0614.
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The UV dose-response behavior of laboratory cultures of waterborne bacteria were examined for UV doses ranging from ca. 0 -100 mW•s/cm2 using a collimated-beam reactor. Specific physiological responses measured in these tests included viability (ability to reproduce) and respiration (oxygen uptake rate). The results of these exposures indicated that resistance to UV-imposed loss of viability in E. coli cultures can be partially attributed to agglomeration during the irradiation process. From these results, it is conjectured that a bacterial population may be comprised of two sub-populations: one with low resistance (discrete or paired cells) and a second with high resistance (bacterial aggregates). A small fraction of the high-resistance portion of the population appears to be essentially unaffected by UV irradiation, thereby causing a discontinuity in the measured dose-response behavior. Moreover, the dose-response behavior of the highly resistant fraction is variable and difficult to describe quantitatively. The basis of these statements and most information in the literature is microbial viability as quantified by the membrane filtration assay. In contrast to these findings, the results of analyses for bacterial activity (respiration) suggest that comparatively little change in the population can be found to result from UV irradiation. This suggests that UV radiation accomplishes inactivation of the bacteria, but does not “kill” the bacterial cells per se, thereby highlighting the importance of considering bacterial repair processes in the design of UV disinfection systems.
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Agwa, Obioma Kenechukwu, Nkechi Joy Eze, and Gideon Chijioke Okpokwasili. "Mutagenic Potentials of Potable Water From Ground Sources." Open Biotechnology Journal 11, no. 1 (August 9, 2017): 81–88. http://dx.doi.org/10.2174/1874070701711010081.
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Background:The presence of compounds with mutagenic activity in drinking water by means of short-term mutagenicity tests have been revealed in many studies. The influence of the different water treatment steps on the mutagenicity of some drinking water samples were evaluated using the Ames test.Method:Four different types of samples were collected from four water treatment factories within Port Harcourt metropolis: raw water from borehole (1), water after sand and granular activated carbon filtration (2), water after reverse osmosis (3), and water after Ozone and UV treatment (4). These samples were subjected to mutagenicity test using two mutant strains ofSalmonella typhimurium(TA 100 and TA 98) without S9 activation enzyme.Result:The mutagenic analysis results revealed that raw water samples from Kent and Rivoli table water products showed mutagenic potential with TA100 and TA 98, respectively. But Kent table water showed more mutagenic potential than Rivoli and Fressi table water samples. Fressi table water is predominantly cytotoxic with all the treatment processes except for UV treatment with TA 98 strain. The finished products (water after ozone and UV treatment) of Kent table water and Rivoli table water also showed mutagenic potentials higher than those treated with TA100 and TA98 without S9 mix, respectively. Only the samples treated with activated carbon showed highly reduced mutagenic potential.Conclusion:This study highlights the mutagenic effects of water treatment as another quality assessment option for assessing the portability of water samples. Water treatment with activated carbon can be reintroduced after disinfection with ozone/ultraviolet to eliminate possible mutagenic by-product in the finished product.
Dissertations / Theses on the topic "Ultraviolet irradiation for potable water"
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Olivier, Francois. "Evaluating the potential of ultraviolet irradiation for the disinfection of microbiologically polluted irrigation water." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97970.
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Thesis (MSc Food Sc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Fresh produce irrigation water from Western Cape Rivers carries faecal coliforms (FC) (Escherichia coli) at concentrations which often exceed the suggested limit of 1 000 FC per 100 mL and presents a health risk to consumers. On-farm ultraviolet (UV) irradiation presents several advantages for water disinfection but is an uncommon practice in South Africa. The aim of this study was to investigate the use of UV irradiation for river water disinfection prior to irrigation. Escherichia coli (E. coli) strains were exposed to low-pressure (LP) UV (4 mJ.cm-2) and UV/Hydrogen peroxide (H2O2) (4 mJ.cm-2/20 mg.L-1) treatments in Sterile Saline Solution (SSS). Strain variation in reductions was observed and ranged from 1.58 to 3.68 and 1.34 to 3.60 log for the UV and UV/H2O2 treatments, respectively. The UV/H2O2 treatment (4 mJ.cm-2/20 mg.L-1) was more effective, compared to UV singly, against some of the E. coli strains. Selected strains showed increased sensitivity at higher UV doses (8, 10 and 13 mJ.cm-2) and H2O2 concentrations (100 and 200 mg.L-1 with 4 mJ.cm-2) but a 3 log target reduction was not always reached. For all UV and UV/H2O2 treatments maximum resistance was shown by an environmental strain. Reference strains should, therefore, not be used for the optimisation of UV based disinfection parameters. At 10 mJ.cm-2 an American Type Culture Collection (ATCC) reference strain and an environmental strain (ATCC 25922 and F11.2) were both significantly less inactivated in sterilised river water compared to SSS. Enhanced water quality allowed for improved inactivation of the ATCC strain. Also, the efficiency of LP UV (5, 7 and 10 mJ.cm-2) and medium-pressure (MP) UV (13, 17 and 24 mJ.cm-2) radiation was investigated using water from the Plankenburg River. Water was sampled and treated on three respective days (Trials 1 to 3). Physico-chemical and microbiological water quality was always poor. The FC concentration reached a maximum of 6.41 log cfu.100 mL-1 while UV transmission was always below 38%. For LP and MP UV irradiation increased doses resulted in increased disinfection but a 3 log reduction of FC was only attained when MP UV light was used in Trial 1. Disinfection efficiency was dependent on water quality and on the characteristics of the microbial population in the water. Since FC were never reduced to below 3 log cfu.100 mL-1, the water did not adhere to guidelines for produce irrigation. Photo-repair following irradiation was investigated in river water using MP UV doses of 13 and 24 mJ.cm-2 and 3.5 kLux reactivating light, initially. Ultraviolet transmission was close to 50% and total coliform (TC) reduction exceeded 3 log, even at 13 mJ.cm-2. However, TC were reactivated from below 1 000 cfu.100.mL-1 to 3.93 and 4.41 log cfu.100 mL-1 for the 13 and 24 mJ.cm-2 treatments, respectively. A higher MP dose (40 mJ.cm-2) and a different treatment regime (2 x 20 mJ.cm-2) inhibited photo-repair (compared to 13 and 24 mJ.cm-2) but TC were always recovered to a final concentration surpassing 3 log cfu.100 mL-1, even under lower light intensities (1.0 to 2.0 kLux). In the current study UV irradiation did not produce water of acceptable standards for produce irrigation, mainly as a result of extremely poor water quality. However, on farm-scale, UV efficiency could be enhanced by improving water quality before irradiation. Also, stronger lamps that deliver higher UV doses may result in adequate disinfection, irrespective of water quality. Higher UV doses and the use of combination treatments (such as UV/Chlorine and UV/Peracetic acid) should be further investigated also to determine its disinfection efficiency and possible capability to inhibit post-disinfection repair.
AFRIKAANSE OPSOMMING: Varsproduk besproeiingswater vanuit Wes-Kaapse riviere bevat fekale kolivorme (FK) (Escherichia coli) in konsentrasies wat dikwels die voorgestelde limiet van 1 000 FK per 100 mL oorskry en hou `n gesondheidsrisiko vir verbruikers in. Plaasvlak ultraviolet (UV) bestraling bied verskeie voordele met verwysing na water dekontaminering, maar word selde aangewend in Suid-Afrika. Die doel van hierdie studie was om die gebruik van UV bestraling vir die dekontaminering van rivierwater, voor besproeiing, te ondersoek. Escherichia coli (E. coli) isolate is blootgestel aan lae-druk (LD) UV (4 mJ.cm-2) en UV/Waterstofperoksied (H2O2) (4 mJ.cm-2/20 mg.L-1) behandelings in Steriele Sout Oplossing (SSO). Isolaat variasie in reduksies is waargeneem en het gewissel tussen 1.58 tot 3.68 en 1.34 tot 3.60 log vir die UV en UV/H2O2 behandelings, onderskeidelik. In vergelyking met UV bestraling alleen was die UV/H2O2 behandeling (4 mJ.cm-2/20 mg.L-1) meer effektief teen sommige E. coli isolate. Geselekteerde isolate was meer sensitief tot hoër UV dosisse (8, 10 en 13 mJ.cm-2) en H2O2 konsentrasies (100 en 200 mg.L-1 met 4 mJ.cm-2), maar `n 3 log teikenreduksie was nie altyd haalbaar nie. Vir alle UV en UV/H2O2 behandlinge was die meeste weerstand deur `n omgewingsisolaat gebied. Verwysingsisolate behoort daarom nie aangewend te word vir die optimisering van UV-gebaseerde behandelingsparameters nie. By 10 mJ.cm-2 was beide `n ATCC verwysingsisolaat en `n omgewingsisolaat (ATCC 25922 en F11.2) betekenisvol minder gedeaktiveer in rivierwater as in SSO. Verbeterde waterkwaliteit het verhoogde inaktivering van die ATCC isolaat toegelaat. Die doeltreffendheid van LD UV (5, 7 en 10 mJ.cm-2) en medium-druk (MD) UV (13, 17 en 24 mJ.cm-2) bestraling is ook ondersoek deur watermonsters vanuit die Plankenburg Rivier te gebruik. Watermonsters was getrek en behandel op drie verskillende dae (Proewe 1 tot 3). Fisies-chemiese en mikrobiologiese kwaliteit van die water was deurentyd swak. Die FK konsentrasie het `n maksimum van 6.41 log kve.100 mL-1 bereik terwyl UV transmissie altyd laer as 38% was. Vir beide LD en MD UV bestraling het verhoogde dosisse gelei tot verbeterde dekontaminering, maar `n 3 log reduksie is slegs bereik toe MD UV lig gebruik is in Proef 1. Die effektiwiteit van die behandelings was afhanklik van waterkwaliteit en die eienskappe van die mikrobiese populasie in die water. Aangesien FK nooit tot onder 3 log kve.100 mL-1 verminder is nie het die water nie voldoen aan riglyne vir varsproduk-besproeiing nie. Fotoherstel na bestraling was ondersoek in rivierwater deur aanvanklik gebruik te maak van MD UV dosisse van 13 en 24 mJ.cm-2 en 3.5 kLux heraktiverende lig. Ultraviolettransmissie het byna 50% bereik en reduksie van totale kolivorme (TK) het 3 log oorskry, selfs by 13 mJ.cm-2. Totale kolivorme was egter geheraktiveer van onder 1 000 kve.100.mL-1 tot 3.93 en 4.41 log kve.100 mL-1 vir die 13 en 24 mJ.cm-2 behandelings, onderskeidelik. In vergelyking met 13 en 24 mJ.cm-2 het `n hoër MD dosis (40 mJ.cm-2) en `n veranderde bestralingstegniek (2 x 20 mJ.cm-2) fotoherstel onderdruk, maar TK was in elke geval geheraktiveer tot `n finale konsentrasie hoër as 3 log kve.100 mL-1, selfs onder laer intensiteit lig (1.0 tot 2.0 kLux). In hierdie ondersoek het UV bestraling nie water van aanvaarbare standaarde vir varsproduk besproeiing gelewer nie, hoofsaaklik as gevolg van swak waterkwaliteit. Nietemin, op plaasvlak mag die effektiwiteit van UV bestraling verhoog word deur waterkwaliteit voor bestraling te verbeter. Die gebruik van sterker lampe, om hoër UV dosisse te produseer, mag verder bydra tot voldoende dekontaminasie, ongeag van waterkwaliteit. Hoër UV dosisse en die gebruik van kombinasie behandelinge (soos UV/Chloor en UV/Perasynsuur) moet ook verder ondersoek word om die dekontaminasie effektiwiteit, en vermoë daarvan om heraktivering na dekontaminering te onderdruk, vas te stel.
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Cheng, Peiyao. "Chemical and photolytic degradation of polyacrylamides used in potable water treatment." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000566.
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Cheung, Lok Man. "Investigation of virus inactivation and by-products formation under sequential disinfection using UV irradiation and free chlorine/monochloramine /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20CHEUNG.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 106-124). Also available in electronic version. Access restricted to campus users.
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Ho, Chiu Man. "Repression of photoreactivation and dark repair of coliform bacteria by TiO[subscript 2]-modified UV-C irradiation /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20HO.
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Matias, Fernando M. G. "Studies on the influence of chemical disinfection, ultraviolet irradiation and pipe matrix on biofilm composition in drinking water distribution systems." Thesis, University of Ottawa (Canada), 2007. http://hdl.handle.net/10393/27887.
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There has recently been a shift in water treatment practices in Canada to a source-to-tap approach on water quality. With this approach comes the understanding that our water distribution systems are covered in biofilms which could contain potentially hazardous opportunistic pathogens. Meanwhile, regulations on control of disinfection byproducts in drinking water have also induced the phase-out of chlorine and its replacement with either chlorine dioxide or monochloramine in conjunction with UV treatment. These changes are based solely on the reduction of known disinfection byproducts and have not considered the impact of changing the disinfection regime on the ecology of biofilms within the distribution system. The objective of this study was to determine what, if any, influence changes in water disinfection would have on the mix of bacterial species in the distribution system biofilms with particular reference to cast iron and polycarbonate as pipe substrata.
Classical culture-based methods can reveal only a fraction of the bacterial content of biofilms because of our rudimentary understanding of the nutritional requirements of the organisms present and their inter-dependency. In contrast, newer techniques in molecular biology have become the norm for studying microbial ecology as they are not subject to the limitations of the culture methods, and thus can provide a much better profile of bacterial populations in biofilms. Although these methods have their own biases, PCR-DGGE was selected to monitor any changes in the profiles of the biofilms obtained under different disinfectant regimes and identify similarities and differences. Identification of the bacterial species would then be obtained by the sequencing of cloned bands, and matching them to the online databases, BLAST and RDP II.
Clear differences were observed in the biofilms from the two pipe materials tested. Aquabacterium parvum, Escherichia coli, Dechloromonas sp., Methylobacillus flagellatus, Phyllobacterium sp., Rhodocyclus sp., and Sphingomonas sp., were only identified in biofilms from cast iron coupons, while Chitinophaga sp., was found in biofilms from only polycarbonate coupons. This confirms that the pipe material can influence the types of organisms growing on its surface.
In general, the bacterial profiles were similar in the presence or absence of upstream UV treatment, except for the uncultivable Flavobacterium spp., which was detected only in the absence of UV treatment. This indicated that UV treatment has a relatively minor impact on altering the biofilm composition.
While a direct comparison between the impacts of the chemical disinfectants was not possible due to the design of the experimental set-up, the data obtained showed that several aspects of the bacterial profiles remained similar irrespective of the dosage levels of chlorine, chlorine dioxide, and monochloramine used.
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Hung, Dang-Quang. "Monitoring of organochlorine pesticides in surface waters in Hanoi and detoxification of organochlorine and organophosphorous pesticides in water by applying novel methods using ultraviolet irradiation, air ionisation and solar photocatalysis /." Berlin : Mensch & Buch Verlag, 2002. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=012967147&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Gandhi, Varun N. "Visualization and quantification of hydrodynamics and dose in UV reactors by 3D laser induced fluorescence." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45895.
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The validation of UV reactors is currently accomplished by biodosimetry, in which the reactor is treated as a "black-box" and hence cannot account for the dependence of the dose delivery on the complex hydrodynamics and the spatial variation in UV intensity. Alternative methods, such as fluorescent microspheres as non-biological surrogates and computational fluid dynamics (CFD) simulations, have been developed; however, each method has its shortcomings.
In this study, a novel technique for the spatial and temporal assessment of the hydrodynamics and the UV dose delivered and the link between these two factors in a lab-scale UV reactor using three dimensional laser induced fluorescence (3DLIF) is developed. This tool can also be utilized for the optimization of UV reactors and to provide data for validation of CFD-based simulation techniques. Regions of optimization include areas around the UV lamp where short-circuiting occurred, a longer inlet approach section that enhances the performance of the reactor by reducing short circuiting paths and a longer outlet region to provide greater mixing.
3DLIF allows real time characterization of mixing and dose delivery in a single lamp UV reactor placed perpendicular to flow by capturing fluorescence images emitted from a laser dye, Rhodamine 6G, using a high speed CCD camera. In addition to three-dimensional mixing, the technique successfully visualized the two-dimensional, transient mixing behaviors such as the recirculation zone and the von Karman vortices and the fluence delivery within the reactor, which has not been possible with traditional tracer test techniques. Finally, a decomposition technique was applied to the flow and fluence delivery based concentration data to reveal similar structures that affect these phenomena. Based on this analysis, changing the flow in the reactor, i.e. the Reynolds number, will directly affect the fluence delivery.
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Abdul, Halim Nadiya. "Quantitative Fr 13 Failure Modelling of Uv Irradiation for Potable Water Production – Demonstrated with Escherichia Coli." Thesis, 2017. http://hdl.handle.net/2440/119334.
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Steady-state ultraviolet (UV) irradiation for potable water production is becoming an important global alternative to traditional disinfection by chlorination. Failure of UV to reduce the number of viable contaminant pathogens however can lead to enduring health legacies (with or without fatalities). To better understand vulnerability of UV operations to failure, the probabilistic Fr 13 risk framework of Davey and co-workers1 is applied for the first time in this thesis. Fr 13 is predicated on underlying chemical engineering unit-operations. It is based on the hypothesis that naturally occurring, chance (stochastic) fluctuations about the value of ‘set’ process parameters can unexpectedly combine and accumulate in one direction and leverage significant change across a binary ‘failure– not failure’ boundary. Process failures can result from the accumulation of these fluctuations within an apparent steady-state process itself. That is to say, even with good design and operation of plant, there can be unexpected (surprise and sudden) occasional failures without ‘human error’ or ‘faulty fittings’. Importantly, the impact of these naturally occurring random fluctuations is not accounted for explicitly in traditional chemical engineering. Here, the Fr 13 risk framework is applied for the first time to quantitatively assess operations of logically increasing complexity, namely, a laminar flow-through UV reactor, with turbulent flow in a concentric annular-reactor, both with and without suspended solids present (Davey, Abdul-Halim and Lewis, 2012; Davey and Abdul-Halim, 2013; Abdul-Halim and Davey, 2015; 2016), and; a two-step ‘global’ risk model of combined rapid-sand-filtration and UV irradiation (SF-UV) (Abdul-Halim and Davey, 2017). The work is illustrated with extensive independent data for the survival of viable Escherichia coli - a pathogenic species of faecal bacteria widely used as an indicator for health risk. A logical and step-wise approach was implemented as a research strategy. UV reactor unit-operations models are first synthesized and developed. A failure factor is defined in terms of the design reduction and actual reduction in viable E. coli contaminants. UV reactor operation is simulated using a refined Monte Carlo (with Latin Hypercube) sampling of UV lamp intensity (I), suspended solids concentrations [conc] and water flow (Q). A preliminary Fr 13 failure simulation of a single UV reactor unit-operation (one-step), developed for both simplified laminar flow and turbulent flow models, showed vulnerability to failure with unwanted survival of E. coli of, respectively, 0.4 % and 16 %, averaged over the long term, of all apparently successful steady-state continuous operations. A practical tolerance, as a design margin of safety, of 10 % was assumed. Results from applied ‘second-tier’ studies to assess re-design to improve UV operation reliability and safety and to reduce vulnerability to Fr 13 failure showed that any increased costs to improve control and reduce fluctuations in raw feed-water flow, together with reductions in UV lamp fluence, would be readily justified. The Fr 13 analysis was shown to be an advance on alternate risk assessments because it produced all possible practical UV outcomes, including failures. A more developed and practically realistic model for UV irradiation for potable water production was then synthesized to investigate the impact of the presence of suspended solids (SS) (median particle size 23 μm) as UV shielding and UV absorbing agents, on overall UV efficacy. This resulted in, respectively, some 32.1 % and 43.7 %, of apparent successful operations could unexpectedly fail over the long term due, respectively, to combined impact of random fluctuations in feed-water flow (Q), lamp intensity (I0) and shielding and absorption of UV by SS [conc]. This translated to four (4) failures each calendar month (the comparison rate without suspended solids was two (2) failures per month). Results highlighted that the efficacy of UV irradiation decreased with the presence of SS to 1-log10 reduction, compared with a 4.35-log10 reduction without solids present in the raw feed-water. An unexpected outcome was that UV failure is highly significantly dependent on naturally occurring fluctuations in the raw feed-water flow, and not on fluctuations in the concentration of solids in the feed-water. It was found that the initial presence of solids significantly reduced the practically achievable reductions in viable bacterial contaminants in the annular reactor, but that fluctuations in concentration of solids in the feed-water did not meaningfully impact overall vulnerability of UV efficacy. This finding pointed to a pre-treatment that would be necessary to remove suspended solids prior to the UV reactor, and; the necessity to improve control in feed-water flow to reduce fluctuations. The original synthesis was extended therefore for the first time to include a rapid sand-filter (SF) for pre-treatment of the raw feed-water flow to the UV reactor, and; a Fr 13 risk assessment on both the SF, and sequential, integrated rapid sand-filtration and UV reactor (SF-UV). For the global two-step SF-UV results showed vulnerability to failure of some 40.4 % in overall operations over the long term with a safety margin (tolerance) of 10 %. Pre-treatment with SF removed SS with a mean of 1-log10 reduction (90 %). Subsequently, an overall removal of viable E. coli from the integrated SF-UV reactor was a 3-log10 reduction (99.9 %). This is because the efficacy of UV light to penetrate and inactivate viable E. coli, and other pathogens, is not inhibited by SS in the UV reactor. This showed that the physical removal of E. coli was accomplished by a properly functioning SF and subsequently disinfection was done by UV irradiation to inactivate viable E. coli in the water. Because the Regulatory standard for potable water is a 4-log10 reduction, it was concluded that flocculation and sedimentation prior to SF was needed to exploit these findings. Flocculation is a mixing process to increase particle size from submicroscopic microfloc to visible suspended particles prior to sedimentation and SF. This research will aid understanding of factors that contribute to UV failure and increase confidence in UV operations. It is original, and not incremental, work. Findings will be of immediate interest to risk analysts, water processors and designers of UV reactors for potable water production.Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering & Advanced Materials, 2017
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Amos, Steve A. "Ultraviolet disinfection kinetics for potable water production." 2008. http://hdl.handle.net/2440/50044.
Full textAbstract:
Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants in the production of potable water, and in the treatment of selected wastewaters. However, efficacy of UV disinfection is limited by the combined effect of suspended solids concentration and UV absorbance. Limited published UV disinfection data are available that account for the combined effects of UV dose, suspended solids concentration and UV absorbance. This present lack of a rigorous quantitative understanding of the kinetics of UV disinfection limits process optimisation and wider application of UV treatment. The development and validation of an adequate model to describe UV disinfection kinetics presented in this thesis can therefore be justified by an increased confidence of reliability of design for UV disinfection. Using the published data of Nguyen (1999), four established model forms were assessed to account for the combined effect of suspended solids and/or soluble UV absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky- Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third order. Criteria for assessment of an adequate predictive model were established including: accuracy of predicted against observed values, percent variance accounted for (%V), and; appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root forms. However, the DL-A form must be used in conjunction with a first-order chemical reaction equation, and was shown to predict poorly at high experimental values of UV dose (> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the observed UV dose range. To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two new, non-linear model forms was undertaken. The two models were a modified exponentially damped polynomial (EDPm) and a form based on the Weibull probability distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient (λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates the onset of tailing. The damping coefficient controls curvature in the survivor curve. The Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape parameter (β1). The scale parameter represents the level of disinfection in the tail of the survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature of the survivor data. Each model was assessed against the independent and published UV disinfection data of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull model form. To rigorously validate the suitability of the new EDPm and Weibull models a series of experimental trials were designed and carried out in a small-scale pilot UV disinfection unit. These trials included data determined specifically at low values of UV dose (<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999). The experimental trials were carried out using a commercially available, UV disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water contaminated with faecal material, and is used as an indicator for the presence of enteric pathogens. E. coli should not be present in potable water. The hydrodynamics of water flow within the disinfection unit were established using digital video photography of dye trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was controlled by manipulating the flow rate of feed water through the UV disinfection unit (i.e. residence time), or by varying the exposed length of the control volume of the disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the addition of either a soluble UV absorbing agent (International RoastTM instant coffee powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth (Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm). The absorbing agent (instant coffee), when in a comparable concentration, was found to produce a greater reduction in water transmission than the suspended material (Celite 503TM). It therefore contributed to a greater reduction in the initial rate of disinfection. Neither agent was found to produce a systematic reduction in the observed efficacy of disinfection however. Experimental results highlight that in the absence of soluble absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer viable bacteria are initially present. Both the new EDPm and Weibull forms gave a good fit to the experimental data. The EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for practical use in modelling UV disinfection data. Results of this research highlight the impact of water quality, as influenced by the combined effect of UV dose, suspended solids concentration and UV absorbance, on small-scale UV disinfection for potable water production. Importantly, results show that the concentration of soluble UV absorbing agents and suspended solids are not in themselves sufficient criteria on which to base assessment of efficacy of UV disinfectionhttp://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342403
Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008
10
Amos, Steve A. "Ultraviolet disinfection kinetics for potable water production." Thesis, 2008. http://hdl.handle.net/2440/50044.
Full textAbstract:
Irradiation with ultraviolet (UV) light is used for the disinfection of bacterial contaminants
in the production of potable water, and in the treatment of selected wastewaters. However,
efficacy of UV disinfection is limited by the combined effect of suspended solids
concentration and UV absorbance. Limited published UV disinfection data are available
that account for the combined effects of UV dose, suspended solids concentration and UV
absorbance. This present lack of a rigorous quantitative understanding of the kinetics of
UV disinfection limits process optimisation and wider application of UV treatment. The
development and validation of an adequate model to describe UV disinfection kinetics
presented in this thesis can therefore be justified by an increased confidence of reliability
of design for UV disinfection.
Using the published data of Nguyen (1999), four established model forms were
assessed to account for the combined effect of suspended solids and/or soluble UV
absorbing compounds, and UV dose on the efficacy of disinfection. The four model forms
were: a log-linear form, Davey Linear-Arrhenius (DL-A), Square-Root (or Ratkowsky-
Belehradek) and a general nth order Polynomial (nOP) form that was limited to a third
order. Criteria for assessment of an adequate predictive model were established including:
accuracy of predicted against observed values, percent variance accounted for (%V), and;
appraisal of residuals. The DL-A model was shown to best fit the data for UV disinfection
of Escherichia coli (ATCC 25922); followed by the nOP, log-linear and Square-Root
forms. However, the DL-A form must be used in conjunction with a first-order chemical
reaction equation, and was shown to predict poorly at high experimental values of UV dose
(> 40,000 μWs cm-2). The DL-A model was not amenable to extrapolation beyond the
observed UV dose range.
To overcome the shortcomings of the Davey Linear-Arrhenius model synthesis of two
new, non-linear model forms was undertaken. The two models were a modified
exponentially damped polynomial (EDPm) and a form based on the Weibull probability
distribution. The EDPm model has three terms: a rate coefficient (k), a damping coefficient
(λ), and; a breakpoint dose ([dose]B). The rate coefficient governs the initial rate of
disinfection prior to the onset of tailing, whilst the breakpoint is the UV dose that indicates
the onset of tailing. The damping coefficient controls curvature in the survivor curve. The
Weibull model has just two terms: a dimensionless scale parameter (β0), and; a shape
parameter (β1). The scale parameter represents the level of disinfection in the tail of the
survivor curve (as log10 N/N0), whilst the shape parameter governs the degree of curvature
of the survivor data.
Each model was assessed against the independent and published UV disinfection data
of Nelson (2000) for treatment of faecal coliforms in a range of waste stabilisation pond
effluents. Both models were found to be well suited to account for tailing in these UV disinfection data. Overall, the EDPm model gave a better fit to the data than the Weibull
model form.
To rigorously validate the suitability of the new EDPm and Weibull models a series of
experimental trials were designed and carried out in a small-scale pilot UV disinfection
unit. These trials included data determined specifically at low values of UV dose
(<10,000 μWs cm-2) to fill the gap in the experimental data of Nguyen (1999).
The experimental trials were carried out using a commercially available, UV
disinfection unit (LC5TM from Ultraviolet Technology of Australasia Pty Ltd). Purified
water contaminated with Escherichia coli (ATCC 25922) with a range of feed water flow
rates (1 to 4 L min-1) was used. E. coli was selected because it is found in sewage, or water
contaminated with faecal material, and is used as an indicator for the presence of enteric
pathogens. E. coli should not be present in potable water. The hydrodynamics of water
flow within the disinfection unit were established using digital video photography of dye
trace studies with Methylene Blue. Nominal UV dose (2,700 to 44,200 μWs cm-2) was
controlled by manipulating the flow rate of feed water through the UV disinfection unit
(i.e. residence time), or by varying the exposed length of the control volume of the
disinfection unit. The transmittance of the feed water (at 254 nm) was adjusted by the
addition of either a soluble UV absorbing agent (International RoastTM instant coffee
powder; 0.001 to 0.07 g L-1), or by addition of suspended matter as diatomaceous earth
(Celite 503TM; 0.1 to 0.7 g L-1, with a median particle size of 23 μm).
The absorbing agent (instant coffee), when in a comparable concentration, was found
to produce a greater reduction in water transmission than the suspended material (Celite
503TM). It therefore contributed to a greater reduction in the initial rate of disinfection.
Neither agent was found to produce a systematic reduction in the observed efficacy of
disinfection however. Experimental results highlight that in the absence of soluble
absorbing agents, or suspended solids, the initial rate of disinfection is higher when fewer
viable bacteria are initially present.
Both the new EDPm and Weibull forms gave a good fit to the experimental data. The
EDPm better fitted the data on the basis of residual sum-of-squares (0.03 to 2.13 for EDPm
cf. 0.16 to 4.37 for the Weibull form). These models are both of a form suitable for
practical use in modelling UV disinfection data.
Results of this research highlight the impact of water quality, as influenced by the
combined effect of UV dose, suspended solids concentration and UV absorbance, on
small-scale UV disinfection for potable water production. Importantly, results show that
the concentration of soluble UV absorbing agents and suspended solids are not in
themselves sufficient criteria on which to base assessment of efficacy of UV disinfectionThesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008
Books on the topic "Ultraviolet irradiation for potable water"
1
Malley, James P. Evaluation of by-products produced by treatment of groundwaters with ultraviolet irradiation. Denver, CO: The Foundation and American Water Works Association, 1995.
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2
Ing, Jo-Anne S. Impacts of medium-pressure UV irradiation on disinfection by-product formation: Residuals management plant, Mannheim Water Treatment Plant, Kitchener, Ontario. [Waterloo: s.n.], 1999.
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3
Canada. Dept. of Fisheries and Oceans. Microfiltration and Ultraviolet Irradiation to Eliminate Ceratomyxa Shasta (Myxozoa: Myxosporea), A Salmonid Pathogen, From Fraser River Water, British Columbia. S.l: s.n, 1985.
Find full textBook chapters on the topic "Ultraviolet irradiation for potable water"
1
Anh, Tuan Phan, and Tan Nguyen Minh. "Design of a Drinking Water Disinfection Systems using Ultraviolet Irradiation and Electrolysis Cell." In Lecture Notes in Civil Engineering, 361–66. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-0802-8_55.
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Budd, George C., Gary S. Logsdon, and Bruce W. Long. "Overview of Chlorine Dioxide, Ozone and Ultraviolet Irradiation." In Providing Safe Drinking Water in Small Systems, 113–20. Routledge, 2019. http://dx.doi.org/10.1201/9780203741726-17.
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Sadeghpour, Parisa, Elham Jalilnejad, and Kamran Ghasemzadeh. "Achievements in ultraviolet irradiation and in advanced oxidation technologies for wastewater and water treatment." In Current Trends and Future Developments on (Bio-) Membranes, 1–39. Elsevier, 2020. http://dx.doi.org/10.1016/b978-0-12-817378-7.00001-x.
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Imai, Hiroaki, Hiroshi Hirashima, and Koichi Awazu. "Alternative modification methods for sol—gel coatings of silica, titania and silica—titania using ultraviolet irradiation and water vapor." In Coatings on Glass 1998, 160–63. Elsevier, 1999. http://dx.doi.org/10.1016/b978-044450247-6.50032-1.
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Abdi, G. "Photocatalytic Membranes in Degradation of Organic Molecules." In Materials Research Foundations, 1–56. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901359-1.
Full textAbstract:
Heterogeneous photocatalysis is a technology widely applied to water purification and wastewater treatment under ultraviolet (UV) or even sunlight irradiation for the removal of a variety of environmental pollutants into harmless species. Application of membrane for immobilization of semiconductors and their suitability in photocatalytic degradation of dyes have recently been developed. Integration of photocatalysis with membrane processes significantly improve the membrane separation performance with reducing membrane fouling and improving permeate quality. This paper reviews recent progress in the photocatalytic membranes for wastewater treatment and water purification with an emphasis on the type of membranes, membrane fabrication, and applications in pollutant removal.
Conference papers on the topic "Ultraviolet irradiation for potable water"
1
Savant, Gaurav, Benjamin Magbanua, and Dennis Truax. "Kinetics ofEscherichia ColiInactivation with Ultraviolet Irradiation." In World Water and Environmental Resources Congress 2003. Reston, VA: American Society of Civil Engineers, 2003. http://dx.doi.org/10.1061/40685(2003)258.
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Birmele, Michele, LaShelle McCoy, Robert Soler, and Michael S. Roberts. "Ultraviolet Light Emitting Diodes for Disinfection of Spacecraft Potable Water Systems." In International Conference On Environmental Systems. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2009. http://dx.doi.org/10.4271/2009-01-2508.
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Wait, Isaac W., Cliff T. Johnston, and Ernest R. Blatchley, III. "Fouling of Quartz Surfaces in Potable Water Ultraviolet Disinfection Systems: Effect of Phosphate Addition." In World Water and Environmental Resources Congress 2004. Reston, VA: American Society of Civil Engineers, 2004. http://dx.doi.org/10.1061/40737(2004)343.
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Vick, Brian D., R. Nolan Clark, Junyi Ling, and Shitao Ling. "Remote Solar, Wind, and Hybrid Solar/Wind Energy Systems for Purifying Water." In ASME 2001 Solar Engineering: International Solar Energy Conference (FORUM 2001: Solar Energy — The Power to Choose). American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/sed2001-136.
Full textAbstract:
Abstract Solar energy, wind energy, and a combination of wind and solar energy have been used successfully to power an UV (ultraviolet) water purification system. The main reason for this success has been the design of the controllers which have been operating for almost two years with various wind and solar energy inputs. Five different solar and wind energy systems have been tested so far and although these renewable energy systems have been used for water purification, graphs contained in the paper can be used to determine the feasibility of powering various other electrical loads. Combining a 100 Watt solar system with a 900 Watt wind turbine resulted in pumping and purifying enough water to satisfy the potable water requirements of 4000 people (16000 liters/day) at an estimated equipment cost of about $4660 (approximately $1/person).
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Guoting Li, Wang Ning, and Shao Jian. "Effect of ultraviolet irradiation and hydrogen P eroxide on the degradation of orange II using Fe(III) and Mn(II)." In 2011 International Symposium on Water Resource and Environmental Protection (ISWREP). IEEE, 2011. http://dx.doi.org/10.1109/iswrep.2011.5893530.
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Al Ruheili, Sharifa Mohammed, Felix Tiefenbacher, Khansaa Hamed Al Mahrami, Nazir Othman Shahin, and Omar Salim Al Jaaidi. "An Innovative Method of Water Management by Desalinating the Produced Water Using Thermal Renewable Energy." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211175-ms.
Full textAbstract:
Abstract Produced water, which in many cases shows a high degree of salinity, is currently managed using water disposal wells and evaporation ponds. Both methods are conventional and have negative environmental impacts. ARA is adopting a unique and innovative method to manage high salinity produced water in an environmentally sustainable way by extracting potable water from produced water and reducing discharge water volume by at least 50%. For desalination of the produced water an innovative combination of forward and direct osmosis technology is used. This process is driven mostly by thermal energy which is provided to 100% solar thermal collectors. The structure of the plant is as follows: A solar thermal power plant consisting of 2 desert- and oilfield-proof solar thermal collectors ("HELIOtubes") with thermal energy storage (TES) using pressurized water for nighttime operations (24/7). The solar thermal plant powers an advanced forward osmosis desalination (FO) and brine concentration Direct Osmosis (DO) unit with pre-treatment unit to cope with the challenging produced water. This project is in the pipeline for implementation. The engineering and the planning design were successfully completed. Two main results are expected from this project, which is: (i) low-cost and low-maintenance thermal power and (ii) desalinated water from the produced water meeting the regulatory specifications. It is a state-of-the-art system integration engineering based on the simulation of the innovative desert-proof solar thermal plant including TES using 10-year historical satellite-based irradiation data to show optimal use of renewable energy. Lab studies show how low energy consumption pre-treatment of the challenging produced water with its difficult chemical composition can be achieved, allowing membrane-based forward osmosis to be applied even at a salinity level that is 3-times higher than seawater. That leads to high energy efficiency for desalination also at nighttime based on thermal power from cost-effective TES instead of expensive batteries. This system could be considered a game-changer in the oil and gas industry because it introduces a new water management methodology.
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Boyle, Paul M., and Brent C. Houchens. "Hands-On Water Purification Experiments Using the Adaptive WaTER Laboratory for Undergraduate Education and K-12 Outreach." In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55108.
Full textAbstract:
A bench-top educational system, the Adaptive Water Treatment for Education and Research (WaTER) Laboratory, has been developed as part of a year-long capstone design project. The Adaptive WaTER Lab teaches students about the effectiveness of various water purification techniques. Stackable housings employ six different filtration and purification methods including: sediment filtration, carbon filtration, chemical disinfection, reverse osmosis, forward osmosis, and ultraviolet light disinfection. Filtration pressure is supplied by a hand or foot pump, and two rechargeable batteries are required for the UV sterilization unit. The advantages and limitations of each technique are investigated, with learning performance criteria measured by knowledge of: material costs, contaminant removal or neutralization capabilities (from large sediment to bacteria and viruses to chemicals), robustness and longevity, and power requirements and efficiencies. Finally, suitable combinations of treatment techniques are studied for specific contamination issues, with the ultimate goal of producing potable water. The importance of sustainable water use is also discussed. Background information and suggested experiments are introduced through accompanying educational packets. This system has had a successful impact on undergraduate education. The metrics of success include a published journal article, an awarded EPA P3 educational grant and a pending patent for the undergraduates involved in the development of the Lab. Other undergraduates are currently involved in a design for manufacturability study. Finally, the Lab has served as a demonstration tool in a new interdisciplinary engineering course “Integrated Approaches to Sustainable Development.” The Adaptive WaTER Lab has also been used in hands-on outreach to over 300 underrepresented K-12 students in the Houston area. Two high school students borrowed the original prototype of the Lab to use in an Earth Day demonstration, and one student recently worked on an individual project using the Lab. Because the Lab is portable and requires only human and solar power (to recharge the batteries via a solar backpack), it is also ideal for educational efforts in developing nations. Labs are currently being produced for outreach and donation via three international projects to install water purification systems and/or educational Labs in schools and clinics in Mexico, Lesotho and Swaziland, in collaboration with the Beyond Traditional Borders and Rice 360 health initiatives.
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Lakeh, Reza Baghaei, Daniel Andrade, Kyle Miller, Mohammad Masoud Modabernia, Thuan John Nguyen, Justine Nguyen, Elbon Flanagan, et al. "Design and Testing of a Solar-Driven Wastewater Treatment Unit for Off-Grid Applications." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87090.
Full textAbstract:
The decline of surface water sources along with periodic droughts has introduced new challenges for the state of California. In order to keep up with the increasing demand for water, the state is heavily relying on imported water from the north to Southern California as well as importing water from the Colorado River. The imported water has a large carbon footprint due to using grid power for water transport. Water reuse (reclaimed) is considered as one of the solutions to reduce the dependency of state on imported water. The research team at Cal Poly Pomona, is developing an off-grid solar-powered greywater treatment system for non-potable use in single households. Greywater is the drained water from bathroom sinks, showers, tubs, and washing machines; not including wastewater from toilets or kitchen sinks. Treating greywater on-site can provide significant water savings, and can reduce the carbon footprint of desalination using solar panels. The developed system is comprised of a three-stage treatment train: micro-filtration, solar-driven reverse osmosis, and ultraviolet disinfection. The end product of the project is capable of reclaiming 90–100 gallons of water per day which is about 60% of residential greywater waste. The system removes large suspended particles (particles of dirt, food, etc.) as well as organic and inorganic dissolved contaminants. It is demonstrated that the system can provide a permeate quality that agrees with recommended guidelines for reclaimed water. The system has a recovery rate of up to 62%.
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Honjo, Yoshio, Masahiro Furuya, Tomoji Takamasa, and Koji Okamoto. "Interfacial Phenomena of Radiation-Induced and Photo-Induced." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48320.
Full textAbstract:
When a metal oxide is irradiated by gamma rays, the irradiated surface becomes hydrophilic. This surface phenomenon is called as radiation induced surface activation (RISA). In order to investigate radiation-induced and photo-induced hydrophilicity, the contact angles of water droplets on a titanium dioxide surface were measured in terms of irradiation intensity and time for gamma rays of cobalt-60 and for ultraviolet rays. Reciprocals of the contact angles increased in proportion to irradiation time before the contact angles reached their super-hydrophilicity state. The reciprocals of contact angles correlate well with integrated intensity by a straight line, regardless of the irradiation intensity and time. Radiation-induced and photo-induced hydrophilicity phenomena are identical to each other in this regard. In addition, an effect of ambient gas was investigated. In pure argon gas, the contact angle remains the same against the irradiation time. This clearly shows that a certain humidity in ambient gas is required to take the place of RISA hydrophilicity. A single crystal titanium dioxide (100) surface was analyzed by X-ray photoelectron spectrometry (XPS). After irradiation with gamma rays, a peak was found in the O 1s spectrum, indicating the adsorption of dissociative water to a surface 5-fold coordinate titanium site, and the formation of a surface hydroxyl group. We conclude that the RISA hydrophilicity is caused by chemisorption of the hydroxyl group on the surface.