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Hicks KA, Schmidt R, Nickelsen MG, Boyle SL, Baker JM, Tornatore PM, Hristova KR, Scow KM. Successful treatment of an MTBE-impacted aquifer using a bioreactor self-colonized by native aquifer bacteria. Biodegradation 2013; 25:41-53. [PMID: 23613160 DOI: 10.1007/s10532-013-9639-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/06/2013] [Indexed: 11/26/2022]
Abstract
A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 μg L(-1)), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes.
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Affiliation(s)
- Kristin A Hicks
- Department of Land, Air and Water Resources, University of California, One Shields Ave, Davis, CA, 95616, USA
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Pablos C, Marugán J, van Grieken R, Serrano E. Emerging micropollutant oxidation during disinfection processes using UV-C, UV-C/H2O2, UV-A/TiO2 and UV-A/TiO2/H2O2. WATER RESEARCH 2013; 47:1237-45. [PMID: 23276426 DOI: 10.1016/j.watres.2012.11.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 11/22/2012] [Accepted: 11/23/2012] [Indexed: 05/22/2023]
Abstract
Regeneration of wastewater treatment plant effluents constitutes a solution to increase the availability of water resources in arid regions. Water reuse legislation imposes an exhaustive control of the microbiological quality of water in the operation of disinfection tertiary treatments. Additionally, recent reports have paid increasing attention to emerging micropollutants with potential biological effects even at trace level concentration. This work focuses on the evaluation of several photochemical technologies as disinfection processes with the aim of simultaneously achieving bacterial inactivation and oxidation of pharmaceuticals as examples of emerging micropollutants typically present in water and widely studied in the literature. UV-C-based processes show a high efficiency to inactivate bacteria. However, the bacterial damages are reversible and only when using H(2)O(2), bacterial reproduction is affected. Moreover, a complete elimination of pharmaceutical compounds was not achieved at the end of the inactivation process. In contrast, UV-A/TiO(2) required a longer irradiation time to inactivate bacteria but pharmaceuticals were completely removed along the process. In addition, its oxidation mechanism, based on hydroxyl radicals (OH), leads to irreversible bacterial damages, not requiring of chemicals to avoid bacterial regrowth. For UV-A/TiO(2)/H(2)O(2) process, the addition of H(2)O(2) improved Escherichia coli inactivation since the cell wall weakening, due to OH attacks, allowed H(2)O(2) to diffuse into the bacteria. However, a total elimination of the pharmaceuticals was not achieved during the inactivation process.
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Affiliation(s)
- Cristina Pablos
- Department of Chemical and Environmental Technology, ESCET, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Madrid, Spain
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Lakretz A, Ron EZ, Mamane H. Biofilm control in water by a UV-based advanced oxidation process. BIOFOULING 2011; 27:295-307. [PMID: 21390914 DOI: 10.1080/08927014.2011.561923] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An ultraviolet (UV)-based advanced oxidation process (AOP), with hydrogen peroxide and medium-pressure (MP) UV light (H(2)O(2)/UV), was used as a pretreatment strategy for biofilm control in water. Suspended Pseudomonas aeruginosa cells were exposed to UV-based AOP treatment, and the adherent biofilm formed by the surviving cells was monitored. Control experiments using H(2)O(2) or MP UV irradiation alone could inhibit biofilm formation for only short periods of time (<24 h) post-treatment. In a H(2)O(2)/filtered-UV (>295 nm) system, an additive effect on biofilm control was shown vs filtered-UV irradiation alone, probably due to activity of the added hydroxyl radical (OH•). In a H(2)O(2)/full-UV (ie full UV spectrum, not filtered) system, this result was not obtained, possibly due to the germicidal UV photons overwhelming the AOP system. Generally, however, H(2)O(2)/UV prevented biofilm formation for longer periods (days) only when maintained with residual H(2)O(2). The ratio of surviving bacterial concentration post-treatment to residual H(2)O(2) concentration played an important role in biofilm prevention and bacterial regrowth. H(2)O(2) treatments alone resulted in poorer biofilm control compared to UV-based AOP treatments maintained with similar levels of residual H(2)O(2), indicating a possible advantage of AOP.
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Affiliation(s)
- Anat Lakretz
- School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
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Gopal A, Coventry J, Wan J, Roginski H, Ajlouni S. Alternative disinfection techniques to extend the shelf life of minimally processed iceberg lettuce. Food Microbiol 2010; 27:210-9. [DOI: 10.1016/j.fm.2009.10.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 10/05/2009] [Accepted: 10/06/2009] [Indexed: 10/20/2022]
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Labas MD, Brandi RJ, Zalazar CS, Cassano AE. Water disinfection with UVC radiation and H2O2. A comparative study. Photochem Photobiol Sci 2009; 8:670-6. [DOI: 10.1039/b817480f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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SCHRÖDER MONIKAJA, BLAND MICHAELA. Post-pasteurization contamination and shelf-life of HTST-pasteurized milk when filled in a Liqui-Pak® conventional or Model 820A cartoning machine. INT J DAIRY TECHNOL 2007. [DOI: 10.1111/j.1471-0307.1983.tb02535.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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BAYLISS CATHERINEE, WAITES WM. Effect of simultaneous high intensity ultraviolet irradiation and hydrogen peroxide on bacterial spores. Int J Food Sci Technol 2007. [DOI: 10.1111/j.1365-2621.1982.tb00202.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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RAJKOWSKI KATHLEENT. INHIBITION OF SHIGELLA SONNEI BY ULTRAVIOLET ENERGY ON AGAR, LIQUID MEDIA AND RADISH SPROUTS. J Food Saf 2007. [DOI: 10.1111/j.1745-4565.2007.00075.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Reidmiller JS, Baldeck JD, Rutherford GC, Marquis RE. Characterization of UV-peroxide killing of bacterial spores. J Food Prot 2003; 66:1233-40. [PMID: 12870758 DOI: 10.4315/0362-028x-66.7.1233] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Advantage is taken in many sterilization processes, especially for food packaging materials, of the synergy between H2O2 and UV irradiation for spore killing. The nature of the synergy is currently not well defined in terms of targets and mechanisms. We found that under some experimental conditions, the synergistic killing of spores of Bacillus megaterium ATCC 19213 appeared to be mainly UV-enhanced peroxide killing, while under other conditions, it appeared to be mainly peroxide-enhanced UV killing. Lethal combinations of H2O2 and UV irradiation for spores resulted in only modest increases in auxotrophic mutations among survivors, indicative of little DNA damage, in contrast to higher mutation levels after dry-heat damage at 115 degrees C. However, the combination of UV light and peroxide did lead to major inactivation of glucose 6-phosphate dehydrogenase, an enzyme that was used to monitor the damage to bacterial protein. Synergistic UV-H2O2 killing was reduced by agents such as pyruvate, thiosulfate, and iron or copper cations, which appeared to act at least in part by reacting chemically with H2O2, and was only slightly affected by the use of UV light at a wavelength of 222 nn rather than 254 nm. Hydrogen peroxide treatment can precede UV irradiation for synergistic killing by some hours with an interim of drying for spores of Bacillus subtilis A, a spore type used commonly for the validation of aseptic processes. Synergistic killing of dried spores or those in suspensions was accelerated at higher temperatures (50 degrees C) rather than at lower temperatures (25 degrees C).
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Affiliation(s)
- Jeffrey S Reidmiller
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, New York 14642-8672, USA
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Devine DA, Keech AP, Wood DJ, Killington RA, Boyes H, Doubleday B, Marsh PD. Ultraviolet disinfection with a novel microwave-powered device. J Appl Microbiol 2001; 91:786-94. [PMID: 11722655 DOI: 10.1046/j.1365-2672.2001.01438.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To evaluate the antimicrobial efficacy of a novel u.v. beaker, powered in a domestic microwave oven. METHODS AND RESULTS Three beakers were compared, with most rapid killing obtained in the Neutra Plasma 50. Ultraviolet light generated within the beakers efficiently killed planktonic and surface-associated Streptococcus mutans, Pseudomonas aeruginosa, vegetative Bacillus stearothermophilus, herpes simplex and polio viruses. Candida albicans and Mycobacterium phleii were less rapidly killed, and only 70% inactivation of B. stearothermophilus endospores was achieved. Irradiation for 45 s reduced viable bacterial counts in saliva by > 99%. CONCLUSIONS The u.v.-generating beakers efficiently reduced viable counts of bacteria, yeast and viruses. Kinetics of killing varied, reflecting the fact that lethal mechanisms are complex, and probably depend on interplay between u.v. and heat. SIGNIFICANCE AND IMPACT OF THE STUDY This novel method of generating u.v., using a cheap and widely available power source, provides a rapid, inexpensive and non-toxic method of disinfection with a wide range of applications in hospitals, clinics and the home.
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Affiliation(s)
- D A Devine
- Oral Microbiology, Division of Oral Biology, Leeds Dental Institute, UK
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AYHAN ZEHRA, STREAKER CHARLESB, ZHANG1 QHOWARD. DESIGN, CONSTRUCTION AND VALIDATION OF A SANITARY GLOVE BOX PACKAGING SYSTEM FOR PRODUCT SHELF-LIFE STUDIES. J FOOD PROCESS PRES 2001. [DOI: 10.1111/j.1745-4549.2001.tb00453.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Warriner K, Rysstad G, Murden A, Rumsby P, Thomas D, Waites WM. Inactivation of Bacillus subtilis spores on aluminum and polyethylene preformed cartons by UV-excimer laser irradiation. J Food Prot 2000; 63:753-7. [PMID: 10852569 DOI: 10.4315/0362-028x-63.6.753] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The efficacy of UV KrF-excimer laser light (at 248 nm) to inactivate Bacillus subtilis spores loaded onto preformed cartons was found to be dependent on the interior carton coating and scheme by which the irradiation was applied. When the carton was held static during UV laser treatment, the majority of the dose was delivered to the base of the carton and to a lesser extent to the upper part of the pack. In this arrangement no irradiation of the interior sides of the carton was observed. A more even distribution of dose was achieved, however, by moving the carton within the laser beam during irradiation treatment. The distribution of UV was also found to be dependent on the type of carton interior coating. With aluminum cartons the dose measured was found to be significantly greater (P < 0.01) and more evenly distributed across the interior compared to when polyethylene packs were tested. Under optimized conditions no spore survivors were detected on aluminum cartons preloaded with 9.5 x l0 B. subtilis spores by applying a UV laser output dose of 160 J. In comparison, the same conditions only achieved a significantly lower (P < 0.01) reduction in spore numbers (log count reduction 4.2) when polyethylene cartons were used. This difference in lethality and UV distribution of laser light was associated with the higher internal reflection of photons with aluminum cartons. The suitability of UV-excimer lasers for sterilizing preformed cartons over traditional germicidal lamp-based methods is discussed.
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Affiliation(s)
- K Warriner
- Division of Food Sciences, School of Biological Sciences, University of Nottingham, Loughborough, Leicestershire, UK
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Warriner K, Rysstad G, Murden A, Rumsby P, Thomas D, Waites WM. Inactivation of Bacillus subtilis spores on packaging surfaces by u. v. excimer laser irradiation. J Appl Microbiol 2000; 88:678-85. [PMID: 10792527 DOI: 10.1046/j.1365-2672.2000.01015.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ultraviolet (u.v.) laser irradiation has been used to inactivate Bacillus subtilis spores deposited on to planar aluminium- and polyethylene-coated packaging surfaces. Kill kinetics were found to be diphasic, with an initial rapid inactivation phase followed by tailing. Although no definitive evidence was obtained, it is thought that spores located within packaging crevices/pores were primarily responsible for the observed tailing. Surviving spores were also found on the unexposed underside of cards and, to a lesser extent, within clumps. The log count reduction in B. subtilis was dependent on spore loading and total u.v. dose. In comparison, packaging surface composition, fluence (2-18 Jm-2) and frequency (40-150 Hz) had only a negligible effect. By irradiating boards carrying 106 spores, with a dose of 11.5 J cm-2, a log count reduction >5 was obtained. The mode of spore inactivation was primarily through DNA disruption. This was confirmed by the high sensitivity of spores lacking protective, small, acid-soluble proteins, in addition to the high frequency of auxotrophic and asporogenous mutations found amongst survivors.
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Affiliation(s)
- K Warriner
- Division of Food Sciences, School of Biological Sciences, University of Nottingham, Loughborough, UK
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Wolfe RL, Stewart MH, Liang S, McGuire MJ. Disinfection of model indicator organisms in a drinking water pilot plant by using PEROXONE. Appl Environ Microbiol 1989; 55:2230-41. [PMID: 2679383 PMCID: PMC203061 DOI: 10.1128/aem.55.9.2230-2241.1989] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PEROXONE is an advanced oxidation process generated by combining ozone and hydrogen peroxide. This process stimulates the production of hydroxyl radicals, which have been shown to be superior to ozone for the destruction of some organic contaminants. In this study, pilot-scale experiments were conducted to evaluate the microbicidal effectiveness of PEROXONE and ozone against three model indicator groups. Escherichia coli and MS2 coliphage were seeded into the influent to the preozonation contactors of a pilot plant simulating conventional water treatment and were exposed to four ozone dosages (0.5, 1.0, 2.0, and 4.0 mg/liter), four hydrogen peroxide/ozone (H2O2/O3) weight ratios (0, 0.3, 0.5, and 0.8), and four contact times (4, 5, 12, and 16 min) in two source waters--Colorado River water and state project water--of different quality. The removal of heterotrophic plate count bacteria was also monitored. Results of the study indicated that the microbicidal activity of PEROXONE was greatly affected by the applied ozone dose, H2O2/O3 ratio, contact time, source water quality, and type of microorganism tested. At contact times of 5 min or less, ozone alone was a more potent bactericide than PEROXONE at all H2O2/O3 ratios tested. However, this decrease in the bactericidal potency of PEROXONE was dramatic only as the H2O2/O3 ratio was increased from 0.5 to 0.8. The fact that the bactericidal activity of PEROXONE generally decreased with increasing H2O2/O3 ratios was thought to be related to the lower ozone residuals produced. The viricidal activity of PEROXONE and ozone was comparable at all of the H2O2/O3 ratios. Heterotrophic plate count bacteria were the most resistant group of organisms. Greater inactivation of E. coli and MS2 was observed in Colorado River water than in state project water and appeared to result from differences in the turbidity and alkalinity of the two waters. Regardless of source water, greater than 4.5 log10 of E. coli and MS2 was inactivated at an applied ozone dosage of 2.0 mg/liter (and a 4-min contact time) when the H2O2/O3 ratio was less than or equal to 0.5. Comparative disinfection experiments indicated that free chlorine was the most potent bactericidal agent, followed (in descending order of effectiveness) by ozone, PEROXONE, and chloramines. These results indicate that the PEROXONE process must be optimized for each source water to achieve microbicidal effectiveness.
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Affiliation(s)
- R L Wolfe
- Metropolitan Water District of Southern California, La Verne 91750
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Croucher SC, Houston AP, Bayliss CE, Turner RJ. Bacterial populations associated with different regions of the human colon wall. Appl Environ Microbiol 1983; 45:1025-33. [PMID: 6847178 PMCID: PMC242405 DOI: 10.1128/aem.45.3.1025-1033.1983] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The microorganisms associated with the undiseased human colon wall were examined in material obtained from four sudden-death victims. In traffic accident subjects (aged 45 and 16 years) the anaerobe-aerobe ratio was about 10(4):1 in all areas of the colon examined, whereas in acute heart failure subjects (aged 74 and 46 years) the ratio was as low as 1.2:1. The flora of each individual was distinct and complex. Although the predominant anaerobes isolated were Bacteroides and Fusobacterium spp., which composed over 50% of the flora in some samples, the species isolated (indicated by morphology and glucose fermentation products) varied between individuals. Other major types observed were gram-positive nonsporing rods, including Bifidobacterium spp., and anaerobic cocci (between 8 and 20% of isolates). Clostridia were only isolated in significant numbers from one individual. Scanning electron microscopy showed that most of the organisms were present below the top surface of the mucin layer overlying the mucosa. The use of several different preparative procedures for microscopy showed a complex microbial structure within the mucus, but major variations in the bacterial populations in different areas of the colon were not found. Spiral-shaped organisms up to 60 mum long in the form of double helices were found in two subjects by scanning electron microscopy but were not isolated during the parallel bacteriological investigation. The differences between this and previous studies are discussed in relation to experimental procedures and also in contrast to results with animals that showed a particularly specialized flora associated with the colon wall.
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Bayliss CE, Shah J, Waites W. Comparison of sensitivity of repair-proficient and repair-deficient strains ofBacillus subtilisto ultraviolet irradiation and hydrogen peroxide. FEMS Microbiol Lett 1982. [DOI: 10.1111/j.1574-6968.1982.tb08245.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Bayliss CE, Waites WM. Resistance of Serratia marcescens to hydrogen peroxide. THE JOURNAL OF APPLIED BACTERIOLOGY 1981; 50:131-7. [PMID: 7014544 DOI: 10.1111/j.1365-2672.1981.tb00877.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Butler M. Virus Removal by Disinfection of Effluents. VIRUSES AND WASTEWATER TREATMENT 1981. [PMCID: PMC7152428 DOI: 10.1016/b978-0-08-026401-1.50025-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The safe disposal of effluents can present a major problem to large urban communities because of their inevitable content of potentially pathogenic enteric viruses. At least one hundred types of virus may be present although many of these are difficult or even impossible to characterise under these conditions. Wastewater treatment does not greatly effect the survival of many enteric viruses and some survive well even after effluent disposal. The use of disinfectants for the inactivation of virus in effluent is practicable but requires careful manipulation in order to avoid the disemination of byproducts toxic to man or capable of interferring with the ecology of the receiving waters or soils. No one system is likely to be either universally acceptable because of the variable quality of effluents and much research remains to be done before guidelines can be recommended or established.
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