Showing papers in "Journal American Water Works Association in 1986"
TL;DR: The physical, chemical, and biological properties of chlorine dioxide as they relate to water treatment are reviewed in this paper, where the generation reactions as well as the reactions likely to occur in treated water are presented.
Abstract: There is increased interest in using chlorine dioxide to treat drinking water for trihalomethane control, taste and odor control, oxidation of iron and manganese, and oxidant-enhanced coagulation -sedimentation. This article reviews the physical, chemical, and biological properties of chlorine dioxide as they relate to water treatment. The generation reactions as well as the reactions likely to occur in treated water are presented. In addition, the biological properties of chlorine dioxide are reviewed and compared with other common disinfectants.
258 citations
TL;DR: In this article, several commonly used techniques for removing organic taste and odor compounds from water were investigated and it was found that chlorine dioxide was the most effective oxidant for removing the five selected compounds.
Abstract: Several commonly used techniques for removing organic taste and odor compounds from water were investigated. These techniques were originally designed to simulate water treatment conditions, but it was necessary to choose test conditions that were often extremes, such as wide ranges of dosages and contact times, so that more conclusive evidence of the efficiencies of these techniques could be determined. A comparison of equivalent dosages showed that chlorine dioxide was the most effective oxidant for removing the five selected compounds.
148 citations
TL;DR: Interaction des desinfectants and des composes organiques naturellement presents: reaction d'oxydation and de substitution as mentioned in this paper, and reaction de substitution and de oxydation.
Abstract: Interaction des desinfectants et des composes organiques naturellement presents: reaction d'oxydation et de substitution
93 citations
TL;DR: The toxicological hazards associated with disinfecting drinking water with either chlorine dioxide or chlorine are reviewed and compared in this paper, where adverse health effects shown in animal experiments as well as human poisoning incidents are reported.
Abstract: The toxicological hazards associated with disinfecting drinking water with either chlorine dioxide or chlorine are reviewed and compared. Adverse health effects shown in animal experiments as well as human poisoning incidents are reported. Toxicological effects, which are associated with the disinfectants themselves and the products formed when the disinfectants react with organic material present in water, are considered.
85 citations
TL;DR: In this article, the performance of activated carbons for removing five specific taste and odor-causing organic compounds that occur at the nanograms-per-litre level in water supplies was evaluated.
Abstract: Equilibrium studies were conducted that used closed-loop stripping analysis in conjunction with experimental methodologies to evaluate the performance of activated carbons for removing five specific tasteand odor-causing organic compounds that occur at the nanograms-per-litre level in water supplies. Both powdered activated carbon (PAC) and granular activated carbon (GAC) proved to be more effective for removing geosmin than for removing 2-methylisobomeol (MIB). Although chlorine and coagulants had no detrimental effect on the adsorption of organics by PAC, the removal of geosmin and MIB by GAC appeared to be adversely affected by background organic compounds, such as humic substances. The mixing technique used was observed to play a significant role in adsorption.
77 citations
TL;DR: In this paper, the authors investigated charge, solubility, and molecular-size characteristics of dissolved organic carbon in raw and treated water from a Virginia reservoir to determine the types of organic compounds removed by ferric sulfate, coagulation, and settling.
Abstract: Charge, solubility, and molecular-size characteristics of dissolved organic carbon in raw and treated water from a Virginia reservoir were investigated to determine the types of organic compounds removed by ferric sulfate, coagulation, and settling. All three parameters influenced removal of dissolved organic carbon. Larger molecules were more readily precipitated than smaller ones. Ionic compounds were more effectively removed than neutral compounds. Hydrophilic and hydrophobic organics were preferentially removed over compounds of intermediate solubility. Two main groups of organic halide precursors were identified. Fulvic acids were the dominant precursors in raw water- they reacted rapidly with chlorine and had high specific yields, but were readily precipitated. Low-molecular-weight neutral compounds were the dominant precursor group remaining in treated waters. These molecules reacted more slowly with chlorine and had lower organohalide yields.
68 citations
TL;DR: Invertebrates collected from the water distribution system of Worcester, Mass., were found to harbor a variety of bacteriasome of which may be pathogenic to humans and to protect them from inactivation by chlorine and monochloramine.
Abstract: Invertebrates collected from the water distribution system of Worcester, Mass., were found to harbor a variety of bacteriasome of which may be pathogenic to humans and to protect them from inactivation by chlorine and monochloramine. Currently, the best approach to invertebrate control is elimination of these organisms before they enter the distribution system or physical or chemical modification of their potential habitats within the system.
63 citations
TL;DR: In this article, the authors reported that two unacceptable tastes and odors, which corresponded with levels of geosmin in the water that were much higher than the background level of 20 ng/L or less, occurred in Philadelphia during 1985.
Abstract: Two episodes of unacceptable tastes and odors, which corresponded with levels of geosmin in the water that were much higher than the background level of 20 ng/L or less, occurred in Philadelphia during 1985. The source of one episode was found to be a localized bed of algae in the Schuylkill River. An existing tasteand odor-control program, which utilizes instrumental and sensory analyses, was largely responsible for the effective management of the episodes. Hydraulic strategies were used to reduce the treatment plant's intake of geosmin, and powdered activated carbon in the treatment train further reduced the geosmin level. Dilution of this treated water with other finished waters in the distribution system also diminished the impact of geosmin on the taste and odor of Philadelphia's water.
59 citations
TL;DR: In this paper, the application of ClO 2 a l'eau brute peut reduire de facon importante la formation des trihalomethanes, i.e.,
Abstract: L'application de ClO 2 a l'eau brute peut reduire de facon importante la formation des trihalomethanes
57 citations
TL;DR: The disinfection of water for potable Evidence has suggested that the use of use is required wherever contamination free residual chlorine results in the or the potential for contamination with formation of halogenated organics that human pathogens exists.
Abstract: The disinfection of water for potable Evidence has suggested that the useof use is required wherever contamination free residual chlorine results in the or the potential for contamination with formation of halogenated organics that human pathogens exists. The disinfec- are carcinogenic to animals.‘-“’ This has tant must be able to inactivate a wide been disputed by Tuthill and Moore.” range of organisms displaying an equally The US Environmental Protection wide range of sensitivities. The ideal Agency hasset theacceptableceilingfor disinfectant destroys all organisms trihalomethanes (THMs) in potable waquickly, under all water quality condi- terat 0.10mg/L.12Anumberof treatment tions, and with no adverse side effects. options have been recommended in order Unfortunately, nosuch ideal disinfectant to reduce the level of THMs in water exists, and water utilities are left with a disinfected with free residual chlorine. number of options, all of which present Among these treatment options, chlocertain advantages and disadvantages. ramination-the addition of chlorine and
56 citations
TL;DR: In this paper, a reverse osmosis (RO) water treatment plant equipped with conventional cellulose acetate membranes, and two pilot RO plants, equipped with polyamide membranes, were tested for their ability to remove total organic carbon and a broad range of trace organics, including volatiles, purgeables, neutrals, bases, phenols, and acids from lime-clarified secondary municipal wastewater.
Abstract: A full-scale (8-cfs [0.22-m3/s]) reverse osmosis (RO) water treatment plant equipped with conventional cellulose acetate membranes, and two pilot RO plants, equipped with polyamide membranes, were tested for their ability to remove total organic carbon and a broad range of trace organics, including volatiles, purgeables, neutrals, bases, phenols, and acids from lime-clarified secondary municipal wastewater. The full-scale RO system removed total organic carbon (TOC) by 89 percent to 0.95 mg/L at 84-percent water recovery, and the pilot RO systems removed TOC by 99 percent to 0. 1 mg/L at water recoveries of 52 and 67 percent, respectively. The two membranes tested showed significant differences in their ability to reject trace organics. All membranes rejected branched, complex molecules but varied in their rejection characteristics for smaller molecules, such as chlorinated solvents. The latter group was rejected to a varying degree by polyamide membranes but passed through cellulose acetate membranes. The use of RO for trace organics removal is evaluated by comparing cumulative removals of different treatment schemes with and without RO treatment.
TL;DR: In this paper, a variety of chemical and physical characterization techniques were used to identify the changes in organic character resulting from chemical treatments of a Mississippi River water sample, and the results showed that the organic content of potable water supplies and the production of potentially toxic chlorinated organic products was increased.
Abstract: In light of increasing concern for the organic content of potable water supplies and the production of potentially toxic chlorinated organic products, a better understanding of the character of organics removed by commonly used treatment processes is desirable. A variety of chemical and physical characterization techniques were used to identify the changes in organic character resulting from chemical treatments of a Mississippi River water sample.
TL;DR: In this paper, les concentrations reduites de trihalomethane dans l'eau traitee en hiver sont fonctions de la vitesse reduite de formation des trihalmethanes.
Abstract: Les resultats de cette etude suggerent que les concentrations reduites de trihalomethane dans l'eau traitee en hiver sont fonctions de la vitesse reduite de formation des trihalomethanes
TL;DR: In this article, an air-stripping tower was designed to treat 1500 gpm (0.09464 m3/s) of groundwater contaminated with trichloroethene, tetrachloroen, cis1,2-dichloroenne, toluene, ethyl benzene, and isomers of xylene.
Abstract: An air-stripping tower was designed to treat 1500 gpm (0.09464 m3/s) of groundwater contaminated with trichloroethene, tetrachloroethene, cis1,2-dichloroethene, toluene, ethyl benzene, and isomers of xylene. A simplified procedure for designing a tower with the smallest volume and energy requirements was used. Data for the first four months of operation demonstrated excellent removals for the six volatile organic compounds. The cost of treatment was about $0.0586/1000 gal (3.785 m3) of water treated. Operating problems, microbiological analyses, and data regarding total organic halogen (TOX) and TOX formation potential are summarized.
TL;DR: McFarland's only water source is groundwater as discussed by the authors, and the composition of the water drawn from four wells and shows that three exceed the US Environmental Protection Agency's (USEPA's) maximum contaminant level (MCL) of 10 mg/L for nitrate as nitrogen (NO3-N).
Abstract: ... „ * ... Well „ supply A (Calif.) plant ber 1-mgd 1983 was (3.8-ML/d) Mutual by completed the Water ion McFarland exchange in OctoComplant was completed in October 1983 by the McFarland (Calif.) Mu ual W ter Company to remove nitrate from the city's drinking water. McFarland, located about 30 mi (48 km) northwest of Bakersfield in the southern part of the San Joaquin Valley, has a population of approximately 6000 people. The area is extensively agricultural, and nitrogen fertilizers are probably the source of nitrate in the well water. Currently, McFarland's only water source is groundwater. Table 1 shows the composition of the water drawn from McFarland's four wells and shows that three exceed the US Environmental Protection Agency's (USEPA's) maximum contaminant level (MCL) of 10 mg/L for nitrate as nitrogen (NO3-N).1 McFarland has been using two wells (1 and 4) with a total capacity of 1400 gpm (88 L/s). Water from well 3 is prohibited for public use because of high nitrate levels.
TL;DR: The sphericity or angularity of the different filter media currently being used shows much variation and greatly influences the fixed bed head loss, the minimum fluidization velocity, and the expansion behavior of the media.
Abstract: As a result of the growing importance of granular media filtration in water and wastewater treatment, several studies dealing with various aspects of fluidization have been reported in the literature during the past two decades. The sphericity or angularity of the different filter media currently being used shows much variation and greatly influences the fixed bed head loss, the minimum fluidization velocity, and the expansion behavior of the media. This article attempts to elucidate the shortcomings of some expansion models and to correct certain concepts that have been presented in the literature, while complementing an earlier article.1
TL;DR: In this article, Wiese, G.R. and Ruckenstein, E.C. and Healy, T.W. present a theory of Heterocoagulation, Interaction and Adhesion of Dissimiliar Particles in Solution of Electrolytes.
Abstract: 28. Lasaga, A.C. Towards a Master Equation in Crystal Growth. Amer. Jour. Sci., 282:1264 (1982). 29. O'Melia, C.R. Aquasols: The Behavior of Small Particles in Aquatic Systems. Envir. Sci. & Technol., 14:1052 (1980). 30. Prieve, D.C. & Ruckenstein, E. The Surface Potential of and Double-Layer Interaction Force Between Surfaces Characterized by Multiple Ionizable Groups. Jour. Theoretical Biol., 56:205 (1976). 31. Wiese, G.R. & Healy, T.W. Effect of Particle Size on Colloid Stability. Trans. Faraday Soc., 66:490 (1970). 32. Derjaguin, B.V. A Theory of Heterocoagulation, Interaction and Adhesion of Dissimiliar Particles in Solution of Electrolytes. Dis. Faraday Soc., 18:85 (1954). 33. Prieve, D.C. & Ruckenstein, E. Role of Surface Chemistry in Primary and Secondary Coagulation and Heterocoagulation. Jour. Colloid Interface Sci., 73:539 (1980). 34. Wiese, G.R. & Healy, T.W. Coagulation and Electrokinetic Behavior of Ti02 and AI2O3 Colloidal Dispersions./owr. Colloid Inter/ace Sci., 51:427 (1975). 35. Matijevic, E. Interactions in Mixed Colloidal Systems. Pure & Appl. Chem., 53:2167 (1981). 36. Letterman, R.D. & Iyer, D.R. Modeling the Effects of Hydrolyzed Aluminum and Solution Chemistry on Flocculation Kinetics. Envir. Sci. & Technol., 19:673 (1985). 37. Prieve, D.C. & Ruckenstein, E. Role of Surface Chemistry in Particle Deposition. Jour. Colloid Interface Sci., 60:337 (1977). 38. Nelligan, J.D.; Kallay, N.; & Matijevic, E. Particle Adhesion and Removal in Model Systems. V. Interpretation of the Kinetics of Particle Detachment. Jour. Colloid Interface Sci., 89:9 (1982). 39. Bales, R.C. & Morgan, JJ. Dissolution Kinetics of Chrysotile From pH 7-10. Geochim. Cosmochim. Acta, 49:2281 (1985). 40. Stone, A.T. Reduction and Dissolution of Mn(III) and Mn(IV) Oxides by Organics: 2. Survey of the Reactivity of Organics. Envir. Sci. & Technol., 18:617 (1984). 41. Waite, T.C. & Morel, F.M.M. Photoreductive Dissolution of Colloidal Iron Oxides in Natural Waters. Envir. Sci. & Technol., 18:860(1984). 42. Berner, R.A. Early Diagenesis; A Theoretical Approach. Princeton Univ. Press, Princeton, N.J. (1980). 43. Kirkpatrick, J.R. Kinetics of Crystallization of Igneous Rocks. Kinetics of Geochemical Processes (A.C. Lasaga & R.J. Kirkpatrick, editors). Reviews in Mineralogy, Vol 8. Mineralog. Soc. Amer., Washington, D.C. (1981). 44. Morgan, J.J.; Sung, W.A.; & Stone, A.T. Chemistry of Metal Oxides in Natural Water: Catalysis of the Oxidation of Mn(II) by y-FeOOH and the Reductive Dissolution of Manganese (III) and (IV) Oxides. Environmental Inorganic Chemistry (K. Irgolic & A. Martel, eds.). VCR Publ. Inc., Deerfield Beach, Fla. (1985). 45. Pruden, A.L. & Ollis, D.F. Photoassisted Heterogeneous Catalysis: The Degradation of Trichloroethylene in Water. Jour. Catalysis, 82:404 (1983).
TL;DR: The results of this study indicate that finished water, with measurable levels of free residual chlorine and meeting standards for coliform bacteria and turbidity, cannot be assumed to be virus free.
Abstract: Reduction of enteroviruses and rotaviruses averaged 81 and 93 percent, respectively, at a full-scale 205-mgd (776-ML/d) plant whose treatment train includes chemical flocculation, sand filtration, and chlorination. The highest reduction of enteroviruses occurred during prechlorination -flocculation and filtration, whereas the highest reduction of rotaviruses occurred during prechlorination -clarification and final chlorination. Enteroviruses or rotaviruses occurred in 24 percent of the finished water samples, which had >0.2 mg free chlorine/L and met coliform bacteria (1/100 mL) and turbidity (1 ntu) standards. Although major plant deficiencies may have been responsible for the occurrence of viruses in the finished water, the results of this study indicate that finished water, with measurable levels of free residual chlorine and meeting standards for coliform bacteria and turbidity, cannot be assumed to be virus free.
TL;DR: Of 207 samples collected from various locations in five small municipal water distribution systems, 103 (49.8 percent) were positive for fungi, and four genera accounted for 58 percent of the isolates, with Aspergillus the most common ( 18.4 percent).
Abstract: Of 207 samples collected from various locations in five small municipal water distribution systems, 103 (49.8 percent) were positive for fungi. Counts ranged between 1 and 6 fungal propagules per 50-mL sample. Four genera, Alternaria, Aspergillus , Cladosporium , and Penicillium, accounted for 58 percent of the isolates, with Aspergillus the most common ( 18.4 percent). Statistical analysis of the data to determine any relationship between the presence and number of fungal isolates and five physicochemical and two bacteriological parameters revealed no significant correlations.
TL;DR: Pilot-plant studies showed that when effective chemical pretreatment is employed in combination with rapid rate filtration, removals of turbidity, total coliform bacteria, and Giardia cysts from low turbidity waters may be greater than 80, 98.9, and 99.9 percent.
Abstract: Pilot-plant studies showed that when effective chemical pretreatment is employed in combination with rapid rate filtration, removals of turbidity, total coliform bacteria, and Giardia cysts from low turbidity waters may be greater than 80, 99.9, and 99.9 percent, respectively. Proper coagulation, however, requires the careful selection of chemicals and dosages. It was also observed that for waters having turbidity levels < 1 ntu, percent reduction of turbidity can serve as a surrogate indicator of the removal of Giardia cysts.
TL;DR: Although most customer complaints concerning taste and odour are not due to a hazardous concentration of a contaminating compound, there is increasing concern among utility managers about taste and odor problems as discussed by the authors.
Abstract: The ganoleptic consumers always water had supply associate problems, to cope industry them with because with has oralways had to cope with organoleptic problems, because consumers associate them with poor drinking water quality. In the United States and Western Europe, the quality and amount of available drinking water is generally good or at least sufficient. Although most customer complaints concerning taste and odor are not due to a hazardous concentration of a contaminating compound, there is increasing concern among utility managers about taste and odor problems. ^ This concern can be precipitated by a desire to prevent customer complaints
TL;DR: In this paper, pH was found to be the most important parameter in determining the extent of organics removal for a specified coagulant dose for the Mississippi River water sample.
Abstract: Data from coagulation studies on Mississippi River water samples indicated that pH was a most important parameter in determining the extent of organics removal for a specified coagulant dose.1 Performance curves indicated that optimum organics removal was attained with alum at a pH of between 5 and 6 and that as solution pH was raised into the neutral range, organics removal deteriorated dramatically. Similar observations are reported elsewhere.2 The adjustment of pH to more acidic values influences the speciation of aluminum and increases protonation of the organic acids that contribute to coagulant demand.1-2 The extent of organics removal that may be achieved by coagulation, however, is limited, and granular activated carbon (GAC) treatment may be required if low concentrations of organics are desired in the treated water. In such cases, conditions employed during pretreatment may have a profound influence on the subsequent performance and useful life of the GAC.
Journal Article•
TL;DR: The physical, chemical, and biological properties of chlorine dioxide as they relate to water treatment are reviewed in this article, where the generation reactions as well as the reactions likely to occur in treated water are presented.
Abstract: There is increased interest in using chlorine dioxide to treat drinking water for trihalomethane control, taste and odor control, oxidation of iron and manganese, and oxidant-enhanced coagulation -sedimentation. This article reviews the physical, chemical, and biological properties of chlorine dioxide as they relate to water treatment. The generation reactions as well as the reactions likely to occur in treated water are presented. In addition, the biological properties of chlorine dioxide are reviewed and compared with other common disinfectants.
TL;DR: In this article, the benefits of separate accounting for water revenues and expenses and full-cost pricing are discussed, and Boston's recent restructuring of water and sewer services is given as an example of improvements made possible by full-Cost pricing.
Abstract: Many municipal water systems have traditionally priced water at far less than the cost of service, thereby requiring subsidies from general funds. Conversely, some water revenues have been diverted to meet other expenses of the city. The author cites the benefits of separate accounting for water revenues and expenses and full-cost pricing, drawing on the situation in Massachusetts. Increased efficiency and ultimate economies can be realized from allocation of sufficient funds to undertake rehabilitation and maintenance programs. Methods of structuring rates and implementing full-cost rates are reviewed, and Boston's recent restructuring of water and sewer services is given as an example of improvements made possible by full-cost pricing.
TL;DR: The design experience at Empire, Colo., and the postdesign evaluation have provided knowledge about the efficiency of the slow sand filtration process at full-scale and the basis for recommendations concerning slow sand filtering practice as discussed by the authors.
Abstract: The design experience at Empire, Colo., and the postdesign evaluation have provided knowledge about the efficiency of the slow sand filtration process at full-scale and the basis for recommendations concerning slow sand filtration practice. Operation of the filter required daily inspection plus measurement of water depth and effluent turbidity, along with monthly scraping. Scraping required only two workhours, however, and only 0.2 in. (0.5 cm) of surface was removed. The projected life of the sand bed at this rate of removal is 15 years, with a residual depth of 1 ft (0.3 m). Giardia cysts were found in the raw water on five occasions, but none were found in the finished water. Microscopic organisms and particles were found in the raw water but either zero or rare numbers were found in the finished water.
TL;DR: Les essais sur unite pilote montrent une elimination a 100% des kystes de Giardia lamblia, pour des particules grossieres ou fines de terre de diatomees.
Abstract: Les essais sur unite pilote montrent une elimination a 100% des kystes de Giardia lamblia, pour des particules grossieres ou fines de terre de diatomees
TL;DR: Weak-acid ion exchange has been shown to effectively remove barium, radium, and hardness, without increasing the sodium content of the product water as mentioned in this paper, and the maximum capacity of the weak-acid resin was about 2.3 times that of strong acid resin, and much less spent regenerant per unit volume of water treated was produced from a weak acid column than from a strong acid column.
Abstract: Weak-acid resin in the hydrogen form was found to effectively remove barium, radium, and hardness, without increasing the sodium content of the product water. The maximum capacity of the weak-acid resin was about 2.3 times that of strong-acid resin, and much less spent regenerant per unit volume of water treated was produced from a weak-acid column than from a strong-acid column. There are, however, some disadvantages to weak-acid ion exchange: swelling of the resin during exhaustion; the need to use acid-resistant materials; the inability to remove noncarbonate hardness; the necessity of stripping carbon dioxide from the product water and adjusting the pH; and the probable higher cost.
TL;DR: In this paper, Camp, T.R. and Conklin, G.F. proposed a Rational Jar Test for Coagulation to measure the strength of the alum floe in the presence of Laminar Shear.
Abstract: AWWA, 63:7:439 (July 1971). 10. Camp, T.R. Water Treatment. Handbook of Applied Hydraulics. McGraw-Hill Book Co., New York (1952). 1 1 . Camp, T.R. Flocculation and Flocculation Basins. ASCE Trans., 2772 (Sept. 1953). 12. Camp, T.R. & Conklin, G.F. Toward a Rational Jar Test for Coagulation. Jour. NEWWA, 84:9:325 (Sept. 1970). 13. Reed, G.D. & Refxe, D.A. Sedimentation Success From Modified Jar Tests. Jour. AWWA , 76:7:101 (July 1984). 14. Reed, G.D. & Robinson, R.B. Similitude Interpretation of Jar Test Data. Jour. Envir. Engrg., 110:3:670(1984). 15. Boadway, J.D. Dynamics of Growth and Breakage of Alum Floe in Presence of Fluid Shear. Jour. Envir. Engrg., 104:EE5 (1978). 16. Irani, R.R. & Callis, C.F. Particle Size. John Wiley & Sons, New York (1963). 17. Cadle, R.D. Particle Size. Reinhold Publishing Co., New York (1965). 18. Cadle, R.D. The Measurement of Airborne Particles. John Wiley & Sons (1975). 19. Crawford, M. Air Pollution Control Theory. McGraw-Hill Book Co. (1976). 20. Wark, K. & Warner, C.F. Air Pollution. Harper & Row, New York (2nd ed.. 1981). 21. Davidson, J.A.; Macosko, C.; & Collins, E.A. Latex Particle Size Analysis. Jour. Colloid & Interface Sci., 25:11:301 (1967). 22. Fair, G.M. & Gemmell, R.S. A Mathematical Model of Coagulation. Jour. Colloid Sci., 19:360(1984). 23. Hudson, H.E. Jr. Evaluation of Plant Operating and Jar Test Data. Jour. AWWA, 65:5:368 (May 1973). 24. Hudson, H.E. Jr. & Wolfner, J.P. Design of Mixing Flocculating Basins. Jour. AWWA, 59:10:1257 (Oct. 1967). 25. Harris, H.S.; Kaufman, W.J.; & Krone, R.B. Orthokinetic Flocculation in Water Purification. Jour, of Envir. Engrg., 92:SA695 (1966). 26. Swift, D.L. & Friedlander, S.K. The Coagulation of Hydrosis by Brownian Motion and Laminar Shear Flow. Jour. Colloid Sci., 19:621 (1964). 27. Hannah, S.A.; Cohen, J.M.; & Roebfxk, G.G. Measurement of Floe Strength by Particle Counting. Jour. A WW A, 59:7:843 (July 1967). 28. Gibbs, R.J. Floe Breakage During HIAC Light Blocking Analysis. Jour. Envir. Sci. & Technol., 16:5:298 (1982).
TL;DR: An analysis of statistics compiled on outbreaks of waterborne disease from 1946 to 1980 and from 1965 to 1982 showed that disinfection was not provided where it was needed and was not properly operated when it was provided as discussed by the authors.
Abstract: An analysis of statistics compiled on outbreaks of waterborne disease from 1946 to 1980 and from 1965 to 1982 showed that disinfection was not provided where it was needed and was not properly operated where it was provided. Chlorine concentration, contact time, pH, temperature, and interfering substances all must be evaluated to determine disinfection requirements. Use of reliable chlorination facilities and proper application of current technology can control and prevent waterborne diseases.