Quality water

Water is essential for human life. Although Earth is often called the water planet with nearly three-fourths of Earth s surface covered by water, most of its tremendous supply of water is salty and not directly available for human use. Only 3% of the planet s water is fresh. Approximately 70% of the human body is composed of water, and we can survive only a few days without it. Most of the water in the world, and the largest percentage in this country, is used for agriculture. Large quantities of water are also used in power generation, for domestic use, and in industry. Table 18.3 

Water pollution results from a number of sources including agricultural runoff, erosion, industrial wastes, domestic wastes, and road runoff. Water pollution can be classified as either point source or nonpoint source. Point source pollution is emitted from a specific, well-defined location such as a pipe. Nonpoint sources refer to pollutants dispersed over a wide area from many different areas. A sewer pipe would be an example of a point source and fertilizer runoff from a field would represent nonpoint source pollution. 

One of the foremost global issues regarding water quality is access to safe drinking water. Currently, one-sixth of the world s 6.1 billion people do not have access to a source of clean water, and 40% do not have adequate sanitation facilities. Polluted water is responsible for diseases such as typhoid, cholera, and dysentery. Three million people die annually due to the latter. The discovery that diseases were transmit- 

As mentioned, chlorine, in the form of CI2 or the hypochlorite ion, OCU, is used as a disinfectant. Free chlorine, Cl, reacts with water to produce hypochlorous acid, HOCl, and hydrochloric acid, HCl  

The hypochlorous acid oxidizes the cell walls and kills bacteria. Solid calcium hypochlorite, Ca(OCl)2, and liquid solutions of sodium hypochlorite, NaOCl, can be used to generate hypochlorous acid in place of chlorine gas, for example, in chlorinating swimming pools. The hypochlorite ion generated from Ca(OCl)2 and NaOCl forms an equilibrium with water represented by the equation  

Water is basic to most detergents and sanitizers and consideration should be given to its chemical as well as sensory properties, if any. By itself and 

1 Dependence of Product Quality on Organic Type and Solution Chemistry 

Fane (1996) proposed an overall water quality index for treatment based on pathogen, turbidity, colour and salt removal. This criterion was modified to suit the study in this project and is presented in Table 8.11. The equation for the water quality parameter (WQP) used in this study, is the sum of the rejections of solute of interest, in this study colloids, organics and cations. For experiments where several colloids, organics and cations were tested, the average is taken (see last equation). 

Pathogens were not included in this study. However, for MF this may not be achieved under all operating conditions as reported byjacangelo et al. (1995a). Log removals of the virus MS2 bacteriophages (0.025 um) reported were as low as 0.4 (60%) for MF (0.2 fxm), while an UF membrane (100 kDa) removed 6 log. Removal of Ciyptosporidium panmm (4 to 6 pm in diameter) and Giardia muris (7 to 14 pm) cysts was complete ( 6 log, below detection limit) by both MF and UF. The removal of viruses is thus a criteria which needs to be considered in the process choice. 

The total score for each parameter suite (colloids, DOC, and ions) is 100. The columns are subdivided into equal fractions, resulting in total points of 25 for the individual colloid fraction, for the organic fraction, and 50 for the major cations (Na+, Car ). For colloids stable primary colloids (OPS system) are assumed as these appear most abundant in a natural water. Ion rejection is represented by sodium and calcium rejection in the absence of organics and DOC rejection of solutions containing 0.5 mM CaCb (except for MF where calcium concentration is 2.5 mM). As a sum criterion, the water quality parameter (WQP) is introduced. The maximum score for WQP is 300. 

The WQP values increase with membrane tightness as expected. The CA-UF membrane performs overall as an UF membrane in the 5 kDa cut-off range. This shows that its classification as a NF membrane is not justified. This is indicated in Chapter 7 also. 

As part of implementing a sanitation program, careful consideration should initially be given to the quality of in-house water, particularly its chemical and sensory properties. In general, water should be potable, free from suspended particulates, and low in compounds that impart odor and 

MacKenzie, Susan Hill (1996). Integrated Resource Planning and Management The Ecosystem Approach in the Great Lakes Basin. Washington, DC Island Press. 

Stanitski, Conrad L. Eubanks, Lucy P. Middlecamp, Catherine H. and Pienta, Norman J. (2003). Chemistry in Context Applying Chemistry to Society, 4th edition. Boston McGraw-Hill. 

Next to a supply of air, nothing is so essential to life as a supply of high-quality water. We drink it, cook our food in it, use it as a source of energy, and lift a hundred pounds or so of it each time we stand up. Water carries nutrients in and removes waste materials from our bodies. Contaminated water also spreads numerous diseases. 

We judge the quality of water by taste, smell, color, and lack of pathogenic organisms or harmful contaminants. Often bad taste, odor, or color indicates contamination. Most of the water we drink has been treated to remove harmful substances and has had chlorine, ozone, or chloramines added to kill bacteria. Ordinary water contains dissolved gases such as oxygen, nitrogen, carbon dioxide, and other atmospheric components, as well as harmless minerals. 

Pollutants are usually present at very low concentrations, commonly measured and reported as parts per milfion (ppm) or parts per bilfion (ppb). A solution containing 2 grams (0.071 ounces) of lead in 1 milfion grams of water (1,000 liters, or 264.2 gallons) is a 2 ppm solution of lead in water. A 

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To ensure disposal water quality is in line with regulatory requirements (usually 40 ppm), the oil content in water is monitored by solvent extraction and infrared spectroscopy. The specification of 40 ppm refers to an oil in water content typically averaged over a one month period. 

The water quality (air content) and the water flow influenced the measurements using one channel. Therefore the four channel system was first tested in the laboratory with a stationary tube. The best results were obtained using tap water and a well controlled flow in a water-filled chamber. A great difference in the concentration of air in the different grades of water was obvious, and the tap water was superior to soft water during these measurements. 

Table 4. General Water Quality Requirements for Trout and Warmwater Aquatic Animals in Fresh Water ...

Table 5. Suggested Water Quality Conditions for Marine Fish Production Facilities ...

C. E. Boyd, Water Quality in Pondsfor Hquaculture Alabama Agricultural Experiment State, Auburn University, 1990. 

W. Harm and P. A. Jensen, Water Quality Characteristics of Ha rdous Materials, Texas A M University, College Station, 1974, p. 4. 

D. W. Nelson and R. H. Dowdy, eds.. Methodsfor Ground Water Quality Studies, University of Nebraska, Lincoln, 1988. 

STORET Water Quality File, Office of Water, U.S. EPA, U.S. Govt. Printing Office, Washington, D.C., 1988. 

G. E. Lauf and M. A. Waer, "Arsenic Removal Usiug Potassium Permanganate," presented at the 1993 Water Quality Technology Conference, Miami, Fla., Nov. 1993. 

Ambient Water Quality Criteria forMercury—19S4, EPA-440/5-84-026 (NTIS No. PB85-227452), U.S. Environmental Protection Agency, Washington, D.C., 1985. 

Secondary System. The water quality specifications for the feedwater and blowdown water in a recirculating steam generator (RSG) and the ... 

BWRs operate at ca 7 MPa (70 bar) and 288°C. Some of the coolant passing through the core is converted into steam which is separated from the water with equipment inside the reactor vessel (see Eig. 2). The steam goes to the turbine generator while the water is recirculated back to the bottom of the core. A side stream is continuously purified using deminerali2ers and filters to control the water quality of the reactor water. EuU-flow condensate deminerali2ers... 

Table 3. Coastal Water Quality Criteria for Toxic Substances Other Than Biocides ...

Water Quality. AH commercial oil shale operations require substantial quantities of water. AH product water is treated for use and operations are permitted as zero-discharge facHities. In the Unocal operation, no accidental releases of surface water have occurred during the last four years of sustained operations from 1986 to 1990. The Unocal Parachute Creek Project compliance monitoring program of ground water, surface water, and process water streams have indicated no adverse water quaHty impacts and no violations of the Colorado Department of Health standards (62). 

W. J. Weber, Jr., Physiochemical Processes for Water Quality Control, olm. Wiley Sons, Inc., New York, 1972. 

R. A. Smith, R. B. Alexander, and M. G. SdJo m.2ia,yinaljsis and Interpretation of Water-Quality Trends in MajorU.S. Rivers, 1974—81, U.S. Geological Survey Water-Supply Paper 2307, U.S. Geological Survey, Reston, Va., 1987. 

C. D. Becker and D. A. Neitzel, eds.. Water Quality in North American River Systems, BatteUe, Columbus, Ohio, 1992. 

Water Quality Standards. Water quaUty standards are usually based on one of two primary criteria, stream standards or effluent standards. Stream standards are based on dilution requirements for the receiving water quaUty based on a threshold value of specific pollutants or a beneficial use of the water. Effluent standards are based on the concentration of pollutants that can be discharged or on the degree of treatment required. 

Treated Water Quality. Predicted analyses of a typical raw water treated by various lime and lime—soda softening processes are presented in Table 3. Treatment by lime converts the sodium bicarbonate in the raw water to sodium carbonate as follows ... 

In many cases, the quality of a stream or another water source can be adequately improved by removing more BOD or suspended solids. In other iastances, the effluent is prepared for groundwater recharge which may require only the removal of nutrient. A classification of wastewater treatment processes is given ia Table 3. Table 4 summarizes water quality criteria for various iadustrial uses (10). 

W. W. Eckenfelder, Jr., Principles of Water Quality Managements CBI Publishing, Boston, Mass., 1980. 

Water Quality Maintenance. In addition to controlling algae and microorganisms such as bacteria, proper swimming pool maintenance requires control of free and combined available chlorine, pH, alkalinity, hardness, and saturation index. Ranges for various swimming pool parameters (Table 2) are recommended by The National Spa and Pool Institute (14). 

Water Quality Maintenance. The NSPI recommends an ideal residual of 3—5 ppm PAG for chlorine sanitizers with CAC not exceeding 0.2 ppm see Table 2 (14). Eor bromine sanitizers, the maintenance of a 3—5 ppm ideal residual is recommended. 

Intensive or extensive culture of aquatic animals requires chemicals that control disease, enhance the growth of cultured species, reduce handling trauma to organisms, improve water quality, disinfect water, and control aquatic vegetation, predaceous insects, or other nuisance organisms. The aquacultural chemical need for various species have been described for rainbow trout, Oncorhjnchus mjkiss (1) Adantic and Pacific salmon, Salmo and Oncorhjnchus sp. (2) channel catfish, Ictaluruspunctatus (3) striped bass, Morone saxatilis (4) milkfish, Chanos chanos (5) moUusks (6) penaeid (Penaeus sp.) shrimp (7) and a variety of other marine species (8). 

E. W. Pontius, ed.. Water Quality and Treatment A Handbook of Community Water Supplies, American Water Works Association, 4th ed., McGraw-HiU, Inc., New York, 1990, pp. 8—59. 

Ameiican Watei Woiks Association, Water Quality andTreatment, )Aed., AcGt.2cw- iT. B>ook Co.,York, 1971, pp. 1—216. 

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