Potable water process

Water systems are expected to be demonstrated to be suitable for their intended uses. At a minimum, water is required to meet the World Health Organization requirements for drinking (potable) water. Processing steps such as isolation and purification will require purified water as outlined in USP 23 (2), pharmaceutical grade water. Validation of water systems is required for all product contact water systems. We... 

Characterization Prototype examples Electricity MW(e) District heat Potable water Process heat Other Reactor heat source Balance of plant Operating crew Front end fuel cycle services Back end and waste Institu- tional training Technology transfer... 

Energy products Electricity heat for district heating potable water process heat... 

UNITHERM NKIET, Russian Federation 30/(2.5 or 6) 20 MW(th) for process heat applications 16.6 years Electricity, district heating, potable water, process steam Yes Conceptual design 5 years n... 

FBNR Federal University of Rio Grande do Sul, Brazil 134/40 more than 10 years Electricity potable water process steam district heating Yes Feasibility study 10 years XII... 

ENHS LLNL, ANL, LANL, and the University of California at Berkeley (125-180)/(50-75) 20 years or more Electricity potable water, process heat district heating Yes Feasibility study 15 years XX... 

Vacuum Treatment. Milk can be exposed to a vacuum to remove low boiling substances, eg, onions, garlic, and some silage, which may impart off-flavors to the milk, particularly the fat portion. A three-stage vacuum unit, known as a vacreator, produces pressures of 17, 51—68, and 88—95 kPa (127, 381—508, and 660—711 mm Hg). A continuous vacuum unit in the HTST system may consist of one or two chambers and be heated by Hve steam, with an equivalent release of water by evaporation, or flash steam to carry off the volatiles. If Hve steam is used, it must be cuUnary steam which is produced by heating potable water with an indirect heat exchanger. Dry saturated steam is desired for food processing operations. 

Water. Water mains should be connected to plant fire mains at two or more poiats, so that a sufficient water supply can be deHvered ia case of emergency. The plant loop and its branches should be adequately valved so that a break can be isolated without affecting a principal part of the system. If there is any question of maintaining adequate pressure, suitable booster pumps should be iastaHed. Any connection made to potable water for process water or cooling water must be made ia such a manner that there can be no backflow of possibly contaminated water check valves alone are not sufficient. The municipal supply should faH freely iato a tank from which the water is pumped for process purposes, or commercially available and approved backflow preventers should be used. 

Desalination. Desalination of seawater and brackish water has been and, as of the mid-1990s, is the primary use of RO. Driven by a need for potable water in areas of the world where there is a shortage, this industry has developed. Desalination involves the reduction of the total dissolved soHds (IDS) concentration to less than 200 mg/L. RO offers several advantages over other possible desalination processes such as distillation (qv), evaporation (qv), and electro dialysis. The primary advantage of RO over the traditionally used method of distillation is the energy savings that is afforded by the lack of a phase change in RO. 

Distillation processes typically reduce the IDS concentration to levels weU below the required specifications. Because the product water from the two processes is combined, the RO process can produce water at higher I DS concentrations and stiU meet the potable water specifications. In addition, the power produced from the MSF process can be used in the RO process, cutting energy costs. 

Abundant supplies of fresh water are essential to the development of industry. Enormous quantities are required for the cooling of products and equipment, for process needs, for boiler feed, and for sanitary and potable water supply. 

Use dictates the quaUty required. Potable water must be bacteriologicaHy safe, and toxic substances must be present at levels that are accepted as safe (1—3) (see Table 1). In addition, the water must be aesthetically acceptable. Water that is suitable for drinking may be iaadequate for many iadustrial processes. On the other hand, many iadustrial processes can use water that is not pure enough to drink. 

The dissolved-air flotation process is most commonly used for sewage and potable water treatment. It is also gaining popularity for the treatment of slaughterhouse, poultry processing, seafood processing, soap, and food processing wastes (Zoubulis et. al., 1991). 

Leading Examples Electrodialysis has its greatest use in removing salts from brackish water, where feed salinity is around 0.05-0.5 percent. For producing high-purity water, ED can economically reduce solute levels to extremely low levels as a hybrid process in combination with an ion-exchange bed. ED is not economical for the produc tion of potable water from seawater. Paradoxically, it is also used for the concentration of seawater from 3.5 to 20 percent salt. The concentration of monovalent ions and selective removal of divalent ions from seawater uses special membranes. This process is unique to Japan, where by law it is used to produce essentially all of its domestic table salt. ED is very widely used for deashing whey, where the desalted product is a useful food additive, especially for baby food. 

Potable Water RO and NF both play a major role in providing potable water, defined either by the WHO criterion of <1000 ppm total dissolved solids (TDS) or the U.S. EPA limit of 500 ppm TDS. RO is most prominent in the Middle East and on islands where potable-water demand has outstripped natural supply. A plant awaiting startup at Al Jubail, Saudi Arabia produces over 1 mVs of fresh water (see Table 22-17). Small units are found on ships and boats. Seawater RO competes with multistage flash distillation (MSF) and multieffect distillation (MED) (see Sec. 13 Distillation ). It is too expensive to compete with conventional civil supply (canals, pipelines, w ls) in most locations. Low-pressure RO and NF compete with electrodialysis for the desalination of brackish water. The processes overlap economically, but they are sufficiently different so that the requirements of the application often favor one over the others. 

Potable Water Systems Process Water General Service... 

However, in heavy industry, meaning metallurgical (steel and aluminum) processes, mining, petroleum refining, pulp and paper production, and the process industries like ehemical and pharmaceutical production, potable water, wastewater, edible products, and manu-... 

The process has two main sources of waste water. These are the condensate streams from the steam strippers. The principal pollutant in both wastewater streams is phenol. Phenol is of concern primarily because of its toxicity, oxygen depletion, and turbidity. In addition, phenol can cause objectionable taste and odor in fish flesh and potable water. 

Like the analogous chrome alums they find use as mordants in dying processes. The sulfate is the cheapest salt of Fe and forms no less than 6 different hydrates (12, 10, 9, 7, 6 and 3 mols of H2O of which 9H2O is the most common) it is widely used as a coagulent in the treatment not only of potable water but also of sewage and industrial effluents. 

Water treatment Clarification of potable water, industrial effluents, municipal waste water thickening and dewatering of sludge filtration of primary sludge, digested sludge food processing... 

Piping system Main steam Process steam Feedwater Raw water Treated water Potable water Aux. cooling system Firefighting system Clarified water Filtered water Water-intake system Circulating-water system Chemical dosing Station drains Fuel oil Fuel gas... 

Boiler water foaming and frothing is undesirable because it contributes to overheating, carryover, and loss of operational control. As a result, antifoam and defoamer products are commonly employed in BW treatment programs. The same active ingredients are also widely used in all types of industrial processes (industrial grades), as well as in cosmetic, food, potable water, and kosher applications (all agents typically are odorless, colorless, and tasteless). 

Intensive technologies are derived from the processes used for the treatment of potable water. Chemical methods include chlorination, peracetic acid, ozonation. Ultra-violet irradiation is becoming a popular photo-biochemical process. Membrane filtration processes, particularly the combination microfiltration/ultrafiltra-tion are rapidly developing (Fig. 3). Membrane bioreactors, a relatively new technology, look very promising as they combine the oxidation of the organic matter with microbial decontamination. Each intensive technique is used alone or in combination with another intensive technique or an extensive one. Extensive... 

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