Document gDZ8jQ27ORm78xe0ZKbEjQjeq

896 CHAPTER 42 1951 Guide CLASSIFICATION AND CHARACTERISTICS OF WATER For industrial use there is no accepted conventional classification of water. Rather, each industry usually develops a body of ideas applicable to its own water problems.4 For heating and ventilating engineers, it is perhaps most convenient to distinguish between mineralized waters and condensates. Mineralized Waters All the waters found in streams, wells, lakes, and the ocean are min eralized. The same is true of all municipal supplies even though they may have been treated. For a given area, ground waters are likely to be more highly mineralized than are surface waters. Conversely, surface waters Table 1. Mineral Analyses Typifying Composition of Waters Available and Used Industrially in the USA Substance SiliPA Iron CalciumMagnesium Potassium-- Bicarbonate Sulphate_____ Chloride Nitrate...... -. ,, Dissolved Solids. Carbonate Hardness-- Non-Carbonate Hardness Unit SiO* Fe Ca Mg Na K HCOi SO Cl NOj CaSO Location oa Abba*** a) (2) (3) (4) (5) <M (i) (8) (9) 2 6 12 37 10 9 22 14 00 0 1 0 6 5 36 62 92 96 3 155 1 2 8 18 34 27 2 46 1.300 2 6 7 44 8 183 215 78 11.000 11 1 1 18 10 3 400 14 13 119 202 339 334 549 210 150 10 2 22 135 84 121 11 389 2.700 2 10 13 13 10 280 22 117 19,000 1 -- 0 2 13 0 1 3 31 66 165 426 4.34 983 564 948 12 11 98 165 5 7 18 40 58 54 0. 295 5,900 All values are parts per million of the amt cited to nearest whole number (see Reference 5). bNumbers indicate location or area aa follows: (i) CatsIdU supply--New York City (6) Well Water--Maywood, IlEntris--2090 ft. (2) Swamp Water (Colored) Black Creek, Middleburg, Florida (7) Well Water--Smithfield. Va.--330 ft. (3) Niagara River (Filtered) Niagara Falls, New York (4) Missouri River (Untreated) Average (8) Well Water--Roeewell, N. Mexico (9) Ocean Water--Average (5) Well Waters--Public Supply--Dayton, .Ohio--30-60 ft. are more likely to be contaminated with municipal sewage and trade wastes. Virtually all mineralized waters also contain biological organisms. Mineralogical Characteristics. The character and amount of extraneous inorganic materials--including deleterious .gases--dissolved and sus pended therein, describe the mineralogical characteristics of any water. Revealing such information is the function of a mineralogical chemical analysis. The analyses in Table 1 disclose the composition of the public water supplies used by about 45 percent of the total population of the cities, in the United States, having more than 20,000 inhabitants.5 All values recorded are in terms of parts per million.* This is the approved standard terminology for reporting the results of mineral analyses.6 Values reported in the other terms commonly used may be converted into the standard form by using the factors listed in Table 2. Parts per million are hereinafter abbreviated ppm. A part per million signifies a unit weight of material per million unit weights of the solution. Corrosion and Water Formed Deposits, Causes and Prevention 897 Table 2. Conversion Factors for Water Analyses To Convert Grains per U. S. gallon...... Grains per Imperial gallon. Grams per liter................... Mg per liter -..................... Into ppm ppm ppm ppm Multiply by 17 14 Yi 1000 1 Data for dissolved gases or pH values have been omitted in Table 1 because even waters of the same mineral contents may vary widely in these respects. Unpolluted natural waters usually have pH values within the ranga 5 to 8, depending upon their free CO2 contents. Polluted waters, which include those derived from wells or swamps in marshy ground, may have pH values well below 5. Biological Characteristics. The slime-forming organisms are mostly lower plants, grouped by botanists into the Phylum Thallophyta. This group is distinguished by the absence of leaves, roots, or stems from the mosses, ferns, and seed plants which comprise the three other phyla of the plant kingdom. The Thallophyta (see Table 3) are divided into algae, which can syn thesize chlorophyll for the production of sugar, and the fungi which lack chlorophyll, and must therefore secure already synthesized carbohydrates. All Thallophyta are of universal distribution and many of them are slime forming. Of the five divisions of algae, only three (the green, the blue-green, and the diatoms) are found in fresh water. Of the five di visions of fungi, all may occur in fresh water, the principal slime formers being indicated in Table 3. The methods of analysis commonly used in the sanitary examination' of a water have, as their principal object, to identify and count pathogens. Most slime-forming organisms are not pathogens. When a water is subjected to a biochemical analysis for the purpose of evaluating its slime producing characteristics, tests, widely different from sanitary bacterio logical tests, must be made. Tests upon the water itself are seldom satis factory, and true indications of the sliming characteristics of a water can only be determined by the analysis of deposits on surfaces having a temperature close to the temperature of the final design equipment. The Phyla Algae Fungi Table 3. Principal Slime Formers Rough Division of Phyla Single celled, sometimes forming slimy sheets. Many celled in either sheets or fronds. Bacteria (Schizomycetes) frequently forming slimy surface coatings. Slime Molds (Myxomycetes) forming slimy sheets as one stage of their life history. Sac fungi (Ascomycetes).of which one division, the yeasts, occasion* ally form slimy aggregates. The alga-like fungi (Phycomyceles) and the stalked fungi (Basidomycetes) rarely form slimes but their filaments may hold together the slimes of other organisms.