Science of Water : Concepts and Applications

More documents

Recommendations

Info

Environmental Biomonitoring, Sampling, and Testing 257 Mixer switch Probe body Mixer FIGURE 8.15 Dissolved oxygen-lab probe. Cable to meter Membrane Temperature sensor methods available for calibration: saturated water, saturated air, and the Winkler method. It is important to note that if the Winkler method is not used for routine calibration method, periodic checks using this method are recommended. Procedure It is important to keep in mind that the meter and probe supplier’s operating procedures should always be followed. Normally, the manufacturer’s recommended procedure will include the following generalized steps: 1. Turn the DO meter on, and allow 15 min for it to warm up. 2. Turn the meter switch to zero, and adjust as needed. 3. Calibrate the meter using the saturated air, saturated water, or Winkler azide procedure for calibration. 4. Collect the sample in a 300-mL bottle, or place the fi eld electrode directly in the stream. 5. Place the laboratory electrode in a BOD bottle without trapping air against the membrane, and turn on the stirrer. 6. Turn the meter switch to temperature setting, and measure temperature. 7. Turn the meter switch to DO mode, and allow 10 s for the meter reading to stabilize. 8. Read the DO mg/L from meter, and record the results. No calculation is necessary using this method because results are read directly from the meter. DO meters are expensive compared to fi eld kits that use the titration method. Meter/probe combinations run between $500 and $1200, including a long cable to connect the probe to the meter.
258 The Science of Water: Concepts and Applications The advantage of a meter/probe is that DO and temperature can be quickly read at any point where the probe is inserted into the stream. DO levels can be measured at a certain point on a continuous basis. The results are read directly as milligrams per liter, unlike the titration methods, in which the fi nal titration result might have to be converted by an equation to milligrams per liter. DO meters are more fragile than fi eld kits, and repairs to a damaged meter can be costly. The meter/probe must be carefully maintained, and must be calibrated before each sample run, and if many tests are done, between sampling. Because of the expense, a small water/wastewater facility might only have one meter/probe, which means that only one team of samplers can sample DO, and they must test all the sites. With fi eld kits, on the other hand, several teams can sample simultaneously. Biochemical Oxygen Demand Testing As mentioned, BOD measures the amount of oxygen consumed by microorganisms in decomposing organic matter in stream water. BOD also measures the chemical oxidation of inorganic matter (the extraction of oxygen from water via chemical reaction). A test is used to measure the amount of oxygen consumed by these organisms during a specifi ed period of time (usually 5 days at 20°C). The rate of oxygen consumption in a stream is affected by a number of variables: temperature, pH, the presence of certain kinds of microorganisms, and the type of organic and inorganic material in the water. BOD directly affects the amount of DO in water bodies. The greater the BOD, the more rapidly oxygen is depleted in the water body, leaving less oxygen available for higher forms of aquatic life. The consequences of high BOD are the same as those for low DO: aquatic organisms become stressed, suffocate, and die. Most river waters used as water supplies have a BOD less than 7 mg/L; therefore, dilution is not necessary. Sources of BOD include leaves and wood debris; dead plants and animals; animal manure; effl uents from pulp and paper mills, wastewater treatment plants, feedlots, and food-processing plants; failing septic systems; and urban stormwater runoff. √ Note: To evaluate raw water’s potential for use as a drinking water supply, it is usually sampled, analyzed, and tested for BOD when turbid, polluted water is the only source available. Sampling Considerations BOD is affected by the same factors that affect DO. Aeration of stream water—by rapids and waterfalls, for example—will accelerate the decomposition of organic and inorganic material. Therefore, BOD levels at a sampling site with slower, deeper waters might be higher for a given column of organic and inorganic material than the levels for a similar site in high aerated waters. Chlorine can also affect BOD measurement by inhibiting or killing the microorganisms that decompose the organic and inorganic matter in a sample. If sampling in chlorinated waters (such as those below the effl uent from a sewage treatment plant), neutralizing the chlorine with sodium thiosulfate is necessary (see Standard Methods). BOD measurement requires taking two samples at each site. One is tested immediately for DO, and the second is incubated in the dark at 20°C for 5 days, and then tested for the DO remaining. The difference in oxygen levels between the fi rst test and the second test [in milligrams per liter (mg/L)] is the amount of BOD. This represents the amount of oxygen consumed by microorganisms and used to break down the organic matter present in the sample bottle during the incubation period. Because of the 5-day incubation, the tests are conducted in a laboratory. Sometimes by the end of the 5-day incubation period, the DO level is zero. This is especially true for rivers and streams with a lot of organic pollution. Since knowing when the zero point was reached is not possible, determining the BOD level is also impossible. In this case, diluting the original sample by a factor that results in a fi nal DO level of at least 2 mg/L is necessary. Special dilution water should be used for the dilutions (see Standard Methods).
Page 2:
Second Edition THE SCIENCE OF WATER
Page 5 and 6:
Cover Image: Falling Spring at Fall
Page 8 and 9:
Contents Preface ..................
Page 10 and 11:
Contents ix Velocity Head .........
Page 12 and 13:
Contents xi Specifi c Conductance .
Page 14 and 15:
Contents xiii (5) Beetles (Order: C
Page 16 and 17:
Contents xv Chlorine Residual Testi
Page 18:
Contents xvii Water Filtration Calc
Page 22:
To the Reader In reading this text,
Page 26 and 27:
1 Introduction When color photograp
Page 28 and 29:
Introduction 3 On second look, we s
Page 30 and 31:
Introduction 5 As mentioned earlier
Page 32 and 33:
Introduction 7 This scream of lost
Page 34:
Introduction 9 Metcalf & Eddy, Inc.
Page 37 and 38:
12 The Science of Water: Concepts a
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 70 and 71:
3 Water Hydraulics Anyone who has t
Page 72 and 73:
Water Hydraulics 47 Another relatio
Page 74 and 75:
Water Hydraulics 49 • • 1 ft 3
Page 76 and 77:
Water Hydraulics 51 √ Important P
Page 78 and 79:
Water Hydraulics 53 FIGURE 3.4 Thru
Page 80 and 81:
Water Hydraulics 55 Example 3.8 Pro
Page 82 and 83:
Water Hydraulics 57 FIGURE 3.6 Lami
Page 84 and 85:
Water Hydraulics 59 With regard to
Page 86 and 87:
Water Hydraulics 61 or hydraulic gr
Page 88 and 89:
Water Hydraulics 63 E 1 smaller fl
Page 90 and 91:
Water Hydraulics 65 √ Note: In de
Page 92 and 93:
Water Hydraulics 67 • Cone of dep
Page 94 and 95:
Water Hydraulics 69 • • • •
Page 96 and 97:
Water Hydraulics 71 The Darcy-Weisb
Page 98 and 99:
Water Hydraulics 73 Of course, pipe
Page 100 and 101:
Water Hydraulics 75 In this section
Page 102 and 103:
Water Hydraulics 77 Slope (S) The s
Page 104 and 105:
Water Hydraulics 79 and important c
Page 106 and 107:
Water Hydraulics 81 and the depth o
Page 108 and 109:
Water Hydraulics 83 TYPES OF DIFFER
Page 110 and 111:
Water Hydraulics 85 √ Important P
Page 112 and 113:
Water Hydraulics 87 Meter backpress
Page 114 and 115:
Water Hydraulics 89 VELOCITY FLOWME
Page 116 and 117:
Water Hydraulics 91 The positive-di
Page 118 and 119:
Water Hydraulics 93 Solution: 1200g
Page 120:
Water Hydraulics 95 Water and Waste
Page 123 and 124:
Page 125 and 126:
100 The Science of Water: Concepts
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 180 and 181:
6 Water Ecology The subject of man
Page 182 and 183:
Water Ecology 157 The environment i
Page 184 and 185:
Water Ecology 159 FIGURE 6.2 Notone
Page 186 and 187:
Water Ecology 161 H 2 O O 2 FIGURE
Page 188 and 189:
Water Ecology 163 FeS FIGURE 6.6 Th
Page 190 and 191:
Water Ecology 165 Algae FIGURE 6.8
Page 192 and 193:
Water Ecology 167 2. Likewise, biom
Page 194 and 195:
Water Ecology 169 Population densit
Page 196 and 197:
Water Ecology 171 succession can be
Page 198 and 199:
Water Ecology 173 dark winter month
Page 200 and 201:
Water Ecology 175 In rain events wh
Page 202 and 203:
Water Ecology 177 long profi le, cr
Page 204 and 205:
Water Ecology 179 THE FLOODPLAIN A
Page 206 and 207:
Water Ecology 181 It is important t
Page 208 and 209:
Water Ecology 183 Specifi c Adaptat
Page 210 and 211:
Water Ecology 185 serve to indicate
Page 212 and 213:
Water Ecology 187 UNITS OF ORGANIZA
Page 214 and 215:
Water Ecology 189 FIGURE 6.20 Stone
Page 216 and 217:
Water Ecology 191 FIGURE 6.22 Midge
Page 218 and 219:
Water Ecology 193 FIGURE 6.25 Riffl
Page 220 and 221:
Water Ecology 195 They push their m
Page 222 and 223:
Water Ecology 197 FIGURE 6.32 Damse
Page 224:
Water Ecology 199 Darwin, C., 1998.
Page 227 and 228:
Page 229 and 230:
Page 231 and 232: 206 The Science of Water: Concepts
Page 281: 256 The Science of Water: Concepts
Page 333 and 334:
Page 335 and 336:
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
Page 345 and 346:
Page 347 and 348:
Page 350 and 351:
10 Water Treatment Calculations Gup
Page 352 and 353:
Water Treatment Calculations 327 We
Page 354 and 355:
Water Treatment Calculations 329 Th
Page 356 and 357:
Page 358 and 359:
Water Treatment Calculations 333 Ex
Page 360 and 361:
Water Treatment Calculations 335 me
Page 362 and 363:
Water Treatment Calculations 337 Fo
Page 364 and 365:
Page 366 and 367:
Water Treatment Calculations 341 So
Page 368 and 369:
Water Treatment Calculations 343 No
Page 370 and 371:
Page 372 and 373:
Page 374 and 375:
Water Treatment Calculations 349 In
Page 376 and 377:
Page 378 and 379:
Page 380 and 381:
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Water Treatment Calculations 363 St
Page 390 and 391:
Water Treatment Calculations 365 WA
Page 392 and 393:
Water Treatment Calculations 367 St
Page 394 and 395:
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Page 402 and 403:
Page 404 and 405:
Water Treatment Calculations 379 Se
Page 406 and 407:
Water Treatment Calculations 381 µ
Page 408 and 409:
Water Treatment Calculations 383 g
Page 410 and 411:
Page 412 and 413:
Water Treatment Calculations 387 No
Page 414 and 415:
Page 416 and 417:
Page 418 and 419:
Page 420 and 421:
Water Treatment Calculations 395 Ca
Page 422 and 423:
Page 424:
Water Treatment Calculations 399 Mo
Page 427 and 428:
Page 429 and 430:
Page 431 and 432:
Page 433 and 434:
Page 435 and 436:
Page 437 and 438:
Page 439 and 440:
Page 441 and 442:
Page 443 and 444:
Page 445 and 446:
Page 447:
show all

Science of Water : Concepts and Applications

Create successful ePaper yourself

Delete template?

Save as template?