Environmental Engineering FOURTH EDITION

204 ENVIRONMENTAL ENGINEERING b. What is the settling velocity in feet per day of the critical particle, assuming 9.16 A rectang ...

Chapter 10 Sludge Treatment and Disposal The field of wastewater treatment and engineering is littered with unique and imagi- na ...

206 ENVIRONIvENTAL ENGINEElUNG treatment is known as the yield, expressed as kilograms of suspended solids produced per kilogram ...

Sludge Treatment and Disposal 207 j = 0.8 for aerobic, i = 0.1 for well-operated activated sludge, i = 0.2 for trickling filters ...

208 ENVIRONMENTAL ENGINEERING lhble 10-1. Sludge Characteristics Physical Chemical Solids Volatile Yield Plastic Nas Pas Kas Slu ...

Sludge Treatment and Disposal 209 do Velocity gradient, - dv Figure 10-2. Rheograms for three different fluids. fluids may be de ...

210 ENVIRONMENTAL, ENGINEEFUNG it would be desirable to treat sludges at the plant to remove metals and toxins, it may not be co ...

Sludge Treatment and Disposal 21 1 Extracellular enzymes Soluble organics e Acid-producing bacteria I“ products Methane-producin ...

2 12 ENVIRONMENTAL ENGINEERING Raw Heated to 95°F Digested sludge out Raw Heated to 95°F Digested sludge out Figure 10-4. Anaero ...

Sludge Treatment and Disposal 213 plant is 1500 kg of dry solids per day. Calculate the required volume of the primary digester ...

214 ENVIRONMENTAL, ENGINEERING Sludge Thickening Sludge thickening is a process in which the concentrations of solids is increas ...

Sludge Treatment and Disposal 215 Feed Underflow Solids concentration - Figure 10-6. Gravity thickener. (Photo courtesy of Dorr ...

216 ENVIRONMENTAL, ENGINEERING The answer is that the maximum SVI for sludge with 40,000 mg/L of suspended solids concentration ...

Sludge Treatment and Disposal 217 Designing a sludge thickener involves choosing a desired sludge solids concen- tration, C, (es ...

218 ENVIRONMENTAI, ENGINEERING Table 10-2. Design Loadings for Gravity Thickenersn Sludge Design loading (kg solids/m2-h) Raw pr ...

Sludge Treatment and Disposal 219 sand ceases. The mechanism of evaporation takes over, and this process is actually responsible ...

220 ENVIRONMENTAL ENGINEERING Fixed Solids collect head in frames Movable head Material enters Figure 10-10. Pressure filters. ( ...

Sludge Treatment and Disposal 221 Gravity drainage zone I Wedge zone I "S" zone 1- I Figure 10-11. Belt filter. Time 0 V Correct ...

222 ENVIRONMENTAL ENGINEERING Funnel 0 Figure 10-12. Buchner funnel test for determining specific resistance to filtration. Tabl ...

Sludge Treatment and Disposal 223 70 55 :I 50 I I II b=573 Figure 10-13. Laboratory filtration data from Example 10.4. t ...