Environmental Engineering FOURTH EDITION

164 ENVIRONMENTAL ENGINEERING From the nomograph, u = 2.75 ft/s for Q = 3.2 mgd, up/u = 0.48 and up = 0.48(2.75 ft/s) = 1.32 f ...

Collection of Wastewater 165 (^2) != 3 8.62.0 EI.6O.O Location IEl. 40.0. Figure 8-10. Final design for Example 8.3. Figure ...

166 ENVIRONMENTALENGINEERING 8.3 A 48-in. circular sewer is required to discharge 100 cfs when full. What is the 8.4 A 12-in. co ...

Chapter 9 Wastewater Treatment As civilization developed and cities grew, domestic sewage and industrial waste were eventually d ...

168 ENVIRONMENTAT.., ENGINEERING some extent. These discharges vary widely with the size and type of industry and the amount of ...

Wastewater Treatment 169 Table 9-1. Characteristics of Typical Domestic Wastewater Parameter Typical value for domestic sewage B ...

170 ENVIRONMENTAL ENGINEERING House ~ v--’ ----------- PLAN VIEW Gravel trench Septic tank ELEVATION Figure 9-2. Septic tank and ...

Wastewater Treatment 171 Undisturbed soil Figure 9-3. Alternative on-site disposal system. its invention in 1778; others (Reybur ...

172 ENVIRONMENTAL ENGINEERING (discussed more fully in Chap. 11) and dictates in large part the type of wastewater treatment req ...

Wastewater Treatment 173 y Bars with 1 -inch spaces Figure 9-4. Bar screen used in wastewater treatment. The top picture shows a ...

174 ENVIRONMENTAL ENGINEERING ide screen (not shown) Figure 9-5. A comminutor used to grind up large solids. Influent lueni Slud ...

Wastewater Treatment 175 Motor luent Figure 9-7. Circular settling tank. or cZar$ers. The settling tank that immediately follows ...

176 ENVIRONMENTAL, ENGINEERING as the solids are more dense than the liquid? Simple settling is, however, affected by other forc ...

Wastewater Treatment 177 which is the well-known Newtonian equation, where d is the particle diameter. If, as is the case in mos ...

178 ENVIRONMENTAL ENGINEERING as shown in Fig. 9-8. In other words, the particle is just barely removed. Had the particle entere ...

Wastewater Treatment 179 EXAMPLE 9.2. A primary clarifier has an overtlow rate of 600 gaVday-f? and a depth of 6 ft. What is its ...

180 ENVIRONMENTAL ENGINEERING -^1 ... ... .. _.. 2ocl:l 20 " ,. .. ... .. .. .. , .. 20 .. .... .. .. .. ,.. .. .. 20 ' .. ...

Wastewater Treatment 18 1 where R = % overall solids recovery, P = solids recovery at the bottommost section, Pi = solids recove ...

182 ENVIRONMENTKENGINEERING U a, U c 20- - a, :: 10- - I I I I 0 200 400 600 800 1000 Figure 9-10. Pedormance of prima ...

Wastewater Treatment 183 i ', Figure 9-11. Trickling filter. The tricklingjlter, shown in Fig. 9-11, consists of a filter bed of ...