a Values in the table are the results of the test for the suspended solids (mg/L) concentration at the given depths.

a Values in the table are the results of the test for the suspended solids (mg/L) concentration at the given depths.

If the percentage removal of particles is 71.58, what is the hydraulic loading rate? The settling column has a depth of 4 m.

5.20 In Problem 5.19, what is the fraction not completely removed xo?

5.21 In Problem 5.19, what fraction in xo is removed?

5.22 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Calculate the volume of the tank. The average daily flow rate is 20,000 m /d. Use rectangular basin.

5.23 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Calculate the overflow area. The average daily flow rate is 20,000 m /d. Use rectangular basin.

5.24 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Assuming the particles are flocculent, calculate the width of the rectangular clarifier. The average daily flow rate is 20,000 m /d.

5.25 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Assuming the particles are flocculent, calculate the recirculated flow. The average daily flow rate is 20,000 m /d. Use rectangular basin.

5.26 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Calculate the volume of the tank. The average daily flow rate is 20,000 m /d. Use circular basin.

5.27 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Calculate the overflow area. The average daily flow rate is 20,000 m /d. Use circular basin.

5.28 The prototype detention time and overflow rate were calculated to be 1.5 h and 28 m/d, respectively. The peaking factor is 3.0 and the minimizing factor is 0.3. Assuming the particles are flocculent, calculate the recirculated flow. The average daily flow rate is 20,000 m /d. Use circular basin.

5.29 The activated sludge bioreactor facility of a certain plant is to be expanded. The results of a settling cylinder test of the existing bioreactor suspension are shown below. Qo + QR is 10,000 m /d and the influent MLSS is 3,500 mg/L. If the sludge is to be thickened to an underflow concentration of 10,000 mg/L, what is the limiting flux?

MLSS (mg/L) 1410 2210 3000 3500 4500 5210 6510 8210 Vc (m/h) 2.93 1.81 1.20 0.79 0.46 0.26 0.12 0.084

5.30 The activated sludge bioreactor facility of a certain plant is to be expanded. The results of a settling cylinder test of the existing bioreactor suspension are shown below. Qo + QR is 10,000 m /d and the influent MLSS is 3,500 mg/L. If the limiting flux is 2200 (m/h) • (mg/L), what is the underflow concentration?

MLSS (mg/L) 1410 2210 3000 3500 4500 5210 6510 8210 Vc (m/h) 2.93 1.81 1.20 0.79 0.46 0.26 0.12 0.084

5.31 Qo + Qr into a secondary clarifier is 10,000 m /d with R - 1. The influent

MLSS is 3,500 mg/L. If the thickener area is 651.5 m , what is the limiting flux?

5.32 Qo + Qr into a secondary clarifier is 10,000 m /d with R - 1. The influent MLSS is 3,500 mg/L. If the limiting flux is 2,200 (m/h) . (mg/L), what is the thickener area?

5.33 The desired underflow concentration from a secondary clarifier is 10,500 mg/L. The influent comes from an activated sludge process operated at 3500 mg/L of MLSS. The inflow to the clarifier is 10,000 m3/d; the thickener area is 158.7 m ; and tu is 7.8 min. What volume at the bottom of the thickener must be provided to hold the thickened sludge.

5.34 The A/S obtained in an experiment is 0.01. The pressure gage reads 276 kN/m and the temperature of the sludge and the subnatant in the flotation cylinder is 20°C. The prevailing barometric pressure is 100.6 kN/m . ¡3 was originally determined to be 0.95. What is the total solids in the sludge?

5.35 The A/S obtained in an experiment is 0.01. The pressure gage reads 276 kN/m and the temperature of the sludge and the subnatant in the flotation cylinder is 20°C. p was originally determined to be 0.95 and the solids are 10,000 mg/L. What is the prevailing barometric pressure?

5.36 The A/S obtained in an experiment is 0.01. The temperature of the sludge and the subnatant in the flotation cylinder is 20°C. The prevailing barometric pressure is 100.6 kN/m2. p was originally determined to be 0.95. Total solids is 10,000 mg/L and the prevailing barometric pressure is 100.6 kN/m2. What is the pressure in the air saturation tank?

5.37 The A/S obtained in an experiment is 0.01. The temperature of the sludge and the subnatant in the flotation cylinder is 20°C. The prevailing barometric pressure is 100.6 kN/m2. p was originally determined to be 0.95.

Total solids is 10,000 mg/L and the prevailing barometric pressure is 22 100.6 kN/m . The pressure gage of the air saturation tank reads 276 kN/m .

What is the value of f ?

5.38 It is desired to thicken an activated sludge liquor from 3,000 mg/L to 4% using a flotation thickener. A laboratory study indicated an A/S ratio of 0.011 is optimal for this design. The subnatant flow rate was determined to be 8 L/m -min. The barometric pressure is assumed to be the standard of 101.33 kN/m and the design temperature is to be 20°C. Assume f = 0.5; p = 0.90. The sludge flow rate is 400 m3/d. Design the thickener with and without recycle.

bibliography

Bliss, T. (1998). Screening in the stock preparation system. Proc. 1998 TAPPI Stock Preparation Short Course, Apr. 29-May 1, Atlanta, GA, 151-174. TAPPI Press, Norcross, GA.

Buerger, R. and F. Concha (1998). Mathematical model and numerical simulation of the settling of flocculated suspensions. Int. J. Multiphase Flow. 24, 6, 1005-1023.

Chancelier, J. P., G. Chebbo, and E. Lucas-Aiguier (1998). Estimation of settling velocities. Water Res. 32, 11, 3461-3471.

Cheremisinoff, P. N. Treating wastewater. Pollution Eng. 22, 9, 60-65.

Christoulas, D. G., P. H. Yannakopoulos, and A. D. Andreadakis (1998). Empirical model for primary sedimentation of sewage. Environment Int. 24, 8, 925-934.

Diehl, S. and U. Jeppsson (1998). Model of the settler coupled to the biological reactor. Water Res. 32, 2, 331-342.

Droste, R. L. (1997). Theory and Practice of Water and Wastewater Treatment. John Wiley & Sons, New York.

Fernandes, L., M. A. Warith, and R. Droste (1991). Integrated treatment system for waste from food production industries. Int. Conf. Environ. Pollut. Proc. Int. Conf. Environ. Pollut.— ICEP-1, Apr. 1991, 671-679. Inderscience Enterprises Ltd., Geneva, Switzerland.

Hasselblad, S., B. Bjorlenius, and B. Carlsson (1997). Use of dynamic models to study secondary clarifier performance. Water Science Technol. Proc. 7th Int. Workshop on Instrumentation, Control and Automation of Water and Wastewater Treatment and Transport Syst., July 6-9, Brighton, England, 37, 12, 207-212. Elsevier Science Ltd., Exeter, England.

Jefferies, C., C. L. Allinson, and J. McKeown (1997). Performance of a novel combined sewer overflow with perforated conical screen. Water Science Technol. Proc. 1997 2nd IAWQ

Int. Conf. on the Sewer as a Physical, Chemical and Biological Reactor, May 25-28, Aalborg, Denmark, 37, 1, 243-250. Elsevier Science Ltd., Exeter, England. McCaffery, S., J. L. Elliott, and D. B. Ingham (1998). Two-dimensional enhanced sedimentation in inclined fracture channels. Mathematical Eng. Industry. 7, 1, 97-125. Metcalf & Eddy, Inc. (1991). Wastewater Engineering: Treatment, Disposal, and Reuse.

McGraw-Hill, New York, 37. Renko, E. K. (1998). Modelling hindered batch settling part II: A model for computing solids profile of calcium carbonate slurry. Water S.A. 24, 4, 331-336. Robinson, D. G. (1997). Rader bar screen performance at Howe Sound Pulp & Paper Ltd.

Pulp Paper Canada. 98, 4, 21-24. Rubio, J. and H. Hoberg (1993). Process of separation of fine mineral particles by flotation with hydrophobic polymeric carrier. Int. J. Mineral Process. 37, 1-2, 109-122. Sincero, A. P. and G. A. Sincero (1996). Environmental Engineering: A Design Approach.

Prentice Hall, Upper Saddle River, NJ. Vanderhasselt, A. and W. Verstraete (1999). Short-term effects of additives on sludge sedimentation characteristics. Water Res. 33, 2, 381-390. Wu, J. and R. Manasseh (1998). Dynamics of dual-particles settling under gravity. Int. J.

Multiphase Flow. 24, 8, 1343-1358. Zhang, Z. (1998). Numerical analysis of removal efficiencies in sedimentation tank. Qinghua Daxue Xuebao/J. Tsinghua Univ. 38, 1, 96-99.

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