Evaluation of Double Perforated Baffles Installed in Rectangular Secondary Clarifiers
Abstract
:1. Introduction
2. Materials and Methods
2.1. Physical Description of the Test Facility
2.2. Physical Description of the Test Clarifier
3. Results and Discussion
3.1. Computational Fluid Dynamics Model Simulation
- Vo = Stokes velocity (settling velocity of a single particle in clear water), m/h.
- K1 = empirical coefficient for rapidly settling floc resulting from fit of batch settling data, m3/kg.
- Xmin = the concentrations of non-settling floc, kg/m3.
- K2 = a settling exponent for the poorly settling particles, m3/kg.
3.2. Experimental Study
4. Conclusions
Acknowledgments
Conflicts of Interest
References
- Fischer, A.J.; Hillman, A. Improved Sewage Clarification by Pre-flocculation without Chemicals. Sew. Works J. 1940, 12, 280–306. [Google Scholar]
- Knop, E. Design Studies for the Emscher Mouth Treatment Plant. J. Water Pollut. Control Fed. 1966, 38, 1194–1207. [Google Scholar]
- Parker, D.S. Assessment of Secondary Clarification Design Concepts. J. Water Pollut. Control Fed. 1983, 55, 349–359. [Google Scholar]
- Bender, J.; Crosby, R.M. Project Summary-Hydraulic Characteristics of Activated Sludge Secondary Clarifiers; US EPA: Cincinnati, OH, USA, 1984; pp. 2–3.
- Kawamura, S. Hydraulic Scale-model Simulation of the Sedimentation Process. J. Am. Water Works Assoc. 1981, 73, 372–379. [Google Scholar]
- Lopez, P.R.; Lavin, A.G.; Lopez, M.M.M.; de las Heras, B. Flow Models Rectangular Sedimentation Tanks. Chem. Eng. Process. 2008, 47, 1705–1716. [Google Scholar] [CrossRef]
- Bretscher, U.; Krebs, P.; Hager, W.H. Improvement of Flow in Final Settling Tanks. J. Environ. Eng. 1992, 118, 307–321. [Google Scholar] [CrossRef]
- Krebs, P.; Vischer, D.; Gujer, W. Improvement of Secondary Clarifiers Efficiency by Porous Walls. Water Sci. Technol. 1992, 26, 1147–1156. [Google Scholar]
- Baumer, P.; Volkart, P.; Krebs, P. Dynamic Loading Tests for Final Settling Tank. Water Sci. Technol. 1996, 34, 267–274. [Google Scholar] [CrossRef]
- Ahmed, F.H.; Kamel, A.; Abdel Jawad, S. Experimental Determination of the Optimal Location and Contraction of Sedimentation Tank Baffles. Earth Environ. Sci. 1996, 92, 251–271. [Google Scholar]
- Younes, M.F.; Younes, Y.K.; El-Madah, M.; Ibrahim, I.M.; El-Dannanh, E.H. An Experimental Investigation of Hydrodynamic Damping due to Vertical Baffle Arrangements in a Rectangular Tank. J. Eng. Marit. Environ. 2007, 221, 115–123. [Google Scholar] [CrossRef]
- Kawamura, S. Integrated Design and Operation of Water Treatment Facilities, 2nd ed.; John Wiley and Sons Inc.: New York, NY, USA, 2000; pp. 159–160. [Google Scholar]
- Tamayol, A.; Firoozabadi, B.; Ashjan, M.A. Hydrodynamics of Secondary Settling Tanks and Increasing Their Performance Using Baffles. J. Environ. Eng. 2010, 136, 32–40. [Google Scholar] [CrossRef]
- Asgharzadeh, H.; Frroozabadi, B.; Afshin, H. Experimental Investigation of Effects of Baffle Configurations on the Performance of a Secondary Sedimentation Tank. Sci. Iran. 2011, 18, 938–949. [Google Scholar] [CrossRef]
- Esler, K.E. Optimizing Clarifier Design and Performance. Available online: http://www.wefnet.org/clarifierdesignperform/part1/Optimize.pdf (accessed on 28 April 2017).
- Zhou, S.; Vitasovic, C.; McCorquodale, J.A.; Lipke, S.; DeNicola, M.; Saurer, P. Improving Performance of Large Rectangular Secondary Clarifier. Available online: http://hydrosims.com/files/Optimization_Rectangular_Clarifiers.pdf (accessed on 28 April 2017).
- McCorquoda, J.A.; Griborio, A.; Georgiou, I. Application of a CFD Model to Improve the Performance of Rectangular Clarifiers. In Proceedings of the WEFTEC, Dallas, TX, USA, 26 October 2006; pp. 310–320. [Google Scholar]
- Wahlberg, E.J. Activated Sludge Bioflocculation. Ph.D. Dissertation, Clemson University, Clemson, SC, USA, 1992; pp. 78–175. [Google Scholar]
- Wahlberg, E.J.; Stahl, J.F.; Chen, C.; Augustus, M. Field Application of the Clarifier Research Technical Committee’s Protocol for Evaluating Secondary Clarifier Performance: Rectangular Co-current Sludge Removal Clarifier. In Proceedings of the WEFTEC, Anaheim, CA, USA, 3 October 1993; pp. 554–566. [Google Scholar]
- Asano, T. Wastewater Reclamation and Reuse; Technomic Publishing Company Inc.: Lancaster, PA, USA, 1998; pp. 219–262. [Google Scholar]
- Water Environmental Federation. Clarifier Design, 2nd ed.; McGraw-Hill: New York, NY, USA, 2006; pp. 507–540. [Google Scholar]
- Takacs, I.; Patry, G.G.; Nolasco, D.A. Dynamic Model of the Clarification-Thickening Process. Water Res. 1991, 25, 1263–1271. [Google Scholar] [CrossRef]
- Standard Methods for the Examination of Water and Wastewater. Available online: http://www.umass.edu/mwwp/pdf/sm2540Btotalsolids.PDF (accessed on 4 June 2017).
- Wahlberg, E.J. WERF/CRTC Protocols for Evaluating Secondary Clarifier Performance; Water Environmental Research Foundation: Alexandria, VA, USA, 2001; pp. 5-1–5-34. [Google Scholar]
- Taeyoung Corporation. Performance Evaluation of Double Perforated Baffle in Secondary Clarifiers (2nd Train, 3rd Bay, No. 5, 6); Construction Supervision Report No. Suwon Wastewater 951-594; Taeyoung Corporation: Suwon, Korea, 2015; pp. 2–5. (In Korean) [Google Scholar]
Elements | Value | Remarks |
---|---|---|
FSS, kg/m3 | 0.005 | Xmin in Equation (1) |
ESS, kg/m3 | 0.009 | |
Vo, m/h | 14.718 | |
K1, m3/kg | 0.242 | |
K2, m3/kg | 70.000 | |
MLSS, kg/m3 | 3.000 |
Date | MLSS Concentration in Aerobic Tank mg/L | SVI of MLSS in Aerobic Tank, mL/g | Effluent SS Concentration in Tank A, mg/L | Effluent SS Concentration in Tank B, mg/L | Effluent Turbidity in Tank A, NTU | Effluent Turbidity in Tank B, NTU | Grab Sampling Time |
---|---|---|---|---|---|---|---|
1/6 | 3981 | 178 | 2.2 | 4.0 | 0.58 | 0.93 | 15:27 |
1/7 | 3780 | 182 | 2.7 | 4.6 | 0.54 | 0.93 | 15:43 |
1/8 | 3764 | 183 | 3.4 | 2.4 | 0.48 | 0.82 | 10:40 |
1/10 | 3925 | 158 | 1.3 | 1.4 | 0.43 | 0.86 | 11:43 |
1/11 | 3775 | 171 | 1.6 | 2.9 | 0.34 | 0.63 | 13:29 |
1/12 | 3728 | 170 | 2.7 | 4.8 | 0.4 | 1.78 | 13:25 |
2/23 | 4714 | 165 | 3.5 | 3.9 | 0.41 | 0.96 | 11:00 |
2/24 | 4786 | 167 | 3.2 | 2.4 | 0.42 | 0.58 | 9:44 |
2/25 | 4800 | 166 | 4.0 | 4.3 | 0.58 | 1.04 | 15:58 |
2/26 | 4629 | 161 | 3.0 | 4.8 | 0.50 | 0.77 | 15:01 |
2/27 | 4109 | 185 | 4.3 | 3.7 | 0.29 | 0.62 | 12:25 |
2/28 | 4313 | 183 | 2.4 | 3.4 | 0.35 | 1.15 | 12:00 |
7/19 | 4031 | 136 | 4.0 | 5.5 | 0.86 | 1.48 | 15:15 |
7/20 | 4178 | 135 | 1.6 | 1.3 | 0.18 | 0.46 | 16:00 |
0.7 | 0.8 | 0.15 | 0.42 | 9:00 | |||
1.1 | 0.7 | 0.30 | 0.37 | 11:00 | |||
0.7 | 1.2 | 0.16 | 0.42 | 13:00 | |||
0.7 | 0.4 | 0.17 | 0.44 | 15:00 | |||
0.4 | 1.3 | 0.17 | 0.38 | 17:00 | |||
0.6 | 0.4 | 0.15 | 0.39 | 19:00 | |||
11/28 | 4288 | 63 | 0.4 | 0.5 | 0.15 | 0.40 | 21:00 |
11/29 | 4366 | 62 | 1.4 | 1.3 | 0.56 | 0.49 | 10:37 |
12/15 | 4393 | 72 | 1.3 | 1.2 | 0.35 | 0.54 | 10:14 |
12/16 | 4370 | 77 | 3.2 | 2.9 | 0.49 | 0.85 | 13:30 |
12/17 | 4475 | 80 | 3.2 | 4.0 | 0.51 | 0.85 | 13:20 |
Mean | 4231 | 141 | 2.1 | 2.6 | 0.38 | 0.74 | |
Max | 4800 | 185 | 4.3 | 5.5 | 0.86 | 1.78 | |
Min | 3728 | 62 | 0.4 | 0.4 | 0.15 | 0.37 | |
SD | 353 | 46 | 1.2 | 1.6 | 0.18 | 0.35 |
Month | Elements | Effluent Turbidity in Tank A NTU | Effluent Turbidity in Tank B NTU | Effluent Turbidity Reduction Ratio % |
---|---|---|---|---|
January | Average | 0.76 | 1.22 | 30.8 |
Max | 3.42 | 2.65 | 77.0 | |
Min | 0.34 | 0.61 | −297.0 | |
February | Average | 0.54 | 1.25 | 54.0 |
Max | 1.15 | 2.11 | 81.0 | |
Min | 0.28 | 0.58 | 10.4 | |
July | Average | 0.20 | 0.41 | 50.4 |
Max | 0.32 | 0.58 | 72.4 | |
Min | 0.11 | 0.32 | 18.2 | |
November | Average | 0.57 | 0.7 | 20.5 |
Max | 0.88 | 1.05 | 46.4 | |
Min | 0.34 | 0.36 | −20.6 | |
December | Average | 0.59 | 0.79 | 28.1 |
Max | 0.87 | 1.35 | 75.8 | |
Min | 0.28 | 0.11 | −42.5 |
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Lee, B. Evaluation of Double Perforated Baffles Installed in Rectangular Secondary Clarifiers. Water 2017, 9, 407. https://doi.org/10.3390/w9060407
Lee B. Evaluation of Double Perforated Baffles Installed in Rectangular Secondary Clarifiers. Water. 2017; 9(6):407. https://doi.org/10.3390/w9060407
Chicago/Turabian StyleLee, Byonghi. 2017. "Evaluation of Double Perforated Baffles Installed in Rectangular Secondary Clarifiers" Water 9, no. 6: 407. https://doi.org/10.3390/w9060407