Design of a Wastewater Treatment Plant

1. Design of a Wastewater Treatment Plant By Danny Dehon Monique Magee Melissa Wason Shreya Purohit

2. Over view • Introduction • Objective • Criteria • General flow chart • Design • Detailed flow chart • Cost analysis • References

3. Introduction What is waste water? It is a combination of liquid wastes from industries, commercial and residential areas. It also includes storm water, ground water and surface runoff Why do we need to treat waste water? Why do we need to treat waste water?

4. OBJECTIVE • To design a waste water treatment plant for a town of 10,000 people, which treats 1 million gallons of waste water per day. • The characteristics of the effluent water are in compliance with current regulatory standards.

5. Criteria

6. GENERAL FLOWCHART Pre-treatment

7. General Design Considerations

8. Main sewer linediameter=14 inchesflow 1MGD= 1.54 ft 3/svelocity 1.3ft/sQ=VAmade of stainless steel

9. Pumping of water to bar screens • Water is pumped 70 ft • 880kw power needed • Vertical Turbine Solids-Handling Pumps VTSH® Series pump- specially designed to handle solids • Head:70 feet and this pump has a head of up to 110 ft • Pump Capacity:30,000 GPM • Impeller:non-clogging, blunt, and made of cast iron, • Shaft: stainless steel

10. CalculationBernoulli’s equation Where h2= 70 ft, V2= .8ft/s, and V1= 1.1ft/s

11. Bar screens • Removes sticks, glass, small rocks etc • Climber type bar screen • Spacing ¼ inches • Fine screening • Stainless steel to prevent corrosion • Mechanically scrapped • Solids collected in hopper and disposed

12. Pre - treatment

13. Pre Treatment Calculations Aerated grit removal chamber Volume Skimming tank Volume Tank dimensions Volume = 4x3

14. Primary Sedimentation Tanks Retention time • 90 min Water velocity .665ft/s Dimensions • width 15.8 ft • length 52.77 ft • Depth 10 ft.

15. Calculations • Water velocity • Dimensions

16. Trickling Filters Tipping tray Retention time: 5 minute Dimensions: h=r =7.04ft Filter Dosing cycle : 5 min Retention time: 25 min Dimensions h=r=13.04ft Drainage = 5o slope ventilation

17. Calculations. • Volume • R=h=x

18. Secondary Sedimentation Tanks Retention Time: • 20 minutes Water Velocity: • drop rest of solids out of suspension • 1/3 of the velocity in the pipes, or .44 ft/s. Dimension: • Required R: H = 2: 1, • R: H =10.57 : 5.29 ft. Skimmer: • fence with extremely small square holes, .5 inches by .5 inches • Catches waste Scraper: • mechanically operated • 5 arms. • Scrape off material from the bottom

19. Calculation • Water velocity • Dimensions • R=2h

20. Chlorination- disinfect water

21. Calculations • Retention time • = 68 minutes

22. De –chlorination chamber • Remove residual chlorine using SO2- above standards .0058 lb/gal • The ratio of the reaction is 2.43 x 10-6 lb sulfur dioxide for every 2.20 x 10-6 lb of chlorine. • .017 lb/ gal chlorine – neutralized with .012/gal of SO2

23. Calculations • Basic chemistry • X = 0.012

24. Cost analysis

25. TOTAL COST INITIAL • $236,100 DAILY • $4981.23

26. References • Al-Layla, M. A., Ahmad, S., & Middlebrooks, E. J. (1980). Handbook of Waste Water Collection and Treatment. (G. l. culp, Ed.) Garland STPM Press. • Droste, R. L. (1997). Theory and Practice of Water and Wastewater. Hoboken: John Wiley & Sons. • Jern, W. (2006). Industrial Waste Water Treatment. New York: World Publishing Company. • Metcalf, L., & Eddy, H. P. (1935). American Sewerage Practice. New York: McGraw-Hill Book Company. • Metcalf, L., & Eddy, H. P. (1930). Sewerage and Sewage Disposal: A Textbook. New York: McGraw-Hill Book Company. • Metcalf, L., & Eddy, H. P. (1972). Wastewater Engineering. New York: McGraw-Hill Book Company. • Noyes, R. (1994). Unit Operations in Environmental Engineering. New York: William Andrew Publishing/Noyes. • Sanks, R. L. (1998). Pumping Station. London: Butterworth Heinemann. • Note: Some of the pictures are not referenced because they were taken by the authors of these papers during a visit to the Baton Rouge Wastewater Treatment Facility.