مشخصات جبهه آلودگی، اختلاط و ترقیق نهایی در تخلیه سطحی فاضلابهای سنگین به آبهای ساکن

نوع مقاله : مقاله پژوهشی

چکیده

تخلیه فاضلابهای شهری و صنعتی در پیکره‌های آبی از طریق تخلیه‌کننده‌های دریایی از روشهای معمول در دفع پسابهای تولیدی در مناطق ساحلی محسوب می‌گردد. تخلیه‌کننده‌های دریایی با تشدید فرایند اختلاط در فاصله محدودی از جلوی تخلیه‌کننده، غلظت آلاینده‌ها را تا حد تحمّل محیط پذیرنده، پایین آورده و تخلیه پیوسته فاضلاب در محیط دریا را ممکن می‌سازند. طی سالیان اخیر به‌واسطه توسعه روزافزون نمک‌زداهای ساحلی، تولید و تخلیه سطحی فاضلابهای شور و سنگین در دریا، به‌طور چشمگیری افزایش یافته است. در این تحقیق تخلیه سطحی جریان‌های سنگین خروجی از کانال مستطیلی از طریق شبیه‌سازی آزمایشگاهی آن در محیط‌های ساکن مورد بررسی و مطالعه قرار گرفت. موقعیت نقطه شیرجه، نقطه برخورد جریان با بستر و موقعیت نقطه دستیابی جریان به ترقیق نهایی خود در محیط از جمله پارامترهایی هستند که در این مقاله مورد بررسی قرار گرفتند. همچنین از طریق جانمایی تعدادی حسگر هدایت الکتریکی در مجاورت بستر، میزان ترقیق جریان در نقطه برخورد و ترقیق نهایی آن در مجاورت بستر برآورد و نتایج آن در قالب مجموعه‌ای از نمودارهای بی‌بعد ارائه گردید. نتایج به‌دست آمده بیانگر رابطه مستقیم مشخصات جریان با عمق محیط و شارهای اولیه جریان خروجی است.

کلیدواژه‌ها


عنوان مقاله [English]

Waste Field Characteristics, Ultimate Mixing and Dilution in Surface Discharge of Dense Jets into Stagnant Water Bodies

چکیده [English]

Direct discharges of municipal and industrial waste waters into water bodies through marine outfalls are considered as a common way to dispose the generated waste in coastal zones. Marine discharge, intensifying flow mixing and entrainment, decrease the concentration of polutant up to accepted concentration and meet the guideline values and to make possible continues discharge of flow into matine environment. During last years due to quick development of coastal desalination plants, surface discharge of preduced salty water into seas and oceans has increased significantly. In this study, releases of dense jets from surface rectangular channel into stagnant bodies are experimentally studied. The location of flow plunge point, impact point and discharge ultimate dilution were drown out by a digital video technology. In addition, using some conductivity probes located in ambient floor, waste filed dilution in flow impact point and discharge ultimate dilution were identified. Finally the obtained results were plotted and explained along with some diagrams to show flow non-dimensional behavior. The results showed that the properties of flow are changing directly with ambient water depth and discharge initial fluxes.

کلیدواژه‌ها [English]

  • Surface Discharge
  • Marin Outfall
  • Negative Buoyancy
  • Mixing
  • Jet
  • Plume
1- Abessi, O., and Saeedi, M. (2009). “Marine wastewater discharge.” J. Water and Envionmental,73, 34-41. (In Persian)
2- USEPA. (1980a). Ambient water quality criteria, EPA 440/5-80-015 to 079, U.S. Environmental Protection Agency, Washington, D.C
3- USEPA. (1994). Dilution models for effluent discharges, Office of Research and development, EPA/600/R-94/086,Environmental Protection Agency,Washington, D.C.
4- Gameson, A. L. H. (1984). Bacterial mortality, Part 1, in investigation of sewage discharge to some British costal waters, Chapter 8mWRc Technical report TR 201,Medmenham,U.K.
5- Roberts, J.W., and Wright, S.J. (1983). “ Descussion of Vertical round buoyant jet in shallow water.” J. Hydrulic Enginieering, 109 (3), 490-496.
6- Roberts, P. J. (1989). “Outfall design consideration.” J. Hydrulic Enginieering, 115, 661-689.
7- Roberts, P.J.W., Snyder, W.H., and Baumgartner, D.J. (1989). “Ocean outfalls. I: Submerged waste field formation.” J. Hydrulic Enginieering, 115(1), 49-69.
8- Roberts, P. J. W., Snyder W. H., and Baumgartner, D.J. (1989). “Ocean outfalls. II: Spatial evolution of submerged waste field.” J. Hydrulic Eng., 115(1), 26-47.
9- Roberts, P. J. W., Snyder, W.H., and Baumgartner, D.J. (1989). “Ocean outfalls. III: Effect of diffuser design on submerged waste field.” J. Hydrulic Enginieering, 115(1), 1-25.
10- Tian, X., Roberts, P. J. W., and Daviro, J. (2004). “Marin wastewater discharge from multiport diffusers. I: Unstratified stationary water.” J. Hydrulic Enginieering, 130(12), 1137-1146.
11- Tian, X., Roberts, P. J. W., and Daviro, J. (2004). “Marin waste water discharge from multiport diffusers. II: Unstratified flowing water.” J. Hydrulic Eng., 130(12), 1147-1155.
12- Yu, D., Ali, M.S., and Lee, J. H. W. (2006). “Multiple tandem jets in cross-flow.” J. Hydrulic Enginieering, 132(9), 971-982.
13- Tian, X., Roberts, P. J. W., and Daviro, J. (2006). “Marin wast water discharge from multiport diffusers. IV: Stratified flowing water.” J. Hydrulic Enginieering, 132(4), 411-419.
14- Jirka, G. H. (1996). User’s manual for CORMIX: A hydrodynamic mixing zone model and decision support system for pollutant discharges into surface waters, DeFrees Hydraulics Laboratory,CornellUniversity,Ithaca,N.Y.
15- Jones, R.G., Nash, D. J., and Jirka, H.G. (1996). User manual: CORMIX3: An experimental system for mixing zone analysis and prediction of buoyant surface discharges, Office of Science and Technology U.S. Environmental Protection Agency, Washington, D.C.
16- Jones, G., Nash, D., Doneker, L., and Jirka, H. (2007). “Buoyant surface discharge into water bodies. I: Flow classification and prediction methodology.” J. Hydrulic Enginieering, 133(9), 1010-1020.
17- Ahmed, M., Shayya, W. H., Hoey, D., and Al-Handaly, J. (2001). “Brine disposal from reverse osmosis desalination plants in Omanand the United Arab Emirates.” J. Desalination., 133, 135-147.
18- Fischer, B., List, J.E., Imberger, J., and Brooks, H. N. (1979). Mixing in inland and coastal waters, Acadmce Press, Inc.,San Diego,California.
19- Hauenstein, W., and Dracos, T. (1983). “Investigation of plunging density currents generated by inflows in lakes.” J. Hydraulic Research, 22(3), 157-179.
20- Nemlioglu, S., Roberts, P.J.W., and Bayat, C. (2006). “Experimental techniques for two dimensional analyses of cool-water outfalls laboratory model tests.” 4th International Conference on Marine Waste Water Disposal (MWWD),Antalya,Turkey.
21- Law, A., Ho, W., and Monismith, S. (2004). “Double diffusive effect on desalination discharge.” J. Hydrulic Enginieering, 130(5), 450-457.
22- Roberts, P.J.W, Ferrier, A., and Daviero, G. (1997). “Mixing in inclined dense jet.” J. Hydrulic Enginieering, 123(8), 693-699.
23- Wright, S. J. (1977). Effects of ambient cross flow and density stratification on the characteristic behavior of round turbulent buoyant jets, Report No. KH-R-36, W.M. Keck Lab. of Hydr. and WaterResour.,California Inst. of Tech.,Pasadena,California.
24- Zhang, H., and Baddour, E. (1998). “Maximum penetration of vertical round dense jets at small and large froud numbers.” J. Hydrulic Enginieering, 124(5), 550-553.
25- Cipollina, A., Brucato, A., Grisafi, F., and Nicosia, S. (2005). “Bench-scale investigation of inclined dense jets.” J. Hydrulic Enginieering, 131(11), 1017-1022.
26- Kikkert, G., Davidson, J., and Noles, I.(2007). “Inclined negatively buoyant ischrges.” J. Hydrulic Enginieering, 133 (5), 545-554.
27- Bleninger, T., and Jirka G. H. (2008). “Modeling and environmentally sound management of brine discharge from desalination plants.” J. Desalination, 221, 585-597. 
28- Alavian, V. (1986). “Behavior of density currents on an incline.” J. Hydrulic Eng., 112 (1), 27-42.
29- Kassem, A., Jasim I., and Jamil, A.K. (2003). “Three-dimensional modeling of negatively buoyant flow in diverging channels.” J. Hydrulic Eng., 129(12), 936-947.
30-Abesi, O., Saeedi, M., Hajizadeh, N., and Kheirkhah Gildeh, H. (2011). “Flow characterization dilution in surface discharge of negative buoyant flow in stagnant and non-stratified water bodies.” J. of Water and Wastewater, 80, 71-82. (In Persian)
31- Pincince, A. B., and List, E. J. (1973). “Disposal of brine into an estuary.” J. Water Pollut. Control Fed., 45, 2335-2344.
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