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
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