Diffused Air / Dissolved Air Flotation Test Apparatus (DADAFTA)

Dissolved Air Flotation and Diffused Air Flotation (both referred to as DAF), are water treatment processes that clarify wastewater by removing suspended matter such as oils and solids.  Fine gas bubbles (usually from compressed air) are introduced into the liquid.  The bubbles attach to the particulate matter and float them to the surface to form a froth.  Chemical flotation aids are often used to enhance the DAF process.

Dissolved Air Flotation

In this method, air is injected into pressurized liquid, causing it to dissolve.  The pressurized liquid (with dissolved air) is then injected into the influent.  The drop in the pressure causes air bubbles to form.

Diffused Air Flotation

Here, aeration is produced by passing air through a porous medium and directly into the influent.  The tiny pores in the medium create air bubbles, which immediately float to the surface.

The OFITE Diffused Air / Dissolved Air Flotation Test Apparatus (DADAFTA) allows the user to simulate the DAF process on a small scale. The DADAFTA can be used to measure the floatability of a particular sludge when designing treatment plants and to evaluate chemical flotation aids.

DADAFTA Applications

• Separation of flocculated matter in the clarification of surface water
• Separation of flocculated or non-flocculated oil in wastewater from refineries, airports, and steelworks
• Separation of metallic hydroxides or pigments
• Thickening of the activated sludge (or mixed sludge and primary sludge) from organic wastewater treatment plants

Features / Benefits

• Clear, unibody pressure cell withstands pressures up to 125 PSI (8.6 bar)
• Oil-less 115-volt piston air compressor for high efficiency and constant performance
• Permeable ceramic disk used for the diffuser can be removed, cleaned, and reused
• Chemical flotation aid inlet with septum
• Stainless steel paddle for additional mixing capabilities
• Easy-to-read flow meter and pressure gauge
• Quick disconnect fittings

Components

• #135-04: Retainer Ring, External
• #141-22: Filter, Felt
• #143-01-1: Gauge, 200 PSI, 1/8″ Back Connection
• #153-09-2: Graduated Cylinder, Nalgene®, 1,000 mL, PMP
• #153-75: Tygon® Tubing, 3/16″, 3 Feet
• #298-04: Flowmeter, 0 – 30 SCFH, 50 mm
• #298-13: Poly Pak Seal
• #298-20: Stopper, O Size, Rubber
• #298-21: Pressure Relief Valve, 100 PSI (689.5 kPa)
• #298-22: Piston Air Pump, 100 PSI (689.5 kPa), 115 Volt
• #298-27: Stopcock Valve, 1/4″ Male × Female
• #298-28: Tubing, 3/16″ ID × 5/16″ OD, Polyethylene
• #298-29: Tubing, Flexible, Polyurethane
• #298-32: Gauge, Glycerine Filled, 100 PSI, 2 1/2″ Face, 1/4″ Back Connection, Stainless Steel
• #298-33: Air Diffuser, 1.5″ Long × 0.75″ Wide, 3/16″ OD Barb, 4 mm, ABS

Optional

• #111-15: Transformer, 230 to 115 Volt, 60 Hz

Part Number

• #298-00