High-Rate Clarifier / Thickener CONTRAFAST® High-Rate Clarifier / Thickener

What is CONTRAFAST®? High-Rate – tube settlers at 6 gpm/ft2 resulting in small footprint Clarifier – produces same overflow as solids contact Thickener – produces same underflow as gravity thickener

Where is CONTRAFAST® applied? Anywhere you would use a Solids Contact Clarifier with a thickener.

Where is CONTRAFAST® applied? Water Supplies Applications Wells (Ground Waters) Lime Softening Lakes & Reservoirs Surface Water Clarification Industrial Process Streams Silica Reduction Waste Water Treatment Processes Phosphorus Removal Heavy Metals Precipitation Rivers Iron Removal Wells Under Influence of Surface Water Backwash waste clarification Cooling Tower Blowdown Clarifier wastes clarification

Where is CONTRAFAST® applied? Anywhere you would use a Solids Contact Clarifier with a thickener. CONTRAFAST® High Rate Clarifier/Thickener

Advantages Smaller footprint Solids Contact 26 ft. CONTRAFAST 25’-4” diameter Thickener 15 ft. Solids Contact 26 ft.

Advantages Smaller footprint Eliminates need for separate thickener / reduced waste sludge volume Lower equipment cost Lower installation cost

Disadvantages Higher energy consumption Steel tank design not available for all sizes yet

How It Works <10 NTU 10 x recirculation >6% TSS underflow 10% sludge recycle

Concentric vs. Eccentric Eliminate transition zone by creating concentric CONTRAFAST® OR, use rectangular concrete basins for eccentric CONTRAFAST®

Concentric Design Mixer Draft Tube Reaction Chamber Stilling Baffle Recirculation Pump

Concentric CONTRAFAST® models 175 gpm 350 gpm 700 gpm 1400 gpm Shop Assembled Field Assembled

Eccentric CONTRAFAST® models Ten “models” from 1500 gpm to 8500 gpm Rectangular concrete basins

Successes Automotive Mfr. Belvedere, IL

Resources Standard pre-engineered design for the concentric (175 gpm to 1400 gpm) models Pilot/Rental unit available (40 to 160 gpm) Retrofit options

Conclusions Use anywhere you could use a solids contact process and thickener. Competes directly with Densadeg. This is a High-rate Clarifier/Thickener. Smaller footprint Better overflow clarity Thicker underflow