Circular Clarifiers and Thickeners

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Circular Clarifiers and Thickeners 2017-07-26T13:12:45+00:00

Circular Clarifier

Circular Clarifiers and Thickeners

New, rebuild, & retrofit designs for nearly all clarifier and thickener applications

Monroe Circular Clarifiers use widely accepted settling technology based on the density difference between water and suspended solids. The Monroe Clarifier is designed to give you the performance you require with long-term reliability. Monroe Environmental realizes that all waste streams are not alike and in many cases standard designs must be modified. Tank sizing, influent and effluent arrangements, flocculation requirements, sludge removal, and skimming methods and mechanisms are some of the considerations necessary for a successful installation.

Circular Clarifier & Thickener Expertise

Circular Clarifier standard scraper designThe Monroe Clarifiers are available in self-supporting prefabricated steel units or they can be designed for installation in a concrete tank. Existing structures and systems can sometimes be utilized and upgraded for cost savings.

Circular Clarifiers normally utilize a center feed inlet well or a peripheral inlet. The center feed well design can be equipped with a chemical addition system with mixing and flocculation. With the center feed well, the effluent is discharged along the outer wall of the clarifier tank. Clarifiers with peripheral inlets will be designed with a center bottom liquid outlet.

Monroe Environmental builds primary and secondary clarifiers for municipal wastewater treatment, as well as flocculating clarifiers and solids contact clarifiers for clean water or potable water applications. Our experienced staff will provide high efficiency, low maintenance systems that will provide the highest return on investment.

Circular Clarifiers Engineered to Meet Your Needs

  • Customized designs for municipal and industrial applications
  • Tank diameter 10 to 250 feet
  • Full and half-bridge designs
  • Steel or concrete tanks
  • Chemical feed system available
  • Flocculator available when required
  • Energy Dissipating Inlet (EDI) designs available
    • MEDIC
    • LA-EDI
    • Alternate designs
  • Thickener mechanism available
  • Sludge removal configurations
    • Scraper
    • Spiral scraper
    • Suction header
    • Riser pipe
  • Skimmer mechanisms
  • Corrosion resistant materials and coatings
    • Epoxy coated steel
    • Stainless steel
    • Galvanization
  • Custom built replacement parts for all manufacturers
  • Clarifier rebuilds

Primary, Secondary (Final), Clean Water Treatment, & Thickeners

Sludge Removal Designs


Clarifier standard scraper designMonroe Environmental’s Primary Circular Clarifiers are designed to receive raw wastewater after it has been pre-screened to remove large objects and grit. This primary sedimentation tank will produce a homogeneous liquid capable of being treated biologically and a sludge that can be separately treated or processed.

Spiral Scraper

Clarifier spiral scraper design

Spiral Scraper type clarifiers utilize long-sweeping, curved scraper blades to move solids across a basin floor. They are similar to scraper-type clarifiers in that they drag settled solids to the collection area, however, they can more quickly remove these solids and thus maintain lower sludge blankets in some applications. This design can be utilized in primary, secondary, and industrial wastewater applications.

Riser Pipe

Clarifier riser pipe designRiser pipe clarifiers rely on differential head pressure to collect settled solids from the tank floor. Each riser pipe is situated at the intersection of a v-plow and receives a continuous feed of sludge that returns to a sludge collection box near the center of the clarifier. This design is intended for secondary, biological, or flocculated solids which are more fluidized and have lower densities than primary wastewater and heavy industrial sludge.

Suction Header

Clarifier suction header designSuction header clarifiers rely on differential head pressure to collect settled solids from the tank floor. These units have a long, tapered collection arm with multiple orifices sized to stabilize and maintain optimum sludge transfer velocities through the header. This design is intended for secondary, biological, or flocculated solids which are more fluidized and have lower densities than primary wastewater and heavy industrial sludge.

Water & Wastewater Applications

  • Steel processing
  • Oil refineries
  • Food processing
  • Mining wastewater
  • Chemical and petrochemical processing
  • Automotive plant wastewater
  • Plastics manufacturing
  • Municipal treatment plants
  • General water and wastewater treatment
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Check out our Circular Clarifier Design Blog

Our senior clarifier design engineer outlines the many considerations that engineers and operators should take into account when evaluating and designing circular clarifiers. Visit Blog

Recent Case Studies

  • High torque Circular Thickener clarifier for separation of dense, sticky solids from gypsum wastewater

Water | High Torque Thickener Clarifier

Monroe Circular Thickener Clarifier provides effective separation of dense, sticky solids from gypsum wastewater.

  • Rebuilt Primary Clarifier with new spiral scrapers ready to return to operation

Water | Detroit Wastewater Treatment Plant

Monroe Clarifier rebuilds replace internal components and convert sludge rakes to higher efficiency spiral scrapers at City of Detroit WWTP.