Conventional Clarifier

A conventional clarifier, also known as a sedimentation tank or settling tank, is a primary treatment unit in water treatment plants that is use to separate suspend solids and particles from water through the process of sedimentation.

Process Description

The conventional clarifier typically consists of a large, rectangular or circular tank with a central inlet for the water to be treat. The water enters the tank and flows slowly through the tank, allowing sufficient residence time for the suspend particles to settle to the bottom of the tank. The settling process is facilitate by the reduction in flow velocity, which allows gravity to pull the particles down.

As the water flows through the clarifier, the larger and denser particles, such as sand, silt, and other suspend solids, gradually settle and form a layer of sludge at the bottom of the tank. The settle particles are periodically remove as sludge and sent for further treatment or disposal.

System Components

Inlet Diffusers: Inlet diffusers are design to distribute the incoming water evenly across the tank, minimizing turbulence and ensuring an even distribution of solids throughout the tank.
Baffles: Baffles are vertical or incline plates install inside the tank to create flow patterns that promote the settling of solids. They help to control the flow direction and prevent short-circuiting, which is the direct flow of water from the inlet to the outlet without proper settling.
Scrape Mechanism: A scrape mechanism, typically consisting of a set of rotating arms with scraper blades, is used to collect and remove the settled sludge from the tank bottom. The collect sludge is then direct to a sludge hopper for further treatment.

The clarified water, known as the effluent, is collected from the upper part of the tank, typically by means of a collection mechanism or a launder system, and is further treat through subsequent processes such as filtration, disinfection, or other advance treatment methods.

Targeted Impurities

  • TSS
  • Turbidity
  • BOD
  • Colloidal Particles
  • Partial Color
  • grit
  • Chemical Sludge
  • Hardness
  • Heavy Metals