Philosophy of Design
Trickle Filter

Revolving distributors are gigantic aeration plants which use the energy available in the velocity head created to cause rotation and oxidation of the pollution by a relative constant dosing over beds constructed from graded media with considerable surface area relative to its volume. This technique with the hydraulic computation of revolving distributors is based on years of experience of the hydraulic performance of revolving distributors.

The philosophy of Water Engineering & Construction Projects (Pty) Ltd is to manufacture, using the most modern facilities available. The seal-less distributor is manufactured locally, making replacement parts easily obtainable. The use of spherical roller bearings provides the best means to carry the slow speed high thrust and radial loads produced by the revolving distributor. The unit can operate 24 hours a day, seven days a week with virtually no preventive maintenance. 

The Model E

Trickle FilterWEC Projects manufactures and supplies a range of biological trickle filters (the model E). These sewage treatment plants are ideal for smaller flow volumes (1-5m3/day). The model e is fabricated form mild steel and is painted with a corrosion resistant coating.

The extended filter is of steel construction, with a GRP or HDPE shroud around the packed tower. The plant incorporates a collection sump, bio-filter (trickle filter), recycle pump with suction screen, pebble-bed clarifier and sterilization zone. The plant is generally preceded by a septic tank.

The process comprises the following:

  • Inlet Collection Sump
  • Suction Screen & Re-Circulation Pump
  • Packed Tower & Distributor for Aerobic Treatment
  • Quiescent Zone
  • Up-Flow Clarifier (Fluidized Sand Filter)
  • Sterilization

It is believed that this equipment will meet your discharge requirements, as the units are selected from our range of four basic sizes, each preceded by a septic tank/balancing tank.

a.)Inlet Screen

The Inlet Screen should be sized to remove solids that will disturb the bio filter and is offered with a 6mm perforated plate screen mounted on the suction of the re-circulation pumps.

b.)Bio Tower (Pack Tower)

The Bio Tower is sized for maximum BOD loading and is filled with ultra high surface area plastic media, giving high BOD reductions.

The raw and recycled effluent is pumped to the reactive Distributor to ensure the best distribution and wetting of the media. (This ensures the plant stays in good condition, even in a no influent condition.)

c.)Quiescent Zone

Stock TankThe Quiescent Zone allows for settling of heavy solids causing an anaerobic condition under the sludge blanket, ensuring that additional denitrification takes place.

d.)Clarifier

The Up-Flow Clarifier comprises a pebble or sand bed through which the final effluent must pass. Backwashing is not required as all solids entrapped eventually settle.

e.)Sterilization

Sterilization – effluent from the clarifier passes to the bottom of a 1 m³ stock tank, where it is chlorinated by a basic month mate chlorine dispenser.

Interesting Facts

"Raindrops are not tear-shaped. Scientists, using high-speed cameras, have discovered that raindrops resemble the shape of a small hamburger bun."

"The average human body is composed of about 55% water"

"Life on earth probably originated in water"

"More than half of the world's animal and plant species live in the water"

"Almost 70% of the earth is covered in water"

"The human body needs 2 litres of water a day in our climate; we can last only a few days without water"

"Most of our food is water: tomatoes (95%), spinach (91%), milk (90%), apples (85%), potatoes (80%), beef (61%), hot dogs (56%). "