Colloide Complete Wessex Water Clarifier System

Colloide has successfully supplied and installed a complete package clarifier system for Wessex Water, at its Codford water treatment works (WTW) in Wiltshire. The compact and efficient system is designed to treat 20m3/hr of backwash water from sand filters.

The Lamella Clarifier Package System shall be used to settle dirty backwash water from seven (7) No. iron removal pressure filters. Codford WTW is a borehole site comprising of oxidation using chlorine gas.

The wastewater will emanate from the backwash line of the pressure sand filter- this is then transferred to the package clarifier system where it is dosed with chemicals and allowed to develop within a series of flash mixing and flocculation in tanks before the chemically treated water is allowed to enter the clarifier itself.

The Lamella Clarifier now produces a supernatant turbidity of ≤5NTU and a minimum sludge thickness of 3%DS. The Lamella Clarifier plant is designed to permit treatment of the following:

  • Maximum treatment flow = 20.0m3/h
  • Minimum treatment flow = 13.1m3/h
  • Maximum total suspended solids = 1,298mg/l
  • Average total suspended solids = 205mg/l
  • Minimum total suspended solids = negligible mg/l
  • Maximum feed temperature = 20°C
  • Average feed temperature = 11°C
  • Minimum feed temperature = 5°C

The clarifier uses Colloide’s DWI certified technology with the sludge settling and thickening in the bottom of the clarifier.

The clarified water is collected in launders at the top of the tank and is recycled to the inlet of the main works.

The system was designed specifically to meet the client’s requirements and is fully certified to WIMES and DWI standard.













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