The Two-in-One Solution for High Rate Flotation and Media Filtration

Improved SWRO membrane protection

Sea Water Reverse Osmosis (SWRO) membranes are highly sensitive and can become fouled if algae, suspended solids, soluble organic molecules and hydrocarbons in feed water are not removed adequately. An effective raw water pre-treatment system upstream of an SWRO system is therefore essential to prevent the risk of membrane clogging and to ensure durability. In order to deal with the most challenging seawater quality (red tide, high levels of nutrients, suspended solids peaks…) and feed SWRO membranes with consistently good quality of seawater, Veolia Water Technologies has developed and patented Spidflow Filter. This unique and compact solution combines into one structure the advantages of two proven pre-treatment processes: high rate Dissolved Air Flotation (Spidflow) and high rate Multimedia Granular Filtration (Filtraflo TGV).

Operating Principle

A - Flocculation phase:

Increases collision probability between particles to increase floc size. Turbomix technology to reduce the footprint of the flocculation tank can be used if required

B - Dissolved Air Flotation

Flocs are carried to the surface by very fine and calibrated air bubbles, resulting from extensive R&D work. Flocs are then removed by skimming:

  • Deals successfully with raw seawater quality upsets (turbidity peaks, algal blooms or hydrocarbon contamination)
  • Guarantees consistent seawater quality to feed the subsequent filtration step
  • Very efficient Veolia Water Technologies’ skimming process: minimizes pre-treatment water losses & lowers disposal volume with highly concentrated sludge production

C - High rate Multimedia Gravity Filtration

  • Removes smallest particles
  • Allows biomass development in the media depth which degrades biofouling molecules – Significant advantagecompared to MF/UF process (only mechanical filtration barrier) which does not remove dissolved nutrients
  • Provides long filtration cycles through constant feed water quality, even in the most challenging conditions
  • Fast maturation enabling to feed quickly & safely SWRO units


Veolia Water Technologies’ expertise on Spidflow and Filtraflo TGV has been proven over many years, with more than 15 Spidflow units & 30 Filtraflo TGV units installed and operating successfully worldwide.

Spidflow Filter is the unique re-engineered combination of these two best-seller processes. Long term performance has been assessed during extensive operation in challenging raw water conditions in different locations of the Gulf region. 

As a technology partner for Masdar (Abu Dhabi Future Energy Company), Veolia developed an innovative, low energy desalination plant in the UAE, incorporating Spidflow Filter, with a performance consistently beyond expectations.