Veolia Water Solutions & Technologies Support

Otv Sa

Otv Sa S.a.

Claus Dahl

Philippe Sauvignet

Jean-Francois Beaudet

Celine Levecq

Joseph Edward Zuback

Patrick Binot

Valery Ursel

Valey Ursel

Céline Levecq

Jean-François Beaudet

A method for treating wastewater using a ballasted flocculation technique includes continuously measuring the concentration of suspended solids, organic matter or other impurities in the water to be treated prior to directing the water to be treated to a flocculation tank. Based on this measurement, the amount of ballast necessary to obtain treated water of a predetermined quality is then calculated. In the flocculation tank, ballast and a flocculating reagent are added to the water to form a water-floc mixture. The water-floc mixture is directed to a settling tank where a sludge-ballast mixture is settled. The sludge-ballast mixture is directed to a mixing tank and then to a separator to separate the ballast from the sludge. The separated ballast is directed to the flocculation tank. The separated sludge is directed to the mixing tank when the level of sludge-ballast mixture in the mixing tank is lower than a predetermined level.

Water treatment process and plant using ballasted flocculation and settling

A method for removing helminth egg and other suspended solids from a wastewater stream includes directing the wastewater to a ballasted flocculation system and adding a coagulation agent, flocculation agent and a ballast into the wastewater. Sludge is settled from the wastewater in a settling tank at a rate of at least 10 meters per hour. The method further includes removing helminth egg by filtering the effluent through a fine screen having a mesh diameter of approximately 5 micrometers to approximately 25 micrometers. After passing through the fine screen, the filtered effluent has less than one helminth egg per liter.

Wastewater treatment method comprising decantation and fine screening stages

The invention concerns a water treatment method which consists in introducing coagulated water in a flocculation zone, to enable flocculation of microflocs in the presence and around a ballast; introducing the mixture in a decantation zone; separating the treated water in overflow and a mixture of sludge and the ballast in underflow; conveying at least part of said mixture to a sludge/ballast separating system and recycling into or upstream of the flocculation zone the ballast and part of the sludge introduced in said separation system. The invention is characterized in that it comprises steps which consists in conveying the mixture to the sludge/ballast separating system; in subjecting said mixture to a ballast concentration, extracting the ballast from the sludge extracted from the separation system; and more than 20% of the volume entering the sludge/ballast separating system is recycled into or upstream of the flocculation zone, after passing through at least part of the sludge/ballast separation system; and the ballast has an effective diameter greater than 60 micrometers, and the sludge extracted from the treatment system has a concentration higher than 5 g/L.

Method for treating water by ballasted flocculation and decantation

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Hedehusene, Denmark

Claus Dahl