INSTALLATION FOR WATER TREATMENT BY MEANS OF INTEGRATED BALLASTED FLOCULATION AND DECANTATION AND APPROPRIATE METHOD

摘要

The invention relates to a water treatment plant comprising: means (1) for supplying water for treatment, wherein said water has been coagulated previously, a flocculation-decantation device (11) having means (5) for dispensing at least one flocculant reagent, means (6) for dispensing at least one ballast, means (20d) for extracting decantation sludge, means (9) for discharging the treated water, means (14) for separating said ballast contained in the ballasted sludge, and means (8) for recycling the ballast that has been cleaned in this manner back into the flocculation-decantation device (11), characterised in that: said flocculation-decantation device (11) has a single tank (12) in the lower portion of which a stirring mechanism (13) is arranged; wherein said single tank (2) comprises slats (10) in its upper portion; and said slats are separated from the stirring mechanism (13) by a distance “d” which is between approximately 0.5 metres and approximately 3 metres. The invention also relates to a method using said plant.