Abstract: 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.

Abstract: A method for treating water in a ballasted flocculation system comprises directing water into a ballasted flocculation zone and adding ballast and a flocculation reagent to the water to form a water-floc mixture. The water-floc mixture is directed into a settling zone to form treated water and sludge containing ballast. The ballast is then directed to a recirculation line where the ballast is recirculated to the ballasted flocculation zone. The method further includes determining the ballast concentration and comparing the ballast concentration with a predetermined threshold value. The rate at which ballast is recirculated to the ballasted flocculation zone is adjusted based on the determined ballast concentration and the predetermined threshold value.

Abstract: A method and apparatus for treating wastewater. The apparatus comprises a reactor having a flow channel generally centrally located in a reactor and immersed in the water or wastewater in the reactor. An agitator is disposed within the flow channel and induces water or wastewater to enter the open upper end thereof and to move downwardly through the flow channel where the water or wastewater is discharged via a flow divider. A reagent is injected into the water or wastewater and the agitator within the flow channel serves to mix the reagent with the water or wastewater passing therethrough and in the process causes at least a slightly turbulent and downward axial flow through the flow channel.

Abstract: A method and apparatus for treating wastewater. The apparatus comprises a reactor having a flow channel generally centrally located in a reactor and immersed in the water or wastewater in the reactor. An agitator is disposed within the flow channel and induces water or wastewater to enter the open upper end thereof and to move downwardly through the flow channel where the water or wastewater is discharged via a flow divider. A reagent is injected into the water or wastewater and the agitator within the flow channel serves to mix the reagent with the water or wastewater passing therethrough and in the process causes at least a slightly turbulent and downward axial flow through the flow channel.

Abstract: A method for treating water in a ballasted flocculation system comprises directing water into a ballasted flocculation zone and adding ballast and a flocculation reagent to the water to form a water-floc mixture. The water-floc mixture is directed into a settling zone to form treated water and sludge containing ballast. The ballast is then directed to a recirculation line where the ballast is recirculated to the ballasted flocculation zone. The method further includes determining the ballast concentration and comparing the ballast concentration with a predetermined threshold value. The rate at which ballast is recirculated to the ballasted flocculation zone is adjusted based on the determined ballast concentration and the predetermined threshold value.

Abstract: A method and apparatus for treating wastewater. The apparatus comprises a reactor having a flow channel generally centrally located in a reactor and immersed in the water or wastewater in the reactor. An agitator is disposed within the flow channel and induces water or wastewater to enter the open upper end thereof and to move downwardly through the flow channel where the water or wastewater is discharged via a flow divider. A reagent is injected into the water or wastewater and the agitator within the flow channel serves to mix the reagent with the water or wastewater passing therethrough and in the process causes at least a slightly turbulent and downward axial flow through the flow channel.

Abstract: The invention relates to a lamellar decanting module comprising two interconnected plates, at least one of said plates being corrugated in such a way that the dips and peaks are inclined in relation to a first edge of said plate according to a non-zero degree angle and define inclined decanting tubes with the other plate. Said module is characterised in that the two plates (2, 3) have the same corrugated profile and are interconnected in connection regions defining a plane of symmetry (P) for the tubes (4) defined by said plates. A plurality of modules can be assembled in such a way as to form a block in which the plates are parallel to one of the faces.

Abstract: A method and apparatus for treating wastewater. The apparatus comprises a reactor having a flow channel generally centrally located in a reactor and immersed in the water or wastewater in the reactor. An agitator is disposed within the flow channel and induces water or wastewater to enter the open upper end thereof and to move downwardly through the flow channel where the water or wastewater is discharged via a flow divider. A reagent is injected into the water or wastewater and the agitator within the flow channel serves to mix the reagent with the water or wastewater passing therethrough and in the process causes at least a slightly turbulent and downward axial flow through the flow channel.

Abstract: The invention relates to a lamellar decanting module comprising two interconnected plates, at least one of said plates being corrugated in such a way that the dips and peaks are inclined in relation to a first edge of said plate according to a non-zero degree angle and define inclined decanting tubes with the other plate. Said module is characterised in that the two plates (2, 3) have the same corrugated profile and are interconnected in connection regions defining a plane of symmetry (P) for the tubes (4) defined by said plates. A plurality of modules can be assembled in such a way as to form a block in which the plates are parallel to one of the faces.

Abstract: The invention relates to a method for treatment of water, permitting the physico-chemical treatment of water, including a ballasted flocculation stage using a granular ballast material with a density greater than water, followed by, a stage of gravity separation of the treated water and the flocculent mass, a stage of separation of the granular material, recycled for the flocculation stage and the muds. Said muds are sent to a stage for treatment of the muds, characterised in comprising a stage in which the functional mode passes from a mode using ballasted flocculation and gravity separation using coagulation and flocculation reagents to a mode functioning by simple gravity separation, without using coagulation and flocculation reagents. The passage from one mode to another is determined using at least one item of information on the water obtained at any stage of the treatment thereof or before said treatment.

Abstract: The invention relates to a method for treatment of water, permitting the physico-chemical treatment of water, including a ballasted flocculation stage using a granular ballast material with a density greater than water, followed by, a stage of gravity separation of the treated water and the flocculent mass, a stage of separation of the granular material, recycled for the flocculation stage and the muds. Said muds are sent to a stage for treatment of the muds, characterised in comprising a stage in which the functional mode passes from a mode using ballasted flocculation and gravity separation using coagulation and flocculation reagents to a mode functioning by simple gravity separation, without using coagulation and flocculation reagents. The passage from one mode to another is determined using at least one item of information on the water obtained at any stage of the treatment thereof or before said treatment.

Abstract: An untreated flow of waste water is normally introduced into a plain sedimentation unit during plain sedimentation periods to separate it into sand and a flow treated by plain sedimentation. During other periods, for example periods of heavy rain, a coagulating agent, ballast sand and a flocculating agent are introduced. The coagulated flow is passed into a maturation intermediate area and then, with substantially all the sand and colloids of particles attached to it, into the plain sedimentation unit. Here effluent is separated by plain sedimentation and evacuated and sludge made up of the sand and the adhering colloids and particles is extracted and evacuated via an extraction system and the sand outlet channel of the plain sedimentation unit. The sludge is collected, the ballast sand is separated from it to be recycled into the sand injection area and the sludge and excess sand are extracted.