Method for treating water by adsorption on activated carbon coupled with an addition of ozone, and facility for implementing said method
View Patent ↗The invention relates to a water treatment method comprising a step of injecting ozone by a Venturi effect into the water to be treated, immediately followed by a step of ozone saturation of the water to be treated, a step of bringing the ozonated water to be treated into a reactor comprising a fluidised bed of activated carbon particles, a step of placing the ozonated water to be treated in contact with the activated carbon particles according to a flow of water ascending in the reactor, a step of discharging the water treated in this way. The invention also relates to a facility comprising an activated carbon reactor, means for bringing the water to be treated into the reactor, means for discharging the treated water, a means for injecting ozone into the water by a Venturi effect and a means for saturating the water with ozone mounted directly, or as a bypass, on the means for bringing water into the reactor.
1 . A method of treating water containing polluting substances, comprising:
directing the water containing the polluting substances through a Venturi;
injecting ozone into the water via the Venturi;
immediately after injecting ozone into the water, directing the water through an ozone saturator and saturating the water with ozone to form saturated ozonated water;
directing the saturated ozonated water into a bottom portion of a reactor containing activated carbon;
directing the saturated ozonated water upwardly through the reactor and fluidizing the activated carbon in the reactor;
contacting the fluidized activated carbon with the saturated ozonated water, causing at least some of the polluting substances to be adsorbed onto adsorption sites on the activated carbon which results in treated water; and
directing the treated water depleted in polluting substances from an upper portion of the reactor.
2 . The method of claim 1 wherein the saturated ozonated water includes dissolved ozone molecules and wherein the method includes reacting the dissolved ozone molecules at the surfaces of the activated carbon to form new surface functional groups and binding at least some of the polluting substances with the new surface functional groups.
3 . The method of claim 1 wherein the time between injecting the ozone into the water and saturating the water with ozone is less than 60 seconds.
4 . The method of claim 2 including maintaining the treated water substantially free of ozone by reacting the ozone molecules with the activated carbon at the surfaces of the activated carbon.
5 . The method of claim 1 including contacting the upward flowing treated water in an upper portion of the reactor with a deflector so as to form a tranquil area in the upper portion of the reactor and to generally reduce the speed of the saturated ozonated water moving upwardly through the reactor.
6 . The method of claim 1 including dissolving the ozone molecules in the water so as to prevent the formation of ozone bubbles in the water.
7 . The method of claim 1 including forming functional groups on the surfaces of the activated carbon and adsorbing the polluting substances by the functional groups on the surfaces of the activated carbon.
8 . The method of claim 1 wherein said activated carbon is in the form of agglomerates having a particle size between 300 μm and 1500 μm.
9 . The method of claim 1 wherein the concentration of the activated carbon in the reactor is between 100 g/L and 400 g/L.
10 . The method of claim 1 wherein the steps of ejecting ozone into the water via the Venturi and directing the water through an ozone saturator and saturating the water with ozone to form the saturated ozonated water has an overall duration less than 1 minute.
11 . The method of claim 1 including reducing the turbulence in the water in the reactor while the activated carbon is fluidized therein and avoiding the formation of a gas in the reactor by dissolving ozone molecules in the water prior to the water entering the reactor.