Method for treating water by ballast flocculation and settling, comprising precontacting water with an adsorbent

Abstract

The invention relates to a method for treating raw water laden with impurities in a treatment facility including at least one step of placing water in contact with a powdered adsorbent agent in an agitated pre-contact area (2), a step of ballasted flocculation, a step of settling, extracting a mixture of sludge, ballast and the powdered adsorbent agent from the bottom of the settlement area (5), and inserting the mixture in a hydrocyclone (11), transporting the overflow consisting of a mixture of sludge and powdered adsorbent reagent from said hydrocyclone (11) to a transition area (14). The method also includes a step of recycling the mixture of sludge and powdered adsorbent agent from the transition area (14) in the pre-contact area (2), continuously measuring at least one datum showingthe concentration of powdered adsorbent agent in the pre-contact area (2), and a step of injecting a suspension of new powdered adsorbent agent in an aqueous medium upstream when the concentration ofpowdered adsorbent agent in the pre-contact area (2) is below a predetermined threshold value, as well as a step of acidifying said suspension of adsorbent agent.

Description

technical field [0001] The invention belongs to the field of drinking water treatment. The field of the invention also relates to industrial water treatment and tertiary wastewater treatment containing adsorbent materials in order to purify the water and in particular reduce the concentration therein of agents with endocrine disrupting effects. [0002] Still further, the present invention relates to a physicochemical treatment of water comprising solid-liquid separation using ballasted flocculation and settling. Background technique [0003] The physicochemical treatment of water, whether it is used to make surface water, karstic water etc. potable or to purify municipal or industrial waste water, is carried out by a process comprising a succession of steps. [0004] This type of treatment generally includes a coagulation step. Coagulation initiates the coalescence of colloidal particles suspended in water. This is generally achieved by introducing the water to be treate...

AI Technical Summary

Problems solved by technology

[0020] In addition to poor adsorption reagent supply control causing problems related to the quality of the water produced, it also causes economic problems

[0021] Insufficient supply of adsorbents leads to production of water of average quality, where improvement in quality level requires use of supplementary treatment at additional cost

[0022] An oversupply of adsorption reagents represents excessive consumption, which in itself creates additional costs

[0023] Additionally, given the relatively mediocre quality of water produced in the presence of an oversupply of sorbent reagents, it is also necessary to use supplemental treatment, which has a negative impact on overall water treatment costs

[0024] Finally, poor sorbent supply control generally results in average quality water produced and / or increased water treatment costs

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