Method of obtaining a coagulant product, product intended for manufacturing the said coagulant, and method of treating wastewater and/or industrial effluent using the said coagulant

Abstract

The invention relates to a method of obtaining a coagulant product. Characteristically, a raw material is prepared which contains the sludge resulting from the treatment of drinking water and an ore containing iron and/or aluminium, this raw material being subjected to acid attack for the purpose of forming iron salts, aluminium salts or a mixture thereof. This coagulant is employed in the realization of a physicochemical step in the treatment of wastewater and/or industrial effluent.

Description

technical field [0001] The present invention relates to a method for obtaining a coagulant product which can be used in particular for the treatment of sewage, whether municipal and / or industrial. Background technique [0002] Generally, a phosphorus removal step, especially a physico-chemical phosphorus removal step, is performed when treating sewage. For this purpose, precipitation is carried out with lime or salts containing trivalent ions, in particular with ferric chloride or aluminum chloride. In some regions, large quantities of ferric chloride (FeCl 3 ). [0003] At the same time, it is well known that when drinking water is treated, the final residues, especially drinking water sludge or sedimentation sludge, contain trivalent ion salts. In fact, in traditional steps for the treatment of water intended for consumption, coagulants based on trivalent ions, in particular of iron or aluminum, are used, so that the treated solid residue contains the aforementioned Es...

AI Technical Summary

Problems solved by technology

It is worth noting that the thermal method yields better recoveries, but it has to be said that this method is relatively expensive compared to the price of commercially available coagulants

[0014] A further disadvantage is that the implementation of one or the other of the above techniques requires the transfer of large volumes of drinking water sludge from a treatment station to a purification station or, more generally, to a where the coagulant is placed, this means that there are additional shipping costs to consider as well

And if the recovery method is carried out directly at the drinking water station, then the coagulant produced needs to be transferred to the purification station for use, which also involves considerable transportation costs

[0015] Moreover, in the aforementioned techniques, lime is often used in the dewatering step, which firstly causes costs associated with the purchase of starting materials and secondly does not adequately dehydrate a volume of material that can be transported economically

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