FR2859634A1 - Method of eliminating legionella bacteria from hot water systems using a cartridge partially filled with granules consisting of activated silica and iron and manganese oxide particles - Google Patents

Abstract

A method of continuous elimination of aerobic bacteria, especially amoebae and legionella in a pH neutral medium in hot water circuits by passing the water through a cartridge containing a catalytic mass consisting of granules capable of rubbing against one another by the action of the water flow consisting of anionic activated silica compounds and metal particles especially of iron oxide and manganese oxide bearing opposing electromagnetic charges. The dipolarization leads to the contraction of the calcium and bicarbonates present in the flow of water in colloidal form and the formation of minute seeds of cationic calcium carbonate which attract small particles of silica detached from the granules by the rubbing action to form around them an anionic belt capable of absorbing in its turn the cations, especially calcium cations present in the water penetrating the bacterial cells by electromagnetic attraction.

Description

The present invention relates to a method for the elimination of

  continuous aerobic bacteria including amoebae and legionella in neutral pH medium in individual or collective domestic hot water circuits and the simultaneous descaling of these circuits.

  In many regions the raw water is loaded with salts including calcium and have a high content of bicarbonate ions HCO3- (limestone or hard water) which, under certain conditions, especially following a rise in temperature, tend to precipitate in form calcium carbonate very little soluble, which is the scale.

  In addition to this drawback, domestic hot water circuits can lead to the proliferation of aerobic bacteria such as amoebae and legionella that can be very dangerous for health.

  Indeed, domestic hot water installations are equipped with boilers raising the temperature of the water to average values of 30 to 45 C.

  However, at this temperature, the bacteria present in the water, in particular amoebae and legionellae, can develop very rapidly, thus making the users run a real risk.

  Specialists know, especially that from the threshold of 106u.f.c. (colony forming units) per liter of water, Legionella can invade human macrophage cells, ie blood cells intended to destroy intruders, and neutralize them by multiplying, causing finally their destruction.

  Amoebae carry legionella, the harmful nature of which is well established: in fact, these bacteria have the particular ability to survive within certain unicellular eukaryotes as intracellular parasites.

  Legionellae also have the particularity of having a very fast nesting, of the order of 4 hours in vivo.

  To stop these bacterial proliferations, it has been proposed to perform chlorine injections, accompanied by regular thermal shocks to 70.

  However, legionellae, which are gram-negative saprophytes (ie having a complex cell wall and a second outer phospholipid membrane) are protected against chlorine attack by amoebae inside. which they live.

  As a result, when chlorine injections are stopped, legionella colonies quickly reappear, as their protective habitat has not been affected by chlorine.

  It should also be noted that such injections of chlorine accompanied by thermal shocks are dangerous for the pipes as well as for the users, and moreover expensive in thermics, except if computerized heat recovery apparatuses are used but very expensive and sophisticated, so likely to fail.

  To destroy the bacteria present in the hot water circuits, it has also been proposed, copper-silver processes which always present a danger of overdose higher than European standards and also have no effect on scaled circuits.

  The object of the present invention is to remedy these drawbacks by proposing a method for the continuous elimination of aerobic bacteria, in particular amoebae and legionella in neutral pH medium, in domestic hot water circuits, without chlorine or thermal shock, and to simultaneously obtain a descaling of these circuits.

  According to the invention, this process is characterized in that the flow of water circulating in the circuit to be treated is continuously passed through at least one cartridge containing a catalytic mass constituted by granules capable of rubbing the against each other under the action of the flow of water in circulation.

  According to the invention, it is possible to provide either a single cartridge or, particularly for higher throughput installations, several cartridges mounted in series so as to increase the efficiency of the process.

  The granules constituting the catalytic mass are on the one hand essentially composed of anionic Si 3 O 12 activated silica and on the other hand contain metal particles, preferably iron oxide particles and polarized manganese oxide particles carrying electromagnetic charges. of opposite sign.

  The presence of these metal particles creates, within the catalytic mass, a dipolarization likely to cause the contraction of calcium and bicarbonates present in the flow of circulating water, mainly in colloidal form, and consequently the formation of tiny seeds. cationic calcium carbonate.

  During their formation and passage through the catalytic mass, these seeds attract small silica particles which are detached from the granules under the action of their friction against each other to form an anionic belt around these germs.

  This anionic belt is in turn capable of absorbing the cations encountered, and in particular the cations, in particular the calcium ions contained in the water penetrating into the bacterial cells present in the flow of water flowing in the circuit to be treated. by electromagnetic attraction.

  The seeds thus coated with a silica belt have in fact a very strong sequestering power vis-à-vis the cations encountered.

  As a result, there is observed within the circulating water flow a rapid growth of very light expanded crystals resulting from the continuous incorporation of cations into their crystalline structure.

  These crystals, which originally have a six-sided garnet-like hexagonal structure, lengthen during their development to become orthorhombic.

  It is thus possible to quickly eliminate scale because of the rapid development of non-incrusting expanded and light crystals due to the continuous incorporation of calcium ions into the crystal structure of these crystals.

  These crystals, very light and very expanded can not indeed be deposited on the walls of the pipes and the bottom of the water heaters and boilers, and can be eliminated by simple rinsing.

  The essential advantage of the process according to the invention is, however, linked to the fact that it makes it possible to continuously eliminate aerobic bacteria, and in particular amoebae and legionella present in the flow of water circulating in the circulating circuit. treat.

  Amoebae are in fact proteinaceous structure bacteria consisting of extremely elastic deformable cells.

  Any hardening of the walls and any blockage of the membranes of these cells removes the ability to move and feed by phagocytion.

  However, the water entering the amoeba with decomposing elements (algae and plant particles of all kinds) carries crystals consisting of cationic seeds surrounded by an anionic S13O12 silica belt which absorb the calcium present. in these residues and hinder the mechanism of operation of the amoeba following the accumulation of limestone clusters in its internal body.

  As a result, it bursts for lack of elasticity.

  Indeed, the salinity of the amoeba increases compared to that of the surrounding aquatic environment, it can no longer compensate for differences in pressure and splits into multiple pieces from where its destruction.

  Legionellae, which, as already mentioned, live harmlessly in most amoeba species, use in their metabolism amino acids such as cysteine, in combination with certain trace elements of which calcium mixed with iron and magnesium, that is to say cations attracted by the anionic silicas surrounding the germs forming in the flow of water circulating in the circuit to be treated.

  As a result, cations such as calcium and magnesium which are fed legionella, through the water entering the amoeba are incorporated into stable structures.

  The growth of Legionella is thus halted and the colonies are quickly destroyed by lack of the necessary conditions for their reproduction.

  The process according to the invention thus makes it possible to effectively and efficiently remove two varieties of aerobic bacteria, namely legionella, which is very dangerous for humans, and amoebae which are less harmful, but convey the legions while protecting them.

  The very particular efficiency of the process according to the invention is essentially related to the very large proportion of silica in the catalytic mass.

  This proportion makes it possible, thanks to the combined action of metals of opposite sign, almost instantaneous formation, around cationic seeds, of anionic elements having a very high sequestering power with respect to all the cations encountered.

  According to the invention, the granules constituting the catalytic mass may advantageously contain between 80 and 95%, preferably approximately 90% of activated silica in volumetric proportion.

  According to the invention, it has been possible to obtain particularly satisfactory results by using a catalytic mass having a bulk density of about 1.00 corresponding to a mass of about 1000 kg / m 3 and being in the form of hard balls. and homogeneous regularly calibrated 1.5 to 2 mm in diameter.

  By way of example, it is possible to use for this purpose catalytic beads which are currently on the market for the treatment of ferruginous waters free of limestone and essentially contain the following compounds: Fe2O3, CaCl2 and Ca3Mn2Si3O12.

  According to another characteristic of the invention, the flow of water to be treated from top to bottom is circulated in the cartridge containing the catalytic mass.

  This flow of water can also, without departing from the scope of the invention, circulate upwardly in the cartridge, in particular if it is installed in a filter body having a central water inlet and a diffusion outlet. lateral.

  According to another characteristic of the invention, the cartridge 15 is only partially filled with granules, preferably about 2/3 of its height.

  This cartridge may advantageously have a configuration substantially similar to that of the first cartridge of the installation described in the document FR-2 700 324, that is to say be constituted by a cylinder, in particular a synthetic material having about 20 cm height and 7 cm in diameter mounted at the middle portion of a container including synthetic material equipped with an upper inlet opening side so as to define at its periphery a sleeve receiving the water to be treated.

  Such a cartridge can thus be provided at its lower part with an inlet for the circulating water flow and at its upper part with a central outlet orifice.

  Going upwards to exit through the central upper orifice of the cartridge, the flow of circulating water passes through the granules which can advantageously be wrapped in a mesh with very flexible loosely mesh allowing the free circulation of the granules and their friction. against each other under the action of the flow of water.

  It is essential for this purpose that the cartridge is not completely filled with pellets.

Claims (8)

  1) A method for the continuous elimination of aerobic bacteria including amoebae and legionella in a neutral pH medium in domestic hot water circuits, characterized in that the stream of circulating water is continuously passed through the circuit to be treated through at least one cartridge containing a catalytic mass constituted by granules capable of rubbing against each other under the action of the flow of water in circulation, these granules being essentially composed of Si3O12 anionic activated silica and furthermore containing metal particles, preferably iron oxide particles and polarized manganese oxide particles carrying electromagnetic charges of opposite sign, so as to cause, under the action of this dipolarization, the contraction of calcium and bicarbonates present in the flow of circulating water essentially in colloidal form, and the formation of tiny germs They are of cationic calcium carbonate, attracting small particles of silica which become detached from the granules under the action of their friction against each other in order to form around these seeds an anionic belt capable of absorbing, in its turn, the cations including calcium ions present in the water penetrating the bacterial cells, by electromagnetic attraction.   2) Process according to claim 1, characterized in that the granules constituting the catalytic mass contain between 80 and 95%, preferably about 90% of activated silica in volumetric proportion.   3) Process according to any one of claims 1 and 2, characterized in that the granules constituting the catalytic mass are in the form of hard and homogeneous balls regularly calibrated from 1.5 to 2 mm in diameter.   4) Process according to any one of claims 1 to 3, characterized in that the catalytic mass has a bulk density of about 1.00 corresponding to a mass of about 1000 kg / m3.   5) Process according to any one of claims 1 to 4, characterized in that the granules constituting the catalytic mass essentially contain the following compounds: Fe203, CaCl2 and Ca3Mn2Si3O12.   6) Process according to any one of claims 1 to 5, characterized in that it circulates the flow of water from top to bottom in the cartridge containing the catalytic mass. to   7) Process according to any one of claims 1 to 5, characterized in that it circulates the flow of water from bottom to top in the cartridge containing the catalytic mass.   8) Process according to any one of claims 1 to 7, characterized in that it fills only partially the granule cartridge, preferably about 2/3 of its height.