ITVT20110013A1 - ENRICHMENT OF ANTIMICROBIAL INSITE PROPERTIES IN THERMAL WATERS - Google Patents

Description

TITLE: â € œProcess for the enhancement of antimicrobial properties inherent in thermal waters "

Summary

The use of thermal waters in swimming pools for bathers raises the problem of reconciling disinfectant treatments with the maintenance of the natural properties of the spring. The management of health and hygiene risks is in principle similar to that of water for recreational use in swimming pools, but the use of traditional procedures and / or chemicals for disinfection, such as the use of chlorine, not only it is complex and sometimes ineffective, but also risky due to the production of potential toxic derivatives. Similar problems can arise from the use of treatments with physical agents, such as UV rays. We have identified natural antimicrobial properties in thermal waters and developed strategies to enhance this disinfectant power naturally present at the source. We claim the application of systems for the enrichment and / or regeneration of antiseptic properties of thermal waters through various methods and their use in the sanitizing treatment of water in pools for recreational use.

Description of the invention

State of the art

The thermal water pools used for bathing for both therapeutic and recreational purposes (hereinafter referred to as â € œRecreational thermal poolsâ €) are fed by thermal springs normally free of microorganisms harmful to man. These springs supply high temperature water, rich in salts (fixed residues at 180 ° C usually above two grams / liter), often containing high values of sulphides, iodides and bromides. The thermal waters acquire these characteristics coming from the depths of the earth's crust and in conditions in which encountering high pressures and in the presence of gases and various minerals at very high temperatures involves a modification in the composition of the water. These characteristics have been used since ancient times for their beneficial properties, and the Italian and European territory includes numerous spas. The uses are manifold, including douching, mineral water treatments, aerosols, mud therapies, etc., but this patent refers to applications in tubs of the recreative hydrotherapy type. In this context it is a question of use in the pool, both for rehabilitation or motor re-education purposes, and for play. If the water used to supply the tanks is initially from the microbiologically safe source, however, following the introduction into the tank and the presence of bathers and / or other sources of external contamination, there is a deterioration of the hygienic-sanitary quality and the water in the tub can pose a health risk if not properly managed. Currently this problem is fundamentally controlled by increasing the reintegration, with chemical disinfectants or physical treatments, respectively such as chlorine, bromine, or, for example, treatment with ultraviolet rays.

The presence of bathers in these recreational thermal pools is an element of contamination which consequently requires adequate spare parts per hour or sanitation / disinfection procedures in order to guarantee the safety of bathers, as also required by some Italian regulations and / or recommendations. from other countries (1, 2). Insufficient levels of sanitation safety can be the cause of epidemics (3). This problem has been addressed in detail by the World Health Organization and described in the guidelines for healthy aquatic environments for recreational use (1). In swimming pools for recreational, non-thermal use, the health problem is effectively solved through well-established and widespread procedures, such as chlorination. However, the use of chlorine in thermal waters, or of other chemical products, can favor the formation of derivatives by interacting with the naturally present salts, and altering the mineral composition of the thermal water with serious impacts on the possible therapeutic effects. they are attributed as well as with counterproductive effects due to the generation of unwanted and potentially dangerous products (2). The problem has already been considered from different points of view and alternative systems have already been proposed such as filtration or based on irradiation with LTV rays. They can be effective, but they involve a series of problems, including mainly the fact that unfortunately they cannot guarantee a residual disinfectant action that therefore further protects users â € œin the tubâ € (3). Therefore, currently, the most widespread practice to maintain adequate hygienic and sanitary levels in recreational thermal baths in respect of natural properties, is that of reintegration: in fact, the introduction of new thermal spring water acts both through the principle of dilution of pollutants and through the restoration of natural characteristics. However, the reintegration involves very serious consequences connected with the environmental damage due to excessive mining, in addition to the costs for the supply, and the problems connected with disposal.

Technical problem

The technical problem consists in the impossibility to date of being able to maintain the natural properties of the thermal waters present in recreational thermal pools, while ensuring their hygienic-sanitary safety, that is, without adulterating them with foreign chemicals or with other artificial disinfection procedures based, for example , on irradiation with physical agents.

Furthermore, the other solution commonly adopted and based on raising the reintegration percentages also involves complications. In fact, since the massive reintegration of the recreational thermal baths with spring water causes the depletion of the thermal aquifer, with consequent environmental damage, and higher management costs per plant, it is urgent to provide managers with adequate disinfection tools that are compatible with the natural and medicinal chemical / therapeutic characteristics of these waters. As evidenced by the state of the art, in fact, the treatments traditionally used and consolidated for non-thermal swimming pools are based on chlorination, or, more generally, on highly oxidizing treatments. This approach in thermal waters with a high concentration of salts and / or sulfur and other specific components, on the other hand, becomes extremely problematic, less effective and also counterproductive as it is harmful to the system due to precipitation phenomena, as well as potentially dangerous due to the products. of degradation that can be generated.

The solution to the technical problem was found through the use of:

1. systems for the concentration of the saline component of thermal water and subsequent solubilization in the water entering the tank;

2. systems for the enrichment of thermal waters through the reuse of the gaseous component of the thermal spring also by bubbling in the recirculation / injection water into the pool;

3. thermal energy naturally present at the source for the pasteurization heat treatment of the water in recirculation, both in counter-current and in bubbling chambers and with other tools useful for the purpose.

Therefore, integrated systems based on the use of the systems indicated in points 1, 2, 3 can be developed and fall within the scope of the present invention.

The present invention consists in the method for enriching the natural antimicrobial characteristics of the thermal waters, and therefore their safe use for bathing purposes, through a withdrawal of the water, treatment and reintroduction in the tub of the components of the thermal water as illustrated. in Figures 1 and 2.

With particular reference to Figure 1, it illustrates a first embodiment of the invention in which a thermal bath (A) for recreational or hydrotherapeutic use is fed with thermal water coming from a thermal spring through the duct (C). Part of this thermal water is conveyed through the duct (D) to module (E) in which it is subjected to the enrichment treatments of the invention identified in points 1, 2, 3 above, to then be re-introduced into the tank ( A) to sanitize it.

According to an alternative embodiment of the invention, illustrated in Figure 2, the water that feeds the thermal bath (A) and that comes from the source (C) is partly added to the module (E) to be treated according to the procedures of the present invention indicated in points 1, 2, 3 above. At the same time the water of the tank (A), which needs sanitization following its use, previously filtered in (F) in a known way, is also fed to the module (E) to be mixed with the water source pre-treated in order to be sanitized, after which it is re-introduced into the tank (A).

Some methodologies for the treatments according to the present invention are given below by way of example: to enrich the natural characteristics of thermal waters, we proceed by taking thermal water and treating it through various methods including, but not exhaustively, with the following methods:

â € ¢ evaporation, (it is an evident process in itself, see Evaporation entry in the Treccani Encyclopedia, and / or the link http://www.treccani.it/encyclopedia/evaporazione).

â € ¢ filtration on ion exchange cartridges, (http://it.wikipedia.org/wiki/Resina_a_scambio_ionico)

â € ¢ Reverse osmosis of the salts present, (http://it.wikipedia.org/wiki/Osmosi_inversa)

â € ¢ bubbling of gases produced at the source and suitably conveyed to the system, coming from pipe C and released by bubbling in module E.

For the natural disinfection of swimming pools fed with thermal water and / or thermal recreational pools, this water, enriched and renewed through the appropriate treatments indicated above, is reintroduced into the circulation and into the pool. Furthermore, even the same natural characteristic connected with the high temperatures at the source can be used for water pasteurization treatments and require lower energy consumption for heating. The heat at the source of those thermal waters that allow it, which are at a high temperature, is used for pasteurization according to methods known to those in the sector (see Encyclopedia Treccani, and / or http://www.treccani.it / encyclopedia / pasteurization / and / or http://it.wikipedia.org/wiki/Pasturization).

This integrated, natural and highly sustainable approach finally allows the use of natural treatment and disinfection methods, which respect the chemical-physical conditions of the thermal water and do not adulterate it with chemical products or processes extraneous and artificial to the composition of the thermal water. , which is characterized, among other things, by the co-presence of salts, sulfur, and high temperatures at the source, which are used here following the enrichment and disinfectant treatment processes.

The application of these properties through suitable devices achievable with any of the technologies available, and already known, manifests evident benefits to the technicians of the sector in terms of environmental sustainability, health and hygiene safety, safeguarding compatibility with the natural, therapeutic and medicinal properties of the thermal waters. In particular, moreover, the reduction in the need for reintegration has an impact on the costs of exploiting the mineral resource with implications for the protection of the aquifer, as well as, among other things, causing a reduction in the elimination of waste water in the environment.

Personal observations and experimental tests have allowed us to consider the potential of a bacteriostatic effect and an obstacle to the growth of microorganisms inherent in the salty-sulphurous thermal waters. Moreover, these waters may contain some salts such as bromine and iodine compounds, which are already well known for their bactericidal characteristics. In addition, other parameters converge in supporting a potential antiseptic effect of the salty-sulphurous thermal waters. Thermal waters and drinking water controls were experimentally contaminated with known charges of microbial indicators and incubated at 37 ° C, according to standard protocols. The microbial count at different times between 6-18 hours showed a reduction in bacterial growth between 70 and 30% already in the presence of processes of natural enrichment of the antiseptic properties even of minimal intensity (eg: variations of less than 10 %).

The high salinity (as known to the expert in the sector, mineral water meets the legal criteria established by Legislative Decree 25/1/1992 n.105 (modified by Legislative Decree 339/99 in implementation of Directive 96/70 / EC, for individual anions and cations see http://it.wikipedia.org/wiki/Acqua_minerale), in fact, represented by salts of manganese, magnesium, calcium, iron, aluminum, sodium and potassium, or carbonates and / or other, as well as the presence of sulfur contribute to the antiseptic value of these waters (4-6). For this reason, natural disinfection / treatment systems are proposed that are based on the properties inherent in thermal spring waters, that is : presence of salts, high temperature, sulfur.

The proposed solution appears particularly suitable for the management of thermal waters in swimming pools, as it ensures the maintenance of the natural composition typical of that thermal water. Obviously, the treatment will be customized on the basis of the composition and starting concentration of the water, but the methods of analysis and the threshold values are already known to the technicians of the sector. Moreover, given the natural presence of potentially disinfectant substances in the thermal waters, the devices that reintegrate and enrich these natural salts and gases, (also exhausted due to the same exposure in the bathing tub to air and bathers), allow the re-use allowing an optimizable recirculation and a consequent significant reduction of external massive supply.

The proposed invention relates to a water treatment process that integrates elements never used for thermal waters and that in the application to swimming pools and thermal recreational tubs provides a system for the natural treatment of the water present in the recreational thermal pools and their subsequent reintroduction into the bathing pool. The restoration of the initial chemical characteristics of these waters takes place through a water conveyance system described in the figure and built according to the principles known for the hydraulics and plant engineering of swimming pools (Eg: Hygiene in the Pool, publisher II Campo, 2007; and / or Swimming pools. Design. Construction. Maintenance. Publisher Flaccovio Dario, 2009), equipped with adequate buffer cells where there are chemical concentrates of the native substances present in the thermal spring (Eg: ISSN 1123-3117 ISTISAN reports 07/11 ; and / or Igiene in Piscina, publisher II Campo, 2007; and / or Piscine. Design. Construction. Maintenance. Publisher Flaccovio Dario, 2009; and / or http://it.wikipedia.org/wiki/Cloro). These combinations of substances are prepared in such a way as to be effectively solubilized in the water that passes through, through standard procedures known to experts in the field. For example, this solubilization could be favored among other things by electrochemical and / or thermal processes (eg. Http://it.wikipedia.org/wiki/Elettrolisi; and / or http://it.wikipedia.org/ wiki / Solution_ (chemistry)). The invention also provides for the rebalancing of the gases that are naturally dissolved in the spring water, strengthening their natural properties that would otherwise be depleted by the storage in water and environmental exposure.

The following examples are illustrative of the invention and are not to be considered as limiting its scope.

Example 1. Effect of the thermal water enrichment process on

proliferation of human-originated bacteria

In order to test the growth and proliferative capacity of human-originated bacteria, the following experiment was performed on a sampling of thermal water from four different thermal sources in central-northern Italy. All the thermal waters sampled came from hot thermal sources, had different chemical compositions as shown in Table 1 and had a fairly high fixed residue (between 2.5 to 3.3 g / 1) at 180 ° C. Sampling was performed in sterile glass bottles immediately sealed to prevent leakage of dissolved gases (or any contamination). Determinations of temperature, pH and hydrogen sulfide were performed during sampling and / or subsequently in the laboratory.

Table 1

Selected water samples

SSC SBA AI SW

Temperature at source 67 ° C 54 ° C 41 ° C 23.9

pH at 180 ° C 6.8 6.5 7.4 6.45 Fixed residue at 2.5 g / 1 3.3 g / 1 2.9 g / 1 2.9 g / 1 180 ° C

H2S 18 mg / 1 2 mg / 1 0.0 mg / 1 29 mg / 1 Iodine 2 mg / 1 <0.01 mg / 1 <0.01 mg / 1 0.07 mg / 1 Bromine 5 mg / 1 < 0.1 mg / 1 0.6 mg / 1 <0.1 mg / 1 Sodium 600 mg / 1 30 mg / 1 38 mg / 1 173 mg / 1 SBA = sulphurous water alkaline bicarbonate earthy;

SSC = alkaline earthy sulphurous water rich in sodium chloride, bromine and iodine;

AI = water rich in arsenic and iron;

SW = water containing high levels of hydrogen sulfide (SW).

The experiments were also performed using a sample of Tyrrhenian sea water filtered with a 0.22 Î1⁄4m filter and bottled mineral water of various national brands (fixed residue at 180 ° C: 0.2-0.4 g / 1; pH 7, 1-7.3). The analyzes of the water samples were performed according to the official methods in force in Italy (APAT-IRSA CNR, 2003; ISS, 2007).

Bacterial strains used

Strains of E. coli ATCC 35218 and E. faecalis ATCC 7080 in TSB medium (DIFCO Laboratories, USA) were used as bacteria of human origin.

In vitro contamination of thermal and non-thermal water samples

Execution of the essay

50 ml of each aforementioned water sample was inoculated with 200 bacterial cells and incubated for 24 hours at 37 ° C without shaking. At the time of inoculation (tO) and at the end of the 24 hours of incubation, triplicate aliquots were collected for each sample which were filtered with 0.45 mm filters and transferred in a sterile environment on agar plates containing the TSA culture medium. (E. coli) or SB (E. faecalis) (Oxoid). Agar cultures were incubated at 37 ° C for 18 hours before proceeding with the bacterial count.

Aliquots of uninoculated water were used for the control of the basic bacterial load. The results obtained were normalized with respect to those obtained with bottled mineral water. The results obtained with E. coli were very similar to those obtained with E. faecalis.

Results

Samples of bottled mineral water have always been shown to have the highest E. coli charge 24 hours after inoculation with this bacterium. The results are shown in Table 2.

Table 2

Reduction of microbial load (%)

water samples

Time (h) BNM SSC SBA SEA AI SW

0 100 (± 5) 100 (± 10) 100 (± 8) 100 (± 1) 100 (± 15) 100 (± 5) 24 1 10 79 ± 3 70 ± 10 16 ± 12 145 ± 3 7 ± 15

All the thermal waters, except in the case of the non-sulphurous water sample AI (water rich in arsenic and iron), showed a reduction in the inoculated bacterial load ranging from 22-27% (SSC and SBA) to 84-91% (sea water and SW). As already mentioned above, the results obtained with E. faecalis were very similar and will not be shown here. These results clearly show that thermal waters, in particular those containing sulfur, possess bacteriostatic activity on bacterial strains of human fecal origin.

Example 2. Enrichment and disinfectant treatment of thermal waters

A 1000 ml sample of thermal water (SW = hypothermic water containing high levels of hydrogen sulphide) was taken at the source as already described above. The sample was then subjected to concentration by evaporation until a volume concentration of about 30% was obtained. The volume of treated thermal water thus obtained (about 700 ml) was combined with 1000 ml of recycled thermal water from the tank (contaminated water; average bacterial load between 200-500 CFU / 100ml). The thermal water thus treated (1000 mi 700 mi) was then also subjected to bubbling with the gases (hydrogen sulphide) collected at the source of the thermal water at temperatures ranging between 25 and 35 ° C (thermal temperatures) and the bacterial load was again analyzed.

The results of the bacterial analysis indicated that the sanitizing effect of the treated thermal water was able to reduce the bacterial load of the pool water (reduction of the microbial load by> 70-100%).

Essential bibliographic references

1. Liguori G, Naples C, Romano Spica V, Motor Sciences for Health GL. World Health Organization Guidelines for swimming pools and similar recreational water environments: Italian translation by thà ̈ Siti Working Group "Enhancing health and physical activity". Ig Health Public. 2009; 65 (5): 507-16.

2. Signorelli C, Pasquarella C, Saccani E, Sansebastiano G. Treatment of thermal pool waters. lg Public Health 2006 Sep-0ct; 62 (5): 539-52.

3. Costa J, da Costa MS, Verissimo A. Colonization of a therapeutic spa with Legionella spp: a public health issue. Res Microbiol. 2010 Jan-Feb; 161 (l): 18-25.

4. Koski TA, Stuart LS, Ortenzio LF. Comparison of chlorine, bramine, lodine as disinfectants for swimming pool water. Appi Microbiol. 1966 Mar; 14 (2): 276-9.

5. Celerier P, Richard A, Litoux P, Dreno B. Modulatory effects of selenium and strontium salts on keratinocyte-derived inflammatory cytokines. Arch Dermatol Res. 1995; 287 (7): 680-2.

6. Akiyama H, Yamasaki O, Tada J, Kubota K, Arata J. Antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis patients. J Dermatol Sci. 2000 Nov; 24 (2): l 12-8.

Claims (5)

CLAIMS 1. Process for the sanitation and disinfection of pools of water fed by thermal springs that can be used for bathing for therapeutic and recreational purposes, in which the contaminated water is placed in contact with an aliquot of thermal water taken from the source and previously subjected to a concentration treatment of the saline component with a method chosen from evaporation, filtration on ion exchange cartridges, reverse osmosis and related combinations and subsequent re-introduction of the treated water into the circulation of its normal use . 2. Process according to claim 1 in which the water to be returned to the tub is subjected to bubbling of the gaseous component present in the thermal source. 3. Process according to any one of claims 1-2 in which the water to be returned to the tank is subjected to pasteurization carried out at the temperature of the thermal spring. 4. Use of thermal waters taken from the source and subjected to a process of concentration of at least 10% to sanitize and disinfect contaminated bathing waters. 5. Use of the gaseous component of thermal waters taken from the source to sanitize and disinfect contaminated bathing waters.