Optimised Composition for Reducing Water Evaporation and Preventing and/or Delaying the Growth of Microalgae

Abstract

The present invention relates to an optimised composition for reducing water evaporation and for preventing and/or N delaying the growth of microalgae, which is an organic microlayer comprising one or more hydrophobic-chain amphiphilic molecules and a biodegradable volatile organic solvent. In addition, the invention relates to a method for reducing water evaporation and for preventing and/or delaying the growth of microalgae, by applying said composition to aqueous surfaces.

Claims

1. A composition optimized to reduce water evaporation and to prevent and/or retard microalgae growth CHARACTERIZED in that it comprises: a) one or more amphiphilic molecules with a hydrophobic chain of 12 or more carbons, at a concentration between 0.001-10 g/L, and b) a biodegradable organic volatile solvent, at a concentration of between 0.1-10 g/L.

2. The composition according to claim 1, CHARACTERIZED in that the amphiphilic hydrophobic chain molecules of 12 or more carbons comprise at least one polar group of the alcohol, carboxylic, amine, amide, ether or ester type.

3. The composition according to claim 1, CHARACTERIZED in that the amphiphilic hydrophobic chain molecules of 12 or more carbons are selected from fatty alcohols and/or fatty acids with long chains of hydrophobic hydrocarbons, such as hexadecanol, octadecanol, (poly)ethylene glycol mono-octadecyl ether, glycol stearate, stearyl citrate, among others.

4. The composition according to claim 1, CHARACTERIZED the biodegradable organic solvent is selected from among the type aromatics, chlorinated hydrocarbons, alcohols, ethers, esters, glycol derivatives, chlorofluorocarbons, miscellaneous.

5. The composition according to claim 4, CHARACTERIZED in that the esters are selected from methyl acetate, ethyl acetate, butyl acetate, among others.

6. The composition according to claim 1, CHARACTERIZED in that it further comprises: a) a polymer salt of natural origin, at a concentration of between 0.01-100 mM; and. b) an inorganic salt or bivalent salts, at a concentration of between 0.1-100 mM.

7. The composition according to claim 6, CHARACTERIZED in that the water-soluble polymer salt of natural origin comprises at least one polar functional group of alcohol, carboxylic, amine, amide, ether or ester type, which interact with the polar group of the amphiphilic molecule.

8. The composition according to claim 6, CHARACTERIZED in that the water-soluble polymer salt of natural origin is selected from sodium alginate, sodium gum arabic, chitosan acetate, chitosan chloride, sodium carboxymethyl cellulose, among others of similar structures.

9. The composition according to claim 6, CHARACTERIZED in that the inorganic salt or bivalent salt is selected from sea salt, comprising magnesium sulfate, calcium chloride, among others.

10. The composition according to claim 1, CHARACTERIZED in that the amphiphilic hydrophobic chain molecules of 12 or more carbons comprise a mixture of hexadecanol and octadecanol.

11. The composition according to claim 10, CHARACTERIZED in that it comprises a mixture of hexadecanol and octadecanol in a ratio of 1:1, dissolved in ethyl acetate, at a concentration of 1 g/L.

12. A method to reduce water evaporation and to prevent and/or retard microalgae growth, according to all of the preceding claims, CHARACTERIZED in that the composition is applied on aqueous surfaces, between 1 to 30 liters of the composition per hectare.

Description

FIGURES

[0028] FIG. 1 corresponds to a graph comparing the percentage of water remaining over time when applying different compositions, such as, Comp. 1: octadecanol dissolved in acetic acid, at a concentration of 1 g/L; Comp. 2: octadecanol and hexadecanol, at a concentration of 1 g/L, dissolved in acetic acid; Comp. 3: diethylene glycol monooctadecyl ether dissolved in acetic acid, at a concentration of 1 g/L; and the control: potable water. The graph represents the amount of water remaining after exposure to room temperature for a period of 31 days.

[0029] FIG. 2 corresponds to a graph where the variation of the total water height over time is measured in different vessels. The black rhombuses correspond to the control (vessel with potable water only). The white triangles correspond to the vessel with potable water and the composition Comp. 2.

[0030] FIG. 3 corresponds to a biotoxicity analysis of the composition Comp.2. The table summarizes the CFU/mL count of the three microbial cultures, namely Staphylococcus aureus, Escherichia coli DH5-α and Candida albicans, in the presence and absence of the Comp.2 composition, at a temperature of 37° C.

[0031] FIG. 4 corresponds to a graph where the change in water coloration in different vessels is measured. The black bars correspond to the control (vessel with potable water only). The white bars with dots correspond to the vessel with potable water and the Comp. 2 composition.

[0032] FIG. 5 corresponds to a graphical representation of the comparison of different vessels of 61 L each. A) corresponds to the control vessel (vessel with potable water only). B) corresponds to the vessel with potable water and the Comp. 2 composition.

EXAMPLES

Example No 1. Analysis of Different Compositions to Reduce Water Evaporation

[0033] In order to identify the best composition to reduce water evaporation, a comparative analysis was carried out between three different compositions, and the water evaporation reducing effect was measured. These compositions were: Comp.1 (octadecanol dissolved in acetic acid, at a concentration of 1 g/L), Comp. 2 (octadecanol and hexadecanol, at a concentration of 1 g/L, dissolved in acetic acid), Comp. 3 (diethylene glycol mono-octadecyl ether dissolved in acetic acid, at a concentration of 1 g/L), and the control (vessel with only potable water).

[0034] Each composition was analyzed in quadruplicate to determine the effectiveness in preventing water evaporation over a period of 31 days. Measurements of the remaining water in each vessel were taken every 2 to 3 days.

[0035] From the measurements performed, it can be observed that when comparing the control (water only) with the different compositions analyzed, the Comp. 2 composition prevents a greater evaporation of water, reaching between 70 and 80% reduction of water evaporation, as shown in FIGS. 1 and 2.

[0036] Likewise, it can be observed that the Comp.2 composition allows reducing water evaporation for a longer period of time than other compositions analyzed. This may be due to the fact that the Comp.2 composition has a combination of hydrophobic chains that are highly compact, which provides greater rigidity and separation between the hydrophobic and polar regions. For this reason, the inventors chose the Comp.2 composition as the one that allows to reduce the percentage of water evaporation in the highest amount.

Example No 2. Analysis of the Effect of Comp.2 Composition to Reduce Water Evaporation

[0037] In order to determine the effectiveness of the Comp.2 composition in reducing water evaporation, measurements of water height variation in different vessels were carried out.

[0038] For this purpose, two different plastic vessels of 61 L each were used, which were filled with potable water to a height of 20 cm. Subsequently, the Comp.2 composition was added to the surface of the water in one of the vessels. The control vessel corresponds to the vessel with potable water without the Comp.2 composition.

[0039] To measure the effect of the Comp. 2 composition in reducing water evaporation, a period of time of 1 month was allowed to elapse under the same environmental conditions (sun, temperature, wind, etc.).

[0040] In addition, measurements were done to the temperature range that fluctuates during the course of the day and night. Maximum temperatures fluctuated between 33° C. and 18° C., and minimum temperatures fluctuated between 13° C. and 4° C.

[0041] As can be seen in FIG. 2, the vessel containing the Comp. 2 composition on its surface, only showed 25% evaporation of water, compared to the vessel not containing the Comp. 2 composition on the surface, where 75% evaporation was detected.

[0042] Thus, it can be seen that the Comp. 2 composition generates a surprising effect, since it considerably reduces water evaporation.

Example No 3. Safety Analysis of the Comp. 2 Composition

[0043] In order to determine whether the Comp. 2 composition is toxic or not, a biotoxicity analysis of this composition was carried out. For this purpose, the growth of different microorganisms such as Staphylococcus aureus, Escherichia coli DH5-α and Candida albicans was analyzed in different cultivation media in the presence and absence of the Comp. 2 composition, at a temperature of 37° C., as shown in FIG. 3.

[0044] Subsequently, aliquots of the different cultivation media were taken for serial dilutions, which were then seeded on LB agar and PDA agar plates, at a temperature of 37° C.

[0045] According to the results obtained, the three cultivations of Staphylococcus aureus, Escherichia coli DH5-α and Candida albicans, were viable both in the presence and absence of the Comp. 2 composition, at a temperature of 37° C.

[0046] Thus, it can be concluded that the Comp. 2 composition is not toxic to any of the three microorganisms.

Example No 4. Effect of Comp.2 Composition to Prevent and/or Retard the Microalgae Growth

[0047] In order to determine the effect of the Comp. 2 composition in preventing and/or retarding the microalgae growth, the coloration of the water in different vessels was measured.

[0048] For this purpose, two plastic vessels of 61 L each were used, which were filled with potable water to a height of 20 cm. Subsequently, the Comp. 2 composition was added to the surface of the water in one of the vessels. The control vessel corresponds to the vessel with potable water without the Comp. 2 composition.

[0049] To measure water coloration, a period of 1 month was allowed to elapse under the same environmental conditions (sun, heat, wind, etc.), taking samples every 7 days, which were measured qualitatively and quantitatively.

[0050] As can be seen in FIGS. 4 and 5, surprisingly, the Comp. 2 composition prevents and/or retards the microalgae growth. Thus, the use of the Comp. 2 composition avoids incurring additional expenses, such as the use of filters or other chemical agents such as algaecides, which are toxic both for the environment and for human consumption.