GB2539978B

GB2539978B - Electrolyzed water composition

Info

Publication number: GB2539978B
Application number: GB1518476.5A
Authority: GB
Inventors: Philip Gardner Stephen
Original assignee: Ozo Innovations Ltd
Current assignee: OZONE PURIFICATION LTD
Priority date: 2014-12-09
Filing date: 2015-10-19
Publication date: 2019-08-07
Anticipated expiration: 2035-10-19
Also published as: GB201518476D0; GB2539978A

Description

E lectrolyzed Water Composition

Field of the Invention

The present invention relates to an electrolyzed water composition, an apparatus and a method for preparing the electrolyzed water composition, and the use of the electrolyzed water composition within the agricultural or retail industry for example for extending the shelflife of cut flowers.

Background

There is a significant time delay, of upto 5 days, between flowers being cut and when a consumer purchases the cut flowers. After the initial cutting, the cut flowers may be packaged fora flight, flown into country and then shipped by road to a flower producer. The flowers are then processed by the flower producer, transported to a retail environment where the flowers are displayed on a shop floor, and then finally displayed in a consumers home. During this time the health of the flowers can begin to deteriorate, for example the flowers may wilt and/or the petals may fall off. This often happens due to the build-up of bacterial biofilms, which clog up the vascular system of the plantstems and prevent the free transport of water and nutrients through the plant.

The cut flowers are therefore typically stored, transported and displayed within the retail environment within a rehydration solution in order to minimise the deterioration of the flowers. Cut flowers are often guaranteed to remain in good health fora certain period oftime within the consumers home. It is therefore important that the rehydration solution is effective in maintaining the health of the cut flowers in orderto minimise any guarantee claims from the consumers.

There is therefore a need for an effective rehydration composition with improved antimicrobial efficiency, low associated energy and cost implications, and/or reduced environmental and health implications. There is a need fora rehydration composition for improving the shelf life of cut flowers. There is also a need fora method of treating and/or storing cut flowers which is quick, safe, cost effective, maintains the flowers” health over an extended time period and has reduced environmental implications.

Summary of the Invention

According to a first aspect the present invention provides a method for producing an electrolyzed water composition for ornamental preservation, the method comprising: preparing an electrolyte solution comprising at least one salt selected from alkali metal chloride, alkali earth metal chloride, or any combination thereof; at least one salt selected from alkali metal carbonate, alkali earth metal carbonate, at least one salt selected from alkali metal nitrate, alkali earth metal nitrate, and ammonium nitrate, or any combination thereof; and at least one salt selected from alkali metal phosphate and alkali earth metal phosphate, or any combination thereof; introducing the aqueous electrolyte solution into an electrolytic cell comprising a plurality of boron-doped diamond electrodes; and operating a power supply to apply a predetermined voltage to the electrolyte solution to produce an electrolyzed water composition comprising a plurality of active molecular and ionic species having rehydration activity, in which the mixture of at least four salts of the electrolyte are selected such that the electrolyzed water composition comprises a free accessible chlorine (FAC) concentration in the range of from 10 to 10,000 ppm, and/or a dissolved O3 concentration in the range of from 0.1 to 750ppm.

The electrolyte solution may be introduced into the electrolytic cell in a continuous or batch process manner.

The predetermined voltage may be in the range of between about 1 and 1000 volts DC.

The power supply may have a current in the range of between about 1 and 1000 ampere.

According to a second aspect, there is provided an electrolyte solution comprising: at least one salt selected from alkali metal chloride, alkali earth metal chloride, or any combination thereof; at least one salt selected from alkali metal carbonate, alkali earth metal carbonate, at least one salt selected from alkali metal nitrate, alkali earth metal nitrate, and ammonium nitrate, or any combination thereof; and at least one salt selected from alkali metal phosphate and alkali earth metal phosphate, or any combination thereof.

Preferably, the electrolyte solution comprises salts selected from the group comprising: alkali metal salts, alkali earth metal salts, ammonium salts, and any combination thereof. The alkali metal salts, alkali earth metal salts, ammonium salts are preferably selected from chlorides, phosphates, carbonates, nitrates, thiosulfates, sulfates, and any combination thereof. The alkali metal salts and/or alkali earth metal salts are preferably selected from chlorides and/or nitrates.

Preferably, the salts are selected from the group comprising: alkali metal chlorides, alkali metal phosphates, alkali metal carbonates, alkali metal nitrates, alkali metal thiosulfates, alkali metal sulfates, alkali earth metal chlorides, alkali earth metal phosphates, alkali earth metal carbonates, alkali earth metal nitrates, alkali earth metal thiosulfates, alkali earth metal sulfates, ammonium chloride, ammonium phosphate, diammonium phosphate, ammonium dihydrogenphosphate, ammonium carbonate, ammonium nitrate, ammonium thiosulfate, ammonium sulphate, and any combination thereof.

The term :phosphate” is used to include monophosphates, diphosphates, triphosphates, and polyphosphates including cyclic polyphosphates, and combinations thereof.

Preferably, the electrolyte solution comprises at least one carbonate salt selected from anhydrous alkali metal carbonate salts, and at least one chloride salt selected from: alkali metal chloride salts and/or alkali earth metal chloride salts.

Preferably, the electrolyte solution comprises at least one alkali metal chloride and at least one alkali earth metal chloride.

Preferably, the ratio of the total concentration of phosphate salt(s): nitrate salt(s): carbonate salt(s): chloride salts(s) within the electrolyte is at least 1:2:1:5; more preferably at least 1:3:2:7, for example approximately 1:4:3:9.

The electrolyte solution may comprise at least one alkali metal carbonate salt;

Preferably the at least one alkali metal phosphate salt is a monophosphate salt.

Preferably, the ratio of the at least one alkali earth metal chloride salt to the at least one alkali metal chloride salt is at least 1:1, preferably at least 2:1, more preferably at least 5:1, for example approximately 5.5:1. Preferably, the ratio of the at least one alkali earth metal chloride salt to the at least one alkali metal chloride salt is no more than 16:1, more preferably no more than 12: 1, for example no more than 10:1.

Preferably, the ratio of the alkali metal carbonate salt(s) to the at least one alkali metal chloride salt is at least 3:1, preferably at least 4:1, for example approximately 5.33:1. Preferably, the ratio of the alkali metal carbonate salt(s) to the alkali metal chloride salt(s) is no more than 16:1, preferably no more than 12:1, for example no more than 10:1.

Preferably, the ratio of the at least one alkali metal nitrate salt to the at least one alkali metal chloride salt is at least 1:1, more preferably at least 2:1, for example approximately 2.67:1. The ratio of the at least one alkali metal nitrate salt to the at least one alkali metal chloride salt is preferably no more than 8:1, more preferably no more than 6:1, for example no more than 5:1.

Preferably, the ratio ofthe at least one alkaliearth metal nitrate to the atleastone alkali metal chloride salt is at least 1:1, more preferably at least 2:1, for example about 2.67:1. The ratio ofthe at least one alkali earth metal nitrate to the at least one alkali metal chloride salt is preferably no more than 8:1, more preferably no more than 6:1, for example no more than 5:1.

Preferably, the ratio of the at least one alkali earth metal nitrate salt to the at least one alkali metal nitrate is at least 0.5:1, preferably at least 0.75:1, more preferably at least 1:1. The ratio of the at least one alkali earth metal nitrate salt to the at least one alkali metal nitrate is preferably no more than 3:1, more preferably no more than 2.5:1, for example no more than 2:1.

Preferably, the ratio of the at least one alkali metal phosphate salt to the at least one alkali metal chloride salt is at least 1.5:1, more preferably at least 2:1, for example at least 3:1. The ratio of the at least one alkali metal phosphate salt to the at least one alkali metal chloride salt is preferably no more than 9:1, more preferably no more than 7:1, for example no more than 5:1.

Preferably, the at least one alkali metal chloride salt is selected from sodium chloride and/or potassium chloride. More preferably, the alkali chloride salt(s) is sodium chloride.

Preferably, the at least one alkali earth metal chloride salt is selected from calcium chloride and/or magnesium chloride. More preferably, the at least one alkali earth metal chloride salt is calcium chloride.

Preferably, the at least one alkali earth metal nitrate salt is selected from: magnesium nitrate (Mg(NO3)2), calcium nitrate Ca(NO3)2 and/or calcium ammonium nitrate 5Ca(NO3)z.NH4NO3XI0H2O, or any combination thereof. Preferably, the at leastone alkali earth metal nitrate salt is magnesium nitrate.

Preferably, the alkali metal nitrate salt(s) is selected from: sodium nitrate (NaNO3) and potassium nitrate (KNO3), or any combination thereof. Preferably, the alkali metal nitrate salt is potassium nitrate.

Preferably, the alkali metal phosphate salt(s) is selected from mono potassium phosphate (KH2PO4) and mono sodium phosphate (NaH2PO4), or any combination thereof.

Preferably, the alkali earth metal phosphate salt(s) is selected from calcium phosphate Ca(H2PO4)2

Preferably, the electrolyte solution comprises: sodium chloride (NaCI) and calcium chloride (CaCI2); magnesium nitrate (Mg(NO3)2) and one or more alkali metal nitrate selected from: sodium nitrate (NaNO3) and potassium nitrate (KNO3), or any combination thereof.

Preferably, the electrolyte solution comprises: sodium chloride (NaCI) and calcium chloride (CaCI2); and magnesium nitrate (Mg(NO3)2) and potassium nitrate (KNO3).

Preferably, the electrolyte solution comprises: 0.3 g/l sodium chloride (NaCI);1.6 g/l calcium chloride (CaCI2); 1.3 g/l magnesium nitrate (Mg(NO3)2); 2.8 g/l potassium nitrate (KNO3).

The electrolyte solution preferably comprises one or more alkali metal phosphate selected from: mono potassium phosphate (KH2PO4) and mono sodium phosphate (NaH2PO4), or any combination thereof.

The electrolyte may comprise anhydrous sodium carbonate (Na2CO3);

According to a further aspect, the present invention provides an apparatus for producing electrolyzed water composition for use in rehydrating cut flowers, the apparatus comprising: a reservoir comprising an electrolyte solution comprising at least one salt selected from alkali metal chloride, alkali earth metal chloride, or any combination thereof; at least one salt selected from alkali metal carbonate, alkali earth metal carbonate, at least one salt selected from alkali metal nitrate, alkali earth metal nitrate, and ammonium nitrate, or any combination thereof; and at least one salt selected from alkali metal phosphate and alkali earth metal phosphate, or any combination thereof; an electrolytic flow cell in fluid communication with the reservoir to receive a feed stream comprising the aqueous electrolyte solution; and a plurality of boron-doped diamond electrodes located within the electrolytic cell and arranged in use to be connected to a power supply.

According to a still further aspect the present invention provides an electrolyzed water composition obtainable by a method as herein described.

The electrolyzed water composition preferably comprises a free accessible chlorine (FAC) concentration in the range of from 10 to 1500 ppm, for example approximately 250 ppm.

The electrolyzed water composition preferably comprises a dissolved O3 concentration of in the range of from 0.1 to 750 ppm, more preferably from 1 to 300 ppm, for example approximately 5 ppm.

According to a still further aspect the present invention provides use of the electrolyzed water composition as herein described as a rehydration solution for cut flowers.

The concentrations of salts within different electrolysed water compositions will be tailored to the specific flower species and transport regime. Different flowers have different tolerances for different salts, and many salts also have fertiliser and micronutrient effects at low concentrations. The specific blend of salts for each flower is designed in order to provide the maximum overall salt concentration that is consistent with keeping each individual salt in its micro-nutrient (and therefore non-phytotoxic) window forthat species, whilst allowing the solution to be efficiently electrolysed. The use of multiple salts allow for creating non-phytotoxic electrolytic solutions.

Brief Description of Figures

Embodiments of the present invention will now be described, by way of example, with reference to the following figures:

Figure 1 is a photographic image illustrating the rehydration effect of the Electrolyzed water composition of Comparative Example 1 on cut flowers;

Figure 2A is a photographic image illustrating the condition of rehydrated roses within varying solutions ata time period of two days post rehydration

Figure 2B is a photographic image illustrating the condition of rehydrated roses within varying solutions ata time period of four days post rehydration;

Figure 2C is a photographic image illustrating the condition of rehydrated roses within varying solutions ata time period of eight days post rehydration;

Detailed Description

Comparative Example 1 " E lectrolyzed water composition

An aqueous electrolyte solution comprising 0.3 g/l sodium chloride, 1.6 g/l calcium chloride, 1.3 g/l magnesium nitrate, and 2.8 g/l potassium nitrate in water was prepared. The electrolyte solution was stored within a reservoir chamber in fluid communication with an electrolytic cell. A feed stream comprising the electrolyte solution was introduced into an electrolytic flow cell. The feed stream can optionally include one or more additional salts to enhance the rehydration properties of the resultant electrolyzed water composition.

The electrolytic cell is a non-membrane electrolytic cell. It is however to be understood that any suitable electrolytic cell may be used.

The electrolytic cell comprises a casing, a plurality of boron doped diamond electrodes (BDEs) located within the cell, and metal :contact plates "used for transmitting charge across the electrolyte solution.

The BDEs are sheet-like components and are provided in a stack of between 3 and 10 sheets. Each sheet is located at a fixed distance away from an adjacent sheet. The distance between adjacent sheets of BDEs provides a cell gap, which is preferably less than 5 mm, for example between approximately 2 and 3 mm. The BDEs are provided in a plastic frame. The BDEs transmit charge across the electrolyte solution, inducing a strong dipole and creating positively and negatively charged radicals on alternate surfaces of the diamonds.

The electrolyte solution may be introduced into the electrolytic cell in any suitable manner so as to produce electrolyzed water composition in a continuous process or in a batch process. In the continuous process, the electrolyte solution may be introduced at a suitable flow rate, such as for example at a flow rate in the range of from 0.1 to 100 l/min, for example in the range of from 3 to 5 l/min. In the batch process, the electrolyte solution may have a flow rate of approximately 16 l/min. A power supply was operated to apply a voltage in the range of between 1 and 1,000 Volt D.C. and a current within the range of from 1-1,000 ampere to the electrolyte solution.

The over-potential provided between the electrodes shifts the equilibrium within the electrolyte solution such that a range of :active species” ions and molecules are produced and remain within the electrolyzed water for a significant amount of time. The term significant amount of time” is used herein to refer to at least a week, preferably at least two weeks, for example at least a month. The combination of active molecular and ionic species together with the over-potential which supports the equilibrium confers a variable degree of rehydration activity to the electrolyzed water composition.

The electrolytic cell preferably comprises an outlet through which the electrolyzed water composition exits the cell. The resulting electrolyzed water composition comprises a range of active molecular and ionic species which have enhanced rehydration properties.

The active molecular and ionic species include dissolved ozone and free accessible chlorine (FAC). The electrolyzed water composition according to this comparative example comprises dissolved ozone at a level of 2.5 ppm. The electrolyzed water composition according to this comparative example comprises free accessible chlorine (FAC) ata level of approximately 250 ppm.

The electrolyzed water composition of the present invention contains dissolved ozone ata level of approximately 5 ppm, it is however to be understood that the electrolyzed water composition of the present invention may comprise any suitable level of dissolved ozone within the range of between 0.1 and 750 ppm. The electrolyzed water composition of the present invention contains and FAC ata level of approximately 250 ppm, it is however to be understood that the electrolyzed water composition of the present invention may comprise any suitable level of FAC within the range of between 10 and 10,000 ppm.

It is also to be understood that the electrolyzed water composition may be varied by varying one or more of: the components of the electrolyte composition, the concentration ofthe components within the electrolyte composition, the degree of over-potential, the current applied, or any combination thereof. In this way the rehydration properties of the electrolyzed water composition may be tailored to suit different ornamental targets, such as for example flower species, microbial contaminants, delivery mechanisms, and growing environment, or any combination thereof. For example, the rehydration properties of the electrolyzed water composition may be tailored in relation to when the composition is to be applied.

The system may further comprise one or more flow regulators arranged in use to adjust the flow ofthe electrolyte feed stream between the reservoir and the cell.

The system may further comprise a heater arranged in use to adjust the temperature ofthe flow ofthe electrolyte feed stream and/or the electrolyte solution within the cell.

The system may further comprise a control system arranged in use to control the flow rate ofthe electrolyte feed stream as required, such as for example by controlling the flow regulators).

The system may comprise a control system arranged in use to control the power supply to the electrodes.

The system may comprise a control system arranged in use to control the temperature ofthe electrolyte solution.

Control ofthe temperature ofthe electrolyte solution, the flow rate ofthe electrolyte solution feed stream, and the power supply to the electrodes may be provided by a single control system. Alternatively, these factors may be controlled by separate control systems.

Example 2 " Rehydration of Cut Flowers

With reference to Figure 1, an experiment was carried out to determine the effect on flowers of being stored in three different rehydration solutions. The flowers were placed in three pairs of buckets. Each pair of buckets contained a different rehydration solution for cut flowers. A first pair of buckets 1 A, 1B contained water; a second pair of buckets 2A, 2B contained a conventional rehydration solution (Chrysal Professional T-bag); and a third pair of buckets 3A, 3B contained the Electrolysed Water Composition of Comparative Example 1 (5g/l total salts, 250 ppm FAC). A first bucket from each pair of bucket contained gerboras and a second bucket from each pair of buckets contained roses.

The stems of the cut flowers (in this case roses and gerboras) were cut to remove about 2 cm in length. The cut flowers are placed within the buckets containing the corresponding rehydration solution. The flowers remained in the solution forfive days at ambient temperature. The results are shown in Figure 1.

As shown in Figure 1, the flowers in the third pair of buckets 3A, 3B are observed to be in a much healthier condition than the flowers placed in either water or in conventional rehydration solution.

The present invention provides compositions with improved rehydration properties for cut flowers compared to conventional rehydration solutions and water.

Example 3 " Method for handling dry roses

Rehydration of Roses: 30 bunches of dry roses (10 pink roses, 10 white roses and 10 yellow roses) arrive dry in boxes after import by air from Kenya. The roses are removed from the boxes. 2 cm of length is cut from the base of the stem. Roses are then placed in the corresponding rehydration solution (either a) water orb) the composition of Comparative Example 1) with cardboard collars in place. The roses remain in the rehydration solution overnight (approx. 9 hours) at ambient temperature. The rehydrated roses are then removed from the rehydration solution and shipped as bunches. The cardboard collars are discarded at this stage.

Shop Floor A further 1 cm is removed from the base of the rehydrated stem. The roses were placed in one of ten buckets (two sets of five buckets). A first set of five buckets (marked B) received the roses which have previously been rehydrated in water, and the other set of five buckets (marked A) received the roses which have previously been rehydrated with the composition of Comparative Example 1.

The roses were placed at room temperature (approx. 20 °C) for four days and time lapse photography is initiated (Figures 2A and 2B).

Each set of five buckets comprises 2 litres of one of five different solutions (as shown in Table 1): 1) water 10 A/B; 2) water and proff2 Crysal T "bag 12 A/B; 3) dilute composition of Comparative Example 1 14 A/B; 4) dilute composition of S1 (1.0 g/l NaCI solution) 16 A/B; 5) dilute S3 variant with alternative formulation as shown in Table 1 18 A/B.

Table 1

The term ORP. is used herein to refer to the Oxidative reduction potential. The oxidative reduction potential is a measure ofthe amount of antimicrobial efficacy that an electrolysed water solution contains.

As shown in Figures 2A and 2B show the condition ofthe re hydrated (eitherwith water or with the composition of Comparative Example 1) roses placed in varying solutions. The roses performed well over the period of four days post-re hydration (Figure 2B). The rehydrated roses placed in water (buckets 10 A/B) appear to begin to droop after four days post-re hydration. A few ofthe roses placed within the water (buckets 10A/B) are also failing to open and a number of petals shrivelled after a period of four days post rehydration treatment.

Customer Vase

The roses are then transferred to cleaned buckets. The consumer sachet instructions for caring for the roses were followed accordingly for 8 days and again time lapse photography was initiated. The number of wilted flowers were counted for each colour rose within each vase on Day 1 (Table 2), Day 3 (Table 3) and Day 8 (Table 4).

Day 1:

Table 2

Day 3

Table 3

Day 8

It was found that roses wilting/drooping was the primary failure, with some roses not opening (N/O). As the blooms aged, the petals become shrivelled or slightly dessicated.

In total, the flower loss after rehydration, 4 days of simulated retail environment, and 8 days of simulated home display was 93% (52/56) for roses rehydrated in water; 48% (28/58) for roses in Chrysal T-Bag solution, and just 27% (16/59) for those stored in the composition of Comparative Example 1.

The compositions of the present invention significantly improve the shelf life of cut flowers. The improvement in shelf life obtained by using the compositions of the present invention to rehydrate cut flowers is equivalent to increasing the shelf life of the cut flowers by 2-3 days. It is to be noted that although the present invention provides results for roses, thatthe compositions of the present invention have a similar effect on other cut flowers. The present invention therefore provides compositions which can be used to increase the shelf life of flowers, to increase the quality of the cut flowers sold to consumers, to increase the effective yield, and thereby reducing the number of guarantee claims brought by customers.

It is to be understood that the Comparative Examples are illustrative of the rehydration properties of the comparative compositions for roses. It is to be understood that the compositions of the present invention may be applied in a suitable manner such as demonstrated in the Comparative Examples to any species of ornamental crop(s) or pathogen.

Claims

1. An electrolyte solution comprising at least four salts, in which the at least four salts are selected from: at least one salt selected from alkali metal chloride, alkali earth metal chloride, or any combination thereof; at least one salt selected from alkali metal carbonate, alkali earth metal carbonate, at least one salt selected from alkali metal nitrate, alkali earth metal nitrate, and ammonium nitrate, or any combination thereof; and at least one salt selected from alkali metal phosphate and alkali earth metal phosphate, or any combination thereof.

2. An electrolyte solution as claimed in claim 1, in which the solution comprises: sodium chloride (NaCI) and calcium chloride (CaCI2); magnesium nitrate (Mg(NO3)2) and one or more alkali metal nitrate selected from: sodium nitrate (NaNO3) and potassium nitrate (KNO3), or any combination thereof; and at least one salt selected from alkali metal phosphate and alkali earth metal phosphate, or any combination thereof.

3. An electrolyte solution as claimed in claim 2, in which the solution comprises: sodium chloride (NaCI) and calcium chloride (CaCI2); and magnesium nitrate (Mg(NO3)2) and potassium nitrate (KNO3).

4. An electrolyte solution as claimed in claim 3, in which the solution comprises: 0.3 g/l sodium chloride (NaCI);1.6 g/l calcium chloride (CaCI2); 1.3 g/l magnesium nitrate (Mg(NO3)2); 2.8 g/l potassium nitrate (KNO3).

5. A method for producing an electrolyzed water composition for ornamental preservation, the method comprising: preparing an electrolyte solution as claimed in any one of claims 1 to 4; introducing the aqueous electrolyte solution into an electrolytic cell comprising a plurality of boron-doped diamond electrodes; and operating a power supply to apply a predetermined voltage to the electrolyte solution to produce an electrolyzed water composition comprising a plurality of active molecular and ionic species having rehydration activity, in which the mixture of at least four salts of the electrolyte are selected such that the electrolyzed water composition comprises a free accessible chlorine (FAC) concentration in the range of from 10 to 10000 ppm, and a dissolved O3 concentration in the range of from 0.1 to 750 ppm.

6. A method as claimed in claim 5, in which the electrolyte solution is introduced into the electrolytic cell in a continuous or batch process manner.

7. An apparatus for producing electrolyzed water composition for use in ornamental preservation, the apparatus comprising: a reservoir comprising an electrolyte solution as claimed in any one of claims 1 to 4; an electrolytic flow cell in fluid communication with the reservoir to receive a feed stream comprising the aqueous electrolyte solution; and a plurality of boron-doped diamond electrodes located within the electrolytic cell and arranged in use to be connected to a power supply.

8. Use of an electrolyzed water composition obtainable by the method as claimed in either of claims 6 and 7.