Prof. Dror Avisar, Mr. Gili Levine, Ms. Rima Gnaim
Faculty of exact sciences, Tel Aviv University
In the period between Dec. 2016 and May, 2017, a series of scientific experiments was conducted at Prof. Dror Avisar’s hydrochemistry laboratory at the Israeli Water Research Institute, in order to examine the claim that Aquanity fresh water technology creates a better quality and tastier water compared to tap water. This work may shed new light regarding the possibility that this technology does improve the quality of drinking water. This research was conducted using purely scientific tools and methods. Samples of tap water and oxygenated tap water were used as control groups. The research team included Prof. Dror Avisar, the head of the Water Research Centre at Tel Aviv University, and the head of the Hydrochemistry lab as a senior tutor, Mr. Gili Levine, a water and environment engineer, who initiated and managed the research, and Miss Rima Gnaim, a third year biology and geography student, as part of an Honors program in which she participates.
Solubility – Determining the degree of solubility of coarse salt and white sugar in various water samples
Experiment 1a: Solubility of coarse salt in water
The rationale of this experiment was to examine whether solubility values in Aquanity water differ from those of tap water. Solubility is usually determined by the maximum amount (in grams) of dissolved matter in 100 ml of a solvent up to a saturated solution in a certain temperature. First, 50 grams of coarse salt were weighed, mixing each time a few grams of the salt until a saturated solution is reached. The amount of salt left is weighed again and subtracted from the total amount to determine the amount of dissolved matter. Table 1 shows the differences in coarse salt (NaCl) solubility using different types of water. Differences were found in the solubility of salt in Aquanity water compared to the solubility of salt in tap or oxygenated tap water. The average of the three salt solubility measurements is shown in the table below. The solubility of salt in 100 ml of Aquanity water is 34.3 grams, and is 2.3 grams lower than tap water (36.6), and 5.6 grams lower than oxygenated tap water (38.9). The percentage of variance between Aquanity water to tap water is -6.28%. The difference shown in this experiment between the water
types is not significant, therefore this measurement is not efficient in testing the quality of Aquanity water compared with tap water.
Experiment 1b: Solubility of white sugar in water
A similar experiment was done with the solubility of white sugar. The results in table 2 show that the total amount of dissolved white sugar in Aquanity water is 207.8 grams, in tap water 211.0 grams, and in oxygenated tap water – 210.3. That is, similarly to the solubility of salt in water, here too, the difference between the water types, as observed in this experiment, is negligible, and therefore this measurement is not effective in examining the quality differences between Aquanity and tap water.
Experiment 2a: Growing plants using various water types for watering
The rationale of this experiment was to examine whether Aquanity water enables better growth and longevity of plants under controlled conditions. Therefore, this experiment was conducted in the laboratory, under suitable and controlled conditions enabling growth of plants. The plants’ growth was done in planters. Each planter contained the types of plants watered with Aquanity water, planter 4 – watered with tap water. In each planter three types of plants were planted (flowers, celery and broccoli), as well as twelve seeds of baby leaves. The observation lasted for a period of several months. Every week, plant development data was taken (height of plant and number of new leaves). The results show that tap watered plant leaves turned yellow within 6 weeks (planter 4), in comparison with Aquanity watered plants, which kept vital for a period of three months (planter 3). Additionally, the number of sprouts in Aquanity watered planter 3 (10 sprouts) was significantly bigger than tap-watered planter 4 (only 5 sprouts). The photos were taken four months after the beginning of the experiment.
Experiment 2b: Measuring different water types, turbidity after growing Chrysanthemums
The rationale of this experiment was to examine whether Aquanity water may inhibit organic material decomposition and create anoxis conditions that increase turbidity values. Turbidity is a measure of the presence of solid particle suspension in water, which may affect the quality of the water. Turbidity measurement is considered a key test of water quality. Using a calibrated turbidity meter (HACH2100Q Elhamma company), the turbidity value of each of the different water types was measured, by measuring the. decline of light intensity as it passes through a sample of water. This experiment lasted about two weeks, in which we placed chrysanthemum in three large glass bottles, each filled with 1 liter of Aquanity water, tap water or oxygenated tap water. This experiment demonstrates very clear results. In picture no. 3, it is clearly shown that tap water had the most turbidity (bottle no. 4), whereas Aquanity water (bottle no. 3) remained the clearest. Additionally, the Chrysanthemum leaves and stems in tap water (bottle no. 4) became more black compared to Aquanity water.
According to the results in Table 3a, it is seen that the average turbidity of tap water is the highest, with the value of 6.17 (NTU), the average measurement of Aquanity water turbidity is of 1.01 (NTU) and is the lowest, , and the average measurement of oxygenated tap water turbidity is 6.07 (NTU). The deviation percentage between Aquanity water turbidity and tap water turbidity is 83.2%.
The difference between tap and Aquanity water turbidity is most significant, and indeed, this dimension enables differentiation between water types and and
determine that regarding turbidity, Aquanity water has the best water quality result. The photos were taken two months after the beginning of the experiment.
Experiment 2c: Measuring the different water types turbidity without growing Chrysanthemums
Using a calibrated turbidity meter (HACH2100Q Elhamma company), the turbidity value of each of the different water types was measured, without growing Chrysanthemum. The results in Table 3b below show clearly that the average measurement of tap water turbidity is the highest, with the value of 5.5 NTU, while the average measurement of Aquanity water turbidity is the lowest with the value of 1.56 NTU. The average measurement of oxygenated tap water is 2.5 NTU. This difference between tap and Aquanity water turbidity is large and most significant. Therefore, it can be clearly determined that, regarding turbidity, the Aquanity water has the best water quality.
Experiment 2d: growing mint roots in various water types
The mint plant grows its roots rapidly. The aim of this experiment was to measure the mint root growth rate with each of the different water types within a period of two weeks. In picture no. 5, the slight root growth in tap water (bottle no. 4) was significantly slight than that in the Aquanity water (bottle no. 3) and oxygenized tap water (bottle no. 5). Additionally, the tap water became more turbid compared with the other water types. That is, the Aquanity water is the clearest, and enabled the largest root-growth rate, which was measured by weight in comparison to the other water types.
At the end of this experiment, the mint roots grown in each of the water types were weighed. It is important to note that the results show dry weight, as the roots were weighed after a drying process of extracting the water. Table 4 shows that the largest root weight was found in those grown with Aquanity water, and equals 2.55 grams, the weight roots grown in tap water equals 1.81 grams, and the root weight grown in oxygenated tap water equals 2.42 grams. Therefore, it can be deduced that the largest root growth was in Aquanity water, followed by oxygenated tap water, and tap water with the lowest root growth result. The photos were taken two weeks after the start of the experiment.
This experiment also showed an advantage to Aquanity water
Decomposition and bacteria development
Decomposition of cooked rice in different water types
The rationale of this experiment was to examine whether Aquanity water inhibits the process of decomposition. We placed 50 grams of cooked rice and 100 ml of the different water types into three separate glass containers that were carefully covered, aiming at measuring the amount of rice decomposition, indicating bacterial growth in relevant conditions. The results clearly show (picture 2) that the measure of decomposition in container no. 4 (tap water) was the largest, showing mold development, the water became yellow and turbid, with bacteria and fungi covering the top of the water. On the other hand, container no. 3 (Aquanity water) and container no. 5 (oxygenated tap water) kept completely clear, with no bacterial growth or turbidity. The similar results in Aquanity water and oxygenated water may indicate that in the process of a natural vortex of the Aquanity apparatus, water is being enriched with dissolved oxygen. Photos were taken just a week after the beginning of the experiment.
Limescale deposition in kettles
The rationale of this experiment was to examine whether Aquanity water inhibits limescale sedimentation on the heating element of a kettle.
This experiment provides an indication of the amount of salt sedimentation as a consequence of the water boiling process. Limescale deposition usually causes a frequent replacement of kettles, as well as a bad aftertaste of hot drinks. Furthermore, limescale deposition on the heating element increases the energy consumption needed for reaching a certain temperature, hence, larger limescale deposition causes a longer boiling time. In this experiment, three identical new kettles were used to compare the three water types. The amount of water used was always 1 liter. Throughout the experiment period, a total of 89 water heatings were conducted, of which 16 were recorded and boiling times were taken.
The results (picture no. 4) show that kettle no. 3 (Aquanity) kept completely clean with no limescale deposition on the heating element or on the inner sides. In kettle no. 4 (tap water) a large limescale deposition was found on both the heating element itself and the bottom. In kettle no. 5 (oxygenated water) a thin layer of limescale depsition was found at the bottom.
Table no. 5 shows the average water boiling times of the different water types over a period of 16 weeks. The average boiling time of tap water reached the highest values (403 seconds), while both Aquanity and oxygenated tap water reached the value of 389 seconds.
In this graph, there is a slight fluctuation of the boiling times, altogether showing an ascending trend, over time, for each of the water types. It is clearly evident that tap water boiling time is far larger than the other water types. This ascent indicates a process of limescale sedimentation and deposition at the bottom of the heating element, consequentially causing a lengthening of boiling time as the instrument as it is used more, as well as a rise in energy consumption. The slight fluctuation is apparently caused by a difference in water temperature or inaccuracy of the amount of water in the kettle.
Taste test of different water types
The rationale of this experiment was to try to evaluate and differentiate the quality of Aquanity fresh water according the taste of examinees.
For this purpose, a blind taste test conducted, including 25 participants. They were asked to taste the different water types and answer the following questions:
What do you feel in your mouth? Does the water flow smoothly in your mouth? Is there any aftertaste? Is it tasty? Does it have a metallic taste?
The results show that a large part of the participants responded that Aquanity water is much tastier than tap or oxygenated tap water.
Of the 25 participants, only one participants (4%) answered that there is no difference between the water types, while the other 24 participants (96%) indicated that Aquanity water has the best quality. The participants’ evaluation summary is shown hereafter:
Tap water: water with aftertaste, metallic as well as chlorine taste. Plain drinking water, not tasty, hard water.
Aquanity water: tasty water, mineral water, has no aftertaste, has no metallic taste, flows smoothly in the mouth.
Oxygenated tap water: has a bitter taste, has a bad smell and aftertaste, dry in the mouth, similar to tap water, has a chlorine taste, not tasty.
In the taste test, it is clearly evident that Aquanity water showed a prominent advantage over other water types.
The rationale of this experiment was to examine differences in the electrical conductivity, indicating salinity, and a redox potential between Aquanity and tap water. Using an accurate and calibrated electrical conductivity meter (El-Hamma model WTW3510), a conductivity test was conducted for each of the water types. The electrical conductivity of a chemical solution indicates the concentration of dissolved salts in the solution.Electrical conductivity is considered as indication of the total dissolved salts in a solution. The results in the following table clearly show that the highest electrical conductivity, among the water types, was found in the Aquanity water, with a mean value of 525-527μs/cm. This indicates a large concentration of dissolved salts in comparison to other water types.
Additionally, a redox test was conducted, indicating the transfer of electrons from one chemical type to another, causing a change in the level of oxidation state. During oxidation, one chemical type transfers an electron, thus raising its own oxidation state. During reduction, a chemical type receives an electron, thus is reducing its own oxidation state. According to the results, there were no meaningful differences found between the different water types (the value for different water types was close to 282 mU). Therefore, water redox reaction did not constitute a differentiating parameter among the water types.
The total bacterial count is highly significant when inspecting water microbiology, for maintaining hygiene, quality of drinking water, and food. Various water samples were sent to “Bactochem” labs, to measure the “total bacteria” count of different water types. Results indicate that the total bacteria in 1 liter of both Aquanity and tap water were less than 1. The total bacteria found in oxygenated tap water was 4.
According to the microbial parameter, there was no increase in bacteria count as a result of using the Aquanity technology, compared with tap water.