5th period. 2015-present: AQUATRON systems — a new step in the development of electrochemical activation

Electrochemical activation is a technologies and systems for electrochemical synthesis and subsequent use in various technological processes of metastable substances in the form of water or solutions with abnormal chemical activity instead of traditional solutions of chemical reagents. Electrochemical activation imitates chemical processes in Nature and accelerates them thousands of times.

Electrochemical activation allows for effective purification and conditioning of large and small volumes of drinking water, waste water, swimming pool water, high-level disinfection with environmentally friendly solutions, which after use are converted into ordinary fresh water. Such solutions are used in the processing of any objects – from medical instruments to premises for storing vegetables and grain products, livestock and poultry farms, slaughterhouses and clean rooms for the preparation of meat and fish food products, as well as for the disinfection of small and large territories and objects, occupied by filtration fields, garbage dumps, including anthrax burials.

During the period of work on the orders of DELPHIN AQUA (2011 – 2015), the design bureau of the Institute has developed vessel-type electrochemical reactors. This technical solution has made it possible to exclude the destruction of tubular ceramic diaphragms at significant internal pressure during filtration from the anode chamber to the cathode one. The change in the polarity of the electrode inside the diaphragm from positive to negative has made it possible to reduce the breaks of the diaphragm many times, but it has become necessary to place the anode chamber in a sealed dielectric housing. It is precisely this design of electrochemical cells that has made it possible to create high-productivity devices with the technology of ion-selective electrolysis with a long service life of ceramic diaphragms, exceeding 20,000 hours of continuous operation.

New possibilities for designing systems appeared in 2016 thanks to the end of research and the beginning of the use of ceramic diaphragms with new properties. In the development of technical electrochemical systems, the diaphragm is the main element that determines the entire design of an electrochemical reactor, the entire technical electrochemical system and a number of technological possibilities for operating an electrochemical reactor.

 Due to the AQUATRON technical electrochemical systems created in 2016, the efficiency of using the electrochemical activation technology has significantly increased in its original key field of application: a multiple reduction in the consumption of non-renewable raw materials used for the synthesis of chemical reagents. Replacing traditional chemical reagents with electrochemically activated water or solutions synthesized at the site of use from water of varying degrees of mineralization allows for complete elimination or significant reduction of the production waste volume.

With the advent of AQUATRON systems, the range of applications for electrochemical activation has expanded. High-performance and economical AQUATRON systems are used in a new capacity, since they are able to provide on-site continuous synthesis in any required amount of the most important products of the chemical industry, such as chlorine, caustic soda, concentrated hydrochloric and sulfuric acids, persulphuric acid and other chemical products.

NEW 2016 ELECTROCHEMICAL REACTORS: WAYS TO IMPROVEMENT.

The main part of the electrochemical system is partition (diaphragm or membrane) separating the anode and cathode chambers. It is the mechanical, geometric, thermophysical, chemical, physical and physicochemical parameters, including filtration, electroosmotic, sorption, catalytic and electrocatalytic properties, that determine the ways of designing an electrochemical reactor, either universal or (most often) intended for use in certain technological processes.  

The use of a ceramic diaphragm chemically resistant, not subject to aging and loss of functional properties, in flow-through MB elements instead of a polymer membrane makes it possible to implement a wide range of various technological processes that are not available when using other types of electrochemical systems.

 In the period from 2016 to 2020, a new generation of electrochemical modular MB elements was created, represented by various modifications depending on the type of technological process being implemented, the field of application (purpose) and operating conditions.

AQUATRON systems is a collective name for technical electrochemical systems with MB elements, created on the basis of new technological concepts and design solutions in accordance with the regulatory documents of 2016: “Flow-through electrochemical modular MB elements for electrolysis of water and aqueous electrolyte solutions. Group technical conditions TU 3614-015-77350578-2016” and “AQUATRON devices for electrolysis of water and aqueous electrolyte solutions. Group technical conditions TU 3614-017-77350578-2016”.  The traditional names of electrochemical equipment, such as EMERALD, STEL-ANK-SUPER, AQUACHLOR, ECOCHLOR and others, produced after 2016 in accordance with the above regulatory documents, have received the additional name AQUATRON-01, AQUATRON-05, AQUATRON-20, AQUATRON- 25, etc. Changes in the designation of electrochemical systems have made it possible to streamline the classification of typical units and parts, as well as unify the elements of electrochemical reactors and auxiliary equipment. For consumers, changes in the designation facilitate the choice and orientation in the technical characteristics of equipment and in the parameters of synthesized products. New technological features of AQUATRON systems with MB elements, in addition to high current densities and low voltages at the electrodes, are characterized by the presence of systems for intensifying electrochemical processes due to equalization of temperature, concentration and gas filling along the entire length of the reactor electrode chamber at a preset pressure drop across the diaphragm; using technological methods and technical systems that change the phase state of the products of electrochemical reactions in a directed manner; the use of technologies for the selection of the chemical composition of the auxiliary electrolyte to control the physicochemical parameters of the medium without changing its elemental chemical composition under unipolar electrochemical treatment.

The developer of AQUATRON electrochemical systems is the research and production company – VitoldBakhir Electrochemical Systems and Technologies Institute. The activities of the Institute are based on the inventions of Vitold Bakhir, the founder of the scientific and technical area called electrochemical activation. The main task of the Institute is the development and creation of a fundamentally new electrochemical technique providing an effective solution to urgent problems in medicine, industry, agriculture and other fields.

 The unique nature of the Institute’s developments is due to the direct participation of the author of electrochemical activation and a team of scientists and specialists he has been heading for many years in the development and production of electrochemical systems for various purposes, which allows the company to occupy a leading position in the world in the creation and implementation of “green” technologies that determine the future of mankind.

NEW DEVELOPMENTS AND PRINCIPALLY NEW TECHNOLOGICAL SOLUTIONS IN THE DESIGN OF AQUATRON TECHNICAL ELECTROCHEMICAL SYSTEMS:

1. The performance of the new generation MB elements has increased from 4 to 12 times. Continuous working time has reached 50,000 hours.

New generation MB elements allow electrolysis of saline solution at a pressure of 6 – 7 bar, which makes it possible to obtain liquid chlorine without compression.

2. The application of the principles of ion-selective electrolysis with a diaphragm (ISED) in the design of STEL-ANK-SUPER devices has made it possible to bring the parameters of ANOLIT ANK SUPER to a new qualitative level, while simultaneously increasing the productivity of STEL-ANK-SUPER devices by several times (up to 2000 liters per hour).

3. A significant (up to 80%) unification of hydraulic circuits of AQUACHLOR, ECOCHLOR, STEL-ANK-SUPER, EMERALD – UNIVERSAL units has been achieved, which has made it possible to increase the reliability of technical electrochemical systems and the quality of their products.

The AQUACHLOR device in this design is a module and is designed to work in a system of several identical modules (from 12 to 64) with common hydraulic systems. From such modules it is possible to mount compact chlorine plants with a chlorine gas capacity of up to 192 kg / h (4.5 tons of chlorine per day).

AQUACHLOR devices minimize the risks associated with typical accidents at production facilities using liquid chlorine and do not require quite a number of standard safety measures

AQUACHLOR: comparison of the reagentsproperties for water disinfection

Electrochemical System OXITRON – 2500 E, 2021

• 1. Basic hydraulic diagram of a solution regeneration system for underground borehole leaching of uranium
• 2. Basic hydraulic diagram of the electrochemical module
• 3. Solution to injection wells
• 4. Catholyte circulating tank (circulating catholyte tank common for all modules)
• 5. Buffer tank
• 6. Initial solution
• 7. Excess alkaline solution – 0.7% of the main stream
• 8. Pressure stabilizer in the anode chambers of the reactor elements
• 9. Regenerated solution for underground borehole leaching of uranium
• 10. Reactor with MB-26-07 elements

AQUATRON-15-500 Electrochemical system (2021)

DEVICE FOR PRODUCING ELECTROCHEMICALLY ACTIVATED

DEIONIZED AND LOW MINERALIZED WATER WITH HIGH AND LOW PH VALUES

These preservatives range from powders to slurries to liquids of various ingredients. Many of the current preservatives do not provide biocide or odor control for flower and vase solutions and the addition of disinfectants is often needed.

Potassium enriched hypochlorous acid solutions, saturated with dissolved oxygen, with or without addition of HOCl- compatible surfactants, provides multiple benefits, including turbidity and odor control of the floral care solutions, into which cut flowers and plants are placed, vase-live extension and water uptake improvement, as well as improvement of “cleanability” of vases and other containers in which cut flowers and plants are placed.  

A family of inventions relates to a preservative or watering solution for cut flowers and plants during their storage life. In particular, the inventions relate to an electrochemically treated solutions that extend the life of cut flowers and plants and prevents biofouling of the stems. Fresh cut flowers begin to loose their freshness as soon as they are cut. As such, there is a desire among floral retailers and consumers to lengthen their lifetime. Adding preservatives to water in which the fresh cut flowers are stored is a common practice.

The family of floral preservative patents covers the FloraFresh® advanced floral care and handling solutions, which combine antimicrobial activity with a natural floral nutrient to provide a proprietary, balanced solution to keep all species of cut flowers fresher, longer, and reduce time on vases and buckets cleaning. There are two groups of products, ready to use solution, and high strength hypochlorous acid enriched with potassium ion, that is developed for on-site dilution with tap water to produce floral care solution. The use of high strength solution eliminates any complications related to water hardness, or other contaminations. PuriCore had developed special dosing systems, which were installed in floral departments of the supermarket across the country. The main benefits of floral concentrates is the same as ready to use floral care solutions:

• Enhances shelf life to reduce shrink
• Eliminates bucket scrubbing and cleaning
• Enhances home life to improve customer satisfaction/loyalty
• Eliminates the need for floral food/bucket cleaners
• Effectively kill non-health pathogens and spoilage organisms in the bucket/vase water

FloraFresh® has been recognized as efficient—one solution for all your cut flowers.

High strength FloraFresh solution is one of a series of stabilized hypochlorous acid prodouocts.

Stabilized Hypochlorous Acid

The terminology Stabilized Hypochlorous Acid is starting with development of Vashe bottles product. Before Vashe, it has been accepted that hypochlorous acid is very unstable chemical.

Chemistry of hypochlorous acid is defined by the following main equations:

HOCl + H⁺ + Cl‾  → Cl₂ + H₂O,

At pH<6: 2 HOCl = 2HCl + O₂

At pH>6: HOCl + 2NaOCl = HClO₃ + 2NaCl

At pH<3.5: HOCl + H⁺ → Cl₂ + H₂O

Stabilized within pH range of 3.5 to 6.0, hypochlorous acid is the main active chlorine species.

The benefits of stabilized hypochlorous acid solutions include products safety, purity and expanded shelf.

Only as a result of stabilized hypochlorous acid products development we were able to introduce our technology to the multiple markets in the US, wounds wash, produce safety and cut flowers applications.

Application of hypochlorous acid solution for infection control and prevention has been studies for multipoint application. One of the outstanding benefit of hypochlorous acid, its sporicidal activity, was demonstrated, but has not find yet commercial application.

Clostridium difficile is an anaerobic, spore-forming bacterium that is the most common cause of healthcare-associated diarrhea in developed countries [1]. Patients with Clostridium difficile infection (CDI) shed spores in stool, resulting in contamination of their skin, clothing, and nearby environmental surfaces [2]. Healthcare workers’ hands serve as a vector for transmission of spores from these sites to susceptible patients [2]. Although sporicidal products are available for disinfection of contaminated surfaces, standard hand hygiene and bathing products have limited efficacy for removal of spores from skin. Hand washing with soap and water reduces C. difficile spore counts by only about 2 log₁₀ colony-forming units (CFU), and use of alcohol-based hand hygiene products does not reduce spore counts [2,3].  Similarly, bed baths using soap and water do not significantly reduce levels of spores on the skin of CDI patients [4]. 

Electrochemically activated solutions of hypochlorous acid have demonstrated sporicidal activity against several species of bacillus and clostridia, including C. difficile [5]. In contrast to other sporicidal disinfectants, electrochemically activated saline solutions are safe for application on skin, and the Vashe Wound solution has been commercially available as a wound care product. The hypothesis that electrochemically activated saline solutions containing hypochlorous acid would effectively reduce the burden of spores on hands and on patients’ skin was studies by The Cleveland Veterans Affairs Medical Center, a 214-bed acute care hospital with an adjacent long-term care facility, Research supported by the Department of Veterans Affairs [6].

The effectiveness of bed baths using Vashe solution versus non-medicated soap and water for removal of spores from skin of patients with recently diagnosed CDI (i.e., bathing was performed within the first 4 days of CDI therapy) was conducted on 47 patients. For bed baths, the patient’s groin, abdomen, chest, arms and hands were thoroughly wiped with a terrycloth towel soaked in the appropriate solution. The towel was soaked a second time in the solution and the test areas were wiped again.

For bed baths with soap and water, 64% of sites on patients’ skin were positive before bathing and 57% of sites remained positive after bed baths (p =0.5).  In contrast, Vashe bed baths resulted in a significant reduction in positive cultures from 54% of skin sites before bathing to 8% after bathing (p <0.0001). Soap and water bathing did not reduce the burden of spores on skin (p =0.7), whereas Vashe bathing significantly reduced the number of spores recovered after bathing (p <0.01). None of the patients reported any adverse effects related to bathing with the Vashe solution.

For a subset of 8 patients in both test groups with positive pre-bathing cultures, skin cultures were collected 4, 8, and 24 hours after bathing. For the soap and water group, all patients continued to have positive cultures for 14 sites that were positive prior to bathing. For the Vashe group, 8 cultures of the chest, abdomen, arm or hand that were positive at baseline became negative after Vashe bathing and remained negative at 4, 8, and 24 hours.  For the Vashe group, 7 patients had positive groin cultures at baseline and only 1 had a positive culture after bathing; however, 2 of 7 patients had positive groin cultures at 4 hours and 3 of 7 by 24 hours.  Because skin contamination often persists after diarrhea has been resolved and after shedding of spores in stool has been reduced to minimal levels by CDI therapy, the Cleveland VA Medical Center results suggested that bathing of CDI patients with hypochlorous acid-containing solutions might help to significantly reduce the burden of spores on skin.

Core Technology 

It has to be noted that Vashe Wound Solution is registered by FDA as a medical device, and no claims on its sporicidal activity for skin decontamination can be made. 

Sources of information.

1. Cohen SH, Gerding DN, Johnson S, et al. Clinical practice guidelines for Clostridium difficile infection in adults: 2010 update by the society for healthcare epidemiology of America (SHEA) and the infectious diseases society of America (IDSA). Infect Control Hosp Epidemiol 2010; 31: 431-55.

2. Oughton MT, Loo VG, Dendukuri N, Fenn S, Libman MD. Hand hygiene with soap and water is superior to alcohol rub and antiseptic wipes for removal of Clostridium difficile. Infect Control Hosp Epidemiol 2009; 30: 939-44.

3. Jabbar U, Leischner J, Kasper D, et al. Effectiveness of alcohol-based hand rubs for removal of Clostridium difficile spores from hands. Infect Control Hosp Epidemiol 2010; 31: 565-70.

4. Jury LA, Guerrero DM, Burant CJ, Cadnum JL, Donskey CJ. Effectiveness of routine patient bathing to decrease the burden of spores on the skin of patients with Clostridium difficile infection. Infect Control Hosp Epidemiol 2011; 32: 181-4.

5. Shetty N, Srinivasan S, Holton J, Ridgway GL. Evaluation of microbicidal activity of a new disinfectant: Sterilox 2500 against Clostridium difficile spores, Helicobacter pylori, vancomycin resistant Enterococcus species, Candida albicans and several Mycobacterium species. J Hosp Infect 1999; 41: 101-5.

6. Nerandzic MM, Rackaityte E, Jury LA,  Eckart K, Donskey CJ.  Novel Strategies for Enhanced removal of Persistent Bacillus anthracis Surrogates and Clostridium difficile Spores from Skin. PLoS One; 8(7): e68706 

AQUATRON electrochemical systems in water purification, disinfection and conditioning technology

 AQUATRON electrochemical systems and the technology of their use for water purification and disinfection were created and developed in close cooperation between the Institute of Electrochemical Systems and Technologies and its research and development partner – Blue Safety company, GMBH. Scientific cooperation between the companies has a history since 2011. Long-term fruitful scientific cooperation has made it possible to create a universal electrochemical technology for water purification of ideal ecological purity and efficiency with the minimum use of a completely safe chemical reagent – table salt. One of the important advantages of this technology is the ability to scale it up by using AQUATRON units with a capacity from several liters per hour (microdevices) to tens of thousands of cubic meters per day. The most important fact is the practical confirmation of the specified performance ranges.

The development of AQUATRON systems in the field of drinking water, waste water and swimming pool water purification is carried out in line with the following principles: increasing productivity, reducing labor, time, energy and material costs, increasing efficiency and quality according to functional purposes.  New markets and new applications are being explored. The mechanism of fresh water purification processes in Nature is represented by two main processes: redox reactions and filtration. Other processes – sorption, ion exchange, coagulation, flocculation, coalescence, sedimentation, are additional and usually occur during the filtration of purified water through soil layers, sedimentary and rock massifs.

Taking into account the need to create a high-performance efficient technical system for water purification with maximum simplicity and minimum number of elements, the concept of hardware design of the purification process included the following stages: 1) oxidation and disinfection; 2) filtration; 3) coagulation, flocculation, hydrate formation; 4) filtration, sorption; 5) additional oxidation, water protection; 6) filtration.

This concept was initially implemented in devices with active electrochemical and passive filter elements, the water purification diagram showing their principle of operation. 

Water hygiene. We only see a fraction of what it really is.

The essence of the electrochemical technology, developed by specialists and scientists of the company Blue Safety for dental practice, consists in obtaining low-mineralized Anolyte ANK at the place of use and dosed it into the drinking water supply line in proportion to the volumetric flow rate of the water. To implement the technology, compact automated electrochemical devices SAFE WATER for the synthesis of Anolyte ANK, as well as automatic dosing systems for Anolyte ANK, have been developed. Further advances in technology have led to the creation of more efficient and versatile systems based on the EM-TURBO process technology.

Relying on the capabilities of the technological developments of the Institute and BLUE SAFETY, the Water.Foundation charity has received new opportunities for its activities. Its goal is dedicated to the protection of nature and the use of technology for charitable purposes to ensure safe water supply and hygiene in emergencies, to support other charitable organizations that work on site, managing various electrochemical systems that purify drinking water and produce an environmentally friendly disinfectant solution – ANOLYTE ANK SUPER.

“Gentle”complete biofilm removal

Source: Expert opinion (2012) Prof. Exner, Dr. Gebel – Hygiene Institute of Bonn University.

The RO water supply hose in the dentist’s chair worked for 35 months. Despite the use of hydrogen peroxide additives in the water, biofilms have formed on the walls of the hose.

 Within one month of using the safe water device, biofilms were removed from the inner surface of the hose.

Practical example

No multi-resistant microorganisms in drinking water after water treatment devices.

EM-DIRECT TECHNOLOGY

The EMERALD-UNIVERSAL-250 device is made according to the EM-DIRECT flow diagram. Tests of a prototype on fresh water and saline aqueous solutions have confirmed the validity of the chosen concept of building a water purification system (2018).

Purification and disinfection of water in the EM-DIRECT technological process are accompanied and caused by the following chemical reactions.

Water first enters the anode chamber of a flow-through diaphragm electrochemical reactor. The pressure in the MB1 anode chamber is higher than in the cathode chamber. The first active stage of water purification is primary anode electrochemical treatment:

In the anode chamber of the MB elements, the oxidation process flows almost instantly due to its combined properties of a perfect-mixing and a plug-flow reactor. Also, the anode chamber destroys microbial microflora of all types and forms, microbial toxins, other organic compounds, including herbicides, pesticides, pharmaceuticals.

All insoluble compounds – coagulated organic compounds, as well as oxides of iron and manganese – are retained by the F1 filter, which performs the function of the first passive stage of water purification.

The second active stage of water purification is cathode electrochemical treatment in the first reactor.

As a result of the cathode treatment of water in the first MB element, the pH of the outlet water reaches values of 7.5–8.2.

The third active stage of water purification is secondary cathode electrochemical treatment.

After leaving the cathode chamber of the second MB element, the water acquires a pH in the range of about 9.

Ions of heavy metals, as well as those of iron, copper, zinc, aluminum are converted into insoluble hydroxides and separated on the F2 filter (the second passive stage of water purification). The water is saturated with hydrogen and becomes suitable for the introduction of the last portion of oxidants in the anode chamber of the MB2 element.

The fourth active stage of water purification is secondary anode electrochemical treatment.

Organic manganese and iron:

In the anode chamber of MB2 element, organic ferrous iron and manganese are oxidized, there is also additional oxidation with simultaneous enlargement of particles of all those impurities that have passed the previous stages. The coagulated particles are separated on the F3 filter, which is the third passive stage of water purification.

Disadvantages of EMERALD-UNIVERSAL-250 device and EM-DIRECT technology

1. The device capacity does not exceed 250 liters per hour when using two MB-26 reactors with a 350 mm diaphragm and nozzles with DN = 8 mm.

2. The current strength does not exceed 4 amperes at a voltage of 50 – 60 volts, at the end of the cycle, before cleaning the cathode chamber, the voltage reaches 100 volts at a current strength of 2.5 – 3 amperes.

3. Periodic removal of cathode deposits with a 5% hydrochloric acid solution with a volume of about 3 liters is required. The frequency of the operation depends on the chemical composition of the water and the daily volume of the treated water. On the water of the Istra district of the Moscow region at a flow rate of 1.0 – 2.0 cubic meters per day, flushing was required every two weeks.

5. Lack of chlorine-containing oxidants in the treatment of sulfate-hydrocarbonate-calcium-magnesium water, which is available in many places in the world and, in particular, in the Istra district of the Moscow region. The content of chloride ions in the source water is only 4 – 5 mg/l with a total mineralization of 0.3 g/l.

EM-TURBO TECHNOLOGY

In order to eliminate these disadvantages and in the development of scientific and technical plans to improve the technology of water purification and conditioning, experimental work and theoretical studies were carried out, as a result of which in 2019 a new technical and process solution was found that fundamentally changed the design of the electrochemical system and made it possible to provide high-quality purification and conditioning of water at almost any volumetric flow rate – from several liters per hour to hundreds and thousands of cubic meters per hour – with very low consumption of electricity and initial reagents used for the operation of the electrochemical system. The new technological solution was named EM-TURBO. This technology is similar to EM-DIRECT one, since it includes the same active and passive stages: 1) oxidation and disinfection, 2) filtration, 3) hydrate formation and coagulation / flocculation, 4) filtration, 5) oxidation and disinfection, 6) filtration. However, the EM-TURBO technology has significant advantages: 1) cleaning of electrochemical reactors is practically not required; 2) much less power consumption; 3) the possibility of regulating the chemical composition of the products of electrochemical reactions; 4) the possibility of using the EM-TURBO technology for the flow rate of purified water from a few liters per hour to hundreds and thousands of cubic meters per hour.

Process flow diagram of fresh water purification and conditioning   in the EMERALD-UNIVERSAL- TURBO-800 device

EM-TURBO water purification and conditioning technology can be used for a wide range of water types (sea and artesian water, domestic and industrial waste water, swimming pool and cooling tower water). Depending on the specific task, the EM-TURBO technology can be used with electrochemical devices for special purposes or serial devices such as AQUACHLOR or ECOCHLOR. Complex water treatment schemes at municipal drinking water supply stations can be modified without significant changes in typical structures. For example, the scheme for the preparation of drinking water at the Rublevskaya water treatment plant can be significantly improved through the use of AQUACHLOR devices.

The amount and composition of the introduced electrochemically synthesized reagents when using the EM-TURBO technology is controlled depending on the chemical composition of the water being purified by changing the current in the electrochemical reactor, the chemical composition of the auxiliary aqueous solution of electrolytes, the feed rate of the starting solutions into the electrode chambers of the reactor, the pressure drop across the reactor diaphragm and dosed removal of excess active electrochemically synthesized reagents – catholyte or anolyte.

The EMERALD – UNIVERSAL – TURBO – 700  device for water purification and conditioning in cottages, 2020

Research into new principles for the design of electrochemical modular MB elements equipped with alpha alumina diaphragms was organized at the end of 2015. Prototypes of electrochemical cells have shown the fundamental possibility of a significant increase in the productivity of reactors while reducing the cost of electricity. However, since the design features of electrochemical elements are in an absolutely close relationship with the physicochemical, hydraulic, thermal and other parameters of the physicochemical processes in the reactor, it is necessary to carry out experimental studies in order to optimize the design. Such work is an absolutely necessary stage in the design of electrochemical systems and requires the study of various design solutions.

The reactors shown in the photo are the first samples used to experimentally substantiate the theoretical concepts of energy and mass transfer processes when operating on electrolytes of various chemical compositions and concentrations, at various pressure drops across the diaphragm, current density, and flow rate. The experimentally found data were subsequently used to create industrial-type reactors for various types of technological processes.

• 1st period, 1972 — 1976: development of flow-through electrochemical diaphragm reactors with flat electrodes.
• 2nd period, 1976 — 1985: development of flow-through electrochemical diaphragm reactors with coaxial electrodes.
• 3rd period, 1985 — 1989: development of flow-through electrochemical diaphragm reactors with coaxial electrodes in the form of monoblocks.
• 4th period, 1989 — 2015: development of flow-through electrochemical diaphragm reactors with coaxial electrodes with consideration of optimal size and materials.
• 5th period. 2015-present: AQUATRON systems — a new step in the development of electrochemical activation