The electrochemical activation technology is based on producing in special technical electrochemical systems of metastable (activated) solutions with anomalous physicochemical and catalytic reactivity for their further use in various technological processes in place of traditionally used special chemical agent solutions. Usual source solutions for electrochemical activation (ECA) processes are sodium chloride water solutions with no more than 5.0 g/l concentration, or fresh water of less than 1.0 g/l mineralization.

  Electrochemical activation is effected by simultaneous electrochemical and electrophysical action on water or diluted water solution in the electric field of the double electric layer (DEL) of one of the electrochemical system electrodes. Water or solution unipolar electrotreatment (simultaneous electrochemical and electrophysical action in the electric field of electrode DEL) is accompanied by controlled mass transfer in the interelectrode space with minimal heat generation and with obligatory creation of conditions for the closest contact of each microvolume of liquid under treatment with the dense and/or diffuse part of the double electric layer on the electrode surface where the electric field intensity reaches several million volts per centimeter.

  As a result of electrochemical activation, water (solution) transforms into metastable state which is due to emergence of chemical and physical excitations and is accompanied by directed changes in pH, oxidation-reduction potential and other physical and chemical parameters in a wider range than under chemical regulation.

  Chemical excitations in electrochemically activated water and solutions are primarily represented by metastable products of electrochemical decomposition of fresh or low-mineralized water, including free radicals, whose reactivity is based on extremely high electron activity in cathodically treated water (catholyte) or extremely low electron activity in anodically treated water (anolyte). Physical excitations are micro-heterogeneous electrically active structures including gaseous electrochemical reaction products (microbubbles and clusters), as well as metastable changes in the ion-hydrated sheath structure charged particles.

  Excessive physical and chemical excitation energy in activated water or solutions is gradually dissipating, and they transform from metastable into stable thermodynamic equilibrium state, i. e. lose their anomalous physicochemical and catalytic reactivity. Thereby, one of the principal specific features of electrochemical activation technology is the need of timely (within the relaxation period) purposeful use of electrochemically activated water or solution’s abnormal properties.

  The relaxation period for electrochemically activated water or solutions, within which they lose their anomalous activity, is from several hours to several days, depending on various factors.

  Specific energy consumption for most liquid activation processes is 0.5 to 5.0 Wxh/l.

  To implement electrochemical activation processes in practice, unique universal standard flow-through electrochemical modulars FEM which have no analogs worldwide have been developed. Most advanced to date third-generation FEM-3 cells, as well as flow electrochemical reactors RFE consisting of several FEM-3 cells united in blocks by manifolds of different configuration, are used in various-purpose technical electrochemical systems, including STEL devices for producing activated ecologically safe sterilizing, disinfecting and washing solutions; EMERALD devices for drinking water disinfection; AQUACHLOR devices for synthesis of gaseous electrochemically activated products (ozone, chlorine, chlorine dioxide); and other technical electrochemical systems.

  Wide range of possible FEM-3 applications is due to their specific design which is based on optimal directed electrochemical transformation parameters for both highly diluted and concentrated water inorganic substances solutions and other liquids.

  Technological processes of water disinfecting in EMERALD-type devices are based on electrochemical water treatment in flow-through electrochemical modular cells FEM-3, used individually or as RFE reactors consisting of several FEM cells. Thus, the leading role in the technological processes of water purification in EMERALD devices belongs to oxidation and reduction processes helping to destroy and neutralize all toxic substances found in nature. In EMERALD devices, the natural processes of ORP destruction and neutralization of toxic substances are greatly accelerated due to direct electrochemical reactions and the involvement in purification processes of highly-active reagents’ salts: ozone, atomic oxygen, peroxide compounds, chlorine dioxide and short-lived free radicals electrochemically synthesized from treated water itself and dissolved in it.

  A peculiar feature of technological water purification processes in the EMERALD devices is that excessive energy of electrochemically activated water is used in the processes where this energy is transformed into a directed physicochemical action which helps eliminate (destroy, decompose, remove, transform) harmful impurities. Such processes include micro-electroflotation, oxidative sorption, micro-heterogenous catalysis and others.

  The term “EMERALD-type devices” implies devices whose hydraulic circuit consists of flow diaphragm-type electrochemical reactors based on FEM cells, as well as some auxiliary units, such as catalytic, flotation, averaging and electrokinetic reactors, and a number of other units and systems specially designed to work in combination with FEM cells. The latter can be used either individually or as part of RFE reactors which can include from 2 to 20 FEM cells depending on capacity.

  Irrespective of time (when stored appropriately), drinking water produced in EMERALD devices preserves parameters required by the existing water quality standards and demonstrates physiologically functional properties, i. e. ability to produce a positive effect on human health when consumed as a component of routine diet.

  In addition to the technological water purification process “EMERALD”, some others have been developed – “SAPPHIRE”, “TOPAZ”, “AGATE”, “QUARTZ” and “DIAMOND”. They are used on the basis of the respective modifications of EMERALD-type devices.

  The above water purification technological processes differ in sequence, character and quantity of water transformation stages, as well as in their functional orientation when certain physical and chemical processes are enhanced in order to better purify water of a certain chemical composition from some contaminating components commonly found in it.

  Process flowsheets of water purification in EMERALD devices are ideologically based on the optimal use of physicochemical processes and functional options of each physical element of the technological process, whether active or passive.

  Active elements of water purification process (electrochemical reactors) require power supply from outside, whereas passive elements’ functioning is based on transforming various forms of energy acquired by water in the active element, i. e. in the process of the preceding electrochemical treatment.

  The principal difference of passive elements in EMERALD devices from other existing elements applied in routine processes of water purification (filters, sorbents, ion-exchange membranes) is that the latter function only due to their own physicochemical and (or) physical/mechanical properties, such as average pore size, type and size of sorbent, ion exchange capacity, etc., whereas the passive elements of EMERALD devices to purify water employ the transformation of various forms of extra energy water acquired in the active elements during electrochemical exposure – chemical energy of oxidized and (or) reduced substances; energy of phase transformations in the process of dissolution or liberation of gases formed at the electrodes – hydrogen, oxygen, ozone, chlorine, chlorine dioxide; energy of water structural transformations in the electric field of the double electric layer (DEL) of the electrode, where electric field intensity reaches several million volts per centimeter; energy of catalytic processes involving metastable products of electrochemical reactions in the working chambers of passive elements. Throughout the whole purification process, this extra energy in various forms comes into the passive elements of EMERALD devices together with purified water and becomes the main factor providing for the removal of unnecessary components from water with the process stability maintained for an unlimited period.

  In routinely used water purification systems, treatment efficiency decreases in time, since it depends on the initial resource of the element’s functionality – the area of its filtering or sorbing surface, exchange capacity, etc.

  In contrast to that, water purification efficiency in EMERALD devices remains constant and is determined by the type of functionally useful transformation of excessive water energy in the passive elements of the hydraulic circuit as well as by the succession of water treatment stages.

  Table 1 gives a list of water purification technological processes applied in the EMERALD devices.

  Table 1. Technological processes of water purification in the EMERALD devices, technical systems for their realization and short description of the processes.

 

  All water purification technological processes presented in Table 1 have been designed specially for use in hydraulic systems containing FEM cells and (or) RFE reactors consisting of FEM cells. The technological process of water purification in EMERALD-type devices proper is a complex of these processes (stages), combined into a common circuit in a definite sequence. Generally, the order and number of purification stages determine the efficiency of the entire process of water purification. Table 2 contains data on developed water purification technological processes, which are implemented in various modifications of EMERALD devices.

  The numbers of process stages in Table 2 correspond to the numbers of water purification technological processes in Table 1.

  Table 2. Technological processes and water purification stages in the EMERALD devices.

 

  Many years of experiments studying the efficiency of various water purification technological processes have resulted in determining an optimum combination of purification stages and using it in the original technological processes “Sapphire-M”, “Agate-M”, “Topaz-M”, “Quartz” and “Diamond”, practically implemented in different modifications of EMERALD devices.

  EMERALD devices ensure production of decontaminated and structurally improved potable water that is no inferior to spring water and the best mineral waters in its beneficial effect. While maintaining in water components essential for human beings, such as calcium, magnesium, potassium and fluorine ions, and saturating it with oxygen, they liberate it from all forms and types of microorganisms, toxic organic compounds and heavy metal ions, among them excessive iron ions. Of special interest is the possibility to control water oxidation-reduction potential in the process of treatment in EMERALD devices.

  One of the most important factors controlling the parameters of oxidation-reduction reactions going on in any liquid medium is electron activity or, in other words, the ORP of the medium.

  The ORP of human body inner milieu, measured with the help of a platinum electrode as compared to a silver chloride reference electrode, is normally always below zero, i. e. it has negative values usually ranging between –100 and –200 millivolts (mV). The ORP of drinking water measured in the same way is almost always above zero and generally ranges from +100 to +400 mV. This is true for nearly all types of drinking water – tap water in all cities of the world, water sold in plastic and glass bottles, water purified in the reverse osmosis devices and in any varieties of big and small water purifying systems.

  The indicated difference between the ORP of the human body inner milieu and that of drinking water suggests that the electron activity in the inner milieu of human body is much higher than the electron activity in drinking water.

  When common drinking water penetrates the tissues of human (or other) organism, it de-electronates cells and tissues which are 80-90% water. As a result, the body biologic structures (cell membranes, cell organoids, nucleic acids and others) are exposed to oxidative destruction. In this way the body wears out, ages, and the functions of the most vitally important organs deteriorate.

  To ensure that the organism uses drinking water in the exchange processes the best way, it should be conditioned in accordance with the ORP parameters. That is achieved by means of ECA technologies.

  If the ORP value of water consumed by the body is close to that of the human body inner milieu, the electric energy of cell membranes (vital body energy) is not spent to correct water electron activity, and water is immediately assimilated, as it is bio-compatible in this parameter. If the ORP of drinking water is more negative than that of the body inner milieu, the body is additionally charged with the energy used by the cells as energy reserve of the body anti-oxidant defense against harmful effects of the environment. Water purified in EMERALD devices in accordance with “Topaz”, “Diamond”, and some other processes has negative oxidation-reduction potential. Hence, such water features anti-oxidant properties and is very promising as a therapeutic remedy.