For the water disinfections practically four different technologies (chlorine, ozone, hypochlorite, chlorine dioxide) are used nowadays in the world. The oldest and the most exploited one, so called conventional, is the disinfections with gaseous or liquid chlorine. The biggest producers of the equipment for the water treatment in the world mainly possess all mentioned technologies for water disinfections. It is easy to concluded that the technology of water disinfections with the hypochlorite solution produced by the electrolysis of 3% solution of sodium chloride on the site of water chlorination is not only the most convenient from the point of economical aspects, but also from the point of the ecological aspect

Gvozdenović, Milica

Jugović, Branimir

Trišović, Nataša

Trišović, Tomislav

Gvozdenović, Milica M.

Serbian Academy of Science and Arts Digital Archive (DAIS)

487 16th International Research/Expert Conference ”Trends in the Development of Machinery and Associated Technology” TMT 2012, Dubai, UAE, 10-12 September 2012   UNIVERSAL MODULAR DEVICE FOR ELECTROCHEMICAL SYNTESIS OF THE DISINFICANT   Tomislav Trišović*, Branimir Jugović*,  Milica Gvozdenović** ,  Nataša Trišović***  *Institute of Technical Sciences of SASA,  Knez Mihailova 35/4, 11000 Belgrade, Serbia  **Faculty of Technology and Metallurgy, University of Belgrade,  Karnegijeva 4, 11000 Belgrade, Serbia   ***Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade, Serbia    ABSTRACT For the water disinfections practically four different technologies (chlorine, ozone, hypochlorite, chlorine dioxide) are used nowadays in the world. The oldest and the most exploited one, so called conventional, is the disinfections with gaseous or liquid chlorine. The biggest producers of the equipment for the water treatment in the world mainly possess all mentioned technologies for water disinfections. It is easy to concluded that the technology of water disinfections with the hypochlorite solution produced by the electrolysis of 3% solution of sodium chloride on the site of water chlorination is not only the most convenient from the point of economical aspects, but also from the point of the ecological aspect. Keywords: water disinfections, water chlorination, in sity water chlorination, hypochlorite production.   1. OVERVIEW OF THE EXISTING TECHNOLOGIES FOR WATER DISINFECTIONS The four main chemical substances used for the water disinfection nowadays in the world are: - disinfection with gaseous or liquid chlorine; - disinfection with ozone; - disinfection with hypochlorite solution produced by the electrolysis of 3% solution of sodium chloride; - disinfection with chlorine-dioxide (ClO2).  The oldest and the most exploited one, which is known as conventional, is the disinfection with gaseous or liquid chlorine. During the last two decades ozonization has also been used, while only recently the other two technologies were applied. The biggest producers of the equipment for the water treatment in the world (CAPITAL CONTROLS, WALLACE & TIERNAN, PROMINENT etc.) mainly possess all mentioned technologies for water disinfection.  2.  UNIVERSAL MODULAR DEVICE FOR ELECTROCHEMICAL SYNTESIS OF THE DISINFICANT System comprises: hypochlorite reactor (electrolyzer), reactor storage tank, hypochlorite storage tank, rectifier with control panel for automatic control of operation, hypochlorite dozing pump, 488 electromagnetic valve, and ventilation system. This type of electrochemical generator is designed with upper, reaction, and lower, reception tanks, while between is modular electrolyzer, as shown on Figure 1.  Above reception tanks two or more modular reactors in which dilute solutions of sodium chloride is converted in active chlorine by electrochemical reaction. Before electrolysis reaction tank is filed with water and specified quantity of sodium chloride. After starting, mixer prepares 3% NaCl solution in reaction tank followed by automatically connection of electrolyzer. After 60 h, electrolysis is finished, power supply is automatically switched off and active chlorine solution is ready for simply manual transfer in reaction tank and use by applying micro dozing pump. At the mean time, reception tank is again manually filed with water and specified quantity of sodium chloride. By this procedure, reception tank always contains some extra volume of active chlorine for unexpected situations.   Figure 1. Schematic representation of the modular charge electrochemical generator for automatic production and dozing dezinfectans with self cleaning electrodes Basic componets of MCEG 1. Modular electrolyser - reactor 2. Switch temperature 3. Reactor tank 4. Hypochlorite  storage tank 5. Heat exchanger 6. Electomagnetic valve 7. Fan pipeline 8. Switch level 9. Dosing pump  Depending on the capacity of the devices a salt reactor tank can contain from 200 dm3 to 1000 dm3 of 3% NaCl. It should be refilled with the 3% NaCl every 15 – 60 days, depending on the capacity. Into the reactor tank which was previously filled with water from fountain, 6 to 30 kg crystals of common table salt-NaCl are added. By using the manual stirrer, salt is mixed until the complete dissolution of the salt. On the end of this operation, setting of the cover provides complete isolation of solution from the environment by the water valve. The only way to the solution to come into contact with air from atmosphere is through ventilating system. On the bottom of the reactor tank, 1 to 8 reactor modules depending on the capacity are placed. The temperature sensor is placed below the reaction modules. If the temperature go over the certain value, electromagnetic valve will active the function of the spiral heat exchanger in the reaction vessel. An electromagnetic valve closes after decreasing of the temperature, and consequently the process of cooling stops. These whole processing steps are necessary due to maintain the electrochemical reaction in optimal conditions which provides maximum efficiency. Gaseous hydrogen, produced on the cathode during the electrolysis,  is  vented out by the ventilation system. A temperature switch is also placed in the generator, switching off the system in the case of possible increase of the electrolyte temperature over the upper limit. The characteristics of the hypochlorite storage tank can contain from 200 dm3 to 1000 dm3 of 1,4% NaOCl.  One switch are placed in the tank. When the hypochlorite level reaches the  low-level  switch,  the  brine  pump  and  the rectifier  are  automatically being switched off and devices automatically being 489 stopped (alarm low level hypohlorite). Depending  on  the  system  capacity,  the characteristics of the rectifiers are:   Voltage   -  2 - 20 V; current   - 0 - 160 A. The operation of the rectifier is automatically controlled from  the control panel. These pumps were made of materials resistant to the very aggressive solutions such as NaCl and NaOCl solution. Among the capacities given in this brochure, we can produce our system which can satisfy much higher needs for equivalent chlorine, up to 10 kg per day. Such system comprises all other elements except the reactor tank and hypochlorite storage tank, which are to big and must be placed separately.  Figure 2. Picture of the modular charge electrochemical generator for automatic production and dozing dezinfectans and with self cleaning electrodes   3. PRINCIPLE OF THE DEVICE FUNCTION Into the reactor tank which was previously filled with water, crystals of NaCl are added. By using the manual stirrer, salt is mixed until the complete dissolution of the salt.  On the end of this operation, setting of the cover through vessel provides complete isolation of solution from the environment by the water valve. Electrolysis process starts by pressing of the button START. Evolution of the chlorine on the anode undergoes to hydrolysis forming hypochlorite ions, until evolution of hydrogen occurs on the cathode and consequently throw the evolved gas into the atmosphere. Considering fact that part of electric energy is transform into the heat, spiral heating exchanger with water circulation is installed in the reaction tank. Circulation of the refrigerate fluid (water) is automatically provided by the measurements of the temperature during electrolysis. If the temperature go over the certain value, electromagnetic valve is opened until refrigerate fluid cooling the reaction solution to the certain stringer temperature, when is closed again. The device is turn off after 40 to 200 hours of constantly function, when the hypochlorite solution is ready to transfer by gravity into the hypochlorite tank. By using pump, the hypochlorite from the tank is dosing water in order to obtain disinfection. In addition, new bach is filled with reaction solution and parallel, new electrolysis-production of hypochlorite starts, too. After whole amount of the hypochlorite in the hypochlorite tank is consumed, alarm of low level of the present hypochlorite is turn on, which inform manipulator of the device about the situation and interrupt function of the pump. All stages in function of the device are connecting by internet and GSM net and are possible to send all the information about operating state of the device to the person in charge for the supervision or distance controller of the device.  The modular charge electrochemical generator is less expensive, trustful, drinking water disinfectant sources (based on the diluted hypo-chlorite solution) designed for the low population suburban areas.  The electrochemical generator consist the preparation-reaction tanks, with adjustable volume depending on the required quantities of disinfectants, and the electrolyser. The electrolyte is prepared in the reaction tanks, filling with water up to the marked volume and adding required mass of commercially available sodium chloride. After manual adding of the required mass of sodium 490 chloride, the electrolyte should be manually mixed with stirrer while whole sodium chloride was dissolved (les than five minutes), and electrolysis units should be start up, simply by pressing start-up button on external power supply. Depending on electrolyte volume, electrolysis can take 40 to 80 hours. During electrolysis, if the temperatures cross the certain value, the cooling of the electrolyte is automatically applied.  By applauing the automatic mode of the electrolysis (reverse curent at the certain times) the electrodes could be cleaned from carbonate deposites which is the main problem for the efficiency in such tupes of electrolysers.  After the electrolysis is complited, the dezinficient solytion is transfered in to the storage tank, and used due to the reqirements (using the dosing pump and active chlorine senzors). REVERSE DSA (dimension stable electrodes) is predicted to work for anodic, as well as for cathodic reaction, so water softening is not necessary. Hence, by using this system, expensive ion exchange columns and their regeneration are avoided. This type of electrolysers is designed for water-works and water polls where constant control and measurements of active chlorine concentrations is necessary due to the regulations. This installation is in trail use. Technological scheme of the device with signal and alarm positions is placed on the control board. Green light bulb is indication of work of the device respective component. Suitable element of the device is not in function if there is no green light on the board. Alarming situations (unsuitable temperature, low level of hypochlorite) are assigned with red light bulb. Function of the device is normal if there is no indication of red light. Red light beside sensor element indicates switching off of the device and it will show light to the length of the manual reset of the device. By pumping the water with 0.3% of NaCl from water units through mechanical (sand) filters and electrolyser small amount of active chlorine is produced, which is used for continual disinfections of water in the rest of the water units. Power consumption is as small as 30 to 80 Wh.   4. CONCLUSION This solution represents confidently technological answer which could be applied for synthesis of different organic and non-organic compounds. Innovation solves the problem of electrochemical synthesis obtainment with usage of modular reactor of simple construction which provides technical support during function of the device, as well. The system can be applied for water disinfections, in disinfections of accessories in food and meat industry. The devices are attested and represent the loves price devices for in site disinfections, comparing with similar ones which can be found at the market.  5. ACKNOWLEDGMENT This work has been performed within the projects TR172046, TR35011 and ON74001 which are supported by the Ministry of Education and Science of the Republic of Serbia, whose financial help is gratefully acknowledged.  6. REFERENCES [1] Elkais Ali Ramadan, Gvozdenovic Milica M, Jugovic Branimir Z, Trisovic Tomislav Lj, Maksimovic Miodrag M, Grgur Branimir N.: Electrochemical Synthesis and Corrosion Behavior of Thin Polyaniline Film on Mild Steel, Copper and Aluminum, HEMIJSKA INDUSTRIJA, (2011), vol. 65 br. 1, str. 15-21 [2] Gvozdenovic Milica M, Jugovic Branimir Z, Trisovic Tomislav Lj, Stevanovic Jasmina S, Grgur Branimir N.: Electrochemical characterization of polyaniline electrode in ammonium citrate containing electrolyte, MATERIALS CHEMISTRY AND PHYSICS, (2011), vol. 125 br. 3, str. 601-605 

English

Universal modular device for electrochemical syntesis of the disinficant

Digital Repository of the Institute of Technical Sciences of SASA

487 
16th International Research/Expert Conference 
”Trends in the Development of Machinery and Associated Technology” 
TMT 2012, Dubai, UAE, 10-12 September 2012 
 
 
UNIVERSAL MODULAR DEVICE FOR ELECTROCHEMICAL 
SYNTESIS OF THE DISINFICANT 
 
 
Tomislav Trišović*, Branimir Jugović*,  Milica Gvozdenović** ,  
Nataša Trišović*** 
 
*Institute of Technical Sciences of SASA, 
 Knez Mihailova 35/4, 11000 Belgrade, Serbia 
 
**Faculty of Technology and Metallurgy, University of Belgrade,  
Karnegijeva 4, 11000 Belgrade, Serbia 
 
 ***Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 
16, Belgrade, Serbia  
 
 
ABSTRACT 
For the water disinfections practically four different technologies (chlorine, ozone, hypochlorite, 
chlorine dioxide) are used nowadays in the world. The oldest and the most exploited one, so called 
conventional, is the disinfections with gaseous or liquid chlorine. The biggest producers of the 
equipment for the water treatment in the world mainly possess all mentioned technologies for water 
disinfections. It is easy to concluded that the technology of water disinfections with the hypochlorite 
solution produced by the electrolysis of 3% solution of sodium chloride on the site of water 
chlorination is not only the most convenient from the point of economical aspects, but also from the 
point of the ecological aspect. 
Keywords: water disinfections, water chlorination, in sity water chlorination, hypochlorite production. 
 
 
1. OVERVIEW OF THE EXISTING TECHNOLOGIES FOR WATER DISINFECTIONS 
The four main chemical substances used for the water disinfection nowadays in the world are: 
- disinfection with gaseous or liquid chlorine; 
- disinfection with ozone; 
- disinfection with hypochlorite solution produced by the electrolysis of 3% solution of sodium 
chloride; 
- disinfection with chlorine-dioxide (ClO2). 
 The oldest and the most exploited one, which is known as conventional, is the disinfection 
with gaseous or liquid chlorine. During the last two decades ozonization has also been used, while 
only recently the other two technologies were applied. The biggest producers of the equipment for the 
water treatment in the world (CAPITAL CONTROLS, WALLACE & TIERNAN, PROMINENT etc.) 
mainly possess all mentioned technologies for water disinfection. 
 
2.  UNIVERSAL MODULAR DEVICE FOR ELECTROCHEMICAL SYNTESIS OF THE 
DISINFICANT 
System comprises: hypochlorite reactor (electrolyzer), reactor storage tank, hypochlorite storage tank, 
rectifier with control panel for automatic control of operation, hypochlorite dozing pump, 
488 
electromagnetic valve, and ventilation system. This type of electrochemical generator is designed with 
upper, reaction, and lower, reception tanks, while between is modular electrolyzer, as shown on Figure 1.  
Above reception tanks two or more modular reactors in which dilute solutions of sodium chloride is 
converted in active chlorine by electrochemical reaction. Before electrolysis reaction tank is filed with 
water and specified quantity of sodium chloride. After starting, mixer prepares 3% NaCl solution in 
reaction tank followed by automatically connection of electrolyzer. After 60 h, electrolysis is finished, 
power supply is automatically switched off and active chlorine solution is ready for simply manual 
transfer in reaction tank and use by applying micro dozing pump. At the mean time, reception tank is 
again manually filed with water and specified quantity of sodium chloride. By this procedure, 
reception tank always contains some extra volume of active chlorine for unexpected situations. 
 
 
Figure 1. Schematic representation of the modular charge 
electrochemical generator for automatic production and 
dozing dezinfectans with self cleaning electrodes 
Basic componets of MCEG 
1. Modular electrolyser - reactor 
2. Switch temperature 
3. Reactor tank 
4. Hypochlorite  storage tank 
5. Heat exchanger 
6. Electomagnetic valve 
7. Fan pipeline 
8. Switch level 
9. Dosing pump 
 
Depending on the capacity of the devices a salt reactor tank can contain from 200 dm3 to 1000 dm3 of 
3% NaCl. It should be refilled with the 3% NaCl every 15 – 60 days, depending on the capacity. Into 
the reactor tank which was previously filled with water from fountain, 6 to 30 kg crystals of common 
table salt-NaCl are added. By using the manual stirrer, salt is mixed until the complete dissolution of 
the salt. On the end of this operation, setting of the cover provides complete isolation of solution from 
the environment by the water valve. The only way to the solution to come into contact with air from 
atmosphere is through ventilating system. On the bottom of the reactor tank, 1 to 8 reactor modules 
depending on the capacity are placed. The temperature sensor is placed below the reaction modules. If 
the temperature go over the certain value, electromagnetic valve will active the function of the spiral 
heat exchanger in the reaction vessel. An electromagnetic valve closes after decreasing of the 
temperature, and consequently the process of cooling stops. These whole processing steps are 
necessary due to maintain the electrochemical reaction in optimal conditions which provides 
maximum efficiency. Gaseous hydrogen, produced on the cathode during the electrolysis,  is  vented 
out by the ventilation system. A temperature switch is also placed in the generator, switching off the 
system in the case of possible increase of the electrolyte temperature over the upper limit. The 
characteristics of the hypochlorite storage tank can contain from 200 dm3 to 1000 dm3 of 1,4% NaOCl.  
One switch are placed in the tank. When the hypochlorite level reaches the  low-level  switch,  the  
brine  pump  and  the rectifier  are  automatically being switched off and devices automatically being 
489 
stopped (alarm low level hypohlorite). Depending  on  the  system  capacity,  the characteristics of the 
rectifiers are:  
 Voltage   -  2 - 20 V; current   - 0 - 160 A. 
The operation of the rectifier is automatically controlled from  the control panel. These pumps were 
made of materials resistant to the very aggressive solutions such as NaCl and NaOCl solution. 
Among the capacities given in this brochure, we can produce our system which can satisfy much 
higher needs for equivalent chlorine, up to 10 kg per day. Such system comprises all other elements 
except the reactor tank and hypochlorite storage tank, which are to big and must be placed separately. 
 
Figure 2. Picture of the modular charge electrochemical 
generator for automatic production and dozing dezinfectans 
and with self cleaning electrodes 
 
 
3. PRINCIPLE OF THE DEVICE FUNCTION 
Into the reactor tank which was previously filled with water, crystals of NaCl are added. By using the 
manual stirrer, salt is mixed until the complete dissolution of the salt.  On the end of this operation, 
setting of the cover through vessel provides complete isolation of solution from the environment by 
the water valve. Electrolysis process starts by pressing of the button START. Evolution of the chlorine 
on the anode undergoes to hydrolysis forming hypochlorite ions, until evolution of hydrogen occurs on 
the cathode and consequently throw the evolved gas into the atmosphere. Considering fact that part of 
electric energy is transform into the heat, spiral heating exchanger with water circulation is installed in 
the reaction tank. Circulation of the refrigerate fluid (water) is automatically provided by the 
measurements of the temperature during electrolysis. If the temperature go over the certain value, 
electromagnetic valve is opened until refrigerate fluid cooling the reaction solution to the certain 
stringer temperature, when is closed again. The device is turn off after 40 to 200 hours of constantly 
function, when the hypochlorite solution is ready to transfer by gravity into the hypochlorite tank. By 
using pump, the hypochlorite from the tank is dosing water in order to obtain disinfection. In addition, 
new bach is filled with reaction solution and parallel, new electrolysis-production of hypochlorite 
starts, too. After whole amount of the hypochlorite in the hypochlorite tank is consumed, alarm of low 
level of the present hypochlorite is turn on, which inform manipulator of the device about the situation 
and interrupt function of the pump. All stages in function of the device are connecting by internet and 
GSM net and are possible to send all the information about operating state of the device to the person 
in charge for the supervision or distance controller of the device. 
 
The modular charge electrochemical generator is less expensive, trustful, drinking water disinfectant 
sources (based on the diluted hypo-chlorite solution) designed for the low population suburban areas.  
The electrochemical generator consist the preparation-reaction tanks, with adjustable volume 
depending on the required quantities of disinfectants, and the electrolyser. The electrolyte is prepared 
in the reaction tanks, filling with water up to the marked volume and adding required mass of 
commercially available sodium chloride. After manual adding of the required mass of sodium 
490 
chloride, the electrolyte should be manually mixed with stirrer while whole sodium chloride was 
dissolved (les than five minutes), and electrolysis units should be start up, simply by pressing start-up 
button on external power supply. Depending on electrolyte volume, electrolysis can take 40 to 80 
hours. During electrolysis, if the temperatures cross the certain value, the cooling of the electrolyte is 
automatically applied.  
By applauing the automatic mode of the electrolysis (reverse curent at the certain times) the electrodes 
could be cleaned from carbonate deposites which is the main problem for the efficiency in such tupes 
of electrolysers.  
After the electrolysis is complited, the dezinficient solytion is transfered in to the storage tank, and 
used due to the reqirements (using the dosing pump and active chlorine senzors). 
REVERSE DSA (dimension stable electrodes) is predicted to work for anodic, as well as for cathodic 
reaction, so water softening is not necessary. Hence, by using this system, expensive ion exchange 
columns and their regeneration are avoided. This type of electrolysers is designed for water-works and 
water polls where constant control and measurements of active chlorine concentrations is necessary 
due to the regulations. This installation is in trail use. 
Technological scheme of the device with signal and alarm positions is placed on the control board. 
Green light bulb is indication of work of the device respective component. Suitable element of the 
device is not in function if there is no green light on the board. Alarming situations (unsuitable 
temperature, low level of hypochlorite) are assigned with red light bulb. Function of the device is 
normal if there is no indication of red light. Red light beside sensor element indicates switching off of 
the device and it will show light to the length of the manual reset of the device. 
By pumping the water with 0.3% of NaCl from water units through mechanical (sand) filters and 
electrolyser small amount of active chlorine is produced, which is used for continual disinfections of 
water in the rest of the water units. Power consumption is as small as 30 to 80 Wh. 
  
4. CONCLUSION 
This solution represents confidently technological answer which could be applied for synthesis of 
different organic and non-organic compounds. Innovation solves the problem of electrochemical 
synthesis obtainment with usage of modular reactor of simple construction which provides technical 
support during function of the device, as well. 
The system can be applied for water disinfections, in disinfections of accessories in food and meat 
industry. The devices are attested and represent the loves price devices for in site disinfections, 
comparing with similar ones which can be found at the market. 
 
5. ACKNOWLEDGMENT 
This work has been performed within the projects TR172046, TR35011 and ON74001 which are 
supported by the Ministry of Education and Science of the Republic of Serbia, whose financial help is 
gratefully acknowledged. 
 
6. REFERENCES 
[1] Elkais Ali Ramadan, Gvozdenovic Milica M, Jugovic Branimir Z, Trisovic Tomislav Lj, Maksimovic 
Miodrag M, Grgur Branimir N.: Electrochemical Synthesis and Corrosion Behavior of Thin Polyaniline 
Film on Mild Steel, Copper and Aluminum, HEMIJSKA INDUSTRIJA, (2011), vol. 65 br. 1, str. 15-21 
[2] Gvozdenovic Milica M, Jugovic Branimir Z, Trisovic Tomislav Lj, Stevanovic Jasmina S, Grgur Branimir 
N.: Electrochemical characterization of polyaniline electrode in ammonium citrate containing electrolyte, 
MATERIALS CHEMISTRY AND PHYSICS, (2011), vol. 125 br. 3, str. 601-605 


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Universal modular device for electrochemical syntesis of the disinficant

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