JSC “The Urals Research chemical Institute
with an Experimental plant”
(JSC “UNICHIM & EP”)
Field experience by water treatment facilities
of “Chlorine Dioxide & Chlorine” Compound
Disinfectant, replacing the traditional
chlorine treatment
.
Infections associated with the factor of water
account for 80% of all infectious diseases in the
world. Inadequate water treatment causes two billion
cases of diarrhea each year, resulting in 4 million
deaths. 1.2 billion people in developing countries
don’t have access to clean drinking water.
Of all the disinfectants Chlorine was
and continues, at least for now,
being the most common one.
Principal hazards associated with
transporting, storing and handling the
liquefied (“liquid”) chlorine are of the
following types:
Environmental
Production induced
Primary alternatives to chlorine
Hypochlorites
of sodium and
calcium
Ozone
UV irradiation
Chlorine Dioxide
«Chlorine Dioxide
& Chlorine» CD*
* «Chlorine Dioxide and Chlorine» Compound Disinfectant produced by the DCh-100 series plants
INTERNATIONAL AND DOMESTIC
PRACTICE IN USING CHLORINE
DIOXIDE FOR DRINKING WATER
DISINFECTION
Advantages of chlorine dioxide over chlorine or
hypochlorites
•
•
•
•
•
•
•
•
5 to 10 times reduced concentration of chlorine dioxide to achieve the same
grade of water disinfection as with chlorine;
no toxic trihalomethanes, chlorophenols or other non-removable organic
halogens formed in water;
strong disinfecting effect along a wide range of water pH ;
strong action against spores, viruses, and algae;
eliminates odors, improves the water’s taste and removes any color;
improves flocculation of suspended impurities during water purification;
better iron and manganese removal from water;
extended (7-10 days) bactericidal effect preventing the possibility of
secondary pollution of water in distributing pipelines.
Attractiveness of chlorine dioxide is rooted in the optimal
correlation of its biocidal effectiveness, stability and aftereffect,
these being the fundamental criteria for assessment of chemical
disinfectants. These properties’ combination allows to consider
chlorine dioxide to be the same as ozone, just without its drawbacks.
Thanks to the prolonged bactericidal action of chlorine dioxide it
is currently used at the last stage in the water treatment process at
major water distribution facilities (in Dusseldorf, Zurich, Brussels and
Paris).
It can be concluded that chlorine dioxide is a valid alternative
to chlorine and hypochlorite for bactericidal purposes.
Use of Chlorine Dioxide in
water conditioning
• Chlorine dioxide introduced at the pre-oxidation step
enhances the coagulation process, reduces the
concentration of organic and inorganic deoxidizers,
improves the water’s taste and smell, inactivates any
bacteria or viruses
• At the post-disinfection stage the chlorine dioxide
provides for the water in long distributing pipelines to
stay in compliance with the sanitary standards, serves to
remove any biofilms or microbial fouling and,
subsequently, to prevent their reappearance.
Chlorine Dioxide cleans and
disinfects equipment
Field tests in disinfection of water
treatment equipment, such as filters and
pipelines, demonstrated efficacy of
chlorine dioxide solutions at
concentrations of 2-10 mg / l. Disinfections
of this type have a lasting bacteriostatic
effect.
Comparison of effectiveness of
oxidizing agents in aftertaste and
odor removal, mg/dm3
Chlorine
5-10
Chlorine Dioxide
0,25-0,75
Potassium
Permanganate
1-10
Ozone
2-4
Chlorine dioxide can
be successfully used
to treat water
containing:
- green algae, diatoms,
and cyanobacteria
- their metabolites
Use of ClO2
for water treatment
•
•
•
•
USA
1944 - Niagara Falls, NY;
1970s - the period of the widespread introduction of ClO2;
1983 - a new US regulation on drinking water, among other things,
defined a limit for chloroform in treated water – 0.1 dm3;
• Introduction of ClO2 at wastewater treatment facilities in
Chesapeake (Virginia) allowed to reduce the dosage of disinfectant
from 0.6 dm3 to 0.02 dm3.
• 1977 - 103 facilities;
• 1986 - 400 facilities and growing.
• Canada, Germany, France, Japan, Italy, Belgium, Switzerland
Standards for residual chlorine dioxide and chlorite ions in
Germany, USA, Italy, Belarus and Ukraine
№
Country
ClO2
ClO2-
1
World Health
Organization
Not regulated
0,2
2
Russian Federation
Not regulated
0,2
3
Germany
0,05-0,2
0,2
4
USA (US EPA)
0,8
1,0
5
Italy
Not regulated
Not regulated
6
Belarus
0,2
0,2
7
Ukraine
0,4
0,2
Recommended residual chlorine dioxide content in
produced drinking water amounts to
0,05 – 0,30 mg/l
(using “Chlorine Dioxide & Chlorine” Compound Disinfectant)
When implementing the “Chlorine Dioxide
& Chlorine” Compound Disinfectant
technology for disinfection and purification, it
is necessary to undertake a study on the
specific water treatment facilities, the way it is
done all over the world and as promoted by
all international water-related programs and
organizations.
JSC «UNICHIM & EP» engineered, manufactures and implements
DCh-100 local automated plants for production of “Chlorine Dioxide & Chlorine”
Compound Disinfectant for water treatment systems.
The “Chlorine Dioxide & Chlorine” Compound Disinfectant is a highly
effective and efficient alternative to treating water with liquid chlorine or
hypochlorites.
The two disinfectants’ simultaneous introduction into the water
ensures that the chlorine dioxide maintains its useful properties - potent
disinfecting action and reduced levels of organochlorines – as well as
eliminates its principal disadvantage – formation of chlorite ions as byproducts
– in the comparable range of delivered doses.
The project has received over fifteen awards at various scientific
events, such as the golden figure of St. George – the highest award of the "XXI
Century's High-Tech" 10th Anniversary International Forum.
Four years of commercial operation have proven the technology’s
competitive advantage, in addition to the water quality improvement, entails a
significant reduction in operating costs compared to any other disinfection
method.
Principal advantages of Chlorine Dioxide & Chlorine
Compound Disinfectant
Compared to chlorine and sodium hypochlorite:
• chlorine dioxide’s concentration required to achieve the same antiseptic effect is 6 to 20
times lower than in case of using chlorine or sodium hypochlorite;
• practically no toxic organochlorines get formed in the water;
• strong disinfecting effect along a wide range of water pH ;
• strong effect on spores, viruses, and algae;
• elimination of odors, improvement of taste and color of water;
• improved flocculation and coagulation of impurities during water purification;
• better iron and manganese removal from water;
• extended (7-10 days) bactericidal effect preventing the possibility of secondary
pollution of water in distributing pipelines;
• does not require organizing any sanitary protection zones (as opposed to the case of
liquid chlorine)
Compared to pure chlorine dioxide (without chlorine):
• with comparable doses of chlorine dioxide no violation of limits on content of chlorite
ions in treated water takes place;
• significantly lower capital and operating costs (no additional treatment to remove
chlorites required, raw materials readily available).
The reaction that takes place in the plant’s
reactor is as follows:
NaClO3 + NaCl + H2SO4 =
ClO2↑ + 0,5Cl2↑+ Na2SO4 + H2O
DCh-100 series Plants
These serve to produce a water solution of the
chlorine dioxide and chlorine compound
(Mass ratio ClO2 : Cl2 = 1 : 0,65)
The plants of the series produce from 20 to 2000
grams of chlorine dioxide per hour, which
corresponds to 50 -14000 m3 per hour of treated
water (depending on the quality of source water
and the water preparation procedures)
Fully automated
Consume no more than 100 W
Dimensions:
1000 х 1000 х 320 mm
Reduction of chlorine dioxide from chlorites
Most chlorites get eliminated due to their interaction with chlorine
which comes as a component of the disinfectant compound, here
are the corresponding reactions:
2ClO2- + HOCl → 2ClO2 + Cl- + OHClO2- + Cl2 → ClO2 + 2Cl-
All necessary approvals for Russia and the
Customs Union's member countries
authorizing the “Chlorine Dioxide and
Chlorine” Compound Disinfectant and the
DCh-100 series plant for its production have
been obtained. Patents have been taken out in
Ukraine and Kazakhstan for the DCh-100
plant.
The project has received positive reviews from leading
water treatment organizations of Russia.
Here are a few extracts from such opinions:
1. "... Given the positive comprehensive laboratory and
industrial tests, it is appropriate to consider the "chlorine
dioxide and chlorine" compound disinfectant produced
through chlorate process on DCh-100 plants as an
alternative to the use of liquid chlorine or sodium
hypochlorite in the centralized water supply systems, and to
recommend continuing work on developing engineering and
operational procedures.
2. “Conclusion.
Positive results of tests of the DCh-100 plant and its
corresponding technology of drinking water disinfection
using the “Chlorine dioxide and chlorine" compound
disinfectant allow to endorse the technology developed by
the “UNICHIM & EP" comprising production of a
compound disinfectant and its application for drinking
water disinfection. We believe it is possible to recommend
the technology for implementation in any relevant
government programs.
3. " As a result of the reviewing and analyzing the submitted materials it
can be concluded that the “Chlorine dioxide & chlorine" compound
disinfectant produced under the process developed by the “UNICHIM &
EP" on plants of the DCh-100 series has a high bactericidal, virucidal
and antiparasitic effect. The oxidizing processes activated during water
treatment improve the water’s color, decrease concentrations of iron,
manganese, and other compounds.
The Compound Disinfectant has a strong prolonged action to
ensure the drinking water is protected against any secondary pollution
during its transportation through the distribution network.
The completed studies allow us to recommend the developed
process of water disinfection and its corresponding equipment for
practical implementation in the water supply industry.
Reviews based on results
of operating the DCh-100 type plants
JSC “The Urals Research chemical Institute
with an Experimental plant”
(JSC “UNICHIM & EP”)
Thank you for your attention!
Manufacturer Company:
JSC “The Urals Research chemical Institute
with an Experimental plant”
(JSC “UNICHIM & EP”)
5, The 8th of March Street, Yekaterinburg, 620014, Russia
Phone: (343) 371-06-51, 323-30-01. Fax: (343) 371-31-01.
marketing@unichim.ru, info@unichim.ru
Yuri Y. Lasychenkov, General Director (CEO)