Download Principle and characteristics of electrolyzed acid water Principle of

Principle and characteristics of electrolyzed acid water
Principle of electrolyzed acid water
The principle of producing electrolyzed acid water is shown in the diagram below.
Anode and cathode plates are divided by a membrane. Water added with sodium
chloride as electrolysis accelerator is supplied to the electrolysis tank of these anode
and cathode chambers.
1
Principle of acid water production
Titanium plated with platinum is used generally for electrodes, and a cation
exchanging membrane is used for the separating membrane. Almost all the chargetransfer is performed by the transfer of cation from the anode chamber to the cathode
chamber. Therefore, there is no reversal transfer of OH-ion which prevents pH of acid
water from lowering. The ion exchanging membrane is a fine membrane, which will
not make mixture of gas from the anode and cathode.
2
Sterilization mechanism and characteristics of electrolytic acid water
The oxidation-reduction potential, pH and residual chlorine of electrolyzed acid water
are correlated one another, and do not change as independent variables. Therefore,
the sterilization mechanism is by a synergistic effect created by oxidation of
hypochlorous acid in addition to pH and oxidation-reduction potential, which makes
the membrane potentials of organelles exceed the stabilizing limit and inhibits the
energy metabolism and breathing, and all these work to kill micro-organisms
synergistically. The biosphere of micro-organisms (bacteria and viruses) is
pH 3 to 10 and oxidation-reduction potential (ORP) +900 to -400 mV, while the
electrolyzed acid water has the range of pH 2.7 or less and ORP 1000 mV or more
where these micro-organisms difficult to survive, and further the disinfecting effect is
strengthened by the residual chlorine to decompose fat and protein of cell
membrane.
In spite of its strong acidity, the electrolyzed acid water rarely shows adverse effect to
the human skin and mucosa, unlike hydrochloric acid and other solutions in the same
acidity. It is considered very safe, because it loses acidity immediately without supply
of hydrogen ion, even when oxidized.
3
How to attack bacteria
Glutaraldehyde
Surfactant
EAW / per acetic acid
Showa University Hospital
4
Characteristics of electrolyzed acid water (EAW)
Advantage:
•
Strong disinfection power (if EAW is used in good control)
•
Wide antimicrobial spectrum
•
No toxic and irritation
•
Short disinfection time
•
Very low running cost
Disadvantage:
•
Very short life
•
Strong dependency on protein, organics
•
Performance required for endoscope disinfection
Requirements
Disinfection power
Toxicity
Length of life of disinfectant
Short infection time
Wide animicrobial spectrum
o = Good, = Fair, x = Not good
EAW
o
o
x
o
o
Glutaraldehyde
9
x
o
x
9
5
Solution of EAW's disadvantage by Cleantop
•
Not allow to only soak in EAW (EAW circulates in disinfection vessel like
washing machine)
•
Continue to supply refreshed EAW (while disinfection and standby, Cleantop
refreshes EAW by flowing maintenance current in electrolysis chamber)
•
Cleantop monitors pH, ORP and residual chlorine content with test paper. (If
ORP reduces lower than 1000 mV, the device stops automatically and
announces operators to change the water.)
Disinfection control system by Cleantop WM-S
•
After 20 cycles disinfection, machine stops and drains automatically. Each
disinfection is counted.
•
Monitor circulation of EAW through channels of endoscope as well as in the
disinfection bath.
•
Monitor pH and ORP, to check EAW's specification
•
Flow maintenance current all the time to refresh EAW
•
Catch bacterium from tap water for rinsing water
•
Acid water and alkaline water is neutralized when EAW is drained
Difference between CLEANTOP WM-1 and WM-S
WM-1
< 2,7
>1000 mV
5 ppm
10 cycles
7 minutes
by test paper
by test paper
WM-S
< 2,7
>1000 mV
10 ppm
20 cycles
3 minutes
automatic
by test paper
6