Hoshizaki ROX-20TA-U - Manual (Page 7)

5
U8AA5540012
4. FEATURES OF STRONG ACID WATER
Electrolyzed water (electrolyzed functional water) is a solution with useful functions caused by
electrolyzation of thin salt water or tap water. Different conditions of electrolyzation produce
various kinds of electrolyzed water whose applications are categorized into: [1] sanitation
(strong acid water, strong alkaline water, weak acid water, hypochlorous acid water) and [2]
consumption (alkaline ionized water). The Water Electrolyzer ROX-20TA-U produces strong
acid water and strong alkaline water in the category [1].
Strong acid water has the following features:
(1) Main Ingredient: Hypochlorous acid* 1)
(2) pH: 2.2 - 2.7
(3) Oxidation-Reduction Potential* 2) : Max. +1100mV
(4) Available Chlorine Concentration* 3) : 20 - 60mg/L
(5) Color: None
(6) Others: Stimulative smell of chlorine
(contains un-electrolyzed salt)
*1) Hypochlorous acid (HOCl)
Dissolution of chlorine gas in water generates hypochlorous acid (HOCl) whose ratio to
hypochlorous acid ion (ClO
-
) varies with the pH of water. In the pH range for strong acid
water, much more HOCl than ClO
-
exists. Both HOCl and ClO
-
have a bactericidal
effect, but HOCl is much stronger than ClO
-
.
*2) Oxidation-Reduction Potential (ORP)
Oxidizing (or reducing) effect of the solution. The larger positive number indicates the
higher oxidizing effect.
*3) Available Chlorine Concentration
Chlorine concentration contributing to the bactericidal activity. It indicates the amount
of chlorine corresponding to iodine isolated in the following reaction:
NaOCl + 2Kl + 2CH
3
•COOH I
2
+ 2CH
3
•COOK + NaCl + H
2
O
Note: The terms related to chlorine are defined as below:
Residual Chlorine: Remaining chlorine as the result of excessive chlorine addition into
tap water to optimize the bactericidal effect of chlorination.
Free Chlorine: Chlorine (Cl
2
), hypochlorous acid (HOCl) and hypochlorous acid ion
(OCl
-
) generated by dissolution of chlorine in water.
Combined Chlorine: Chloramine (NH
2
Cl, NHCl
2
, NCl
3
) generated by dissolution of chlorine
in water containing ammoniate or organic nitride. Combined chlorine
is stable and durable, but not so effective in a quick bactericidal activity.
Available Chlorine: Combination of free chlorine and combined chlorine.