The True Cost of Sodium Hypochlorite
The use of Sodium hypochlorite has been the standard in most applications, BUT why then does it not work and why do you still fail most audits and don’t meet compliance objectives?
Sodium Hypochlorite is NOT a cheap solution and you don’t get compliance!
Let’s for the moment exclude all mechanical, maintenance and logistic challenges on the application side. Even if you look after the installation, which is cheap and easy, there is one fundamental principle you can’t do ANYTHING about.
That principle is the dissociation of sodium hypochlorite in water at various pH values. Unless you control this in a predetermined range you otherwise rely on the quality and pH supplied from the source, whether this is municipality or borehole.
If you Google dissociation of chlorine you will see all the facts backing up the information below.
So let’s do the sums:
Let’s use R7.50 per kg of product delivered, with a typical concentration of around 12%
Sodium hypochlorite is 12 % active, let’s convert it to 100 %, new hypo cost will be R 62.50/kg at full activity.
@ pH 6.5 HOCl available for disinfection is 95 %
@ pH 7.5 HOCl available for disinfection is 48 %
@ pH 8.0 HOCl available for disinfection is 22 %
@ pH 8.5 HOCl available for disinfection is 10 %
@ pH 9.0 HOCl available for disinfection is 3 %
Then, if hypo cost R 62.50/kg delivered, at 100 % activity, if the water source pH varies, this is what the costs are:
@ pH 6.5 cost will be R 65.78/kg
@ pH 7.5 cost will be R 130.21/kg
@ pH 8.0 cost will be R 284.10/kg
@ pH 8.5 cost will be R 625.00/kg
@ pH 9.0 cost will be R 2083.33/kg
So, don’t be fooled by low and cheap cost per kg, this is one of the industry’s trade secrets.
YOU ARE PAYING MORE THAN YOU THINK!