Carbon dioxide is a colourless, odourless, non-flammable and slightly acid gas.
It is produced by different processes in the petrochemical industry, or by natural
gas combustion in cogeneration plants.

The main water treatment applications with CO are recarbonation and pH control.
With the recarbonation process, the principal objective is to increase the hardness
of potable water arising from a reverse osmosis process, maintaining the equilibrium
between carbonate, bicarbonate and free carbon dioxide.

With pH control, the carbon dioxide acts as a mineral acid substitute for reducing
the alkaline water pH, in accordance to the environmental rules.
Carbon dioxide is less prone to overdosing than sulphuric and othermineral acids,
and is safer to handle on site.

These applications could be very interesting for all industrial sectors which have
these needs. Air Products has important references in the food, petrochemical,
textile, soap and pulp & paper industries, and in the public segment, drinking water
and wastewater treatment plants.