Reducing sulfate level in cooling tower! 1

[bigdog50]

Hello all, I have a question concerning are sulfate levels. Currently ph control in are cooling tower (8 cell forced draft)is done by sulfuric acid which will increase sulfate level correct? Does Hydrochloric acid produce less sulfates and why? And would this be an option for a large cooling tower such as this 8 cell, 2 X 97,000 gpm circ pumps operation. We have strict sulfate levels because blowdown is sent to a city spray field! any thoughts would be helpfull..


Florida,USA

 

[aspearin1]

Sulfuric acid H2SO4 in solution is essentially 2 hydrogen ions and 1 sulfate ion per molecule of sulfuric acid. Yes, sulfate is inherent in sulfuric acid. You are actually introducing it into the system. Hydrochloric acid HCl is 1 hydrogen ion and 1 chloride ion in solution. Using this will reduce your sulfate concentration, but it will increase your chloride concentration.

ChemE, M.E. EIT
"The only constant in life is change." -Bruce Lee

 

[bigdog50]

Thanks Aspearin1

FLORIDA,
BIGDOG50

 

[jalvarez]

bigdog50:
The correction of pH in cooling towers is normally done by adding sulfuric or hydrocloric acids.
They normally doesn't affect very much the total amount of sulfates or chlorides in the circulating water.
The concentration of these ions will rather depend on purge flowrate and the salts content of the make up.
The decision of which acid to use, normally depends on cost or availability. In plants where HCl is a byproduct, it's the normal election. If no acid is available, normally sulfuric is cheaper.
Have a safe day