water treatment and pH correction with acid

[cwca]

we are correcting elevated pH water from a construction related project site. We are using diluted sulfuric acid at 36% and injecting it into a pvc pipe of flowing water. Do I need to be concerned about the exothermic heat produced using the diluted concentration? And other considerations do I need to think about? Thank you

 

[ash9144]

What is the material of your acid delivery system? 36% is rather corrosive so it should be pvc as well.

If you are doing pH adjustment you are adding a very small amount of acid to large amount of water so dHmix shouldn't be large. Just be sure your pH probe is properly placed to get an accurate reading and your system should be fine.

 

[bimr]

It depends on the amount of acid compared to the amount of water. If you are adding a small amount of acid to a much larger volume of water, it should be of little concern because the large amount of water will carry the heat away.

You should have the acid gravity drain into the water rather than inject the acid. If you inject the acid, you should be concerned about water backing up into your acid piping and tank. If that acid backup occurs, you may generate localized exothermic heat in the piping. A double block and bleed valves arrangement will prevent backup. You also need to be concerned should the system stop operating with acid in the piping.

It would probably be more practical for your operation if you were using a more dilute acid. The process may be safer and easier to control.