CO2 pH neutralization 1

[HawksHockey]

I am presently researching the availability of CO2 pH adjustment systems to replace an old acid (HCl) dosing system. The pH of the inflow is approximately 13-14, and the pH has to be reduced to 6-8.
The waste water is presently produced through a batch process, and the inflow is manually controlled. The typical daily flow rate is up to 2000 gpd of highly alkaline water, that needs to be neutralized and forwarded to the city sewer system.
Obviously this is the "Coles Notes" version, but does anybody know of suppliers that offer such systems - all inclusive?

 

[bimr]

Using CO2 is not simple, easy or cost effective. CO2 forms carbonic acid (H2CO3) when dissolved in water; and it is carbonic acid that leads to the neutralization of alkalinity in solution. Carbon dioxide is not easy to use and its use is limited.

Carbon dioxide can be difficult to use because the gas must be dissolved into solution to be used. This requires the use of a carbonator, or some method to dissolve the gas into solution. Generally a tall tank must be used to ensure that there is sufficient fluid pressure to promote the dissolution of CO2 in water. Significant out-gassing will occur, which is not a problem unless the process also requires the settling of solids. Of course, out-gassing is wasting of the chemical and effects the economics.

Asphyxiation may be a hazard since CO2 is heavier than air. The gas is also stored at hazardous pressures.

You have not provided a water analysis so it is not possible to determine the volume of CO2 required. But you should be aware that if you have high alkalinity, you will generate suspended solids when the CO2 reacts with the alkalinity.

Contact this firm if you have any questions:

http://www.phcontrol.com/home.htm

 

[Unotec]

Why not just keep using HCl and replacing the old system for a new one?

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[HawksHockey]

That could very well be the final solution due to the cost of operating a CO2 system, or the initial capital cost of the equipment for the CO2 system. There are no available options that we are discounting, we are just starting with a CO2 system.