Water Treatment - Chlorine Inactivation

[Cheese]

This may be a stupid question, but I have never had any treatment class.

What is chlorine inactivation? What is all of this log 2 or log 4 inactivation stuff?

Is there a table or some book that describes the level of inactivation required for each process (ie surface water, disinfection process, etc). Possibly the EPA?

I don't see this covered in the CERM.

Thanks for the help.

Cheese

 

[RIP - VTEnviro]

The log inactivation stuff is pretty straightforward. You know how "log" is essentially a base 10 exponential scale? One log removal leaves one-tenth (10^-1) of what you started with. Two log leaves one-hundreth (10^-2) of what you started with, etc.

Look at it as moving the decimal place over.

Say you have a water sample with total coliform level of 1,000/100 mL, and 3-log inactivation is required. 1000 * 10^-3 = 1/100 mL.

EPA's Surface Water Treatment Rule addresses this. Link.

In general, crytposporidium requires 2-log removal, 3-log for giardia, 4-log for viruses.

 

[Cheese]

Exactly what I thought/and needed.

Thanks VTEnviro

 

[RIP - VTEnviro]

Thank the advanced unit ops class I took in grad school!

 

[Guest]

I wonder what is going to happen when fudgepump finds the log references on this thread ...

Actually ....

JR