PAC dosing problems in SBR 2

[smantai]

Good day to all,
I haven't posted on here much but when I do I always get a lot of help, hopefully now is one of those times!
While I know all plants are built differently, I was curious if anyone could give me an idea where I should start. We are dosing our SBR's with PAC, and were very much so over dosing. I would like to optimize, and wonder if there is a standard (Say 50-100 ppm) that I could begin at?
Like I said we were pretty high, and while I don't want to make any sudden changes and shock my system, I need to optimize and it needs to happen quickly.
PAC is added after the Equalization tank, before it hits my basins.
Any help would be greatly appreciated, I know we're all busy but ... Well I was handed a set of keys and told to operate. So any insite would be wonderful!
Thank you!
Samantha

 

[bimr]

You will find that there is no standard quantity of PAC because each process is unique for the application.

If you feel that you have been overdosing PAC, you should experiment by making small changes in the PAC dosage and monitoing the treatment results.

 

[ch81pc]

I'm guessing you havent got access to a jar test rig? If not, improvise with some clear plastic bottles of some sort. Take say 10 bottles and fill each with 1000ml of the liquor. Then add 20mgl of PAC to the first, 30 to the second, 40 to the 3rd and so on. Keep one sample with no PAC in it to act as a comparison. Once the PAC has been added to the bottles, invert each one say twice (imporantant to keep this consistant across all bottles) to give the mixing energy and let stand for a couple of minutes. By comparing the floc structure and clarity of the top water, you should very quickly be able to home in on the ideal dose.
Once you got a baseline figure for your PAC dose, repating this test every now and then helps you to dose the optimum ammount and save money on chemical!

Ideal kit would be to use a jar test rig, but the above works well enough to get you started