Low pH in Clarigester 1

[Jasper21]

Hello All,
I've come across a treatment plant in upstate NY that has a problem with their Clarigester. The pH in the Clarigester dropped from 6.3 to 5.5. There is also a sweet odor emitting from the Clarigester which is indicative of the low pH.
Would anyone know a possible cause along with a fix or solution to this problem?
Thanks!

 

[bimr]

Aside from mechanical failure, the two most likely causes of
digester process failure are:
• metabolic overloading of the micro-organisms and consequent
pH drop; and
• loss of biomass.

Addition of lime will be necessary to raise the pH to an optimum operating range.

http://www.wrc.org.za/Lists/Knowledge Hub Items/Attachments/4086/463 abstract.pdf

http://www.ragsdaleandassociates.com/WastewaterSystemOperatorsManual/Chapter 5 - Digesters.pdf

http://www.iweasite.org/Conferences/plt_ops_conf/2010_smr_anr_dgst.pdf

 

[Jasper21]

Since I can find out the Alkalinity and Volume of the Clarigester, is there a way to determine how much lime to add to raise the pH?

 

[bimr]

The alkalinity is test is very inexpensive.

Short of that, experiment by adding lime. Lime is also inexpensive.