[Digestion] Alkalinity

[Alexander Eaton]

Dear List,

Yesterday I was visiting a handful of "problem" digesters to help get them
back on track.  The issues is almost always acidity due to overloading
(either stemming from too much waste, not enough water, or dropping
temperatures), and a big dilution, some bicarbonate, and a new "seeding"
from another nearby system is almost always the fix.

However, yesterday I went to a system that had a pH of 7.2 (in the range of
OK), but was producing almost no gas.  I checked everything before I
decided to check the pH of the irrigation water from a deep well they used
with the waste.  It had a pH of 8.6.  That was the most alkaline reading I
had seen in input water, which must indicate it is highly mineralized.
 This pH seems out of a healthy range for AD, but there is no other water
source.  So, two questions:
1.  Please confirm that input water with such high alkalinity could be
inhibiting the AD process, and;
2.  What could be done to cost effectively (eg no cost) lower the
alkalinity, or at least the impact on the AD process.

I had them start using less water, arriving at the lowest possible dilution
levels for the cow manure, hoping that less water would mean less
inhibition of the process.  Thought?

Best

-- 
Alexander Eaton
Sistema Biobolsa
IRRI-Mexico
RedBioLAC

Mex cel: (55) 11522786
US cel: 970 275 4505

alex at irrimexico.org
alex at sistemabiobolsa.com

sistemabiobolsa.com
www.irrimexico.org
www.redbiolac.org
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