PPT Slide
.Diel cycles of pH
Utilization of carbonates have interesting consequences for pH
plants use bicarbonate by converting to CO2 and liberating hydroxide ions:
HCO3 + HOH <=>HOH + CO2 +OH-
and
CO3+ HOH <=> CO2 + 2 (OH)-
Photosynthesis in Aq systems tends to drive pH up during the day;
respiration drives it down
--> diel pH cycles driven by biology (like O2).
Daily changes of 1-3 pH units are not uncommon where photosynthesis rates are high.