A high concentration of aggressive carbon dioxide disturbs many technological processes in water treatment. It also causes the development of corrosion in steel and concrete. De-acidification of groundwater by means of air bubbles alters pH and the concentration of aggressive carbon dioxide. This was investigated for the variables of air flow (Q = 20–50 L h−1) and height of water layer (H = 25–75 cm) as well as aeration time (t = 0–20 min). The obtained three-parameter models showed good correlation with the experimental results, except in a few cases where r2 was bigger than 0.9. Furthermore, they allow for prediction of an increase of pH and a decrease in concentration of aggressive carbon dioxide in aerated water. The effectiveness of de-acidification of groundwater was evaluated using indices of water stability (Langelier Saturation Index, Precipitation Index, Ryznar Stability Index, Aggressiveness Index and Index of Aggressiveness). Although as a result of aeration an increase of pH over 7 was observed, the non-corrosive values of the indices were not reached. This was due to a very low alkalinity of water, which was 0.7 meq L−1.
The influence of aeration on the change in corrosiveness and aggressiveness of groundwater
Tadeusz Siwiec, Magdalena M. Michel, Lidia Reczek, Piotr Nowak; The influence of aeration on the change in corrosiveness and aggressiveness of groundwater. Water Science and Technology: Water Supply 1 April 2016; 16 (2): 445–452. doi: https://doi.org/10.2166/ws.2015.155
Download citation file: