Theoretical and Analytical Aspects of Carbonic Species Determination in Rain, Ground, Geothermal and Petroleum Waters

• Main Authors: Mahendra P Verma, Peter Birkle, Domingo Sánchez
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Carbonic acid
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1084.5429

ABSTRACT We present the acid-base titration procedure for the determination of carbonic species in four types of waters: The calibration of standards is crucial. The NaOH solution mostly contains a small amount of CO 2 dissolved. Therefore, the standardization of NaOH solution is performed with titrating up to the carbonic acid equivalence point (H 2 CO 3 EP) instead of pH = 7.0. The Gran titration method for rainwater is performed with adding a small amount of NaOH (or HCl) and then titrating with HCl (or NaOH). The NaOH standard solution must be free from dissolved CO 2 . The H 2 CO 3 EP alkalinity method requires the subtraction of other alkalinities (such as boric, silicic) from the total alkalinity in order to obtain a representative carbonic alkalinity for geothermal waters. This method is also applicable for ground waters. The preliminary results for the determination of carbonic species in petroleum waters show the existence of very little or no carbonic alkalinity in them. However, the proposed method requires a complete analysis of all parameters which contribute to the H 2 CO 3 EP alkalinity including dissolved gases like H 2 S.