Abstract

Acid neutralising capacity (ANC) is substituted by CBALK, a term that has been theoretically introduced in the early 1990s, to evaluate a simple pH equilibrium model used for Swedish surface waters. The CBALK approach with its simple three pK(a) organic acid analogue is re-evaluated with a new data set of 900 stream water samples. End-point alkalinity and TOC suffice to predict air equilibrated pH in the range 4.5 to 7.5 within 0.08 pH units. This is equivalent to an error in the charge balance of about 5 ueq L-1. In the studied pH range it renders more precise predictions than when using ANC. The model equations can be used to estimate the effect of organic carbon or carbon dioxide on ambient pH during episodes as well as for sample quality control.

Keywords

alkalinity; organic acids; buffering; pH; CBALK and ANC; acid neutralising capacity

Published in

Water, Air, and Soil Pollution
2001, Volume: 130, number: 1-4, pages: 799-804

SLU Authors

• Wilander, Anders

  • Department of Environmental Assessment, Swedish University of Agricultural Sciences
    

• Löfgren, Stefan

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Bishop, Kevin

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Köhler, Stephan

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Geochemistry
Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1023/A:1013810324218

Permanent link to this page (URI)

https://res.slu.se/id/publ/39227