Keywords
alkalinity
dissociation constants
How to Cite
Abstract
Measurements of parameters expressed in terms of carbonic species such as Alkalinity and Acidity of saline waters do not analyze the influence of external parameters to the titration such as Total free and associated Carbonic Species Concentration, activity coefficient, ion pairing formation and Residual Liquid Junction Potential in pH measurements. This paper shows the development of F5BC titration function based on the titrations developed by Gran (1952) for the carbonate system of natural waters. For practical use, samples of saline waters from Pocinhos reservoir in Paraiba were submitted to titration and linear regression analysis. Results showed that F5BC involves F1x and F2x Gran functions determination, respectively, for Alkalinity and Acidity calculations without knowing “a priori” the endpoint of the titration. F5BC also allows the determination of the First and Second Apparent Dissociation Constant of the carbonate system of saline and high ionic strength waters.
References
APHA, Am. Publ. Health Assoc., Standard Methods for the Examination of Water and Wastewater, USA, 2000.
Araújo, L.M.L., A Determinação da Alcalinidade Total de Águas Naturais a 25°C, M. Sc. Thesis, Federal University of Campina Grande, 1984.
Cavalcanti, B. F., Residual Liquid Junction Potentials in Binary Chloride Systems, M.Sc. Thesis, University of Cape Town, South Africa , 1981.
Cavalcanti, B.F., Influence of Temperature and Ionic Strength on the First Dissociation Constant of the Carbonic System in Natural Waters, I SIBESA, In: Anais ABES/ANDIS, Vol.2, Tomo I, RJ, 1992, .256 – 272.
Friend, J.F.C. and Loewenthal, R.E., Chemical conditioning of low and medium salinity Waters, Stasoft Version 3, 0, Water Research Commission Report, Pretoria, 1992, 80p.
Gran, G., Determination of the Equivalent Point in Potentiometric Titration, Part II, Analyst, V.77,1952, p.661– 672.
Laraque, A., Estudo e Previsão da Qualidade da Água de Açudes no Nordeste Semi – Árido Brasileiro, Relatório SUDENE/DPG/PRW, Convênio ORSTOM, SUDENE, Recife, PEE, 1989, 95p.
Liesching, P, Loewenthal, R.E. and Marais, G.v.R., Ion Pairing Determination in High Salinity Waters, Water Research Report, UCT, South Africa, 1979.
Loewenthal, R.E. and Marais, G.v.R., Carbonate Chemistry of Aquatic Systems: Theory and Application, Ann Arbor Science, Michigan, USA, 1976.
Loewenthal, R.E., Wiechers, H.N.S. and Marais, G.v.R., Softening and Stabilization of Municipal Waters, Water Com. Report., Pretoria, South Africa, 1986.
Santos, P.G., Determinação da Primeira Constante Aparente de Dissociação de Águas de Alta Força Iônica à 25°C, M.Sc. Thesis, UFPB, Campina Grande, PB, 1983.
Stumm, W. and Morgan J., Aquatic Chemistry, Wiley Interscience, N.Y., USA, 1980, 780p.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2018 Eclética Química Journal