Chemical conditioning of drinking water to reduce Ca precipitation using water pinch methodology for sources with different Ca and Mg hardness composition

ABSTRACT

A mixture of drinking water sources with different chemical characteristics could encourage calcium precipitation. High Ca concentration and/or high Ca/Mg ratio cause recurrent piping scaling. Water pinch is a methodology used to reduce the concentration of contaminants through the mixture of water sources with different compositions; this approach might be used to reduce calcium concentrations. Another option is the reduction of Ca/Mg ratio through the Mg increase concentration. Both cases were developed and discussed using water pinch methodology and a modified procedure, respectively. Kinetics of precipitation of Ca²⁺ at different Ca/Mg ratios were performed to determine the ratio that minimize the Ca precipitation. Increase of Mg²⁺ concentration resulted better option compared to the reduction of Ca²⁺ concentration because the Ca/Mg ratio obtained reduces the precipitation of salts with a lesser amount of water treatment.

KEYWORDS:

• Chemical conditioning
• Ca/Mg ratio
• water pinch
• pipeline obstruction

Acknowledgements

This study was financially supported by the Council of Science and Technology of Mexico (CONACYT, Postdoctoral Fellowship Grant CVU: 426810).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Consejo Nacional de Ciencia y Tecnología [CVU: 426810].