State and federal laws rule the control of pH of industrial effluents aiming discharge and environmental protection. Improper effluent discharges can occur if obtained pH measurements do not meet traceability to national and/or international standards and are not associated with their uncertainties. This work focuses the quality of the pH measurements and follows the ISO GUM instructions by demonstrating the traceability and estimating the uncertainty of the measurements. The experiment was carried out using an alkaline effluent sample of a textile industry, involving the neutralization reaction with carbon dioxide. Having pH measurements associated with its uncertainty can prevent risks of improper discharge of effluent to the environment.
Alkaline effluent; carbon dioxide; pH; uncertainty
