Designing a formulation of synthetic wastewater as proficiency testing sample: a feasibility study on a laboratory scale

Abstract

Monitoring water quality is very crucial for sustainability and availability of clean water on earth. Electrolytic conductivity is one of the important water quality parameters to be monitored according to American Environmental Protection Agency, World Health Organization and Ministry of Environment and Forests Republic of Indonesia. Testing laboratories have a significant role in producing the accurate measurement related to the water quality parameters including electrolytic conductivity. Therefore, participating in a proficiency testing (PT) is mandatory, especially for the accredited testing laboratories, to demonstrate the competency of laboratories in doing the measurement. As PT provider, Chemical Metrology Laboratory held annual PT round since 2013. In 2018 PT round, the Chemical Metrology Laboratory provided a PT to measure the electrolytic conductivity of synthetic wastewater. Before preparing the PT test samples, the feasibility study was conducted to determine the best formulation of synthetic wastewater. During this study, two different formulations were compared in terms of simplicity formulation, electrolytic conductivity value, total dissolved solid/electrolytic conductivity conversion value, homogeneity and stability of the synthetic wastewater. The results show that both candidates are sufficient to be used as PT test samples; however, only one candidate was selected due to its ease and simplicity formulation.