Extraction and characterization of distilled water from by-product of salt refinery processing

Salt-making is a major agro-industry in the coastal municipalities and cities of Pangasinan, Philippines. During salt refining, vapor with corrosive properties is released as a by-product, contributing to infrastructure deterioration in surrounding communities. This study aimed to develop a salt-making machine with a built-in distillation system to capture and utilize this vapor by converting it into distilled water. A prototype salt-making machine equipped with an integrated distiller was fabricated and operated under typical refining conditions. Distilled water produced during the refining process was collected and subjected to laboratory analysis to evaluate its chemical quality. Results showed that the recovered water contained measurable amounts of magnesium, potassium, sodium, calcium, chlorides, and bicarbonates, indicating incomplete removal of dissolved ions during distillation. While the system effectively recovered water vapor and refined salt simultaneously, the chemical composition of the collected distilled water did not meet the purity requirements for direct use in automotive radiators or lead-acid batteries. The distilled water, however, may be suitable for other non-automotive applications following appropriate treatment. The findings highlight the potential of vapor recovery in salt refining as a sustainable practice, while emphasizing the need for further purification to expand the utility of the recovered water.