Storage Stability and Disinfection Performance on Escherichia coli of Electrolyzed Seawater

Abstract

The study investigated the effect of storage conditions on the stability of electrolyzed seawater (ESW)’s physicochemical properties (pH, oxidation-reduction potential (ORP), and free chlorine (FC) concentration), and bactericidal efficiency on the fecal coliform Escherichia coli for 30 days. Preliminary experiments were conducted to determine the optimal current and electrolysis time. Two batches of 2750 mL filtered seawater were electrolyzed using 50 mm × 192 mm platinum–titanium mesh electrodes at a current of 1.5 A for 20 min. One hundred milliliters of electrolyzed solution was transferred into each amber glass and high-density polyethylene (HDPE) bottles. The bottles were stored in a dark area at ambient temperature. The results showed an increase in pH and a decrease in ORP and FC concentration through time. Hypochlorous acid remained as the dominant component since the pH levels of the solutions remained below 7.5. FC decay was investigated using Chick’s Law. It was determined that the decay in HDPE bottles (k = −0.066 day−1) was faster compared to amber glass bottles (k = −0.046 day−1). Nonetheless, HDPE bottles could still be used as an alternative container for 30 days only due to observed instability beyond 30 days. ESW remained effective since no surviving population of E. coli was observed throughout the experimentation.

Effects of storage conditions on superoxidised water

“…The concentration of hypochlorous acid (HOCl), a key active ingredient in superoxidised water, decreased significantly in both containers over time. 22 The stability of HOCl in a solution is influenced by the storage condition and mechanism of storage. 23 The researchers attributed this to the permeability of plastic to oxygen, which could lead to the oxidation of HOCl.…”

The In Vivo Toxicity and Antimicrobial Properties for Electrolyzed Oxidizing (EO) Water-Based Mouthwashes

“…The storage stability of EO water is an important issue that needs to be overcome before its possible us in medical applications. The storage stability of EO water bottles made of amber glass and high-density polyethylene (HDPE) were investigated by measuring the dependence of pH, oxidation-reduction potential (ORP), and free chlorine concentration with storage conditions through various time periods [ 32 ]. The HOCl decomposition was determined as first-order decay, and the decay rate of the stored samples in the HDPE bottle was faster than that in an amber glass bottle.…”