TESTS OF THE KRIA IONIZER SUPEROXIDE GENERATOR BENCH-SCALE BALLAST WATER TREATMENT TECHNOLOGY

Abstract

This technical report presents findings from bench-scale tests evaluating the performance of the Kria Ionizer Superoxide Generator Model DG-100, hereafter Kria Ionizer, developed by EcoUSA, LLC of Denver, Colorado, United States of America. This evaluation was the first to assess the Kria Ionizer as a potential, in-tank, recirculating ballast water treatment method for the Laurentian Great Lakes. The evaluation began in May 2019 and ended in September 2019 at the Lake Superior Research Institute (LSRI) of the University of Wisconsin-Superior (UWS) in Superior, Wisconsin, USA. The treatment technology uses atmospheric oxygen to create superoxide (O2-). According to the developer, the injection of this superoxide into water not only creates a supersaturated oxygenated environment but can also promote cavitation and microbubble reactions upon discharge. The system can be used for oxygenation of fish farms and for remediation of water bodies containing harmful cyanobacteria, wastewater bacteria, and organic contaminants. Previous testing has been completed in the lab and field setting for these previously mentioned applications, but the testing described herein is the first testing evaluating Kria Ionizer’s potential application for ballast water treatment. The ability of the Kria Ionizer to increase dissolved oxygen and oxidation-reduction potential in a 1000-L treatment tank was tested at two water temperatures (~10°C and ~25°C) using both dechlorinated laboratory water and amended dechlorinated laboratory water. Water-only experiments were conducted and showed that dissolved oxygen increased with time in both dechlorinated laboratory water and amended dechlorinated laboratory water at both temperatures. Dissolved oxygen in ~10°C water had higher concentrations than in ~25°C water. ORP measurements conducted during testing with both water temperatures and types did not show a high degree of correlation in ORP values with increased treatment time. During treatment it was also determined that ozone and hydrogen peroxide were not produced as by-products. Biological effectiveness testing was completed with the algae, Selenastrum capricornutum and bacteria, Escherichia coli and Enterococcus faecium, in dechlorinated laboratory water. The system was found to be ineffective in the treatment of algae and bacteria when operated for approximately 30 minutes, and ineffective in treatment of algae when operated for 6 hours. However, when operated for 24 hours results suggest that the Kria Ionizer was effective against bacteria.