Comparison of ferrate (FeO4 2-) and ultrasonic waves ability as Coliform antibacterial in Kahayan River water Central Kalimantan

Abstract

This study aims to compare ferrate (FeO4 2-) and exposure of ultrasonic waves as an antibacterial coliform in the Kahayan River water in Central Kalimantan. Sampling in this study used the Grab Sampling method with the Kemmerer Sampler tool. Ferrate (FeO42-) was made by reacting to a solution of Fe(NO)3 with NaOCl in alkaline conditions. Application of Ferrate (Fe(VI)) done by varying the concentration (0.03125; 0.0625; 0.125; 0.25; 0.5 mmol/L) to get the best concentration, and follow by varying times (0, 5, 10, 15, 20, 25, 30 minutes) at optimum concentration. Ultrasonic wave exposure was carried out with varying frequencies to get the optimum frequency and followed by variations in the exposure time at the optimum frequency. The coliform test was carried out by the MPN method with stages of detection tests, affirmation tests, and colony counting. The MPN analysis showed that ferrate could kill coliform bacteria at a concentration of 0.0625 mmol/L during the 5 minutes stirring time with 100% efficiency. Ultrasonic wave exposure could kill coliform bacteria optimally at a 40 kHz frequency during 3 hours of exposure time with 96% efficiency These results showed that ferrate was more effective in killing coliform bacteria compared with ultrasonic wave exposure.