Application of Self-Produced Membraneless Electrolyzed Water on Suppression of the Major Pathogens of Phalaenopsis

• Main Authors: Yi-Cheng Wang, 王奕程
• Other Authors: Wei Fang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/78119506384299603266

碩士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 96 === 　Impacts of various electrolysis conditions on pH, ORP and FAC (free active chlorine) were investigated for the production of membraneless electrolyzed water, including electrolyte concentration, voltage, time elapsed, types of solvent and distance of electrodes. Results showed that condition of using KCl as the solute, using de-ionized water as solvent, high electrolyte concentration and low electrolyzed voltage has the highest efficiency in producing FAC in terms of electricity cost. Membraneless electrolyzed water has high EC, thus making it not suitable for irrigation. Method to produce saltless electrolyzed water with low EC was introduced. 　Self-produced membraneless electrolyzed water was applied to the suppression of 5 major pathogens of Phalaenopsis. The lowest FAC concentrations required to kill pathogens of soft rot, botrytis blight, southern blight, phytophthora rot, and yellow rot were identified. They are: 60, 30, 60~120, 120~200 and 120 ppm, respectively. Among those pathogens, pathogen of botrytis blight required the lowest FAC concentration (30 ppm) to reach 99 % disinfection effect. 　Cyclic voltammetry was used to analyze the FAC concentration of the electrolyzed water. The linear relationship of oxidation peak current at 1100 mV and FAC concentration of sodium hypochlorine (NaClO) from 10 to 1000 mM were established. Same linear relationship can be found with the membraneless electrolyzed water using KCl as the solute. The equation is listed as follows: Y = 18.509 * X . Where X is the oxidation peak current in μA at 1100 mV at 50 mV/s sweep rate and Y is the FAC concentration in ppm. 　Based on this finding, measurement of FAC value can be greatly simplified. The lowest oxidation peak current at 1100 mV of membraneless electrolyzed water to kill 99% of the above listed pathogens are 3.24, 1.62, 3.24~6.48, 6.48~10.81 and 6.48 μA, respectively.