Method of generating enhanced biocidal activity in the electroylsis of chlorine containing solutions and the resulting solutions

Abstract

Abstract An aqueous medium or dilute brine containing about 10 p.p.m. to 21,000 p.p.m. of chloride ion, and essentially free of other halogen, is electrolyzed between spaced electrodes, with the exposed surface of at least the anode being a continuous surface of a platinum metal, at a minimum potential in the general range of about 10 volts for a 21,000 p.p.m. medium to 100 volts for a 10 p.p.m. medium, and current density below about 5 amps per square inch of electrode surface, with the effluent medium at a temperature in the range of about 55* to 95* F. and preferably about 60* to 75* F., and at a pH within the range 6 to 8.5 to thereby generate in said medium chlorine together with free radicals and other oxidizing species including ozone, said ozone being present in an amount to provide at least one part by weight of ozone to each 50 parts by weight of available chlorine in said effluent. Narrowing the pH range, adjusting the effluent temperature and increasing the voltage may increase the proportion of ozone. At a pH of 7 to 8, a temperature in excess of 60* F., and a potential about 25 percent above the minimum for a particular chloride ion concentration, the proportion of ozone to chlorine is generally in excess of one part ozone to 20 parts chlorine; and at a pH of 7.2-7.8, a temperature in excess of about 66* F. and a potential about 50 percent above said minimum this proportion may be as high as one part ozone to five or ten parts chlorine. Chloride is suitably supplied as NaC1 solution in varying concentrations in the fractional normality range, preferably about 0.003 N to 0.6 N corresponding with about 10 p.p.m. to 21,000 p.p.m. of chloride ion.

Inventors

• 👤 Ross M Gwynn
• 👤 Tim Themy

Bibliographic Details