Sterilization of Spent Bathwater and Washed Fabrics by the Addition of Weakly Acidic Electrolyzed Water

This paper attempts to propose a laundry use of spent bathwater in Japan sterilized by non-diaphragm electrolytic treatment (Single cell). Twenty liters of spent bathwater was treated with 25 mL of electrolyzed water obtained by electrolytic treatment to examine its bactericidal effect. The treated bathwater also was used for washing fabrics to examine the antibacterial effect of the treatment on the washed fabrics. Before the experiment, non-treated bathwater was used for washing fabrics and revealed that the washed fabrics had as many as 8.19x10(3) CFU/mL viable bacteria. When distilled water was used for "rinsing" the washed fabrics, many viable bacteria remained on the washed fabrics, even after "rinsing" for 12 minutes. Addition of 25 mL of aqueous HCl to 20 L of spent bathwater indicated that the acid did not have any bactericidal effect. In contrast, addition of 25 mL of electrolyzed aqueous HCl to 20 L of spent bathwater almost completely eliminated viable bacteria. Moreover, when the treated bathwater was used for washing fabrics dipped in the spent bathwater, few viable bacteria were found on the washed fabrics. These results demonstrate that non-diaphragm electrolytic treatment was very effective at killing bacteria in spent bathwater and at sterilizing fabrics washed in the treated bathwater.