the test waters after the bubbling in the case of the cl u2212 5 mg l electrolytic water and the cl u2212 17 mg l electrolytic water it was presumed from the above that hydrogen sulfide was decomposed by hypochlorous acid into odorless sulphuric acid a degradation reaction of hydrogen sulfide by hypochlorous acid is shown below in reaction formula 4 h 2 s 4hclo u2192 6h so 4 2 u2212 4cl u2212 4 in addition no difference was recognized in the concentration of hydrogen sulfide after the bubbling between the case where the electrolysis was also implemented during the bubbling table 2 and the case where the electrolysis was not implemented table 1 however the concentration of hypochlorous acid after the bubbling was higher in the case where the electrolysis was also implemented during the bubbling it is thus considered that more hydrogen sulfide can be decomposed in the case where the electrolysis is implemented and that sterilizing and odor eliminating effects are improved when the electrolytic water in the electrolytic cell 23 of the present invention is flown into the bowl 2 as described later table 3 shows the concentration mg l of hypochlorous acid in the test waters before and after bubbling and the concentration ppm of methyl mercaptan as the gas concentration of the odor component in the recovery gas pack in this case the test waters.