Original Articles
Yu Bo, Zhou Ying, Huang Zhengw
Abstract
Combined disinfection with UV radiation and sodium hypochlorite was applied in disinfection the effluent after secondary treatment of hospital sewage. The inactivation effect of different combination modes and sequences of UV and sodium hypochlorite was studied. The contrast experiments of disinfection effect and the levels of residual chlorine were conducted by adding different dosage of sodium hypochlorite and exposing on different UV radiation time. The results of first experiment showed that the removal rate of fecal coli-group was ascending with the increase of the dosage of Sodium hypochlorite. When the dosage was 18 mg·L-1, the fecal coliforms cannot be detected. When the dosage was less than 6 mg·L-1, the total residual chlorine could meet the emission limits. And the results of next experiment showed that the removal rate of fecal coliforms was ascending with the increase of ultraviolet dosage. When the ultraviolet dosage was 0 J/m2, the fecal coliforms cannot meet the Chinese discharge standard. When the dosage was more than 100J/m2, the disinfection effect was not influenced by ultraviolet dosage.