Effect of Combination Disinfection of Chlorine Dioxide and Chlorine on Formation Amount of Chlorate and Chlorite in Water

[Objective] To observe the effect of combination disinfection of chlorine dioxide(ClO2)and chlorine(Cl2)on formation amount of chlorate and chlorite in water.[Methods] Adding different doses of ClO2 and Cl2 into mineral water,to analyze the concentration of chlorate and chlorite in different conditions.[Results] Under different pH value,when adding ClO2/ Cl2 by 2 ∶1,the chlorate concentration raised with pH value.The concentration of Cl2 residue and free chlorine do not vary with pH value.Under the sunshine condition,chlorite and ClO2 concentration did not increase with the time after combination disinfection of ClO2 and Cl2.Meanwhile,the chlorate and free chlorine decreased with the time.Under different pH conditions,when chlorine dioxide and chlorine are added in mineral water by 2 ∶1 and by 1.5 ∶2,the first chlorite concentration was lower than the second.[Conclusion]Chlorite concentration has no relationship with pH value,the different proportion of chlorine dioxide and chlorine,sunshine and disinfection time.