Application of break point chlorination in sodium hypochlorite disinfection of reclaimed water
折点加氯反应在次氯酸钠消毒中水中的应用

The relationship of break point chlorination reaction and disinfection effects was studied to reveal process of reclaimed water disinfection using sodium hypochlorite as disinfectant. Contact time and chlorine dosage formulas according to ammonia nitrogen concentration were obtained through analyzing the relationship of positions of chlorine dosage on break point curve and corresponding disinfection effects, contact time and ammonia nitrogen concentration. The results showed that ensuring chlorine dosage enough to exceed that of break point with 30 minutes of contact time when ammonia nitrogen concentration was less than 2 mg/L, or chlorine dosage nearby that of peak point with 60 minutes of contact time when ammonia nitrogen concentration was more than 2 mg/L, both could achieve disinfection effects.