次氯酸钠氧化脱除废水中氨氮的研究

Removal of ammonia-nitrogen from wastewater by sodium hypochlorite oxidization

与传统的氯系氧化剂液氯相比,次氯酸钠不仅使用安全无氯气外泄的危险,而且可进一步减少消毒副产物的产生,因此用于废水中氨氮的去除是较合适的氯化氧化剂。研究以质量浓度为100mg/L的氨氮模拟废水为对象,通过正交试验和单因素试验系统地探讨了氯与氨氮的量比、反应时间和pH值等因素对次氯酸钠氧化脱除氨氮的影响。结果表明,影响次氯酸钠氧化脱除氨氮的主次因素顺序为氯与氨氮的量比、反应时间、pH值。此外,分别在高低两种氨氮浓度下,考察了有机污染物苯酚的存在对氨氮去除效果的影响,试验结果表明两种氨氮浓度条件下,氨氮去除率都随苯酚浓度增加而减少,但高浓度氨氮受苯酚的影响程度较低浓度的小。

Abstract： Compared with traditional chlorine series oxidants, sodium hypochlorite can not only avoid the leakage of chlorine, but can further reduce the disinfection byproducts as well, therefore, it is an appropriate chlorine oxidant for NH3-N removal. With simulant ammonia-nitrogen wastewater whose mass concentration was 100 mg/L as the study object, the effects of mass ratio of chlorine to ammonia-nitrogen, reaction time, pH value and some other factors on sodium hypochlorite removing ammonia-nitrogen were systematically studied through orthogonal test and single-factor test. The results showed that, the influence degree of the above factors presented the following descending order： mass ratio of chlorine to ammonia-nitrogen, reaction time, pH value. Besides, the effect of phenol on ammonia-nitrogen removal under two different ammonia-nitrogen concentrations was also investigated, it was found that, the removal rate of ammonia-nitrogen under the two conditions decreased with the increasing of the phenol concentration, and the influence degree of phenol on ammonia-nitrogen with low concentration was greater than that with high concentration.