NO2-N含量对预臭氧化工艺效果影响研究

探讨了深圳某给水厂原水中NO2--N含量对预臭氧化工艺效果的影响.室内静态试验结果表明,深圳原水的O3消耗量与NO2--N完全去除的比例为51(O3消耗量/NO2--N的理论值约为3.4);当原水NO2--N＜0.1 mg/L时,NO2--N对预臭氧工艺无影响,而当NO2--N＞0.18 mg/L后,预臭氧化工艺去除有机物效果(以UV254表征)明显降低;水厂生产结果表明,NO2--N含量对预臭氧化工艺中的臭氧投加量及处理效果具有显著影响,原水中较高的NO2-N还会对后续混凝沉淀和砂滤工序造成不良影响,原水经生物预处理和封闭管道改造后,NO2--N由0.12～1.85 mg/L降低到0.02～0.14 mg/L,CODMn去除率明显升高.

NO2- - N content effects on preozonation process in drinking water treatment

The effect of NO2- - N content in raw water on the preozonation process was investigated in a waterworks n Shenzhen. By both bench scale and pilot plant experiments evident correlations between NO2- - N content and O3 dosage for full removal of nitrites was observed, and the rate of 03 and NQ2- - N is 5:1. In case when NO2- - N is less than 0.1 mg/L, the effect on preonzonation is neglect. Otherwise in case when NQ2- - N>0.18 mg/L, the UV254 removal decreased after preonzonation. The practice result shows that NQ2- - N content obvious affect the preoznoation process and the high NQ2- - N content will deteriorate to affect the subsequent processes like sedimentation and filtration. After the preoznoation and reconstruction close pipe, NQ2- - N content decreases from 0. 12 - 1. 85 mg/L to 0.02-0.14 mg/L and the removal of CODMn increased obviously.