投量比对氯胺/ClO_2联合消毒灭活氨氧化菌的影响

Impact of Dosage Ratio of Chloramine /Chlorine Dioxide on Ammoniaoxidizing Bacteria Inactivation

管网中发生硝化作用会带来一系列水质问题,而氨氧化菌(AOB)是硝化作用的主要菌群。研究了二氧化氯(ClO2)与氯胺(NH2Cl)对AOB的灭活效果,分析了投量比对两者联用灭活AOB效果、消毒剂衰减及亚氯酸盐(ClO-2)生成的影响,并考察了两者联用灭活滤池工艺出水中AOB的效果,以寻求一种安全高效的控制管道硝化作用的消毒方法。结果表明:ClO2及NH2Cl对AOB均具有一定灭活效果,但达到相同灭活率所需的ClO2量更少,30 min灭活AOB达5.380-lg时,1.5 mg/L氯胺与0.3 mg/L二氧化氯等效。投量比对联用灭活AOB的效果及ClO-2的生成量有影响,当NH2Cl∶ClO2=3∶1时,对AOB的灭活效果最佳,且ClO-2的生成量最低;相比单独消毒,NH2Cl和ClO2联合消毒能够提高对砂滤出水中AOB的灭活效果,降低ClO-2生成量,并减缓消毒剂的衰减;当两者的投量分别为0.45、0.15 mg/L时即可满足水质标准的要求。

Ammonia-oxidizing bacteria （AOB） are mainly responsible for nitrification in the pipe network, which brings about numerous water quality problems. Inactivation effects of AOB by chloramine （NH2Cl）, chlorine dioxide （ClO2） and combined NH2Cl and ClO2 disinfection were studied. The impact of combined NH2Cl and ClO2 dosage ratio on AOB inactivation, disinfectant decay and chlorite formation were investigated to determine a safe and effective disinfection method of controlling pipeline nitrification. The results indicated that inactivation effects of AOB were observed when using NH2Cl and ClO2. The ClO2 demand was lower than NH2Cl demand to achieve the same inactivation effect. 1.5 mg/L NH2Cl and 0.3 mg/L ClO2 achieved equivalent AOB inactivation of 5. 380-lg within 30 min. When NH2Cl ： ClO2 was 3 ： 1, the inactivation effect of AOB was optimal, and the chlorite yield was the lowest. Compared with individual disinfection, the combined NH2Cl and ClO2 could improve the disinfection effect of AOB, and reduce chlorite formation and disinfectant decay effectively. Dosages of 0.45 mg/LNH2Cl and 0.15 mg/L ClO2 could meet the water quality requirement.