臭氧-氯联合灭活饮用水中枯草芽孢杆菌芽孢的研究

Evaluation of sequential inactivation of Bacillus subtilis spores in drinking water with ozone and chlorine

以枯草芽孢杆菌芽孢为模型微生物,研究了实际水体中单独氯消毒、单独臭氧消毒和臭氧-自由氯联合作用的灭菌效果。结果表明,枯草芽孢杆菌芽孢对单独氯消毒的抗性很大,6 mg/L氯作用240 min后灭活率仅为0.84个对数级;臭氧对枯草芽孢杆菌芽孢有较好的灭活效果,臭氧作用5 min,对其有4.68个对数级的灭活率。与单独氯消毒相比,臭氧-氯联用消毒对枯草芽孢杆菌芽孢的灭活效果大大增强;当臭氧作用2 min后投加6 mg/L氯,对枯草芽孢杆菌芽孢的灭活率可达7.1对数级,远高于两者单独作用效果之和。臭氧与氯联合灭菌是一种协同作用,并且随着臭氧预处理时间增加,协同作用增强。

The inactivation effect of Bacillis subtilis（B.subtilis） spores with individual chlorine disinfection,individual zone disinfection and sequential disinfection with ozone followed by free chlorine,was examined in natural water samples.Results show that B.subtilis spores were highly resistant to free chlorine disinfection.Only 0.84 log reduction was achieved by chlorine when initial chlorine concentration was 6 mg/L and contact time was 240 min.Ozone disinfection is more effective than chlorination.At contact time of 5 min,ozone disinfection results in 4.68 log reduction.Up to 7.1 log reduction was achieved with 2 min ozone pretreatment followed by 6 mg/L chlorine,which is much higher than the sum of inactivation rate of zone and chlorine disinfection individual.The effect of the combined applications of ozone and chlorine in inactivating B.subtilis spores is a kind of synergistic effect,which is enhanced with the increase of the level of ozone pretreatment.