二氧化氯对不同微生物的灭活特性及其对群落结构特征的影响

CHLORINE DIOXIDE’S INACTIVATION ON DIFFERENT MICROORGANISMS AND ITS INFLUENCE ON THE CHARACTERISTICS OF MICROBIAL COMMUNITY STRUCTURE

二氧化氯是一种性能优良、应用广泛的消毒剂,可通过破坏细胞或病毒的组成结构、阻碍细胞代谢等方式实现微生物灭活。在自配水条件下,以二氧化氯投加量×消毒时间计算,二氧化氯剂量在15 (mg·min)/L时,可实现对常见病毒(包括肠病毒71型、大肠杆菌噬菌体MS2等)3 log以上灭活率,在60 (mg·min)/L时,可实现对常见细菌(包括大肠杆菌、金黄色葡萄球菌等)1.5 log以上灭活率,但灭活隐孢子虫卵则需要更高的剂量(如1.9 log灭活率可能需约600 (mg·min)/L剂量);在实际污水厂进水中,30 (mg·min)/L二氧化氯剂量只能分别实现0.8 log和0.5 log的大肠杆菌和总大肠菌群灭活率。二氧化氯消毒效果随温度升高显著提升,对于不同微生物,pH的变化对二氧化氯消毒效果的影响可能存在不同,而水中的有机物通常会因消耗二氧化氯而降低消毒效果,但在自然水体中也存在由于天然有机物可能的影响导致消毒效果优于自配水的情况。关于二氧化氯消毒后细菌群落结构的变化研究不多,仅有少量研究涉及市政污水、再生水、饮用水等。二氧化氯消毒一定时间后,悬浮态和生物膜上的微生物均可能出现再生长现象,但再生长过程中这些残生细菌的群落结构变化及其生长分泌特性仍有待研究。

Chlorine dioxide is a kind of disinfectant with excellent performance and wide application. Chlorine dioxide disinfects microbe by means of damaging the structure of cells and viruses and inhibiting cell metabolism. Calculated by multiplying chlorine dioxide dosage by the contact time, chlorine dioxide was able to inactivate many common viruses(for example, Enterovirus 71, coliphage MS2, etc.) for more than 3 log inactivation rate with a dose of 15(mg·min)/L, and effectively inactivate bacteria(for example, Escherichia coli, Staphylococcus aureus, etc.) for more than 1.5 log with a dose of 60(mg·min)/L;however, more doses of chlorine dioxide were needed to achieve efficacious disinfection of Cryptosporidium parvum oocysts(for instance, achieving 1.9 log inactivation rate with about 600(mg·min)/L dose);in wastewater treatment plant(WWTP) influent, only 0.8 log of Escherichia coli and 0.5 log of total coliform inactivation rate were achieved with 30(mg·min)/L chlorine dioxide dose. The efficiency of chlorine dioxide inactivation was improved as the temperature rise, but the impact of pH for chlorine dioxide inactivation efficiency of different microbe may be different. Usually, organic matter in water samples weakened chlorine dioxide effect for disinfection by consuming chlorine dioxide. However, there were exceptions in natural waters with better inactivation efficiency than that in pure water which may result from the influence of natural organic matter. Research on microbial community structure after chlorine dioxide disinfection was insufficient with only a few studies concerning municipal sewage, reclaimed water and drinking water, etc. In a certain time after chlorine dioxide disinfection, both suspended and attached microbe may regrow, but changes of microbial community structure and secretion characteristics still remained to be studied.