微生物杀灭效果试验中的游离氯转化研究 |
摘要点击 2520 全文点击 1725 投稿时间:2007-12-12 修订日期:2008-05-10 |
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中文关键词 消毒 游离氯 大肠杆菌 有机氯胺 |
英文关键词 disinfection free Chlorine E.coli organic N-chloramines |
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中文摘要 |
在实验室研究游离氯灭活微生物的试验中发现,由于试验体系中有机氮的存在,投加游离氯消毒后,游离氯会迅速与之反应转化为无消毒作用的有机氯胺.在对大肠杆菌、铁细菌、铜绿假单胞菌的研究中均发现同样的问题,投加2 mg·L-1的游离氯消毒剂对初始菌浓度为108 CFU·mL-1的大肠杆菌进行灭活试验,反应5 min后游离氯就已经为0,而一氯胺和二氯胺的量分别为0.92 mg·L-1和0.4 mg·L-1.为了降低有机氮的干扰,采用多次离心纯化菌液、膜过滤纯化菌液和增加受试菌液的稀释倍数的方法进行测试,发现当菌液浓度降至105CFU·mL-1以下时,游离氯转氯胺的比例可以明显降低;而2种纯化过程并不能分离菌液中的有机氮,进而改善试验中出现的游离氯转氯胺的现象.该结论也说明参加反应的有机氮应来源于细菌自身的细胞物质,有机氮的干扰在消毒的相关研究中需要引起关注. |
英文摘要 |
Due to organic N exiting in the pure bacterial cultures, when using free chorine to inactivate microorganisms, freest chlorine transforms into organic N-chloramines which are no use in disinfection process. This reaction happens in E.coli, Pseudomonas aeruginosa inactivation experiments. Added 2 mg·L-1 free chlorine to inactivate E.coli of 108 CFU·mL-1, free chlorine exhausts in 5 min while chloramines and dichloramines become 0.92 mg·L-1 and 0.4 mg·L-1.E.coli is used as test microorganism in following inactivation experiments. E.coli suspension is purified by centrifugal and membrane filtration, but the purification can't help to separate the organic N from E.coli suspension, which indicating that the source of oaganic N may be from bacterium cells. Dilution is worked when E.coli concentrations are diluted under 105 CFU/mL. This result should be regarded in related researches in future. |