桶装饮用水的饮用时间对细菌学指标的影响

目的探讨桶装饮用水的饮用时间及其卫生安全性。方法于2004年7—10月,随机抽取河南省新乡市饮用水市场中同一批次的桶装饮用水,将其中检测合格的桶装饮用水分为对照组与实验组。将实验组安装在事先选定的饮水机上,并置于饮用状态;对照组则封口保存于无菌室内。在第5、10、15、20天,采集对照组与实验组水样进行检测和评价。结果夏季,实验组在第5、10天,水样均未超标;在第15、20天,分别超标39、40桶,超标率为97.5%,100%。大肠菌群在各饮用时间均未超标。菌落总数在第5天变化不明显;第10天开始升高,但还在国家标准范围内;第15天急剧升高,超标39桶,超标率为97.5%;第20天则全部超标。霉菌、酵母菌在第5、10天均未检出;第15天急剧升高,分别超标7、5桶,超标率分别为17.5%,12.5%;第20天分别超标12、9桶,超标率分别为30.0%,22.5%。夏季对照组水样均未超标。秋季,实验组和对照组水样均未超标。结论夏季,饮用时间在10d之内;秋季,饮用时间在20d之内,桶装饮用水微生物学指标是卫生安全的。

Hygienic Assessment of Barreled Drinking Water Quality

Objective To do a hygienic assessment for the preservation time of barreled drinking water. Methods 40 kinds of barreled drinking water samples, all passed the water quality test, were collected from the market in summer and autumn respectively. Each sample was put into a sterile bottle and then taken into the laboratory in 2 hours to detect the microorganism indicators in 0 day, 5 days, 10 days, 15 days and 20 days periodically. Results The qualified rate of microorganism indexes reached 100% in 10 days. As for total bacteria count, 97.5% exceeded the hygiene standard limit,the detected rate of fungi and yeast were 17.5% and 12.5% in 15 days, and 100% exceeded the standard limit,the detected rate of fungi and yeast were 30.0% and 22.5% in 20 days in summer. The qualified rate of microorganism indexes reached 100% in 20 days in autumn. Conclusion Barreled drinking water is safe for drinking in 10 days in summer and in 20 days in autumn.