谢文芳, 陈中文, 闫硕, 周哲华. 管道直饮水加热后颜色变深原因的调查[J]. 环境与职业医学, 2014, 31(5): 385-387,391. DOI: 10.13213/j.cnki.jeom.2014.0086
引用本文: 谢文芳, 陈中文, 闫硕, 周哲华. 管道直饮水加热后颜色变深原因的调查[J]. 环境与职业医学, 2014, 31(5): 385-387,391. DOI: 10.13213/j.cnki.jeom.2014.0086
XIE Wen-fang , CHEN Zhong-wen , YAN Shuo , ZHOU Zhe-hua . Cause Analysis on Color Deepening of Heated Piped Direct Drinking Water[J]. Journal of Environmental and Occupational Medicine, 2014, 31(5): 385-387,391. DOI: 10.13213/j.cnki.jeom.2014.0086
Citation: XIE Wen-fang , CHEN Zhong-wen , YAN Shuo , ZHOU Zhe-hua . Cause Analysis on Color Deepening of Heated Piped Direct Drinking Water[J]. Journal of Environmental and Occupational Medicine, 2014, 31(5): 385-387,391. DOI: 10.13213/j.cnki.jeom.2014.0086

管道直饮水加热后颜色变深原因的调查

Cause Analysis on Color Deepening of Heated Piped Direct Drinking Water

  • 摘要: 目的 调查某公司管道直饮水加热后颜色变深的影响因素,阐明水质深度净化处理过程中产生二次污染的主要原因。

    方法 分3次随机采集嘉兴市某公司地下室至17楼经管道直饮水系统净水设备处理后的水样33份及贮水箱底部可疑结晶物1 g,同时采集未通过管道直饮水系统的市政自来水16份作为对照,以GB/T 5750-2006《生活饮用水标准检验方法》为依据检验色度、浑浊度、臭和味、亚硝酸盐、肉眼可见物、铅、砷、铜、镉、铁、锰、锌、耗氧量、pH值、菌落总数、总大肠菌群。

    结果 33份直饮水冷水合格率为27.3%; 16份市政水合格率为100.0%。直饮水冷水的菌落总数、铜的超标率分别为57.6%、69.7%,铜的平均值是水质标准限值的1.12倍,其余14项指标合格率100.0%; pH值范围在5.0~6.8,均值是6.1。作为对照的市政供水各项指标检验结果均符合GB 5749-2006《生活饮用水卫生标准》。直饮机冷水检出的菌落总数、铜的超标率和市政供水比较差异均有统计学意义(P<0.05)。净化处理的出水(直饮水)亚硝酸盐含量高于进水(市政水)浓度,进水和出水中亚硝酸盐含量差异有统计学意义(P<0.05)。贮水箱底部结晶物确定是氢氧化铜结晶,黑色物质是氧化铜。

    结论 铜质管材输送及净水在管网中滞留时间过长,分支管道的水循环不完全导致的二次污染是引起直饮水加热后颜色变深的主要原因。反渗透装置出水偏弱酸性,在新铜管内发生吸氧腐蚀,蓝色的氢氧化铜加热变成黑色的氧化铜。

     

    Abstract: Objective To identify the main causes of secondary pollution in the process of deep water purification treatment by analyzing potential factors for color deepening of heated piped direct drinking water in a company.

    Methods Totally 33 water samples purified in piped direct drinking water system were collected from basement to the 17th floor of a company in Jiaxing City, and 1 g of suspicious crystal substances in the bottom of the water tank were also collected. Another 16 samples of unpurified water from municipal water supply system were collected as controls. Color, turbidity, odor and taste, nitrite, visible substances, lead, arsenic, copper, cadmium, iron, manganese, zinc, oxygen consumption, pH value, total bacterial count, and total coliform were tested according to the Standard Test Methods for Drinking Water (GB/T 5750-2006).

    Results The qualification rate of the 33 samples of cold direct drinking water was 27.3%, and that of the 16 samples of water from municipal water supply was 100.0%. The disqualification rates of total bacteria count and copper in the cold direct drinking water samples were 57.6% and 69.7% respectively. The average content of copper in the cold direct drinking water samples was 1.12 times of the compulsory water quality limit. Other 14 indicators were all 100.0% qualified. The pH values ranged between 5.0 and 6.8, with an average of 6.1. In contrast, all test results of the control samples met the requirements of Standards for Drinking Water Quality (GB 5749-2006). There were differences in disqualification rates of total bacteria count and copper between the water samples from direct drinking device and municipal water supply (P<0.05). The nitrite contents in the outlet water of purification device (direct drinking water) were significantly higher than in the inlet water (municipal water supply water) (P<0.05). The crystal substances in the bottom of water tank were confirmed as crystal of copper hydroxide, and the black substances were copper oxide.

    Conclusion Using copper pipes, long-time stay in pipes of purified water, and incomplete circulation of water in branch pipes cause secondary pollution, and they are main contributors for color deepening of heated direct drinking water. The weak acid outlet water in reverse osmosis apparatus tends to corrode fresh copper pipes with absorption of oxygen, which will turn blue copper hydroxide into black copper oxide when heated.

     

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