Department of Water Treatment Technology, Faculty of Chemistry, A. Mickiewicz University, Drzymały St. 24, 60-613 Poznań, Poland.
Water Res. 2010 Mar;44(6):1863-72. doi: 10.1016/j.watres.2009.12.020. Epub 2009 Dec 21.
Corrosion processes in drinking water distribution systems have been investigated for years. This paper proves the existence of a layer of steady water surrounding and partly filling corrosion scale in corroded water pipes. It is expected that steady water may substantially influence the corrosion. The idea of steady water explains why longer retention times would lead to more turbid waters containing more suspended Fe oxides (hydroxides). During stagnation period stagnant water mixes partially with steady water and the compensation of ions' concentration as well as particle diffusion is observed. Steady water is rich in ions and has reductive properties causing quick disappearance of nitrates and unwanted ammonia formation. Ammonia in turn may be responsible for fast oxygen and chlorine decay in the distribution system due to nitrification. Nitrates may also undergo denitrification in steady water, i.e. they would support bacterial existence in the distribution system. Such an environment makes favourable conditions for sulphate reducing bacteria and in fact in all of the steady water samples we have detected sulphides. Moreover, our results have shown that considerable amounts of assimilable organic carbon (AOC) can be formed in the corroded distribution system.
多年来，人们一直在研究饮用水分配系统中的腐蚀过程。本文证明了在腐蚀的水管中，存在一层稳定的水，包围并部分填充了腐蚀层。预计稳定的水可能会对腐蚀产生重大影响。稳定水的概念解释了为什么较长的停留时间会导致含有更多悬浮 Fe 氧化物（氢氧化物）的更浑浊的水。在停滞期间，停滞水部分与稳定水混合，观察到离子浓度的补偿和颗粒扩散。稳定水富含离子，具有还原性，导致硝酸盐迅速消失和不必要的氨形成。氨反过来可能会由于硝化作用而导致在分配系统中氧气和氯气迅速衰减。硝酸盐也可能在稳定水中进行反硝化作用，即它们会支持细菌在分配系统中的存在。这样的环境为硫酸盐还原菌创造了有利条件，事实上，在我们检测到的所有稳定水样中都检测到了硫化物。此外，我们的研究结果表明，在腐蚀的分配系统中可以形成相当数量的可同化有机碳（AOC）。
