使用自来水模拟管道循环系统的实验结果表明，水质变化主要与铁金属的氧化有关。在管道循环系统中观察并鉴定了多种水生微生物，其中包括构成碳、氮、硫和铁转化微生物循环的生物体。随着微生物的生长，铸铁试样出现局部腐蚀。包括42个参考文献、表格和图表。

That water quality changes are related primarily to the oxidation of iron metal was indicated by results of an experiment with a simulated pipe loop system using tap water. A variety of aquatic microorganisms was observed and identified in the pipe loop system, among them the organisms that constitute the microbiotic cycles of carbon, nitrogen, sulfur, and iron transformation. With microbial growth, cast iron test specimens exhibited localized corrosion. Includes 42 references, tables, figures.