AWWA JAW3896

Tubercle deposits collected from pipelines in the Columbus, Ohio, distribution system and examined for their microbiological, chemical, and mineralogical composition were found to contain several kinds of organisms, including sulfate reducers, nitrate reducers, nitrite oxidizers, ammonia oxidizers, sulfur oxidizers, and various unidentified heterotrophic microorganisms. Chemical analysis revealed that the tubercles consisted almost exclusively of iron oxides, the total iron amounting to approximately 50 percent of tubercle dry weight. Also covered were coupon experiments, scanning electron microscopy (SEM), carbon determinations, mineralogical characterization, Eh and pH, bacterial characterization, elemental transport analysis, and X-ray diffraction. Includes 35 references, tables, figures.