Abstract
Experiments described in this paper demonstrated changes in the chemistries and microflora of two natural coastal seawaters collected from Key West, FL and the Persian Gulf as a result of storage and environmental conditions. Exposure to an anaerobic atmosphere containing a mixed gas of nitrogen, carbon dioxide, and hydrogen generated the highest microflora concentration, especially sulfate-reducing bacteria (SRB). Biotic dissolved sulfide levels were also highest in the mixed gas atmosphere. In contrast, sulfides were not detected in seawater maintained anaerobic with bubbled nitrogen. Separate introductions of carbon steel and agitation also affected chemistries and microflora. Key West seawater consistently had equal or greater bacterial numbers in all conditions when compared with Persian Gulf seawater. Bubbling nitrogen into natural seawater to achieve an anaerobic condition is not conducive to the growth of SRB and the resulting biotic sulfide. Laboratory experiments that mimic anaerobic conditions by bubbling nitrogen may not produce conditions found in field due to pH changes. A follow on paper is planned to address influences of chemistry and microflora on corrosivity.
