BIANNUAL MONTHLY CHANGES OF SEA SLUDGE COMPOSITION FROM HIDAKA PORT, WAKAYAMA, JAPAN

Abstract

The composition of sea sludge varies from location to location and from time to time, since it
is affected by various external environmental factors. In this study, we analyzed the organic and inorganic
contents of sludge samples collected for two years (25 months) from the Hidaka Port in Wakayama. Weightloss analyses for 25 months indicates that the highest inorganic content was in July 2016 (99.11%), and the
lowest in April 2018 (87.46%). We then conducted EDX Spectrometry analyses on some samples, focused
on Si, Al, Fe, and S, for the samples of the first 16 months. Our result indicated that while the dynamics of
total inorganic content was naturally synchronized inversely with that of the organic content, it was not
completely reflected in the dynamics of individual inorganic elements. For example, Fe and Al changes were
not congruent with the changes of the total organic and inorganic contents. However, Si and S showed
possible agreements with the changes of total inorganic and organic contents. From these results, we deduced
that the dynamics were probably caused by environmental factors such as weather and water temperature,
and the activities of living organisms such as diatoms, alga, and microbes.