ORGANIC-MATTER AND SEVERAL METALS IN SEDIMENTS FROM THE HIRO BAY, HIROSHIMA-KEN

Organic carbon, iron, manganese, zinc and copper in the sediments of the Hiro Bay contaminated with a pulp mill effluent were determined. There were positive correlations between organic carbon and iron, zinc/or copper in humic substances extracted from the sediments with 0.5 N sodium hydroxide solution. First of all, humic and fulvic acids extracted from the sediments were fractionated on Sephadex gel columns. The humic acid fraction showed a molecular weight distribution from 0 to over 200000. Humic acid with mol. wt. 10000~50000 covered 48.3% of the total eluted from the column, and iron, zinc and copper were eluted down with respective proportions of 45.1, 30.2 and 47.0% along with the humic acid fraction just mentioned. Fulvic acid exhibited a relatively narrow mol. wt. range not exceeding 10000. Fulvic acid fraction having mol. wt. less than 700 was as high as 70.1% of the total eluted from the column, and iron, zinc and copper were removed along with it with proportions of 78.2, 61.1 and 60.7%, respectively. © 1979, The Chemical Society of Japan. All rights reserved.