Mechaism of Sulfide Formation in Polluted Mud

cases of Lake Barato and Otaru Canal, Hokkaido, Japan

Abstract

The concentration of sulfide in the mud of many polluted water basins in Japan practically exceeds 0.2mg/g dry mud, the fishery standard.
In this research on Lake Barato (fresh water, partially brackish water) in the suberbs of Sapporo city and on Otaru Canal (sea water) of Otaru city which is connected to the Bay of Ishikari, I comprehended the actual condition of sulfide in the mud measuring its concentration and the number of sulfate reducing bacteria which form it, and I made its formation mechanism clear by laboratory work.
The resultes of this research are as follows:
(1) Sulfide in the mud of these water basins (especially sea water basin) polluted by the urban waste water exists in proportion to organic content and exceeds far beyond the standard.
(2) Sulfide as iron sulfide accumulates more in sea water than in fresh water.
(3) The sulfide formation rate is influenced by temperature but not by concentration of sulfate nor the number of sulfate reducing bacteria.