<；P>；PROBLEM TO BE SOLVED: To surely inhibit generation of hydrogen sulfide due to water stagnation in a recessed part etc. formed in a water bottom and generation of a blue tide caused by it over a long period of time. <；P>；SOLUTION: A laying material entirely or partially made of slag generated in a steel manufacturing process is laid on one of hydrogen sulfide sources among (1) the recessed part formed in the water bottom, (2) a water bottom in a water area where hydrogen sulfide is detected in its bottom layer water, or in a water area where dissolved oxygen concentration in its bottom layer water is equal to or lower than a fixed value, (3) a water bottom in a water area where the flow rate of the bottom layer water is equal to or lower than a fixed value, and (4) a water bottom in a water area where a pycnocline by a water temperature or/and salt concentration is formed in water. The generation of hydrogen sulfide is inhibited by CaO contained in the slag, and hydrogen sulfide and phosphorus in water are fixed on the slag, which stably inhibit the generation of hydrogen sulfide and the generation of the blue tide caused by it over a long period of time. <；P>；COPYRIGHT: (C)2004,JPO&NCIPI
