PROBLEM TO BE SOLVED: To provide an improvement method for soil contaminated with a heavy oil or the like also performing treatment of mytilus edulis deposited on a cooling water-taking pipe of a power plant, a buoy and a fish-net. SOLUTION: The deposition substance making mytilus edulis as a main substance is crushed, dehydrated, dried and extracted to make granules into which a homogenate liquid contained in a digestive gland is mixed. By spraying and pouring this, the soil contaminated by the heavy oil or the like can be improved, and the shell and the body of the mytilus edulis are separated as a residue and can be made to a fertilizer or a cleaning agent. COPYRIGHT: (C)2009,JPO&INPIT
