CIRCULATORY RAISING SYSTEM FOR FISH-AND-SHELLFISH AND CONTAMINATION REMOVAL

摘要

PROBLEM TO BE SOLVED: To economically perform the maintenance of a circulatory raising system for fish-and-shellfish by adding an aqueous solution of sodium hypochlorite to a filtration tank during every temporary halt of raw water circulation to easily remove a contamination of the system. SOLUTION: In the circulatory raising system for fish-andshellfish designed to feed a filtration tank 18 with the raw water from a fish-and-shellfish raising tank 10 to subject the raw water to filtration and then return the resulting raw water thus filtered to the raising tank 10, raw water circulation is halted at time intervals, and during every temporary halt of the circulation, an aqueous solution of sodium hypochlorite produced by electrolysis of part of the raw water in the raising tank 10 in a saline solution electrolytic bath 46 is added to the filtration tank 18 to remove a contamination of the system including a filter medium 2O; wherein the sodium hypochlorite concentration of the aqueous solution is set pref. at 0.1-4 ppm.