| 摘要 |
<p>PROBLEM TO BE SOLVED: To directly clean water in a raising tank of fish and shellfish by using a fiber sheet having adsorbed a nitrifying bacterium and a denitrifying bacterium in a high density. SOLUTION: In this water storage circulation type fish farm for fish and shellfish, at least one of bacterium carriers 7 and 8 having adsorbed a nitrifying bacterium and a denitrifying bacterium in a high density, respectively is movably stretched at a fixed position in the raising water tank 2. Nitrogen compounds discharged from raised fish and shellfish are brought into contact with the bacterium, decomposed and removed. The bacterium carriers are immersed in culture solution tanks 9 and 10 which are cultured in high density and have densities of the nitrifying bacterium and the denitrifying bacterium to be adsorbed on the bacterium carriers 7 and 8 in high densities of >=10<7> -10<9> cells/ml, taken in the raising water tank while maintaining the same densities and recirculated through the high-density culture solution tanks. A fiber sheet having adsorbed the bacteria in high densities is shaken or waved to stir ambient raising water and to promote the contact of the bacteria with nitrogen compounds.</p> |
