| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a packing material for water treatment to be used as a packing material for biological waste water treatment by a dip filter bed method and to provide a packing material which has high holding ability of microorganisms, fast dissolving rate of oxygen and high strength and which is hardly crushed and can be easily supplied to pack a treating tank. SOLUTION: This packing material 2 has a hollow tetrahedral structure and all faces have a neat-like structure. Alternatively, the packing material has such a structure that is produced by crushing and fixing a peripheral wall of a cylinder to seal one end in the axial direction of the cylinder while the other end is open and that the material has net-like faces. In this case, the packing material is made of a thermoplastic plastic material. More preferably, the pore area of each pore in the net-like face 4 is controlled to 1 to 100cm<2> and the porosity per unit area is controlled to 60 to 99%.</p> |
