| 摘要 |
<p>PURPOSE:To obtain a rational water treating filter medium which is porous from the surface to the inner layer, excellent in permeability to gas and water and water retentivity, having sufficient strength and durability and suitable for the implantation bedding and propagation of aquatic microorganisms. CONSTITUTION:Water or a soln. contg. nitrogen and phosphorus is added to 30-50vol.% of granulated porous mineral and 10-40vol.% of charcoal (including carbonized bamboo) to obtain a mixture 1, and 0.1-0.5wt.%, based on the gross weight, of a disintegrated mineral fiber or its suspension is added to 50-15vol.% of charcoal (including carbonized bamboo) or diatomaceous earth or their mixtures and 0-3vol.% of bentonite, and water is added and kneaded to obtain a kneaded material 2. The mixture 1 and the kneaded material 2 are kneaded and formed into a desired shape, and the shaped material is placed in a steam chamber heated at 63+ or -3 deg.C, hardened for 12-24hr. and aged.</p> |
