| 摘要 |
<p>PURPOSE:To obtain a filter material for treating waste water showing high treatment efficiency by forming the filter material from baked clay having a specific void ratio and forming the specific ratio parts of voids from random pores and micro-pores respectively having specific diameters and holding bacteria to the aforementioned pores with high density. CONSTITUTION:Clay composed of silicate/alumina (iron content about 10% or less), saw dust (pref. particle size : about 2mm or less, pref. apparent specific density : about 0.23g/ml) and other porous material (pumice) are mixed and baked at about 800 deg.C to obtain a filter material. The void ratio of this filter material is set to 60-85% and 85-97% of voids is formed from random pores having a diameter of 20-2000mum and 3-15% thereof is formed from random micro-pores having a diameter of 0.01-10mum and bacteria are held to the aforementioned pores with high density. By this filter material thus formed, bacteria can be held with high density and raw water can be supplied in a sufficiently diffused state and biological treatment of waste water can be realized with high treatment efficiency.</p> |
