Abstract
Experiments were executed to make clear the effectiveness of crushed roof tiles as the packing material of slant soil layer method. The following conclusions were obtained from the results. 1) Aerobic reaction could happen more actively in the case using crushed roof tiles than in the case using Akadama soil or Kanuma soil. 2) The reaction could happen at about 10 degrees Celsius. 3) The removal of ammoniac nitrogen and phosphoric acid phosphorous was mainly caused by absorption. 4) The nitrogen and phosphorous removal ability of Akadama soil and Kanuma soil was superior to that of crushed roof tiles. 5) A high denitrification ability of a slant soil laiyer could be obtained by adjusting the particle size of crushed roof tiles. Therefore, it is possible to make an advanced sewage treatment slant soil layer system by combining some types of slant soil layers.
