The medium- or coarse-grained slag showed lower removal
efficiency than the fine-grained slag. When the medium-grained
slag was tested, as shown in Fig. 2(c), the efficiency decreased to
31.5% and pH became lowered less than 8.0 at 25 BV. The least
phosphorus removal rate was observed in Fig. 2(e) in which the pH
level decreased to 7.3 at 8 BV.