1996 Volume 32 Issue 2 Pages 111-121
The Effects of magnesium, aluminium, ferric and manganese ions, and silitic acid on the growth of Bacillus sp. (32 strains) isolated from aerobic and malodorless digestion tanks of night soil were elucidated. By the comparison of OD value after 15 hr-incubation, the growth of 22 strains was fbund to be stimulated by magnesium ion at the concentration of 63 mg⋅l-1, and 25 strainsby the mixture of magnesium ion (32 mg⋅l-1) and silitic acid (53 mgl-1) . The fission of thefilaments was observed in the latter case. Aluminium, ferric and manganese ions promoted thegrowth of them at the concentration of 5 mg·l-1, and inhibited the growth in the concentration from 20 to 30 mg⋅l-1. By the addition of magnesium (300 g⋅day-1) into the digestion tank of night son (200 kL⋅day-1), the ratio of the excess activated sludge to the discharge decreased from 3.3: 100 to 2.73: 100 (the weight of excess sludge, 45t/week to 36t/week, water content, 79%) .
