ABSTRACT
Growth of the ammonium-tolerant green alga Scenedesmus quadricauda was examined in effluents from methane fermentors which used swine wastes as a substrate. The alga grew well in 1% and 10% effluents, but did not grow in 20% effluents. The addition of ammonium of 0 to 28 mM to the 1% effluents did not affect rate constants for growth. The addition did not also affect photosynthetic activities during the exponential phase of growth. Potosynthetic activities in the 10% effluents were lower, but were still comparable to the activity in the 1 % effluents. Electron micrographs showed that starch granules were prominent in cells grown in 1% effluents with no addition of ammonium, and became smaller with the increased addition of ammonium. In the 10% effluents, the starch granules were small and the membrane systems of chloroplasts were well developed, although the cells were swollen. These results indicate that growth and physiology did not vary so much in the 1% and the 10% effluents, though the morphology changed a little. Percentage of removal of ammoniuml-nitrogen and phosphate-phophorus in the 1% effluents was 99.7 and 73.8%, respectively. In the 10% effluents, the percentage was 78.0% for ammonium and 62.8% for phosphate. This removal efficiency suggests that S.quadricauda can be used for the treatment of effluents after methane fermentation of livestock wastes.HomePage