Abstract
In recent years, the amount of sludges issued from water purification process is increasing with high demand of city water. Since the sludges are mainly composed of soil particles and fine organic debris floated in row water, effective utilization on plant production is desirable. The purpose of this experiment is to investigate the utilization methods of the used sand scraped from slow water filtration pool and the pressed sludge issued from precipitation pond. The results obtained are as follows.
1. Turfgrass grew well in the lysimeter filled with the used sand from slow water filtration pool than in the lysimeter filled with river sand for horticulture as top soil.
2. Turbidity and phosphorus concentration of the leached water from lysimeter markedly decreased by packing the sludge from water purification process as subsoil in the lysimeter. In seme manner, the leaching of chemicals foliar-sprayed also decreased by packing of the sludge as subsoil in lysimeter.
3. However, the pucking of sludge did not reduce the potassium leaching. Besides, it increased nitrate nitrogen concentration in leached water from lysimeter.
It was considered from this investigation that the used sand from slow filtration pool was useful as culture sand for turf, and that the sludge from water purification process was available as absorbent material for phosphorus leached from turf green.
