Abstract
Abnormal growth of phytoplanktons (water bloom) in eutrophic lakes impedes water utilization. In a eutrophic lake, pH increases with the carbon dioxide assimilation of the algae. Phosphorus should be released from suspended solids (SS) when pH increases. Therefore, the pH rise may promote eutrophication. The release of phosphorus from SS has not attracted attention until now. However, it is an important problem. In this study, we investigated the release of phosphorus from SS. The possibility that algae utilize the particulate phosphorus was examined by algal culture experiments. The relationship between pH and the amount of phosphorus released from SS was examined by the phosphorus release experiments. The major results obtained in this study are as follows: (1) The amount of phosphorus released from SS depends on the strength of the alkali, and the release is fast. (2) It is thought that the release of phosphorus from SS promotes algal growth in eutrophic lakes (lakes where the pH increased with the carbon dioxide assimilation of the algae).
