| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥2,700,000 (Direct Cost: ¥2,700,000)
|
|---|
| Research Abstract |
To solve the problems of eutrophication of lakes, nutrient removal, especially phosphorus removal, is being desired. Focusing adsorption removal, this research used ceramics pretreated by iron sulphate and basic investigation was conducted.
The phenomenon of increase of adsorption capacity of certain ceramics for phosphorus caused by iron sulphate pretreatment could be explained by the gradual release of ferrous ion to water resulting in the formation of iron phosphate precipitation. On the other hand, ceramics which was washed till no iron release was observed showed adsorption capacity that could be due to the existence of ferrous ion on the surface of the ceramics.
Adsorbed phosphorus could be detouched by washing with alkali.
Released iron was bivalent but iron phosphate precipitation was formed by trivalent iron. To clarify the mechanisms of iron phosphate formation, ozonation was conducted in the ferrous iron and phosphate suspension to oxidize the ferrous iron. Ozonation resulted in the large amount of iron phosphate precipitaion, that is the mechanisms of phosphorus removal. Namely, to remove phosphate in water, if ferrous ion and oxidizer were existed, ferrous ion would settle down with phosphate after oxidized.
To design the ceramics for phosphate removal, ferrous ion rather than ferric ion should be on the surface of the ceramics. Furthermore, if oxidation power could be controlled, both of phosphate removal and iron discharge could be managed and a new process for phosphorus removal could be developed.
|
