Simulation of Phosphorus Concentrations in River Water Based on Phosphorus Load

Abstract

Phosphorus concentrations (DIP, DOP, PP) were measured about 12 Km downstream from Namitakidera in the Kurose River basin in three periods under different discharge of river water. Their concentrations were simulated by using a tank model from the view point of unsteady state. The simulated values of the concentrations reasonably agreed with the observed ones.
From the analysis of phosphorus concentrations in dry weather (10th December 1986), it was found that the ratio for direct effluence of phosphorus load into river (L₀) was 0.50-0.60. It was suggested that 0.35 g P·d^-1·capita^-1 was relevant to the unit for phosphorus load of gray water. The mass balance of phosphorus in river was estimated on the basis of this simulation results.