Optimal management of total phosphorus in Xinlicheng Reservoir

In order to scientifically manage the water environment of the Xinlicheng Reservior and ensure the safety of the drinking water source of Changchun City,an optimal management model of total phosphrous(TP) for reservior coupling with the pollution factors from point and non-point sources was developed.Three schemes were designed to realize the optimal management of TP.The results showed that the present amount of TP entering the reservoir was about six times the permitted amount;TP from point and non-point source pollution caused serious contamination in reservoir;non-point source TP pollution was the largest pollution source in the reservoir,accounting for 92% of the TP pollution;and TP pollution from breed aquatics was the largest non-point source of TP pollution,accounting for 79% of TP pollution.The scheme for optimal management of TP was that the amount of TP entering the reservoir from point sources was zero;non-pollution fertilizer management was applied to control the non-point source pollution from croplands,and the permitted amount of TP entering the reservoir from non-point sources was 15.10 kg/d;and the maximum scale of animal husbandry was 25 416 pigs.TP from point and non-point source pollution should be intensively treated,constructed wetlands should be developed upstream of the reservoir,and the watershed management for the reservoir should be enhanced,all of which are rational measures for achieving the optimal management of TP for the Xinlicheng Reservoir.