Effects of waterfowl sewage treatment by integrated artificial wetland running for 2 years

A integrated artificial wetland was constructed by surface and subsurface wetland to dispose the effect of eutrophication caused by waterfowl. The removal efficiencies of chemical oxygen demand (CODcr), total suspended solids(TSS), total nitrogen(TN) and total phosphorus(TP) in the integrated artificial wetland which had running for 2 years have been studied. The results showed that the average removal rates of CODcr, TSS, TN and TP were 42.64%, 72.64%, 31.69% and 52.67%, respectively and the removal rates varied with the runtime. The analysis for seasonal effects of summer and autumn showed that, the average removal rate of CODcr in summer was higher than that in autumn for surface wetland, while in both subsurface and integrated wetlands, the seasonal tendencies were reverse. For disposing TSS, in surface, subsurface and combined constructed wetlands, the autumn outperformed the summer. The average removal rate of TN in the summer was higher than that in the autumn for surface wetland. For TP average removal, the performance of the autumn was better than the summer’s in both surface and integrated artificial wetlands, but less efficient than summer’s in subsurface wetland. The relationships of CODcr, TSS, TN and TP concentrations between the influent and effluent were different in integrated artificial wetland. There was no clear relationships between the influent and effluent concentrations of TSS in both subsurface and integrated artificial wetlands. Moreover, the influent and effluent concentrations of CODcr, TP and TN had significant linear correlation in different types of integrated constructed wetlands. The results of this study could provide scientific support for the application of integrated constructed wetlands in treating the eutrophic water in northern China.