Experimental study on swine wastewater treatment by using the simulated subsurface constructed wetland

The ability of pollution purification by four kinds of substrate materials (soil, vermiculite, cinder and detritus) in pots as simulated subsurface constructed wetlands was studied. The results showed that the removal rates of COD_Cr, NH₄⁺-N and T-P were 95.3%、90%、91.6% after 14 days, respectively. The best combination of filtering media was soil and vermiculite at the up layer，the cinder and detritus at the low layer. In the forepart of experiment, there were significant differences between the four different combinations in the removal rate of COD_Cr , NH₄⁺-N and T-P. However,in the later part of experiment the differences became not significant , except in the removal rate of T-P.