论文部分内容阅读
To investigate the feasibility of using corncob charcoal substrate in constructedwetland,four lab-scale vertical flow constructed wetlands(VFCWs,system A:corncob charcoal substrate under aeration; system B: raw corncob substrateunder aeration;system C: clay ceramisite substrateunder aeration; system D: corncob charcoal substrate without aeration)were built.Effluent pollutants(COD,NH4+-N,TP)concentrations during the experiment were determined to reveal pollutants removal mechanisms and efficiencies in different stage.In the stable stage,VFCW using clay ceramisite substrateunder aeration attained higher COD(95.1%),NH4+-N(95.1%)removal efficiencies than VFCW using corncob charcoal substrate(91.5%COD,91.3%NH4+-N)under aeration,but lower TP removal efficiency(clay ceramisite32.0%and corncob charcoal 40.0%).VFCW with raw corncob substrate showed strongerCOD release(maximum concentration 3108mg/L)than corncob charcoal substrate(COD was lower than influent).And artificial aeration played a crucial role in pollutants removal in VFCWs with corncob charcoal substrate.In C/N ratio experiment,VFCW using corncob charcoal substrateperformed much better than VFCW using clay ceramisite substrate under aeration when C/N ration was low(C/N=1.5,TN removal efficiency 36.89%,4.1%respectively).The remained organic substances in corncob charcoal can be used as organic source in denitrification process.These results suggest that corncob charcoal is a potential substrate in VFCWs under aeration with unique self –supplying carbon source property in denitrification process.