| Constructed wetland running effect of the fillings of the wetland system used play a key role, in order to comprehensive advantage of the fillings, fillings often consists of a variety of materials. Grading fillings is very important, proper grading fillings can effectively remove all kinds of pollutants, effectively avoid the congestion at the same time, improve the operation cycle. This experiment through the design of three kinds of fillings does not supplement at the same level matching different leaching under the volume of sewage pollution factor removal efficiency was studied, at the same time, through the different hanging membrane in the process and not hanging membrane under the condition of two kinds of substrate is studied, in order to find the laws of substrate removal pollution factor. The results showed that:In the conditions of same water quality and hydraulic loading, the fly ash has good removal rate on COD,TN,and NH4+-N in the system had formed membrane and not membrane. Hollow brick has good removal rate on TP. However, the three fillings has no significant effect on NO3-- N.In the conditions of not membrane, as fly ash, cinder, hollow brick were mixed with the volume ratio of 3:1:1,the removal effect of the CODcr,TN,NH4+-N was the best, the best removal ratio were 47.8%,81.9%,93.5%,respectively.As fly ash, cinder, hollow brick were mixed with the volume ratio of 1:1:3,the removal effect of the TP was the best, and the best removal ratio was 86.0%.In the conditions of had membrane, as fly ash, cinder, hollow brick were mixed with the volume ratio of 3:1:1, the removal ratio were 82.3%,91.9%,92.3%, respectively.As fly ash, cinder, hollow brick were mixed with the volume ratio of 1:1:3,the removal ratio was 89.6%.After hanging membrane, as a result of microbial action, the fillings for each pollutant removal efficiency are improved, especially for COD, as a result of the TP removal rely mainly on the adsorption effect of fillings, so the fillings after hanging membrane, impact on the TP removal is not very big.The volume ratio of 3:1:1 mixed with the fly ash, cinder, and hollow brick was most suitable for the constructed wetland substrate combination to treat domestic sewage, avoiding the abuse of the non-removal effection on the traditional wetlands. |
