A new operation mode solving clogging problems of horizontal subsurface constructed wetlands

摘要

Horizontal subsurface constructed wetland (SSFCW) has been widely used to treat wastewater,nhowever the capacity of SSFCW is severely confined by clogging problems which are veryncommon during the lifespan of a SSFCW. Therefore it is of great practical significance to improventhe performance of SSFCW. In this study, a new operation mode by changing the flow directionnperiodically was executed and the performance on the pollutants removal was studied. Threenyears’ experimental results showed that the SSFCW with new operation mode achieved betternpollutant removal efficiency compared with the performance obtained under traditional operationnmode. The microorganism test showed that the reciprocating SSFCW had larger quantitynmicroorganism which effectively prevented organic compounds accumulation. The readings ofngauge glass in the traditional SSFCW rose gradually, while the water level kept stable innreciprocating one, which also reflected the severity of the clogging problem in the two wetlands.nDuring the whole operation period, the SSFCW with reciprocating operation mode didn’t have anyninfiltration problem, while SSFCW with traditional operation mode had visible clogging problemsnas a result of pollutants accumulation in the inlet zone.