A conceptual approach based on suspended solids to estimate clogging time in constructed wetlands

Abstract

A conceptual model has been developed by using the parameter of influent suspended solids (SS) concentration to estimate the clogging time in constructed wetlands (CWs). The depth of the clogging layer is estimated through the effective porosity vertically along the CWs. The basis of the model to predict the clogging time lies in the fact that, when clogging occurs, the pore spaces were reduced and thus the infiltration rate was reduced. A group of laboratory scale CWs was employed to develop the model and validate its utilization. Good agreement between the experimental data and the predicted clogging time was obtained. This indicates that the model can be used in different operation conditions for estimating clogging time in CWs.

Keywords:

• Clogging time
• influent suspended solids
• pore space
• vertical flow constructed wetland

Acknowledgments

The authors would particularly like to thank Dr. Yaqian Zhao in University College Dublin, Ireland for his kind assistance during the preparation of the paper. Financial support from Natural Science Foundation (50979028) and Public Project (200801065) of P.R. China are gratefully acknowledged.