Monitoring of horizontal subsurface flow constructed wetlands for tertiary treatment of municipal wastewater

Abstract

This paper explores the feasibility of the electrical resistivity (ER) method as non-invasive technique to detect dysfunctions of full-scale tertiary wastewater treatment wetlands, such as clogging, that ultimately limit the system lifetime and performance. ER measurements were carried out according to the Werner’s method on two (overloaded) horizontal subsurface wetlands (HSF-CW1 and HSF-CW2) operated in parallel since the end of 2017, while still achieving satisfactory treatment efficiencies. Layered clog-induced preferential flow pathways through the HSF-CW beds and premature deterioration of the wetland’s liner with a possible development of dead zones associated with a low/heterogeneous density of vegetation could be confirmed by analysis of ER profiles. These results suggest that the ER method is a promising and feasible technique, as simplified then adapted/adopted to local context, for better monitoring and assessment of treatment wetlands with early process failure.

Performance of Horizontal Subsurface Flow Constructed Wetland in Domestic Wastewater Treatment Using Different Media

“…Factors that influence performance include the materials used, vegetation, configuration design, and process form (Guadarrama-Pérez et al, 2019). Constracted wetlands can reduce the quality of polluted water even with high waste concentrations and excessive use of solid/organic materials (Ergaieg et al, 2021). In the constracted wetlands process, organic nitrogen is converted into nitrate (𝑁𝑁𝑁𝑁 3 − ) under aerobic and anaerobic conditions, while ammonia nitrogen (NH 3 -N) is removed through hydrophyte absorption, evaporation, nitrification, and denitrification (Bedu-Addo et al, 2023).…”