Simulation of peak loads for horizontal flow constructed wetlands - Poster

Constructed wetlands (CWs) are a wastewater treatment technology that exploits the physical, chemical, and biological processes developed in soil in order to improve the water quality. The low operation and maintenance costs allow for a widespread use of CWs, especially in treating wastewater from small communities (up to 2000 population). Despite the wide application of CWs, many aspect of CW behaviour in real environment still needs to be investigated, including buffering capacity to sudden peak loads. Indeed, the stochastic behaviour of real influent loads are generally neglected during the typical CW design procedure, and CW parameters should highly overestimated to face real load variability. Hence, further efforts are still need to improve the ability to properly design CWs. Here a process-based model approach is used to better understand the response of a horizontal flow (HF) CW subjected to peak loads. Laboratory experiments were conducted by Galvão and Matos [2012], where HW-CWs were subjected to sudden load of different intensities. Data from these laboratory experiments are used to calibrate a model of the HF-CW set-up using the HYDRUS wetland module [Langergraber and Šimůnek, 2012]. The calibrated model fits the data well and is further used to explore different loading scenarios. In this way, we are able to understand in which case the CW fails the maximum allowed effluent concentrations. In future, we will use the calibrated model to investigate the behaviour of HF-CW to stochastic processes such as loading and temperature seasonal variations.