BIO_PORE model was built using Comsol Multiphysics™ and implements fluid flow and transport equations coupled with the biokinetic expressions of CWM1 in a 2D domain representing a longitudinal section of a wetland (Fig. 1). As a distinctive feature from the original CWM1's formulation, in BIO_PORE slowly biodegradable and inert particulate COD (XS and XI, respectively) are divided into aqueous (XSm and XIm) and solid (XSf and XIf) phases to be able to simulate attachment and detachment processes of particulate matter (refer to Samsó and García (2013) for further details).