Roles of root porosity, radial oxygen loss, Fe plaque formation on nutrient removal and tolerance of wetland plants to domestic wastewater

Root properties including rates of radial oxygen loss (ROL), root porosity, and Fe plaque formation on the root surface, in six wetland plant species, namely Acorus calamus, Arundo donax var. versicolor, Cyperus flabelliformis, Canna indica, Iris tectorum, and Scirpus validus, and their relationships with nutrient removal and tolerance to domestic wastewater were investigated. Results showed that different species had different root porosities (18–36%) and Fe plaque formation (1.76–5.3 mg Fe g−1 root d.w.), which were significantly correlated with ROL (67–157 mmol O2 kg−1 root d.w. d−1) (p