AN INTEGRATED APPROACH FOR THE ASSESSMENT OF CONSTRUCTED WETLANDS OPERATIONAL EFFICIENCY, USING BOTH CHEMICAL AND BIOLOGICAL DATA

The present study evaluated the operational efficiency of a constructed wetland (CW) located at Andritsaina/Krestena municipality (Western Greece, Peloponnese, Greece), using a battery of tests and bioassays. Specifically, raw WWs entering the CW basins with broadleaf cattail Typha latifolia (raw-WWs) and biologically treated WWs effluents ending up in the adjustment tank were randomly collected in October, December 2018, and January 2019. Thereafter, freshwater algae (i.e., Chlorococcum sp., Scenedesmus sp.), invertebrates (i.e., Thamnocephalus platyurus, Brachionus calyciflorus), higher plant species (i.e., Sorghum saccharatum, Lepidium sativum and Sinapis alba) as well as human lymphocytes were treated with WWs for determining critical toxic endpoints in any case. The obtained data were further interpreted with physicochemical parameters, like total and dissolved COD (tCOD and dCOD respectively), total suspended solids (TSS) and volatile suspended solids (VSS), commonly measured in both raw- and treated-WWs samples. The results showed that almost all chemical parameters measured in treated-WWs were lower than those occurred in raw-WWs, and significantly related with the obtained critical toxic endpoints in all cases. Those preliminary findings give rise to the importance of using a battery of bioassays as useful tools for assessing CWs treatment process efficiency thus contributing to the environmental sustainability and human health.