Proceedings

This presentation aims to report on the performance of four types of constructed wetlands (CWs) (free water surface-FWSCW, vertical flow-VFCW, horizontal flow-HFCW and hybrid-HCW) for the removal of 33 pharmaceuticals (PhCs) and 19 metabolites using a global data compiled for 195 CWs reported in 55 peer reviewed journal papers. A large compound specific variation in the removal was observed caused by a complex array of factors. Biodegradation (aerobic efficient than anaerobic) is the major removal mechanism for 18 out of 33 PhCs besides the influence of other processes (e.g. adsorption/sorption, plant uptake and photodegradation). The HCW performed better followed by VFCW, HFCW and FWSCW. Moreover, the performance is governed by several design and operational factors (area, depth, HLR, HRT and OLR), and physicochemical parameters (effluent DO, temperature and pH), as confirmed by their significant correlation with most of the studied PhCs. The removal of some of the PhCs takes place by the formation of their transformation products (TPs) and the nature of these TPs (persistent or non-biodegradable/biodegradable) plays a major role in the removal. The effective PhCs removal requires integrated design of CWs ensuring the occurrence of biodegradation along with other processes, but also enabling optimal values of design and operational parameters.