This study deals with the ability of constructed wetlands (CWs) in removing 138 pharmaceutical compounds (PhCs) belonging to 20 therapeutic classes from wastewater. It reviews 50 peer-reviewed journal articles, referring to experimental investigations carried out in about 100 plants including surface flow systems (SF), horizontal and vertical subsurface flow beds (H-SSF, V-SSF) (pilot or full scale) acting as primary, secondary or tertiary treatment. Occurrence of the selected PhCs in the CW influent and effluent, as well as in sediments and gravel is presented and discussed; removal mechanisms and efficiencies for the different compounds are presented, discussed and correlated to the main chemical properties of the compounds themselves (pKa, LogKd, LogKow…), the design parameters and the operational and environmental conditions of the corresponding treatment system; average pharmaceutical mass load for the effluents of a CW is evaluated. Finally an environmental risk assessment, based on the risk quotient RQ, is carried out for treated effluents providing to a ranking of the most critical compounds that can be present in the final effluent. This is compared with that found for activated sludge effluents (Verlicchi et al., 2012). The study completes with a discussion of the perspectives in the adoption of CWs in removing such persistent organic compounds.
How efficient are constructed wetlands in removing pharmaceuticals from wastewater? - A review
VERLICCHI, Paola;ZAMBELLO, Elena;AL AUKIDY, Mustafa Kether
2013
Abstract
This study deals with the ability of constructed wetlands (CWs) in removing 138 pharmaceutical compounds (PhCs) belonging to 20 therapeutic classes from wastewater. It reviews 50 peer-reviewed journal articles, referring to experimental investigations carried out in about 100 plants including surface flow systems (SF), horizontal and vertical subsurface flow beds (H-SSF, V-SSF) (pilot or full scale) acting as primary, secondary or tertiary treatment. Occurrence of the selected PhCs in the CW influent and effluent, as well as in sediments and gravel is presented and discussed; removal mechanisms and efficiencies for the different compounds are presented, discussed and correlated to the main chemical properties of the compounds themselves (pKa, LogKd, LogKow…), the design parameters and the operational and environmental conditions of the corresponding treatment system; average pharmaceutical mass load for the effluents of a CW is evaluated. Finally an environmental risk assessment, based on the risk quotient RQ, is carried out for treated effluents providing to a ranking of the most critical compounds that can be present in the final effluent. This is compared with that found for activated sludge effluents (Verlicchi et al., 2012). The study completes with a discussion of the perspectives in the adoption of CWs in removing such persistent organic compounds.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
