TY - JOUR
T1 - Evaluation of attenuation of pharmaceuticals, toxic potency, and antibiotic resistance genes in constructed wetlands treating wastewater effluents
AU - He, Yujie
AU - Nurul, Sabri
AU - Schmitt, Heike
AU - Sutton, Nora B.
AU - Murk, A.J.
AU - Blokland, Marco H.
AU - Rijnaarts, Huub H.M.
AU - Langenhoff, Alette A.M.
PY - 2018/8/1
Y1 - 2018/8/1
N2 - The performance of constructed wetlands (CWs) in the removal of pharmaceutically active compounds (PhACs) is generally evaluated on the basis of chemical analysis. In this work, we used a combination of chemical, toxicological, and molecular analyses to assess the attenuation of PhACs, toxic potency and antibiotic resistance genes (ARGs) in a field study of three CWs serving as tertiary treatment of wastewater treatment plants. First, 17 PhACs were analysed chemically, of which 14 were detected and seven at concentrations >0.1 μg/l. Even though some of the individual PhACs were moderately or highly removed in the CWs investigated, median removal of overall PhACs was approximately 50% in the vertical subsurface flow CW (VSF-CW) with a lower hydraulic loading rate while the removal in the other two free water surface flow CWs (SF-CWs) was negligible. Second, toxic potency of wastewater extracts was assessed in a range of bioassays. Estrogenicity was overall attenuated in CWs, while the neurotoxic potency of wastewater extracts did not decrease after passage through the two CWs investigated. Third, the VSF-CW and one of the SF-CW showed a positive removal of an integrase gene and three ARGs tested. The increased concentrations of ARGs in the other SF-CW, as well as the increase of total bacteria in all CWs, may relate to regrowth of resistance-carrying bacteria. Finally, multivariate analysis shows that most PhACs are positively correlated to the observed toxic potency. Additionally, low removal of organics and nutrients seems to parallel with low removal of PhACs. ARGs positively correlated with organics, nutrients and some PhACs, and the integrase gene but not to the respective antibiotics. The insufficient removal of PhACs, toxic potency, and ARGs indicates the need of an optimal design of CWs as tertiary treatment facilities.
AB - The performance of constructed wetlands (CWs) in the removal of pharmaceutically active compounds (PhACs) is generally evaluated on the basis of chemical analysis. In this work, we used a combination of chemical, toxicological, and molecular analyses to assess the attenuation of PhACs, toxic potency and antibiotic resistance genes (ARGs) in a field study of three CWs serving as tertiary treatment of wastewater treatment plants. First, 17 PhACs were analysed chemically, of which 14 were detected and seven at concentrations >0.1 μg/l. Even though some of the individual PhACs were moderately or highly removed in the CWs investigated, median removal of overall PhACs was approximately 50% in the vertical subsurface flow CW (VSF-CW) with a lower hydraulic loading rate while the removal in the other two free water surface flow CWs (SF-CWs) was negligible. Second, toxic potency of wastewater extracts was assessed in a range of bioassays. Estrogenicity was overall attenuated in CWs, while the neurotoxic potency of wastewater extracts did not decrease after passage through the two CWs investigated. Third, the VSF-CW and one of the SF-CW showed a positive removal of an integrase gene and three ARGs tested. The increased concentrations of ARGs in the other SF-CW, as well as the increase of total bacteria in all CWs, may relate to regrowth of resistance-carrying bacteria. Finally, multivariate analysis shows that most PhACs are positively correlated to the observed toxic potency. Additionally, low removal of organics and nutrients seems to parallel with low removal of PhACs. ARGs positively correlated with organics, nutrients and some PhACs, and the integrase gene but not to the respective antibiotics. The insufficient removal of PhACs, toxic potency, and ARGs indicates the need of an optimal design of CWs as tertiary treatment facilities.
KW - ARGs
KW - Bioanalyses
KW - Domestic wastewater
KW - Micropollutants
KW - Multivariate analysis
KW - Tertiary treatment
U2 - 10.1016/j.scitotenv.2018.03.083
DO - 10.1016/j.scitotenv.2018.03.083
M3 - Article
AN - SCOPUS:85044149662
SN - 0048-9697
VL - 631-632
SP - 1572
EP - 1581
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -