Evaluation of attenuation of pharmaceuticals, toxic potency, and antibiotic resistance genes in constructed wetlands treating wastewater effluents

Yujie He; Sabri Nurul; Heike Schmitt; Nora B Sutton; Tinka A J Murk; Marco H Blokland; Huub H M Rijnaarts; Alette A M Langenhoff

doi:10.1016/j.scitotenv.2018.03.083

Evaluation of attenuation of pharmaceuticals, toxic potency, and antibiotic resistance genes in constructed wetlands treating wastewater effluents

Sci Total Environ. 2018 Aug 1:631-632:1572-1581. doi: 10.1016/j.scitotenv.2018.03.083. Epub 2018 Mar 28.

Authors

Yujie He¹, Sabri Nurul², Heike Schmitt³, Nora B Sutton², Tinka A J Murk⁴, Marco H Blokland⁵, Huub H M Rijnaarts², Alette A M Langenhoff⁶

Affiliations

¹ Sub-department of Environmental Technology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, 210023 Nanjing, China.
² Sub-department of Environmental Technology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
³ Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
⁴ Marine Animal Ecology group, Wageningen University and Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
⁵ RIKILT-Institute of Food Safety, Wageningen University and Research, P.O. Box 2306, 6700 AE Wageningen, The Netherlands.
⁶ Sub-department of Environmental Technology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: alette.langenhoff@wur.nl.

PMID: 29727981
DOI: 10.1016/j.scitotenv.2018.03.083

Abstract

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 >0.1μg/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.

Keywords: ARGs; Bioanalyses; Domestic wastewater; Micropollutants; Multivariate analysis; Tertiary treatment.