Removal of pharmaceuticals from wastewater through constructed wetland-based systems in rural Canada

• Published in: Environmental Pollution
• Main Author: Chaves Barquero, Luis Gerardo
• Other Authors: Hanson, Mark (Environment and Geography) Wong, Charles (Environment and Geography), Wang, Feiyue (Environment and Geography), Cicek, Nazim (Biosystems Engineering), Brooks, Bryan (Environmental Science, Baylor University)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2022
• Subjects: Wastewater; Pharmaceuticals; Constructed wetlands; Arctic; Manitoba; Nunavut; Canada; Cambridge Bay
• Online Access: http://hdl.handle.net/1993/36185

The main goal of the dissertation was to assess the occurrence and removal of pharmaceuticals in constructed wetlands (CWs) treating wastewaters under Arctic and temperate climates. To this end, we examined the relevance of observations and strength of methods found in the literature for the removal of 48 drugs through a weight-of-evidence-based rubric. Statistically greater relevance scores were obtained for hybrid CWs compared to single-step CWs for the removal of some pharmaceuticals. Also, CWs from all climates showed potential for pharmaceutical removal. Finally, studies from temperate climate (N=76) were stronger in methods than Arctic- (N=2) or tropical-based (N=9) efforts. Three case studies are also part of this dissertation. First, we examined a treatment system in Cambridge Bay, Nunavut, Canada, where common pharmaceuticals such as atenolol, carbamazepine, clarithromycin, metoprolol, sulfamethoxazole and trimethoprim were detected with greatest concentrations at the treatment lagoon, and limited to no offshore detection. Second, the dissipation of atenolol, carbamazepine, and sulfamethoxazole was observed in mesocosm modelled wetlands using glass or gravel as substrates. Atenolol dissipated the fastest from the system, followed by sulfamethoxazole, and carbamazepine, with no significant differences across treatments. Also, tertiary pilot-scale subsurface filters made of crushed recycled glass or sand were studied in a treatment facility in the village of Dunnottar, Manitoba, Canada. These materials showed no statistically significant differences for pharmaceutical removals. Finally, we assessed a full-scale lagoon-subsurface filter in Dunnottar to remove pharmaceuticals in 2015 and 2016. Out of six detected pharmaceuticals, atenolol, clarithromycin, metoprolol, propranolol were efficiently removed by lagoon treatment, while carbamazepine and sulfamethoxazole persisted to a certain extent after subsurface filtration. Taken together, the thesis has shown that the removal of pharmaceuticals from ...