Role of Design and Operational Factors in the Removal of Pharmaceuticals by Constructed Wetlands

Abstract

This study evaluates the role of design, operational, and physicochemical parameters of constructed wetlands (CWs) in the removal of pharmaceuticals (PhCs). The correlation analysis demonstrates that the performance of CWs is governed by several design and operational factors (area, depth, hydraulic loading rate, organic loading rate, and hydraulic retention time), and physicochemical parameters (dissolved oxygen, temperature, and pH); the removal efficiency of about 50% of the examined PhCs showed a significant correlation with two or more factors. Plants contributed significantly in the removal of some of the PhCs by direct uptake and by enhancing the process of aerobic biodegradation. The use of substrate material of high adsorption capacity, rich in organic matter, and with high surface area enhanced the removal of PhCs by adsorption/sorption processes, which are the major removal mechanisms of some PhCs (codeine, clarithromycin, erythromycin, ofloxacin, oxytetracycline, carbamazepine, and atenolol) in CWs. Although the removal of almost all of the studied PhCs showed seasonal differences, statistical significance was established in the removal of naproxen, salicylic acid, caffeine, and sulfadiazine. The effective PhCs removal requires the integrated design of CWs ensuring the occurrence of biodegradation along with other processes, as well as enabling optimal values of design and operational factors, and physicochemical parameters.

A review of nature-based solutions for urban water management in European circular cities: a critical assessment based on case studies and literature

“…In addition to the removal of traditional pollutants such as suspended solids, organic matter and nutrients (Zhang et al 2014a(Zhang et al , 2014bMachado et al 2017;Arden & Ma 2018), CWs are capable of removing organic and inorganic pollutants (Verlicchi & Zambello 2014;Krzeminski et al 2019). Among these, the removal of pesticides (Barceló & Petrovic 2008), heavy metals (Wang et al 2017), pharmaceuticals (Li et al 2014;Zhang et al 2014aZhang et al , 2014bIlyas & van Hullebusch 2019;Zraunig et al 2019) and various other contaminants of emerging concern (CEC) (Imfeld et al 2009;Matamoros et al 2010;Gorito et al 2017;Talib & Randhir 2017) have been explored in the last decade. The observed removal of heavy metals was between 23 and 97% depending on the heavy metal, CWs' type, type of water matrix and others (Malaviya & Singh 2012).…”

“…Regarding the CEC, plant-associated NBS have been reported to be crucial for the removal of different CEC (Carvalho et al 2014;Zhang et al 2016;Ilyas & van Hullebusch 2019), which can favour the solution of creating more 'green' in the cities. Therefore, the key removal pathways are the uptake by plants (e.g., carbamazepine), microbial degradation (e.g., ibuprofen, salicylic acid, galaxolide), adsorption and subsequent sedimentation (e.g., triclosan, tetracycline) and photodegradation (e.g., ketoprofen, naproxen, triclosan, diclofenac) (Bi et al 2019).…”

“…Although treatment wetlands can achieve high removal of up to 100% of different organic and inorganic chemicals, the removal effectiveness varies significantly and the removal effectiveness of particular compounds may vary depending on the CW design, its operation mode and seasonal conditions (Verlicchi & Zambello 2014;Zhang et al 2016;Ilyas & van Hullebusch 2019;Krzeminski et al 2019;Zraunig et al 2019). This indicates that for efficient removal, CWs need to be designed and/or adjusted for targeted pollutants.…”

Recent Advances in the Application, Design, and Operations & Maintenance of Aerated Treatment Wetlands

“…Research on micropollutant removal in conventional (non-aerated) HF treatment wetlands started in the 2000s [89], whereas the first study on micropollutant removal in an aerated wetland was conducted nearly ten years later [90]. A recent review on the role of design and operational factors in the removal of pharmaceutical compounds in treatment wetlands identifies aerobic biodegradation as a predominant removal mechanisms for a range of pharmaceutical compounds [91]. Studies on outdoor pilot and full-scale wetland systems treating real wastewater generally show that aerated wetlands exhibit higher micropollutant removal efficacy than conventional (non-aerated) wetland types [92].…”

Wetlands for environmental protection

“…The removal efficiency of pharmaceutical (PhCs) pollutants in CWs has been governed by different design factors (hydraulic loading rate, area, depth, organic loading rate, and HRT) and physicochemical parameters (dissolved oxygen, temperature, and pH) in which depth and organic loading rate showed significant correlations with removal efficiencies (Ilyas & van Hullebusch, 2019). In a free water surface CW receiving treated wastewater, the photodegradation of micropollutants was effective at least the top 10 cm (Mathon, Coquery, Miège, Vandycke, & Choubert, 2019).…”