Microcontaminants removal in constructed wetlands with different baffle arrangements and cultivated with Pennisetum setaceum

Abstract

The present study aimed to evaluate the potential of horizontal subsurface flow constructed wetlands (HSSF-CWs) with different arrangements of baffles inside and cultivated with fountain grass (Pennisetum setaceum) in the removal of microcontaminants from wastewater from a university campus. The HSSF-CWs were made of fiberglass with three different configurations: CW-A without baffles; CW-B with baffles fixed to the sides; and the CW-C with baffles fixed above and below the reactor. It was analyzed the contaminants ibuprofen (IBU), acetaminophen (PAR), 4-octylphenol (4OC), caffeine (CAF), 4-nonylphenol (4NP), naproxen (NPX), bisphenol-A (BPA), diclofenac (DCF), estrone (E1), estradiol (E2), ethinylestradiol (EE2), and estriol (E3) by pre-concentration using Strata SAX cartridge and determined by gas chromatography coupled with mass spectrometry. Microcontaminants were monitored monthly between November/2018 and April/2019. Among the twelve microcontaminants evaluated, the endocrine disrupters 4NP and EE2 were not identified in any of the samples. In the affluent, the average concentrations ranged from 87.3 to 2559.2 ng L−1 for pharmaceuticals, 584.6 to 1658.3 ng L−1 for caffeine, and 49.1 to 584 ng L−1 for endocrine disruptors. The CWs with different baffle arrangements were efficient in removing the organic pollutants evaluated. Caffeine stimulant was the contaminant that presented the highest removal, followed by pharmaceuticals, and endocrine disruptors. Considering the risks related to the presence of these contaminants in wastewater, the results from this work represent an important contribution for studies related with the microcontaminants removal in HSSF-CW.