Environmental aspects of wastewater recycling from the point of view of emergent pollutant removal

Abstract

This study evaluates the removal efficiency of 15 estrogenic endocrine-disrupting compounds in two operational constructed wetlands with different designs: a hybrid system (constructed wetland A) and a horizontal system (constructed wetland B). The assessment involved analyzing composite water samples obtained from passive samplers through liquid chromatography-mass spectrometry coupled with yeast assays. Additionally, grab samples of sludge and sediment were examined to determine the endocrine-disrupting compound's adsorption efficacy. The application of the full logistic model enabled the discernment and ranking of the chemicals contributing to mixture toxicity. The findings revealed constructed wetland A's superior efficacy in the removal of individual endocrine-disrupting compounds (with an average efficiency of 94%) compared to constructed wetland B (60%). Furthermore, constructed wetland A displayed a higher estimated estrogenic activity removal efficiency (83%) relative to constructed wetland B (52%). Estrogenic activity was adequately accounted for (58-120%) in half of the analyzed samples, highlighting estrone as the primary estrogenic agent. The investigation underscores constructed wetlands' effectiveness in purging endocrine-disrupting compounds, suggesting that their integration as secondary or tertiary treatment systems for such pollutants removal merits further exploration.