Biodegradation of natural and synthetic endocrine-disrupting chemicals by aerobic granular sludge reactor: Evaluating estrogenic activity and estrogens fate
| Autor: | Daniele Maia Bila, Márcia Dezotti, João Paulo Bassin, Reynel Martínez Castellanos |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Denitrification
010504 meteorology & atmospheric sciences Nitrogen Health Toxicology and Mutagenesis Sequencing batch reactor 010501 environmental sciences Endocrine Disruptors Toxicology 01 natural sciences Waste Disposal Fluid chemistry.chemical_compound Bioreactors Ammonium Effluent 0105 earth and related environmental sciences Sewage Estrogens General Medicine Biodegradation Phosphate Pollution Biodegradation Environmental chemistry Environmental chemistry Nitrification Aeration |
| Zdroj: | Environmental pollution (Barking, Essex : 1987). 274 |
| ISSN: | 1873-6424 |
| Popis: | In this study, the biodegradation of endocrine-disrupting chemicals (EDCs) (namely the natural and synthetic estrogens 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), respectively) was assessed in an aerobic granular sludge (AGS) sequencing batch reactor (SBR) treating simulated domestic sewage. To better understand the fate of these compounds, their concentrations were determined in both liquid and solid (biomass) samples. Throughout the operation of the reactor, subjected to alternating anaerobic and aerated conditions, the removal of the hormones, both present in the influent at a concentration of 20 μg L−1, amounted to 99% (for E2) and 93% (for EE2), with the latter showing higher resistance to biodegradation. Through yeast estrogen screen assays, an average moderate residual estrogenic activity (0.09 μg L−1 EQ-E2) was found in the samples analysed. E2 and EE2 profiles over the SBR cycle suggest a rapid initial adsorption of these compounds on the granular biomass occurring anaerobically, followed by biodegradation under aeration. A possible sequence of steps for the removal of the micropollutants, including the key microbial players, was proposed. Besides the good capability of the AGS on EDCs removal, the results revealed high removal efficiencies (>90%) of COD, ammonium and phosphate. Most of the incoming organics (>80%) were consumed under anaerobic conditions, when phosphate was released (75.2 mgP L−1). Nitrification and phosphate uptake took place along the aeration phase, with effluent ammonium and phosphate levels around 2 mg L−1. Although nitrite accumulation took place over the cycle, nitrate consisted of the main oxidized nitrogen form in the effluent. The specific ammonium and phosphate uptake rates attained in the SBR were found to be 3.3 mgNH4+-N gVSS−1.h−1 and 6.7 mgPO43--P gVSS−1 h−1, respectively, while the specific denitrification rate corresponded to 1.0 mgNOx−-N gVSS−1 h−1. |
| Databáze: | OpenAIRE |
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