Removal efficiency and mass balance of polycyclic aromatic hydrocarbons, phthalates, ethoxylated alkylphenols and alkylphenols in a mixed textile-domestic wastewater treatment plant

Chiara Berardi; Donatella Fibbi; Ester Coppini; Lapo Renai; Claudia Caprini; Cristina Vanessa Agata Scordo; Leonardo Checchini; Serena Orlandini; Maria Concetta Bruzzoniti; Massimo Del Bubba

doi:10.1016/j.scitotenv.2019.04.096

Removal efficiency and mass balance of polycyclic aromatic hydrocarbons, phthalates, ethoxylated alkylphenols and alkylphenols in a mixed textile-domestic wastewater treatment plant

Sci Total Environ. 2019 Jul 15:674:36-48. doi: 10.1016/j.scitotenv.2019.04.096. Epub 2019 Apr 10.

Affiliations

¹ GIDA S.p.A., Via di Baciacavallo 36, 59100 Prato, Italy. Electronic address: laboratorio@gida-spa.it.
² GIDA S.p.A., Via di Baciacavallo 36, 59100 Prato, Italy. Electronic address: d.fibbi@gida-spa.it.
³ GIDA S.p.A., Via di Baciacavallo 36, 59100 Prato, Italy. Electronic address: e.coppini@gida-spa.it.
⁴ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: lapo.renai@unifi.it.
⁵ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: claudia.caprini@unifi.it.
⁶ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: cscordo@unifi.it.
⁷ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: leonardo.checchini@unifi.it.
⁸ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: serena.orlandini@unifi.it.
⁹ Department of Chemistry, University of Turin, Via Pietro Giuria 7, 10125 Turin, Italy. Electronic address: mariaconcetta.bruzzoniti@unito.it.
¹⁰ Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: delbubba@unifi.it.

PMID: 31003086
DOI: 10.1016/j.scitotenv.2019.04.096

Abstract

In this work the occurrence and fate of polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), mono and diethoxylate alkylphenols (AP_1-2EOs) and alkylphenols (APs) have been investigated during a two-weeks period in a facility treating mixed textile-domestic wastewater (Prato, Italy). The wastewater treatment plant (WWTP) consists of primary sedimentation, activated sludge biological oxidation, secondary sedimentation, clariflocculation and ozonation. The sludge is treated within the facility by thickening, dewatering and final incineration, thus providing the almost quantitative removal of the adsorbed micropollutants. Naphthalene (50%), di(2-ethylhexyl) phthalate (74%) and branched 4-nonylphenols (59%) were the individual main representative compounds of each class in the influent wastewater, which showed concentration ranges of 5.6-66, 85-290 and 21-133μg/L for PAHs, PAEs and APs+AP_1-2EOs, respectively. The WWTP efficiently removed PAHs, PAEs and APs+AP_1-2EOs, providing effluent concentrations of 0.075-0.16ng/L 0.38-9.9μg/L and 0.53-1.4μg/L. All targeted priority and priority-hazardous micropollutants showed effluent concentrations in line with the European environmental quality standards (EQS), even though for di(2-ethylhexyl) phthalate and benzo(a)pyrene after correction for the dilution factor of the recipient. The WWTP performance was evaluated by mass balance, verifying its accuracy by monitoring Pb and Cd as conservative species. The biological treatment sections provided mass losses of 85.5%, 74.5% and 56.8% for APs+AP_1-2EOs, PAEs and PAHs, highlighting efficient biotransformation performances of the activated sludge process. However, for the more volatile PAHs (e.g. naphthalene), a significant contribution of stripping cannot be excluded. A remarkable mass loss was also determined in the ozonation stage for PAEs (72.9%) and especially PAHs (97.0%), whereas a lower efficiency was observed for APs+AP_1-2EOs (41.3%). The whole plant allowed for obtaining an almost quantitative removal (96.7-98.4%) for all targeted compounds.

Keywords: Activated sludge; Biotransformation; Environmental quality standard; Organic micropollutants; Ozonation; Sludge sorption.