[1] M. Česen, K. Lenarčič, V. Mislej, M. Levstek, A. Kovačič, B. Cimrmančič, N. Uranjek, T. Kosjek, D. Heath, M.S. Dolenc, E. Heath, The occurrence and source identification of bisphenol compounds in wastewaters, Sci. Total Environ 2018. doi: 10.1016/j.scitotenv.2017.10.252.
The concern over the safety of industrial chemical bisphenol A, a known endocrine disrupting compound, has resulted in its gradual replacement by other structurally similar bisphenol compounds. Compared to bisphenol A, less is known about their occurrence and sources in wastewaters. The findings confirmed the presence of bisphenols in wastewaters within the EU region for the first time and showed the high removal efficiency of the biological treatment. This paper contributes knowledge on the occurrence and cycling of bisphenols during WWT and in the environment.
[2] C. Gys, A. Kovačič, C. Huber, F.Y. Lai, E. Heath, A. Covaci, Suspect and untargeted screening of bisphenol S metabolites produced by in vitro human liver metabolism, Toxicol. Lett. 2018, 295 115–123. doi: 10.1016/j.toxlet.2018.05.034.
Bisphenol S is increasingly used as a substitute for bisphenol A, resulting in a higher potential of human exposure to this compound. However, information on the human metabolism of bisphenol S is limited, and biomonitoring studies rely only on measurements of bisphenol S, leading to an underestimation of human exposure. This paper reports the in vitro metabolic pathways of bisphenol S using human liver microsomes and cytosol fractions. Significant findings are two Phase I in vitro human liver metabolites for bisphenol S and four Phase II metabolites, of which three were identified and structurally elucidated for the first time. As such, the study contributes to a reliable assessment of bisphenol S exposure in future biomonitoring studies by proposing new identified in vitro metabolites as potential additional biomarkers, for which in vivo pharmacokinetics can be evaluated.
[3] A. Kovačič, C. Gys, T. Kosjek, A. Covaci, E. Heath, Photochemical degradation of BPF, BPS and BPZ in aqueous solution: Identification of transformation products and degradation kinetics, Sci. Total Environ. 2019. doi: 10.1016/J.SCITOTENV.2019.02.064.
Bisphenols can potentially have toxic effects once in the aqueous environment, but their fate remains largely uninvestigated. This paper reports the photochemical degradation of three common bisphenols: bisphenol F, S, and Z and determines their degradation kinetics, and characterise their transformation products UV photolysis, cyclodextrin-enhanced photolysis, and photo-Fenton reaction. The findings reveal how photodegradation effectively removes (> 90%) bisphenols from aqueous samples. The paper also reports 11 novels in addition to eight known transformation products. This new data will contribute to a better understanding of the bisphenols fate during water treatment and the environment.
[4] A. Kovačič, M. Česen, M. Laimou-Geraniou, D. Lambropoulou, T. Kosjek, D. Heath, E. Heath, Stability, biological treatment and UV photolysis of 18 bisphenols under laboratory conditions, Environ. Res. 2019. doi: 10.1016/J.ENVRES.2019.108738.
The primary source of bisphenols in the aquatic environment is wastewater effluent, but except for bisphenol A, little is known about the fate of other bisphenols during wastewater treatment. This paper reports the stability of 18 bisphenols and the optimum preparation and storage conditions of samples and laboratory standards. It also reports their removal efficiencies during biological treatment and UV photolysis under controlled laboratory conditions. It is the first work to address the stability of bisphenols and removal by bacterial consortia and photolysis. The paper’s findings are important from an analytical perspective and for understanding the behaviour of bisphenols in the environment and during water treatment.
[5] A. Kovačič, C. Gys, M.R. Gulin, T. Kosjek, D. Heath, A. Covaci, E. Heath, The migration of bisphenols from beverage cans and reusable sports bottles, Food Chem 2020. doi: 10.1016/j.foodchem.2020.127326.
Bisphenols are used as a monomer in polycarbonate plastic and epoxy-resin, both of which find broad application in food contact materials. However, bisphenols other than bisphenol A have not typically been included in migration studies plastic containers or cans. This paper reports the development and validation of an accurate and sensitive analytical method based on GC–MS/MS to determine 12 bisphenols migrating from beverage cans and sports bottles. The paper is the first to highlight the stability of bisphenols during migration studies and their derivatives during analysis. It confirms the leaching of bisphenols from food contact materials and that consuming beverages from cans is more concerning than consuming beverages from reusable sports bottles. These findings provide insights into bisphenol migration from food contact materials that can lower the risk to consumer health.
[6] A. Kovačič, Š. David, M. Zupanc, J. Gostiša, B. Bizjan, N. Kri, M. Sollner, E. Heath, The removal of bisphenols and other contaminants of emerging concern by hydrodynamic cavitation: From lab-scale to pilot-scale, Sci. Total Environ 2020. doi: 10.1016/j.scitotenv.2020.140724.
The rapid growth in the variety and quantity of contaminants of emerging concern in wastewater indicates the necessity for developing efficient and environmentally friendly methods for their removal. This paper investigates the effectiveness of hydrodynamic cavitation, UV photolysis, and their combination (lab- and pilot-scale) for removing contaminants of emerging concern from wastewater. The paper is the first to examine the possibility of hydrodynamic cavitation for this purpose. The results show the potential of hydrodynamic cavitation as an advanced oxidation process representative, which could be used for the full-scale application as a (pre)treatment technology. It also makes suggestions for improving cavitation reactors.
[7] T. Elersek, T. Notersberg, A. Kovačič, E. Heath, M. Filipič, The effects of bisphenol A, F and their mixture on algal and cyanobacterial growth: from additivity to antagonism, Environ. Sci. Pollut. Res. 2020. doi: 10.1007/s11356-020-10329-7.
Although concern that bisphenol A and other bisphenols in the environment can affect aquatic organisms has increased, their ecotoxicological effect on algae and cyanobacteria, which as primary producers play an important role in aquatic ecosystems, remains unknown. This paper investigates the toxicity of individual bisphenols towards cyanobacteria and green algae and the effects of their mixtures. The paper reports how cyanobacterium S. leopoliensis is more sensitive than green algae P. subcapitata, whereas the toxic potential of the bisphenol A and F is comparable and represents a hazard for phytoplankton. An additive effect was observed in P. subcapitata. The findings also show that bisphenol A represents more of an environmental risk than bisphenol F. The paper’s significance is that it provides a better understanding of the environmental risks posed by bisphenols, highlights new gaps in our understanding of their occurrence in the aquatic environment and provides important ecotoxicological data.
[8] A. Kovačič, C. Gys, M.R. Gulin, T. Gornik, T. Kosjek, D. Heath, A. Covaci, E. Heath. Kinetics and biotransformation products of bisphenol F and S during aerobic degradation with activated sludge, Journal of hazardous materials, 2020. doi: 10.1016/j.jhazmat.2020.124079.
Despite progress, the fate of bisphenol F and bisphenol S in wastewater treatment plants remains poorly understood. This paper is the first to report their biodegradation kinetics during biological treatment using accurate mass high-resolution mass spectrometry to identify and characterise their biotransformation products. Its findings show that bisphenol F degrades faster than bisphenol S and that the initial concentration affects the degradation rate. The machine-learning algorithm adopted as part of the non-targeted workflow identified three known and one novel biotransformation products of bisphenol F, and one known and ten new biotransformation products of bisphenol S. Possible novel biotransformation pathways are also postulated, namely sulfation, methylation, cleavage of the S ̶ C bond between the phenyl rings and the joining of smaller moieties. The findings contribute to a better understanding of the fate of bisphenols in the environment and during biological water treatment.
[9] D. Škufca, A. Kovačič, M. Pflieger, E. Heath. Determination of 18 bisphenols in aqueous and biomass phase of high rate algal ponds: development and validation of analytical methods, Chemosphere 2021. doi.org/10.1016/j.chemosphere.2021.129786, Open access.
While the high-rate algal ponds system presents an alternative to conventional wastewater treatment with the potential for wastewater and biomass reuse, a significant knowledge gap remains concerning the fate of bisphenols in the aqueous and biomass phases. This paper addresses this gap and describes method development, including validation (recoveries from 78%-106%) and uncertainty determination (relative expanded uncertainties were 16%-66%). The findings are important in comparing algal treatment to conventional wastewater treatment and how it could affect the valourisation of biomass.
[10] D. Škufca, A. Kovačič, F. Prosenc, T. B. Griessler, D. J. Heath, E. Heath. Phycoremediation of municipal wastewater: removal of nutrients and contaminants of emerging concern, Sci. Total Environ 2021. doi: 10.1016/j.scitotenv.2021.146949, Open access.
High-rate algal ponds could significantly contribute to the circular economy by valorising reclaimed water and algal biomass, but further investigation is needed regarding the presence of contaminants of emerging concern. This paper reports the removal efficiencies of contaminants of emerging concern and nutrients from municipal wastewater in a pilot-scale high-rate algal pond. The findings show how 51% - 92% of the contaminants of emerging concern studies are removed and that removal efficiency is comparable to biological treatment with activated sludge. The obtained results provide new insights into the potential of high-rate algal ponds as an alternative to conventional wastewater treatment and the valourisation of reclaimed water and algal biomass.
[11] T. Gornik, A. Kovačič, E. Heath, J. Hollender, T. Kosjek, Biotransformation study of antidepressant sertraline and its removal during biological wastewater treatment, Water Res. 2020. doi: 10.1016/j.waters.2020.115864.
Sertraline is one of the most commonly prescribed antidepressants in the last few years, and not surprisingly, it is regularly detected in wastewaters, surface waters, sediments, biosolids and biota. While the toxicity and occurrence have been extensively studied, there is a lack of data on sertraline biodegradation and biotransformation. The objectives of this study were to assess the sertraline biodegradability, identify its biotransformation products, and determine its removal efficiency during wastewater treatment. The paper reveals that sertraline is mainly removed from wastewater by adsorption and that despite high removal efficiencies, it is still likely to be present in the environment. The paper also reports seven novel biotransformation products revealing the mechanism of sertraline transformation and sorption, biodegradation and its removal in the environment and during biological treatment. The newly discovered biotransformation products will be essential in future toxicity investigations.
[12] A. Kovačič, M. Modic, N. Hojnik, A. Vehar, T. Kosjek, D. J. Heath, J. L. Walsh, U. Cvelbar, E. Heath. Degradation of bisphenol A and S in wastewater during cold atmospheric pressure plasma treatment, Sci. Total Environ 2022. doi: 10.1016/j.scitotenv.2022.155707, Open access.
Developing novel, fast and efficient ecologically benign processes for removing organic contaminants is important for the continued development of water treatment. For this reason, this study investigates the implementation of Cold Atmospheric pressure Plasma (CAP) generated in ambient air as an efficient tool for the removal of Bisphenol A (BPA) and Bisphenol S (BPS)—known endocrine disrupting compounds in water and wastewater, by monitoring degradation kinetics and its transformation products. High removals of BPA (>98%) and BPS (>70%) were obtained after 480 s of CAP exposure. A pseudo-first-order kinetic revealed that BPA (-kt = 4.4 ̶ 9.0 ms-1) degrades faster than BPS (-kt = 0.4 ̶ 2.4 ms-1) and that the degradation is also time- and CAP power-dependent, while the initial concentration or matrix type had a negligible effect. Three previously reported and one novel transformation product of BPA and four novel transformation products of BPS were tentatively identified. The absence of additional chemicals and the relatively lower energy requirements of cold atmospheric pressure plasma make it a promising novel technology for water and WW treatment.
[13] A. Vehar, A. Kovačič, N. Hvala, N. Škufca, M. Levstek, M. Stražar, A. Žgajnar Gotvajn, E. Heath. An assessment of mass flows, removal and environmental emissions of bisphenols in a sequencing batch reactor wastewater treatment plant, Molecules 2022. doi: 10.3390/molecules27238634, Open access.
[14] A. Kovačič, M. Modic, N. Hojnik, M. Štampar, M. R. Gulin, C. Nannou, L.A. Koronaiou, D. J. Heath, J. L. Walsh, B. Žegura, D.A. Lambropoulou, U. Cvelbar, E. Heath. Degradation and toxicity of bisphenol A and S during cold atmospheric pressure plasma treatment, Journal of Hazardous Materials, doi: 10.1016/j.jhazmat.2023.131478, Open access.
[15] A. Kovačič, E. Andreasidou, A. Brus, A. Vehar, D. Potočnik, M. Jagodic Hudobivnik, D. J. Heath, M. Pintar, N. Kacjan Maršic, N. Ogrinc, E. Heath, Contaminant uptake in wastewater irrigated tomatoes, Journal of Hazardous Materials, doi: 10.1016/j.jhazmat.2023.130964, Open access.
[16] A. Kovačič, M. R. Gulin, C. Nannou, L.A. Koronaiou, T. Kosjek, D. J. Heath, M. S. Maier, D.A. Lambropoulou, E. Heath. Aerobic degradation of tetramethyl bisphenol F (TMBPF) with activated sludge: kinetics and biotransformation products. Environmental research, doi: 10.1016/j.envres.2023.115790, Open access.