Ana Kovačič

Although sewage sludge in agriculture can promote circular economy goals, concerns remain about the transfer of contaminants of emerging concern (CECs) into crops and soils. This study evaluated the uptake and risk of 27 CECs in tomatoes cultivated in peat substrate amended with stabilised anaerobically digested (dried) sludge from a local municipal wastewater treatment plant at two rates corresponding to nitrogen and nitrogen/potassium requirements. Peat substrate served as the control. Additional treatments included CEC-spiked media and peat amended with non-dried sludge. Analysis was performed with LC–MS/MS. In tomato fruits, ibuprofen (15.8 ng/g) and triclosan (17.9 ng/g) were quantified at the low amendment rate, while caffeine (381 ng/g), carbamazepine (18.1 ng/g), ciprofloxacin (306 ng/g) and ibuprofen (5.3 ng/g) were quantified at the high amendment rate. Dietary exposure estimates were below the health-based reference values for most compounds; however, a potential risk was identified for bisphenol S when non-dried anaerobically digested sludge was applied. Soil risk quotients (RQ > 1) for several CECs at the end of the experiment indicate possible ecological concern. These findings emphasise that monitoring CECs in sludge-amended soil remains essential to ensure the safety of sludge reuse in agriculture.

Despite growing evidence linking diet to neurodegenerative diseases, the connection remains unclear. Tomatoes, a widely consumed food, have been proposed as potential sources of neuroactive compounds. Using LC-MS/MS, we profiled organic and conventional “datterini,” plump, and processed tomatoes. Six carotenoids were quantified, with phytoene and lycopene being the most abundant. Multivariate analysis revealed that processing and variety, rather than organic vs. conventional methods, drove dataset variability. Seventy neuroactive compounds were identified, some distinguishing tomato variety, processing, and/or production methods. Processed tomatoes generally showed higher abundance of neuroactive compounds than fresh tomatoes, and “datterini” tomatoes contained more neuroprotective compounds than plump tomatoes. Organic “datterini” did not have higher neuroprotective compound levels than conventional ones. These findings suggest thermal processing may alter the compositional quality of tomatoes, potentially enhancing the levels of certain bioactive constituents, while organic cultivation does not inherently increase the abundance of neuroprotective compounds. Overall, tomatoes represent a complex source of both neuroprotective and neuro-disrupting compounds, warranting further research on their bioaccessibility and physiological relevance.

This study analyzed 16 bisphenols (BPs) in wastewater and sludge samples collected from different stages at a municipal wastewater treatment plant based on sequencing batch reactor technology. It also describes developing an analytical method for determining BPs in the solid phase of activated sludge based on solid-phase extraction and gas chromatography-mass spectrometry. Obtained concentrations are converted into mass flows, and the biodegradation of BPs and adsorption to primary and secondary sludge are determined. Ten of the sixteen BPs were present in the influent with concentrations up to 434 ng L⁻¹ (BPS). Only five BPs with concentrations up to 79 ng L⁻¹ (BPA) were determined in the plant effluent, accounting for 8 % of the total BPs determined in the influent. Eleven per cent of the total BPs were adsorbed on primary and secondary sludge. Overall, BPs biodegradation efficiency was 81%. The highest daily emissions via effluent release (1.48 g day⁻¹) and sludge disposal (4.63 g day⁻¹) were for BPA, while total emissions reached 2 g day⁻¹ via effluent and 6 g day⁻¹ via sludge disposal. The data show that the concentrations of BPs in sludge are not negligible, and their environmental emissions should be monitored and further studied.

Veronika Kralj-Iglič, ur. 2022, IX, 201 str. ISBN 978-961-7128-20-8