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The effects on the adsorption of fluoroquinolone antibiotics of long-term soil heterogeneity induced by land-use were investigated. Three different land use areas with their two organic matter (OM) pools were tested for the adsorption of three antibiotics widely detected in the environment (ciprofloxacin, norfloxacin, ofloxacin). The soils were separated into two size fractions, > 63 µm fraction and < 63 µm fractions for the fast and slow OM pools, respectively. Any effect of land use on adsorption was only observed in the slow pool in the increasing order: arable land, grassland, and forest. The composition of the soil organic matter (SOM) did influence adsorption in the slow pool, but not in the bulk soilsThis was, because: 1) the ratio of the slow pool was low, as in forest, 2) the ratio of the slow pool was high but its adsorption capacity was low due to its SOM composition, as in arable land and grassland. Soils containing a large slow SOM pool fraction with aliphatic dominance were found to be more likely to adsorb micropollutants. It is our contention that the release of contaminated water, sludge, manure or compost into the environment should only be undertaken after taking this into consideration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Small streams are crucial but vulnerable elements of ecological networks. To better understand the occurrence of pharmaceutically active compounds (PhACs) in streams, this study focused on the occurrence, distribution, and environmental risk of 111 PhACs and 7 trace elements based on a total of 141 water and sediment samples from small streams located in the urbanizing region of Budapest, Hungary. Eighty-one PhACs were detected in the aqueous phase, whereas sixty-two compounds were detected in the sediment. Carbamazepine (CBZ) was the most frequently identified PhAC in water, and was found in 91.5% of all samples. However, the highest concentrations were measured for lamotrigine (344.8 μg·L -1 ) and caffeine (221.4 μg·L -1 ). Lidocaine was the most frequently occurring PhAC in sediment (73.8%), but the maximum concentrations were detected for CBZ (395.9 ng·g -1 ) and tiapride (187.7 ng·g -1 ). In both water and sediment, more PhACs were found downstream of the wastewater treatment plants (WWTPs) than in the samples not affected by treated wastewater, even though no relationship was observed between the total amount of treated wastewater and the number of detected PhACs. The PhAC concentrations were also independent of the distance from the WWTP effluents. PhAC-polluted samples were detected upstream of the WWTPs, thereby suggesting the relevance of diffuse emissions in addition to WWTP outlets. The most frequently detected PhACs in the sediment were usually also present in the water samples collected at the same place and time. The varying concentrations of PhACs and the fluctuating water-sediment properties resulted in a lack of correlation between the general chemical properties and the concentrations of PhACs, which makes it difficult to predict PhAC contamination and risks in urbanized small streams. The environmental risk assessment indicated that diclofenac had the highest risk in the sampling area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the results presented in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

The role of the chemical properties of Pharmaceutically Active Compounds (PhACs) in their sorption behaviour and consequently in their fate and mobility is of major environmental interest, but a comprehensive evaluation is still lacking. The sorption of nine PhAC molecules with distinct physico-chemical properties on soils and goethite was described using linear, Freundlich and Langmuir models and the relationship between the chemical structures of the compounds and the parameters of the adsorption was evaluated using redundancy analysis (RDA). The latter showed that the sorption of the pharmaceuticals was determined by the intrinsic chemical characteristics of the molecules, as shown by the 35% value of constrained variability. For the hydrophobic estrogens, E1, E2 and EE2, the logD value and the number of hydrogen bond sites were found to be the main controlling factors for adsorption, indicating that hydrophobic interaction and hydrogen bonding are the dominant sorption mechanisms. The π energy of the molecules also proved a very important parameter, governing the retention of PhACs in soils, especially in the case of carbamazepine, oxazepam and lamotrigine. The main controlling factor for ionic compounds, such as diclofenac sodium, tramadol or lidocaine, is the fraction of PhACs present as charged species, revealing the importance of Coulomb forces. The results of this study will allow semi-quantitative predictions to be made on how the molecular structure governs the sorption of PhACs and which sorption mechanism could be involved., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)