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In small populations and scattered communities, wastewater treatment through vegetation filters (VFs), a nature-based solution, has proved to be feasible, especially for nutrient and organic matter removal. However, the presence of pharmaceuticals in wastewater and their potential to infiltrate through the vadose zone and reach groundwater is a drawback in the evaluation of VF performances. Soil amended with readily labile carbon sources, such as woodchips, enhances microbial activity and sorption processes, which could improve pharmaceutical attenuation in VFs. The present study aims to assess if woodchip amendments to a VF's soil are able to abate concentrations of selected pharmaceuticals in the infiltrating water by quantitatively describing the occurring processes through reactive transport modelling. Thus, a column experiment using soil collected from an operating VF and poplar woodchips was conducted, alongside a column containing only soil used as reference. The pharmaceuticals acetaminophen, naproxen, atenolol, caffeine, carbamazepine, ketoprofen and sulfamethoxazole were applied daily to the column inlet, mimicking a real irrigation pattern and periodically measured in the effluent. Ketoprofen was the only injected pharmaceutical that reached the column outlet of both systems within the experimental timeframe. The absence of acetaminophen, atenolol, caffeine, carbamazepine, naproxen and sulfamethoxazole in both column outlets indicates that they were attenuated even without woodchips. However, the presence of 10,11-epoxy carbamazepine and atenolol acid as transformation products (TPs) suggests that incomplete degradation also occurs and that the effect of the amendment on the infiltration of TPs is compound-specific. Modelling allowed us to generate breakthrough curves of ketoprofen in both columns and to obtain transport parameters during infiltration. Woodchip-amended columns exhibited Kd and μw values from one to two orders of magnitude higher compared to soil column. This augmentation of sorption and biodegradation processes significantly enhanced the removal of ketoprofen to over 96%. [ABSTRACT FROM AUTHOR]

• A simultaneous method to quantify CECs in water and soil matrices was developed. • Targeted CECs covered a wide range of properties and environmental occurrences. • A method validated for 21 CECs not included in the EPA method for soil samples. • A successfully monitored VF by applying the developed analytical method. Nonconventional wastewater treatments, such as vegetation filters (VFs), are propitious systems to attenuate contaminants of emerging concern (CECs) in small municipalities. The development of standardised multiresidue and multimatrix methods suitable for measuring a reliable number of CEC in environmental samples is crucial for monitoring infiltrating concentrations and for ensuring these systems' treatment capacity. The objective of this study is to develop and validate an analytical method for the simultaneous determination of CECs, including transformation products (TPs), with diverse physico-chemical properties, in environmental samples. The optimised method is based on sample clean-up and preconcentration by solid-phase extraction (SPE), followed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS). The method is able to detect and quantify 40 target CECs, including pharmaceuticals of different classes (analgesics, antibiotics, antihypertensives, lipid regulators, anticonvulsants, antidepressants, antiarrhythmics, beta-blockers, amongst others), hormones and lifestyle products with good reproducibility (variations below 23%), in different water matrices, and 28 CECs, in soil samples. Acceptable recoveries (65–120%) were obtained for most of the CECs in all the matrices. However in the soil samples, as complexity required a prior extraction treatment, the recovery of some analytes was affected, which reduced the number of target CECs. The achieved methodological quantification limits (0.05–5 ng/L and 0.04–1.1 ng/g levels for the water and the soil matrices, respectively) were reasonably low for most CECs. The proposed method was successfully applied to monitor CECs in a VF. The CECs detected at higher concentrations are some of the world's most widely used products (e.g. acetaminophen or caffeine and its main TP, paraxanthine). The results showed an almost 70% reduction in CEC concentrations during infiltration. The groundwater data indicated that the VF treatment operation did not affect the underlying aquifer (Cmax found in GW <1 µg/L). [ABSTRACT FROM AUTHOR]

[Display omitted] • The impact of unplanned water reuse in agriculture on human health is addressed. • Natural attenuation processes in the soil are effective for most drugs and TPs. • The ionization state of pharmaceuticals affects plant uptake processes. • Maize consumption does not pose a threat to human health due to drug intake. • Additional toxicity tests are recommended for the TP 4AAA and acetaminophen. In urban and periurban areas, agricultural soils are often irrigated with surface water containing a complex mixture of contaminants due to wastewater treatment plant (WWTP) effluent discharges. The unplanned water reuse of these resources for crop irrigation can represent a pathway for contaminant propagation and a potential health risk due to their introduction in the food chain. The aim of this study is to provide data about the magnitude of attenuation processes and plant uptake, allowing for a reliable assessment of contaminant transfer among compartments and of the human health risk derived from unplanned water reuse activities. Target compounds are 25 pharmaceuticals, including transformation products (TPs). The field site is an agricultural parcel where maize is irrigated by a gravity-fed surface system supplied by the Jarama river, a water course strongly impacted by WWTP effluents. Throughout the 3-month irrigation period, irrigation water and water infiltrating through the vadose zone were sampled. The agricultural soil was collected before and after the irrigation campaign, and maize was sampled before harvesting. All selected compounds are detected in irrigation water (up to 12,867 ng L−1). Metformin, two metamizole TPs and valsartan occur with the highest concentrations. For most pharmaceuticals, results demonstrate a high natural attenuation during soil infiltration (>60%). However, leached concentrations of some compounds can be still at concern level (>400 ng L−1). A persistent behavior is observed for carbamazepine, carbamazepine epoxide and sulfamethoxazole. Pharmaceutical soil contents are in the order of ng g−1 and positively ionized compounds accumulate more effectively. Results also indicate the presence of a constant pool of drugs in soils. Only neutral and cationic pharmaceuticals are taken up in maize tissues, mainly in the roots. There is an insignificant threat to human health derived from maize consumption however, additional toxicity tests are recommended for 4AAA and acetaminophen. [ABSTRACT FROM AUTHOR]