Fate, modeling, and human health risk of organic contaminants present in tomato plants irrigated with reclaimed water under real-world field conditions.

Using reclaimed water to irrigate crops can be an important route for organic contaminants of emerging concern (CECs) to be introduced into agricultural production and thus find their way into the food chain. This work aims to establish accumulation models for the different parts of a crop (fruit/leaves/roots) and the soil of some of the most commonly detected CECs in reclaimed water, through field trials in greenhouses. For this, tomato plants were permanently irrigated under realistic agricultural conditions with a mixture of the selected compounds at approx. 1 µg/L. A total of 30 contaminants were analyzed belonging to different compound categories. A modified QuEChERS extraction method followed by liquid chromatography coupled to tandem mass spectrometry was the procedure used. The study revealed the presence of 21 target contaminants in the tomatoes, and 18 CECs in the leaves, roots, and soil. The average total concentration of pesticides detected in the tomatoes was 3 µg/kg f.w., whereas the average total load of pharmaceuticals was 5.8 µg/kg f.w. after three months, at the time of crop harvesting. The levels of pharmaceutical products and pesticides in the non-edible tissues were up to 3.5 and 2.1 µg/kg f.w., respectively, in the leaves and up to 89.3 and 31.3 µg/kg f.w., respectively, in the roots. In the case of the soil samples, the pesticide concentration found after crop harvesting was below 11.4 µg/kg d.w., and less than 3.0 µg/kg d.w. for pharmaceuticals. Overall, the concentration levels of CECs detected in the tomatoes, which were permanently irrigated with contaminated reclaimed water, do not pose a risk to human health via dietary intake.

Occurrence and persistence of organic emerging contaminants and priority pollutants in five sewage treatment plants of Spain: two years pilot survey monitoring.

This work summarized all results obtained during almost two-years of a monitoring programme carried out in five municipal sewage treatment plants (STPs) located in the north, centre and south-east of Spain. The study evaluated the occurrence and persistence of a group of 100 organic compounds belonging to several chemical groups (pharmaceuticals, personal care products, pesticides and metabolites). The average removal efficiencies of the STPs studied varied from 20% (erythromycin) to 99% (acetaminophen). In analysed samples, we identified a large number of compounds at mean range concentrations between 7-59,495 ng/L and 5-32,720 ng/L for influent and effluent samples, respectively. This study also identified 20 of the mostly detected and persistent compounds in wastewater effluent, of which hydrochlorothiazide, atenolol, gemfibrozil, galaxolide and three metabolites (fenofibric acid, 4-AAA and 4-FAA), presented the highest average contribution percentages, in relation to the total load of contaminants for the different STPs effluent studied.

Evaluation of selected ubiquitous contaminants in the aquatic environment and their transformation products. A pilot study of their removal from a sewage treatment plant.

A simple method using direct sample injection combined with liquid chromatography tandem mass spectrometry has been developed for the simultaneous analysis of six alkaloid compounds in environmental samples. The target list includes two psychostimulants (nicotine and caffeine), three metabolites (cotinine, nicotinic acid and paraxanthine) and a coffee chemical (trigonelline). The analytical method was evaluated in three different matrices (surface water, influent and effluent wastewater). The method developed showed an adequate sensitivity, below 0.6 µg L(-1) for wastewater and 0.1 µg L(-1) for river matrices, without any prior treatment of the samples. Finally, the methodology was applied to real samples for evaluation of their removal from a sewage treatment plant and their persistence/fate in the aquatic environment. All compounds studied in this work were detected at all sampling points collected along the Henares River. However, nicotinic acid was only detected three times in treated sewage samples at levels above its detection limit.