Thiabendazole (TBZ), is a persistent fungicide/anthelminthic and a serious environmental threat. We previously enriched a TBZ‐degrading bacterial consortium and provided first evidence for a ...Sphingomonas involvement in TBZ transformation. Here, using a multi‐omic approach combined with DNA‐stable isotope probing (SIP) we verified the key degrading role of Sphingomonas and identify potential microbial interactions governing consortium functioning. SIP and amplicon sequencing analysis of the heavy and light DNA fraction of cultures grown on 13C‐labelled versus 12C‐TBZ showed that 66% of the 13C‐labelled TBZ was assimilated by Sphingomonas. Metagenomic analysis retrieved 18 metagenome‐assembled genomes with the dominant belonging to Sphingomonas, Sinobacteriaceae, Bradyrhizobium, Filimonas and Hydrogenophaga. Meta‐transcriptomics/‐proteomics and non‐target mass spectrometry suggested TBZ transformation by Sphingomonas via initial cleavage by a carbazole dioxygenase (car) to thiazole‐4‐carboxamidine (terminal compound) and catechol or a cleaved benzyl ring derivative, further transformed through an ortho‐cleavage (cat) pathway. Microbial co‐occurrence and gene expression networks suggested strong interactions between Sphingomonas and a Hydrogenophaga. The latter activated its cobalamin biosynthetic pathway and Sphingomonas its cobalamin salvage pathway to satisfy its B12 auxotrophy. Our findings indicate microbial interactions aligning with the ‘black queen hypothesis’ where Sphingomonas (detoxifier, B12 recipient) and Hydrogenophaga (B12 producer, enjoying detoxification) act as both helpers and beneficiaries.
Polycyclic aromatic hydrocarbons (PAHs) are compounds widespread in the environment, many of them showing carcinogenic effects. These compounds can reach the food chain by different ways and, ...therefore, the analysis of PAHs in food is a matter of concern. This article reviews the extraction methodologies together with the separation and detection techniques which are currently applied in the determination of PAHs in food and beverages. Specific extraction conditions, performance characteristics, chromatographic and detection parameters are discussed. A review of the occurrence of these compounds in the matrixes under study is also provided.
A fast and straightforward generic procedure for the simultaneous extraction of various classes of pesticides, mycotoxins, plant toxins, and veterinary drugs in various matrixes has been developed, ...for subsequent analysis by liquid chromatography with mass spectrometric detection. As a first step, four existing multianalyte procedures and three newly proposed methods were compared for a test set of 172 pesticides, mycotoxins, and plant toxins spiked to a feed matrix. The new procedures, which basically involved extraction/dilution of the sample with water and an acidified organic solvent (methanol, acetonitrile, or acetone), were most promising. The three new generic extraction methods were further tested for applicability to other matrixes (maize, honey, milk, egg, meat). Overall, the best recoveries were obtained for acetone, followed by acetonitrile. With respect to matrix effects, acetonitrile was the most favorable solvent and methanol was the worst. The occurrence of matrix effects decreased for the matrixes in the order of feed > maize > meat > milk > egg > honey. The extraction method selected as the default procedure (water/acetonitrile/1% formic acid) was also evaluated for applicability to multiple classes of veterinary drugs in all six matrixes, with satisfactory results. Finally, the generic extraction procedure was validated for 136 pesticides, 36 natural toxins, and 86 veterinary drugs in compound feed and honey at three levels (0.01, 0.02, and 0.05 mg/kg) using ultraperformance liquid chromatography tandem mass spectrometry (UPLC−MS/MS) for analysis of the extracts. For over 80% of the analytes, recoveries were between 70 and 120% and precision (expressed as relative standard deviation) was mostly in the range of 5−10% (except for feed at 0.01 mg/kg; adequate recoveries for 62% of the analytes). The limits of detection were from <0.01 to 0.05 mg/kg for most analytes, which is usually sufficient to verify compliance of products with legal tolerances. The results clearly demonstrate the feasibility of the generic approach proposed. Application of the method in routine monitoring programs would imply a drastic reduction of both effort and time.
•A simple and rapid analytical method using direct sample injection has been validated for the determination of pesticides and contaminants of emerging concern in wastewater samples.•High sensitive ...LC–QqLIT-MS/MS analysis has been successfully applied.•By direct injection it was possible to detect ngL−1 levels in real water samples, up to 67 compounds could be accurately identified and quantified.•The method can be easily implemented in wastewater studies.
It is well known that wastewater treatment plant (WWTP) effluents usually contain micropollutants such as pharmaceuticals (or their transformation products, TPs) or pesticides, which is a major issue when evaluating their possible reuse (e.g. for irrigation in agriculture). In search for an improved accuracy and simplicity, methods based on the direct injection of the sample (DI) represent a recent trend taking advantage of the increasing sensitivity of new mass spectrometry (MS) instruments. Thus, the present study shows the development and validation of a DI-based method by ultra-high-performance liquid chromatography quadrupole-linear ion trap analyser (UHPLC-QqLIT-MS/MS). The proposed method was applied to the monitoring of 115 organic microcontaminants (including pharmaceuticals, TPs and pesticides) at the ngL−1/μgL−1 level in wastewater effluents from urban WWTPs. Sample pre-treatment was reduced to acetonitrile addition and filtration of the mixture previous to LC–MS analysis. Total analysis time was <15min. A subsequent validation protocol was carried out in treated WW (TWW), following indications of SANTE and Eurachem Guidelines. Linearity and matrix effect were evaluated in the range of 10–1000ngL−1. 70% of the analytes showed a moderate matrix effect (≤25%). Trueness (expressed as recovery) and precision (calculated as relative standard deviation, RSD) were evaluated at four concentration levels (20, 50, 500 and 1000ngL−1) in TWW samples. The LODs ranged from 1 to 357ngL−1 and the LOQs from 10 to 500ngL−1. 92% of the compounds showed limits of quantification ≤100ngL−1. In most cases, mean recoveries were in the range 70–120%, and RSD values were ≤20%. The validated method was successfully applied to the analysis of 10 TWW samples, demonstrating the occurrence of 67 target compounds at concentration levels from 26705ngL−1 (4-aminoantipyrine) to 10ngL−1 (tebuconazole and bezafibrate).
In many regions, reuse of reclaimed water (RW) is a necessity for irrigation. The presence of organic microcontaminants (OMCs) in RW and their translocation to plants may represent a risk of human ...exposure. Nevertheless, information available about real field crops is scarce and focused on a limited number of compounds. The novelty of this work relies on the application of a wider-scope analytical approach based on a multianalyte target analysis (60 compounds) and a suspect screening (>1300 compounds). This methodology was applied to real field-grown tomato crops irrigated with RW. The study revealed the presence of 17 OMCs in leaves (0.04–32 ng g–1) and 8 in fruits (0.01–1.1 ng g–1), 5 of them not reported before in real field samples. A health-risk assessment, based on the toxicological threshold concern (TTC) concept, showed that RW irrigation applied under the conditions given does not pose any threat to humans.
The effect of the UV-C/free chlorine (FC) process on the removal of contaminants of emerging concern (CECs) from real urban wastewater as well as the effect of UV-C radiation on the formation of ...trihalomethanes (THMs) compared to FC process alone was investigated. Unlike of FC process, UV-C/FC was really effective in the degradation of the target CECs (carbamazepine (CBZ), diclofenac, sulfamethoxazole and imidacloprid) in real wastewater (87% degradation of total CECs within 60 min, QUVC = 1.33 kJ L−1), being CBZ the most refractory one (49.5%, after 60 min). The UV-C radiation significantly affected the formation of THMs. THMs concentration (mainly chloroform) was lower in UV-C/FC process after 30 min treatment (<1 μgL−1 = limit of quantification (LOQ)) than in FC process in dark (2.3 μgL−1). Noteworthy, while in FC treated wastewater chloroform concentration increased after treatment, UV-C/FC process resulted in a significant decrease (residual concentrations below the LOQ), even after 24 h and 48 h post-treatment incubation. The formation of radicals due to UV-C/FC process can reduce THMs compared to chlorination process, because part of FC reacts with UV-C radiation to form radicals and it is no longer available to form THMs. These results are encouraging in terms of possible use of UV-C/FC process as advanced treatment of urban wastewater even for possible effluent reuse.
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•UV-C/FC was effective in the degradation of the target CECs (87%, QUVC = 1.33 kJ L−1).•CBZ was the most refractory CEC (49.5%, after 60 min) to UV-C/FC process.•THMs concentration was lower in UV-C/FC than FC process.•THMs increased after FC treatment (up to 48 h), while decreased after UV-C/FC.•FC reacts with UV-C to form radicals and it is only partially available to form THMs.
The knowledge about the interaction of nanoplastics with other aquatic pollutants and their combined effects on biota is very scarce. In this work, we studied the interaction between polystyrene ...nanoplastics (PS NPs) (30 nm) and the micropollutants in a biologically treated wastewater effluent (WW). The capacity of PS NPs to sorb micropollutants was studied as well as their single and combined toxicity towards three freshwater organisms: the recombinant bioluminescent cyanobacterium, Anabaena sp. PCC 7120 CPB4337; the duckweed, Spirodela polyrhiza and the cladoceran, Daphnia magna. The endpoints were the inhibition of bioluminescence, the growth inhibition of the aquatic plant and the immobilization of D. magna after 24, 72 and 48 h of exposure, respectively. Combination Index (CI)-isobologram method was used to quantify mixture toxicity and the nature of interactions. PS NPs sorbed a variety of chemicals present in WW as micropollutants in a range of tens of ng/L to μg/L. It was found that those pollutants with positive charge were the main ones retained onto PS NPs, which was attributed to the electrostatic interaction with the negatively charged PS NPs. Regarding the toxicological effects, single exposure to PS NPs affected the three tested organisms. However, single exposure to WW only had a negative impact on the cyanobacterium and S. polyrhiza with no observed toxicity to D. magna. Regarding PS NPs-WW combined exposure, a reduction of toxicity in comparison with single exposure was observed probably due to the sorption of micropollutants onto PS NPs, which resulted in lower bioavailability of the micropollutants. In addition, the formation of PS NPs-WW heteroaggregates was observed which could result in lower bioavailability of PS NPs and sorbed micropollutants, thus lowering toxicity. This study represents a near-realistic scenario approach to the potential sorption of wastewater pollutants onto nanoplastics that could alter the toxicological effect on the biota.
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•Up to 44 wastewater pollutants were sorbed by polystyrene nanoplastics (PS-NPs).•Positively charged pollutants were preferably sorbed onto negatively charged PS-NPs.•Joint exposure resulted in lower toxicity to the three tested freshwater organisms.•Removal of PS-NPs-sorbed pollutants from the solution explains the lower toxicity.•Aggregates in joint exposure may also account for lower pollutant bioavailability.
Agriculture is considered as the main source of water contamination by pesticides. However, food packaging or processing industries are also recognised as relevant point sources of contamination by ...these compounds, not yet investigated in depth. The objective of this work has been to improve current knowledge about the presence and concentration of pesticides in the effluent of a food processing industry, as well as to investigate their main transformation products (TPs). An analytical strategy combining target and suspect analysis has been applied to provide an evaluation of the effluents. The methodology involves solid-phase extraction (SPE) of wastewater samples followed by (i) liquid chromatography quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for quantitative target analysis and (ii) liquid chromatography coupled to quadrupole-time-of-flight high resolution mass spectrometry (LC-QTOF-HRMS) to identify non-target pesticides and possible TPs. The results revealed the presence of 17 of the target pesticides analysed and 3 additional ones as a result of the suspect screening performed by HRMS. The TPs were investigated for the pesticides found at the highest concentrations: imazalil (7038-19802 ng/L), pyrimethanil (744-9591 ng/L) and thiabendazole (341-926 ng/L). Up to 14 TPs could be tentatively identified, demonstrating the relevance of this type of studies. These data provide a better understanding of the occurrence of pesticides and their TPs in agro-food industrial effluents.
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•Analysis of pesticides in wastewater effluent of an agro-food industry was carried out.•Imazalil, pyrimethanil, thiabendazole, propiconazole and etoxazole were detected at the highest concentrations.•Presence of imazalil, pyrimethanil and thiabendazole TPs was also evidenced in the effluents.•Imazalil and cyprodinil concentrations can eventually pose a risk for the environment.
This work proposes the evaluation of an aluminized surface on the bottom of open reactors to perform a photo-Fenton process, at circumneutral pH (using Fe III-Ethylenediamine-N,N′-disuccinic acid ...complex), for elimination of micropollutants (MPs) in real effluents from municipal wastewater treatment plants (EMWWTP). Firstly, the strategy was to initially investigate the real EMWWTP spiked with several MPs (acetaminophen, diclofenac, carbamazepine, caffeine, trimethoprim and sulfamethoxazole) with 20 and 100 μg L−1 in a laboratory scale (evaluated by HPLC-UV) using a solar simulator. Finally, the removal of all MCs present in the real EMWWTP was monitored (evaluated by HPLC-MS) in a pilot-scale (90 L) in a raceway pond reactor (RPR). The treatment time required for degradation above 80% for the investigated MPs was over 30 min, and the predominant effect could be mainly associated with organics present in the real EMWWTP due to the light attenuation and scavenging of radical species. Moreover, the results confirmed that chloride and sulfate would most likely equally not affect the process. The use of an aluminized surface on the bottom of RPRs has been confirmed as a suitable option to improve the photo-Fenton reaction, enabling the use of lower doses of iron. Up to 60 different MPs found in EMWWTP have been successfully degraded using 0.1 mM of Fe at circumneutral pH with a consumption of 30 mg L−1 H2O2 with less than 45 min.
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•Near-neutral photo-Fenton at low iron concentration on open reactors.•Low contaminant level simulation approximates kinetic values to real effluents.•Higher treatment time on real MTWWP effluent than on natural water•Reaction's inhibition mainly to DOM's light attenuation than inorganic scavenging•Aluminized surface would improve treatment at low liquid depth and with less DOM.
► Creation of a database for the identification of >350 compounds in Orbitrap. ► Comprehensive database for pesticides and veterinary drugs. ► Analysis by UHPLC–Orbitrap-MS. ► Application to honey ...analysis using a generic approach. ► UHPLC–Orbitrap-MS provide adequate quantification/identification capabilities.
A database has been created for the simultaneous analysis of more than 350 pesticides and veterinary drugs (including antibiotics) using ultra-high performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry (UHPLC–Orbitrap-MS). This is a comprehensive exact mass database built using the Exactive-Orbitrap analyzer. The developed database includes exact masses of the target ions and retention time data, and allows the automatic search of the included compounds. Generic chromatographic and MS conditions have been applied. The presented database is suitable for qualitative analysis, and it was also evaluated for quantitative purposes in routine analysis, after the optimization and validation of a generic extraction method in honey samples. Adequate recovery and precision values for most of the studied analytes were obtained and the limits of detection (LOD) ranged from 1 to 50μgkg−1. For pesticides, LODs were always lower than the MRLs established by European Union in honey, except for a few compounds. This method was applied to the analysis of 26 real honey samples and some pesticides (azoxystrobin, coumaphos, dimethoate and thiacloprid) were detected in 4 samples. Azoxystrobin and coumaphos were determined in two different samples (organic honey) at 1.5μgkg−1 and 5.1μgkg−1. Veterinary drugs were not detected in the analyzed samples.
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