Continuous flow operation of solar photo-Fenton fused with NaOCl as a novel tertiary treatment.

A novel strategy based on solar photo-Fenton mediated by ferric nitrilotriacetate (Fe3+-NTA) combined with NaOCl in continuous flow mode for wastewater reclamation has been studied. Escherichia coli (E. coli) inactivation attained ≥ 5 log10-units, meeting the most restrictive EU 2020/741 target (10 CFU/100 mL), and 75% of organic microcontaminant total load was removed. As a remarkable finding, trihalomethanes (THMs) concentration was insignificant, complying by far with the Italian legislation limit. To attain these results, first the effect of liquid depth on E. coli inactivation and imidacloprid (IMD) removal from spiked municipal effluents was evaluated in continuous flow pilot-scale raceway pond reactors at 60-min hydraulic residence time with low reagent concentrations (0.10 mM Fe3+-NTA, 0.73 mM H2O2 and 0.13 mM NaOCl). Disinfection was due to the bactericidal effect of chlorine. In contrast, liquid depth notably influenced microcontaminant removal, highlighting that operation at 10-cm liquid depth allows achieving treatment capacities higher than at 5 cm (16.50 vs 28.20 mg IMD/m2∙day). Next, the monitoring of THMs was carried out to evaluate the generation and degradation of disinfection by-products, along with the removal of actual microcontaminants. These promising results draw attention to the treatment potential and open the way for its commercial application.

Continuous solar photo-Fenton for wastewater reclamation in operational environment at demonstration scale.

For the first time, a continuous flow solar photo-Fenton demonstration plant has been assessed for wastewater reclamation according to the EU 2020/741 regulation. The treated water qualities achieved under two operating strategies (acidic and neutral pH) in a 100-m2 raceway pond reactor were explored in terms of liquid depth, iron source, reagent concentrations, and hydraulic residence time over three consecutive days of operation. The results obtained at acidic pH showed removal percentages of contaminants of emerging concern (CECs) > 75% and water quality classes B, C and D according to EU regulation at both assessed operating conditions, with treatment capacities up to 1.92 m3 m-2 d-1. At neutral pH with ferric nitrilotriacetate (Fe3+-NTA), 50% of CEC removal and only water quality class D were achieved with the most oxidizing condition assessed, giving a treatment capacity of 0.80 m3 m-2 d-1. The treatment capacities obtained in this work, which have never been achieved with solar water treatments, demonstrate the potential of this technology for commercial-scale application.

Quemadura iatrogénica por bisturí eléctrico / Iatrogenic burn by electric scalpel

Introducción: En el proceso de una intervención quirúrgica actúa un equipo multidisciplinar, cada uno de estos miembros realiza sus funciones correspondientes y son interdependientes, pero se complementan entre sí. La seguridad del paciente no consiste en crear un dispositivo complejo y muy costoso o en un profesional excelente, sino en aplicar a nuestro trabajo diario y en nuestra práctica habitual el mejor conocimiento posible. La gestión de riesgos clínicos se basa en la identificación, el análisis y la corrección de las causas que originan o pudieran originar daño secundario al paciente tras el procedimiento o la administración de cuidados, y la iatrogenia es uno de los factores de análisis y control. Caso clínico: Paciente de 15 años, que tras ser intervenido de torsión testicular derecha presentó quemadura por bisturí eléctrico en cara interna del muslo, producida de forma iatrogénica durante el procedimiento quirúrgico. La causa de la quemadura fue el descontrol de la placa de seguridad del bisturí electrónico usado en la intervención. Plan de actuación: Se realizó cura en ambiente húmedo con apósito de alginato de Ag, que se fijó con apósito de espuma de silicona con reborde. El retroceso y estancamiento de la evolución precisó de antibioterapia sistémica tras cultivo y antibiograma, que propició la resolución del caso hasta la cicatrización total de la herida. Discusión y conclusiones: La cura en ambiente húmedo se convierte en una alternativa efectiva ante este tipo de lesiones. El abordaje integral y multidisciplinar del paciente y la posterior planificación de actuaciones se han mostrado eficaces a la hora de solucionar los problemas detectados en la valoración inicial, conllevando determinadas ventajas, así como el análisis y evaluación del proceso de seguridad del pacient (AU)

Introduction: In the process of a surgical intervention, a multidisciplinary team acts, each of these members performs their corresponding functions, and they are interdependent, but they complement each other. Patient safety does not consist in creating a complex and very expensive device or in an excellent professional, but in applying the best possible knowledge to our daily work and habitual practice. Clinical risk management is based on the identification, analysis and correction of the causes that cause or could cause secondary damage to the patient after the procedure or the administration of care, with iatrogenesis being one of the analysis and control factors. Clinical case: A 15-year-old patient who, after undergoing surgery for right testicular torsion, presented an electric scalpel burn on the inner side of the thigh, produced iatrogenically during the surgical procedure. The cause of the burn was the lack of control of the security plate of the electronic scalpel used in the intervention. Action plan: A humid environment cure was performed with an Ag alginate dressing fixed with a silicone foam dressing with a border. The setback and stagnation of the evolution required systemic antibiotic therapy, after culture and antibiogram, which led to the resolution of the case until the total healing of the wound. Discussion and conclusions: Humid environment cure becomes an effective alternative to this type of injury. The comprehensive and multidisciplinary approach to the patient and the subsequent planning of actions have been shown to be effective in solving the problems detected in the initial assessment, entailing certain advantages. as well as the analysis and evaluation of the patient safety process (AU)

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry.

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). The scope of the proposed QuEChERS-based method allows the monitoring of 107 CECs, including pharmaceuticals (58), antibiotics (16) and pesticides (33). The proposed method was successfully validated in urban TWW at two concentration levels (50 and 500 ng L-1) and it is a feasible alternative to conventional and time-consuming solid-phase extraction (SPE) methodologies. 89% of the CECs presented mean recovery values in the 70-120% range with relative standard deviations (RSDs) always < 20% (intra and inter-day precision), and limits of quantification (LOQs) in the range 5-500 ng L-1 (89% of the compounds showed a LOQ ≤ 50 ng L-1). The applicability of the method was demonstrated by the analysis of urban TWW samples (7 sampling events). In total, 35 CECs (23 pharmaceuticals, 2 antibiotics and 10 pesticides) were detected in the monitored samples with concentrations ranging from 5 to 677 ng L-1.

Assessment of the presence of transformation products of pharmaceuticals in agricultural environments irrigated with reclaimed water by wide-scope LC-QTOF-MS suspect screening.

The transformation that pharmaceuticals can undergo during the water reclamation cycle, or by biotic/abiotic reactions when reclaimed water (RW) is used for irrigation, can lead to the presence of transformation products (TPs) in agricultural environments. However, data on TPs in real crops are scarce. Herein, a suspect screening approach was applied for the comprehensive investigation of 262 potential TPs, associated with 20 prioritised pharmaceuticals found in real tomato crops exposed to long-term RW irrigation. The occurrence and fate of the TPs was evaluated by the retrospective analysis of RW, soil, leave and tomato samples from 4 intensive production greenhouses. Sample analysis was accomplished by liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). Up to 18 TPs were tentatively identified, of which 2 were not previously reported. 7 TPs were finally confirmed with analytical standards. 5 TPs were determined in RW, 15 TPs in soil and 2 TPs in leaves. Remarkably, the investigated TPs were not found in tomato fruits. These results shed light on the variety of TPs that can be found in the water reuse cycle and contribute to the assessment of the global risks of wastewater reuse and the safety of the vegetable and fruit production system.

Effects of ocean acidification on acid-base physiology, skeleton properties, and metal contamination in two echinoderms from vent sites in Deception Island, Antarctica.

Antarctic surface waters are expected to be the first to experience severe ocean acidification (OA) with carbonate undersaturation and large decreases in pH forecasted before the end of this century. Due to the long stability in environmental conditions and the relatively low daily and seasonal variations to which they are exposed, Antarctic marine organisms, especially those with a supposedly poor machinery to eliminate CO2 and protons and with a heavily calcified skeleton like echinoderms, are hypothesized as highly vulnerable to these environmental shifts. The opportunities offered by the natural pH gradient generated by vent activities in Deception Island caldera, Western Antarctic Peninsula, were used to investigate for the first time the acid-base physiologies, the impact of OA on the skeleton and the impact of pH on metal accumulation in the Antarctic sea star Odontaster validus and sea urchin Sterechinus neumayeri. The two species were sampled in four stations within the caldera, two at pH (total scale) 8.0-8.1 and two at reduced pH 7.8. Measured variables were pH, alkalinity, and dissolved inorganic carbon of the coelomic fluid; characteristic fracture force, stress and Young's modulus using Weibull statistics and Cd, Cu, Fe, Pb and Zn concentrations in the integument, gonads and digestive system. Recorded acid-base characteristics of both studied species fit in the general picture deduced from temperate and tropical sea stars and sea urchins but conditions and possibly confounding factors, principally food availability and quality, in the studied stations prevented definitive conclusions. Reduced seawater pH 7.8 and metals had almost no impact on the skeleton mechanical properties of the two investigated species despite very high Cd concentrations in O. validus integument. Reduced pH was correlated to increased contamination by most metals but this relation was weak. Translocation and caging experiments taking into account food parameters are proposed to better understand future processes linked to ocean acidification and metal contamination in Antarctic echinoderms.

Removal of contaminants of emerging concern by continuous flow solar photo-Fenton process at neutral pH in open reactors.

For the first time, the operational feasibility of the solar photo-Fenton process at neutral pH in continuous flow has been tested for three consecutive days. The aim of the treatment was to remove of contaminants of emerging concern (CECs) from wastewater treatment plant secondary effluents. To this end, a 5 cm-deep raceway pond reactor was run in continuous flow mode and the degradation of the CECs present in real secondary effluents was monitored at their natural concentrations. To keep dissolved iron at neutral pH, ethylenediamine-N,N'-disuccinic acid (EDDS) was used to form the complex Fe(III):EDDS as an iron source for the photo-Fenton reactions. At pilot scale the effects of the Fe(III):EDDS molar ratio (1:1 and 1:2) and hydraulic residence time (HRT) (20 and 40 min) on CEC removal were studied. The best operating condition was 20 min of HRT, giving rise to a treatment capacity of 900 L m-2 d-1 with CEC removal percentages of around 60%. The reactant concentrations were 0.1 mM Fe(III):EDDS at a 1:1 M ratio and 0.88 mM H2O2. Under these operating conditions, the short-term stability of the process was also demonstrated, thus pointing out the potential of this solar technology as a tertiary treatment.

Advanced evaluation of landfill leachate treatments by low and high-resolution mass spectrometry focusing on microcontaminant removal.

Conventional wastewater treatments are not usually effective in the remediation of specific landfill leachates due to their high content in toxic and recalcitrant compounds. Advanced and intensive treatments are needed for the decontamination and possible recycling of these effluents. Here, the combination of advanced oxidation processes (solar photo-Fenton) and an aerobic biological reactor have been applied to treat urban landfill leachates. The effectiveness of the proposed treatment line was also evaluated considering the removal of organic microcontaminants (OMCs) identified in the different phases, which is an innovative practice. The analytical strategy included: (i) a target approach (115 analytes) by liquid chromatography-mass spectrometry (LC-MS/MS); and two suspect approaches using (ii) LC-high-resolution MS (database with >1300 compounds) and (iii) gas-chromatography-MS (database with >900 compounds). OMCs on the treated landfill leachate was reduced up to 94% of the initial concentration. 8 target compounds (mainly pharmaceuticals) out of 115 target analytes represented 85% of the OMC concentration in the raw leachate: cotinine, diclofenac, gabapentin, ketoprofen, lidocaine, mecoprop, nicotine and trigonelline. 3 non-previously reported OMCs were confirmed: di-n-nonyl phthalate, o-phenylphenol and tonalide. Leachate partially oxidized by solar photo-Fenton process can be successfully incorporated to biological systems to complete the treatment by means of specifically adapted biomass.

Identification of transformation products of carbamazepine in lettuce crops irrigated with Ultraviolet-C treated water.

Transformation of organic microcontaminants (OMCs) during wastewater treatments results in the generation of transformation products (TPs), which can be more persistent than parent compounds. Due to reuse of reclaimed wastewater (RWW) for crop irrigation, OMCs and TPs are released in soils being capable to translocate to crops. Furthermore, OMCs are also susceptible to transformation once they reach the soil or crops. The recalcitrant antiepileptic carbamazepine (CBZ) and some of its frequently reported TPs have been found in agricultural systems. However, there is no knowledge about the fate in reuse practices of multiple CBZ TPs that can be formed during wastewater treatment processes. For the first time, this work presents a study of the behavior of CBZ TPs generated after a conventional Ultraviolet-C (UVC) treatment in an agricultural environment. The UVC-treated water was used for the irrigation of lettuces grown under controlled conditions. The latter was compared to the fate of TPs generated in the peat and plant by irrigation with non-treated water containing CBZ. A suspect screening strategy was developed to identify the TPs using liquid chromatography coupled to quadrupole-time-of-flight (LC-QTOF-MS). The results revealed the presence of 24 TPs, 22 in UVC-treated water, 11 in peat and 9 in lettuce leaves. 4 of the TPs identified in peat (iminostilbene, TP 271B, TP 285A-B); and 3 in leaves (10-11 dihydrocarbamazepine, TP 271A-B) were not previously reported in soils or edible parts of crops, respectively. Comparing the TPs found in peat and lettuces derived from both irrigation conditions, no significant differences regarding TPs formation or occurrence were observed. UVC treatment did not contribute to the formation of different TPs than those generated by transformation or metabolism of CBZ in peat or plant material. This research improves the current knowledge on the fate of CBZ TPs in agricultural systems because of reuse practices.

Determination of organic microcontaminants in agricultural soils irrigated with reclaimed wastewater: Target and suspect approaches.

Water scarcity is a problem worldwide, affecting specially countries with desert/semi-desert areas and low/irregular rainfall. In this context, reuse of reclaimed wastewater (RWW) for agricultural irrigation is undoubtedly a key strategy to reduce fresh water consumption. It is well-known that current wastewater treatments do not effectively remove organic microcontaminants (OMCs), and research in water analysis of OMCs is extensive. However, the focus on agricultural soils irrigated with RWW as potential recipients of OMCs and potential sources of OMCs to crops is still in their beginnings. This study aims to apply a target and a suspect approach for the multi-residue monitoring of OMCs in agricultural soils and a soilless subtract, both irrigated with RWW for more than ten years. The study involved, firstly, the development and validation of an extraction method for target analysis of 73 OMCs using a QuEChERS-based method and liquid chromatography coupled to quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS/MS); and secondly, the application of a suspect workflow for the screening of a list of 1300 potential contaminants using LC coupled to quadrupole-time-of-flight MS (LC-QTOF-MS). The results demonstrated the occurrence of 11 OMCs in the agricultural soil samples and 26 in the soilless subtract (0.1-100 ng g-1, dry weight, d.w.). The suspect analysis leaded to the confirmation of 28 OMCs analytes from the list of candidates. The subsequent combination of both strategies (suspect and target) revealed the presence of 11 new OMCs which were not previously reported. Furthermore, this study presents the first application of a OMCs suspect screening to agricultural soils irrigated with RWW for a long period. These results highlight the importance of monitoring soils with RWW-based irrigation and the application of wide-scope approaches for environmental analysis.

Application of a multivariate analysis method for non-target screening detection of persistent transformation products during the cork boiling wastewater treatment.

Cork boiling wastewater is a very complex mixture of naturally occurring compounds leached and partially oxidized during the boiling cycles. The effluent generated is recalcitrant and could cause a significant environmental impact. Moreover, if this untreated industrial wastewater enters a municipal wastewater treatment plant it could hamper or reduce the efficiency of most activated sludge degradation processes. Despite the efforts to treat the cork boiling wastewater for reusing purposes, is still not well-known how safe these compounds (original compounds and oxidation by-products) will be. The purpose of this work was to apply an HPLC-high resolution mass spectrometry method and subsequent non-target screening using a multivariate analysis method (PCA), to explore relationships between samples (treatments) and spectral features (masses or compounds) that could indicate changes in formation, degradation or polarity, during coagulation/flocculation (C/F) and photo-Fenton (PhF). Although, most of the signal intensities were reduced after the treatment line, 16 and 4 new peaks were detected to be formed after C/F and PhF processes respectively. The use of this non-target approach showed to be an effective strategy to explore, classify and detect transformation products during the treatment of an unknown complex mixture.

Validation and application of a multiresidue method based on liquid chromatography-tandem mass spectrometry for evaluating the plant uptake of 74 microcontaminants in crops irrigated with treated municipal wastewater.

Reuse of treated wastewater for agricultural purposes can mitigate water stress in some regions where the lack of water is an extended problem. However, the environmental long-term consequences of this practice are still unknown. It is demonstrated that using reclaimed water for irrigation lead to accumulation and translocation of some microcontaminants (MCs) in soil and crops. However, so far, only a small group of contaminants has been investigated. This study aims to develop and validate a simple and efficient multiresidue method based on QuEChERs (Quick, Easy, Cheap, Effective and Rugged) extraction coupled to liquid chromatography tandem mass spectrometry (LC-MS/MS). The novelty of the study relays in the large number of MCs analyzed (74), some of them not previously investigated, in three commodities (lettuce, radish and strawberry). Optimized conditions yielded good results for the three commodities under study. Up to 84% of the compounds were recovered within a 70-120% range, with good repeatability (relative standard deviations below 20% in most cases). Method detection (MDLs) and quantification limits (MQLs) ranged from 0.01 to 2 ng/g. The proposed method was successfully applied to assess the potential uptake of MCs by lettuce and radish crops irrigated with wastewater under controlled conditions for 3 and 1.5 months, respectively. 12 compounds were detected in the crops with concentrations ranging from 0.03 to 57.6 ng/g. N-Formyl-4-aminoantipyrine (4FAA) was the most concentrated compound. The application of this method demonstrated for the first time the accumulation of 5 contaminants of emerging concern (CECs) not previously reported: 4FAA, N-Acetyl-4-aminoantipyrine (4AAA), hydrochlorothiazide, mepivacaine and venlafaxine.

Combination of nanofiltration and ozonation for the remediation of real municipal wastewater effluents: Acute and chronic toxicity assessment.

The purpose of this work was to study the ozonation of nanofiltration (NF) retentates of real municipal wastewater treatment plant (MWTP) effluents for removal of microcontaminants (MCs) and toxicity. MCs present in these effluents were monitored using LC-MS/MS. Acute and chronic toxicity was addressed with Daphnia magna, Vibrio fischeri and Selenastrum capricornutum. Up to 40 MCs were found, most of them in concentrations over 100ng/L. 90% degradation of the sum of MCs was the critical point of comparison. When the NF membrane system was applied to MWTP effluents, treatment of NF rejection needed 2.75-4.5g O3/m3,4.5g O3/m3, which is less than 50% of the ozone needed for direct treatment of MWTP effluent. Treatment time (lower than 11min) was not influenced by MCs concentration, at least in the range tested (25-190µg/L). It has been demonstrated that consumption of ozone increased with organic load and inorganic content of different real effluents. MCs were eliminated by ozonation but acute toxicity (against V. fischeri and D. magna) increased. Chronic toxicity results were different and contrary in D. magna and S. capricornutum, due to the generation of new transformation products more toxic to D. magna than the parent contaminants. S. capricornutum inhibition percentage decreased in all cases after ozonation treatment. According to these results, before ozonation is implemented in MWTPs for the removal of MCs, the transformation products must first be examined and the treatment time or ozone doses should be extended to complete degradation if necessary.

Ecotoxicity evaluation of a WWTP effluent treated by solar photo-Fenton at neutral pH in a raceway pond reactor.

Some pollutants can be resistant to wastewater treatment, hence becoming a risk to aquatic and terrestrial biota even at the very low concentrations (ng L-1-µg L-1) they are commonly found at. Tertiary treatments are used for micropollutant removal but little is known about the ecotoxicity of the treated effluent. In this study, a municipal secondary effluent was treated by a solar photo-Fenton reactor at initial neutral pH in a raceway pond reactor, and ecotoxicity was evaluated before and after micropollutant removal. Thirty-nine micropollutants were identified in the secondary effluent, mainly pharmaceuticals, with a total concentration of ≈80 µg L-1. After treatment, 99 % microcontaminant degradation was reached. As for ecotoxicity reduction, the assayed organisms showed the following sensitivity levels: Tetrahymena thermophila > Daphnia magna > Lactuca sativa > Spirodela polyrhiza ≈ Vibrio fischeri. The initial effluent showed an inhibitory effect of 40 % for T. thermophila and 20 % for D. magna. After 20 min of photo-Fenton treatment, no toxic effect was observed for T. thermophila and toxicity dropped to 5 % for D. magna. Graphical abstract Ecotoxicity removal by solar photo-Fenton at neutral pH. ᅟ.

Cork boiling wastewater treatment and reuse through combination of advanced oxidation technologies.

Industrial preparation of cork consists of its immersion for approximately 1 hour in boiling water. The use of herbicides and pesticides in oak tree forests leads to absorption of these compounds by cork; thus, after boiling process, they are present in wastewater. Cork boiling wastewater shows low biodegradability and high acute toxicity involving partial inhibition of their biodegradation when conventional biological treatment is applied. In this work, a treatment line strategy based on the combination of advanced physicochemical technologies is proposed. The final objective is the reuse of wastewater in the cork boiling process; thus, reducing consumption of fresh water in the industrial process itself. Coagulation pre-treatment with 0.5 g/L of FeCl3 attained the highest turbidity elimination (86 %) and 29 % of DOC elimination. Similar DOC removal was attained when using 1 g/L of ECOTAN BIO (selected for ozonation tests), accompanied of 64 % of turbidity removal. Ozonation treatments showed less efficiency in the complete oxidation of cork boiling wastewater, compared to solar photo-Fenton process, under the studied conditions. Nanofiltration system was successfully employed as a final purification step with the aim of obtaining a high-quality reusable permeate stream. Monitoring of unknown compounds by LC-QTOF-MS allowed the qualitative evaluation of the whole process. Acute and chronic toxicity as well as biodegradability assays were performed throughout the whole proposed treatment line.

Fate of thiabendazole through the treatment of a simulated agro-food industrial effluent by combined MBR/Fenton processes at µg/L scale.

This study has been carried out to assess the performance of a combined system consisting of a membrane bioreactor (MBR) followed by an advanced oxidation process (Fenton/Photo-Fenton) for removing the fungicide thiabendazole (TBZ) in a simulated agro-food industrial wastewater. Previous studies have shown the presence of TBZ in the effluent of an agro-food industry treated by activated sludge in a sequencing batch reactor (SBR), thus reinforcing the need for alternative treatments for removal. In this study, a simulated agro-food industry effluent was enriched with 100 µg L(-1) TBZ and treated by combined MBR/Fenton and MBR/solar photo-Fenton systems. Samples were directly injected into a highly sensitive liquid chromatography-triple quadrupole-linear ion trap-mass spectrometer (LC-QqLiT-MS/MS) analytical system to monitor the degradation of TBZ even at low concentration levels (ng L(-1)). Results showed that the biological treatment applied was not effective in TBZ degradation, which remained almost unaltered; although most dissolved organic matter was biodegraded effectively. Fenton and solar photo-Fenton, were assayed as tertiary treatments. The experiments were run without any pH adjustment by using an iron dosage strategy in the presence of excess hydrogen peroxide. Both treatments resulted in a total degradation of TBZ, obtaining more than 99% removal in both cases. To assure the total elimination of contaminants in the treated waters, transformation products (TPs) of TBZ generated during Fenton degradation experiments were identified and monitored by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS). Up to four TPs could be identified. Two of them corresponded to mono-hydroxylated derivatives, typically generated under hydroxyl radicals driven processes. The other two corresponded with the hydrolysis of the TBZ molecule to yield benzoimidazole and thiazole-4-carboxamidine. All of them were also degraded during the treatment.

Liquid chromatography-high-resolution mass spectrometry for pesticide residue analysis in fruit and vegetables: screening and quantitative studies.

This work reviews the current state-of-the-art of liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) techniques applied to the analysis of pesticides in fruit-based and vegetable-based matrices. Nowadays, simultaneous trace analysis of hundreds of pesticides from different classes is required, preferably in just one run. The most commonly used QqQ-MS technology presents certain limitations in its application in a cost and effective way when analyzing a large number of pesticides. Thus, this review includes HRMS technology as a reliable complementary alternative allowing the analysis of a wide range of pesticides in food. Its capabilities and limitations in identifying, confirming and quantifying pesticides are discussed. HRMS instruments can adequately address such issues; however, the main drawbacks are as a result of insufficient prior optimization of the operational parameters during non-target analysis in full-scan mode and due to software shortcomings.

Application of solar AOPs and ozonation for elimination of micropollutants in municipal wastewater treatment plant effluents.

Conventional municipal wastewater treatment plants are not able to entirely degrade some organic pollutants that end up in the environment. Within this group of contaminants, Emerging Contaminants are mostly unregulated compounds that may be candidates for future regulation. In this work, different advanced technologies: solar heterogeneous photocatalysis with TiO(2), solar photo-Fenton and ozonation, are studied as tertiary treatments for the remediation of micropollutants present in real municipal wastewater treatment plants effluents at pilot plant scale. Contaminants elimination was followed by Liquid Chromatography/Quadrupole ion trap Mass Spectrometry analysis after a pre-concentration 100:1 by automatic solid phase extraction. 66 target micropollutants were identified and quantified. 16 of those contaminants at initial concentrations over 1000 ng L(-1), made up over 88% of the initial total effluent pollutant load. The order of micropollutants elimination efficiency under the experimental conditions evaluated was solar photo-Fenton > ozonation > solar heterogeneous photocatalysis with TiO(2). Toxicity analyses by Vibrio fischeri and respirometric tests showed no significant changes in the effluent toxicity after the three tertiary treatments application. Solar photo-Fenton and ozonation treatments were also compared from an economical point of view.

Photo-Fenton and modified photo-Fenton at neutral pH for the treatment of emerging contaminants in wastewater treatment plant effluents: a comparison.

This study compares two different solar photo-Fenton processes, conventional photo-Fenton at pH3 and modified photo-Fenton at neutral pH with minimal Fe (5 mg L⁻¹) and minimal initial H2O2 (50 mg L⁻¹) concentrations for the degradation of emerging contaminants in Municipal Wastewater Treatment Plants effluents in solar pilot plant. As Fe precipitates at neutral pH, complexing agents which are able to form photoactive species, do not pollute the environment or increase toxicity have to be used to keep the iron in solution. This study was done using real effluents containing over 60 different contaminants, which were monitored during treatment by liquid chromatography coupled to a hybrid quadrupole/linear ion trap mass analyzer (LC-QTRAP-MS/MS) operating in selected reaction monitoring (SRM) mode. Concentrations of the selected contaminants ranged from a few ng L⁻¹ to tens of µg L⁻¹. It was demonstrated in all cases the removal of over 95% of the contaminants. Photo-Fenton at pH3 provided the best treatment time, but has the disadvantage that the water must be previously acidified. The most promising process was photo-Fenton modified with Ethylenediamine-N,N'-disuccinic acid (EDDS), as the pH remained in the neutral range.

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.