Water pollution by pesticides used in agriculture is currently a major concern both in Spain and in Europe as a whole, prompting the need to evaluate water quality and ecological risk in areas of ...intensive agriculture. This study involved monitoring pesticide residues and certain degradation products in surface and ground waters of the Denomination of Origin (DO) Jumilla vineyard area in Spain. Sixty-nine pesticides were selected and evaluated at twenty-one sampling points using a multi-residue analytical method, based on solid-phase extraction (SPE) and analysis by liquid chromatography coupled with mass spectrometry (LC-MS), providing reliable results. Twenty-six compounds from those selected were detected in the samples analyzed (eleven insecticides including one degradation product, nine herbicides, and six fungicides) and fifteen of them were found in concentrations over 0.1 μg L−1 (upper threshold established by the EU for pesticides detected in waters for human consumption). Indoxacarb was present in more than 70% of the samples, being the most frequently detected compound in water samples. Some pesticides were ubiquitous in all the water samples. Ecotoxicological risk indicators, toxic units (TUs) and risk quotients (RQs), for algae, Daphnia magna and fish were calculated to estimate the environmental risk of the presence of pesticides in waters. The compounds with the highest risk were the herbicides pendimethalin, with RQ values > 1 for the three aquatic organisms, and diflufenican, posing a high risk for algae and fish, and the insecticide chlorpyrifos, with a high risk for Daphnia magna and fish. The ∑TUi determined for water at each sampling point posed only a high risk for the three aquatic organisms in a sample. These results are important for considering the selection of pesticides with less environmental risk in intensive agricultural areas.
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•69 pesticides at 21 sampling points of a Spanish vineyard area were evaluated.•Twenty-six pesticides were detected, 15 of them in concentrations over 0.1 μg L−1.•Insecticides were the most frequently detected pesticides.•Acute toxicity risk for some aquatic organisms was revealed at most of the samples.•Some compounds detected pose a chronic risk unacceptable in several trophic levels.
This study reports the effect that adding spent mushroom substrate (SMS) to a representative vineyard soil from La Rioja region (Spain) has on the behaviour of azoxystrobin in two different ...environmental scenarios. Field dissipation experiments were conducted on experimental plots amended at rates of 50 and 150 t ha−1, and similar dissipation experiments were simultaneously conducted in the laboratory to identify differences under controlled conditions. Azoxystrobin dissipation followed biphasic kinetics in both scenarios, although the initial dissipation phase was much faster in the field than in the laboratory experiments, and the half-life (DT50) values obtained in the two experiments were 0.34–46.3 days and 89.2–148 days, respectively. Fungicide residues in the soil profile increased in the SMS amended soil and they were much higher in the top two layers (0–20 cm) than in deeper layers. The persistence of fungicide in the soil profile is consistent with changes in azoxystrobin adsorption by unamended and amended soils over time. Changes in the dehydrogenase activity (DHA) of soils under different treatments assayed in the field and in the laboratory indicated that SMS and the fungicide had a stimulatory effect on soil DHA. The results reveal that the laboratory studies usually reported in the literature to explain the fate of pesticides in amended soils are insufficient to explain azoxystrobin behaviour under real conditions. Field studies are necessary to set up efficient applications of SMS and fungicide, with a view to preventing the possible risk of water contamination.
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•Azoxystrobin dissipation was evaluated under field and laboratory conditions.•Fungicide dissipation was faster in unamended soil than in SMS-amended soils.•Initial dissipation was much faster in the field than in the laboratory experiments.•Fungicide mobility through the soil profile was observed in all the treatments.•Field studies are necessary to explain azoxystrobin behaviour under real conditions.
Soil amendment with organic wastes is becoming a widespread management practice since it can effectively solve the problems of uncontrolled waste accumulation and improve soil quality. However, when ...simultaneously applied with pesticides, organic wastes can significantly modify the environmental behaviour of these compounds. This study evaluated the effect of sewage sludges (SS), grape marc (GM) and spent mushroom substrates (SMS) on the leaching of linuron, diazinon and myclobutanil in packed columns of a sandy soil with low organic matter (OM) content (<1%). Soil plus amendments had been incubated for one month (1m) or 12months (12m). Data from the experimental breakthrough curves (BTCs) were fitted to the one-dimensional transport model CXTFIT 2.1. All three amendments reduced leaching of linuron and myclobutanil relative to unamended soil. SMS was the most effective in reducing leaching of these two compounds independent of whether soil was incubated for 1m or 12m. Soil amendments increased retardation coefficients (Rexp) by factors of 3 to 5 for linuron, 2 to 4 for diazinon and 3 to 5 for myclobutanil relative to unamended soil. Leaching of diazinon was relatively little affected by soil amendment compared to the other two compounds and both SS and SMS amendment with 1m incubation resulted in enhanced leaching of diazinon. The leaching data for linuron and myclobutanil were well described by CXTFIT (mean square error, MSE<4.9·10−7 and MSE<7.0·10−7, respectively) whereas those of diazinon were less well fitted (MSE<2.1·10−6). The BTCs for pesticides were similar in soils incubated for one month or one year, indicating that the effect of amendment on leaching persists over relatively long periods of time.
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•Organic residues modified leaching of pesticides in amended soil columns.•Experimental breakthrough curves were fitted to the one-dimensional transport model.•Grape marc was the most effective residue in reducing diazinon leaching.•Spent mushroom substrate was the most effective in reducing linuron and myclobutanil leaching.•Amendment effect on pesticide leaching persists in both one month or one year incubated soils.
Spatial and temporal evaluations of seventeen pesticides and some of their degradation products were carried out in seventeen vineyard soils from La Rioja region (Spain). The soils were sampled in ...March, June and October 2012, and the pesticides were selected among those previously detected in surface and ground waters from the same area. All pesticides were detected in some of the soils in the three different areas of La Rioja at the different sampling times, with only the metalaxyl metabolite, CGA-62826, not being detected in any of the soils sampled in October. The highest concentrations were determined for the fungicides metalaxyl (11.5μgkg−1) and triadimenol (26.1μgkg−1), the herbicides fluometuron (174.6μgkg−1) and terbuthylazine (403.3μgkg−1), and the insecticide methoxyfenozide (4.61μgkg−1). While the highest total concentration of pesticides was detected in March, the highest number of positive detections was recorded in June (46), as opposed to 26 and 19 in March and October, respectively. Significant differences were detected in the concentrations of herbicides in soils from the three areas in La Rioja, but this was not the case for the fungicides and the insecticides. The study revealed a more intensive use of herbicides in March, while the use of insecticides and fungicides probably depended on the specific needs of crops and/or the onset of diseases. The results are consistent with the residues found in waters in the region, and highlight the need to implement strategies for more efficient application of these compounds to avoid risk of water contamination.
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•Temporal evaluation of pesticides was carried out in Spanish vineyard soils.•All pesticides were detected in some of the soils at the different sampling times.•The highest total concentration of pesticides was detected in March.•The highest number of positive detections was recorded in June.•Pesticide residues in soils are consistent with those found in waters in the region.
The precise characterization of the microstructure of fibrous composites is essential for an accurate determination of their properties and behaviour. However, fabrication processes usually introduce ...serious deviations from simple ideal spatial arrangements of preform fibres and matrix. The characterization of composites has been performed using destructive and non destructive testing techniques, many of them based on image analysis. Carbon fibres in carbon matrix composites, however, pose a difficult challenge to image analysis systems due to the poor contrast between the different phases. We describe a procedure for the reconstruction of the true microstructure of carbon/carbon composites using phase contrast X-ray microtomography, show some results, and discuss its performance.
In this work, extraction of antioxidant compounds from Dunaliella salina microalga is optimized by combining pressurized liquid extraction (PLE) and experimental design (three-level factorial design) ...with three different solvents (hexane, ethanol, and water). Two main factors were considered, the extraction temperature (40, 100, and 160 °C) and the extraction time (5, 17.5, and 30 min). As response variables, the extraction yield (percent dry weight/initial weight) and the antioxidant activity of the extracts (determined using the TEAC method) were used. The parameters of the model were estimated by multiple linear regression. Results showed that the extraction temperature was the factor having the strongest influence (positive) on the two response variables. The best yields were obtained with ethanol at the higher extraction temperature and time tested. Besides, although hexane extracts provided the best antioxidant activity, ethanol extracts were also very active. The chemical characterization of ethanol extracts was carried out using HPLC-DAD, and attempts have been made to correlate their chemical composition with the antioxidant activity measured. Results pointed out that the extracts contained, besides all-trans-β-carotene and isomers, several different minor carotenoids that seemed to make a contribution to the antioxidant activity of the extracts. Keywords: PLE; Dunaliella salina; TEAC; antioxidant compounds; optimization
We present the first detection of the ortho-H2O 423 − 330 transition at 448 GHz in space. We observed this transition in the local (z = 0.010) luminous infrared (IR) galaxy ESO 320-G030 (IRAS ...F11506-3851) using the Atacama Large Millimeter/submillimeter Array (ALMA). The water 423 − 330 emission, which originates in the highly obscured nucleus of this galaxy, is spatially resolved over a region of ~65 pc in diameter and shows a regular rotation pattern compatible with the global molecular and ionized gas kinematics. The line profile is symmetric and well fitted by a Gaussian with an integrated flux of 37.0 ± 0.7 Jy km s-1. Models predict this water transition as a potential collisionally excited maser transition. On the contrary, in this galaxy, we find that the 423 − 330 emission is primarily excited by the intense far-IR radiation field present in its nucleus. According to our modeling, this transition is a probe of deeply buried galaxy nuclei thanks to the high dust optical depths (τ100μm> 1, NH> 1024 cm-2) required to efficiently excite it.
A
bstract
The
Neutrino Experiment with a Xenon TPC
(NEXT) searches for the neutrinoless double-beta (0
νββ
) decay of
136
Xe using high-pressure xenon gas TPCs with electroluminescent amplification. ...A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0
νββ
decay better than 10
27
years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.
A new method to tag the barium daughter in the double-beta decay of ^{136}Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba^{++}) ...resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (∼2 nm), and detected with a statistical significance of 12.9σ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.
The changes of physicochemical and biochemical parameters of a silty loam (S1) and sandy loam (S2) vineyard soils added with spent mushroom substrate (SMS) or SMS composted with ophite (OF) as rock ...dust (SMS + OF) were studied. Two doses of SMS or SMS + OF (25 and 100 Mg ha−1) were applied for two consecutive years (2020–2021) and changes of soil physicochemical parameters, and dehydrogenase activity (DHA), respiration (RES), microbial biomass (BIO), and the phospholipid fatty acids (PLFAs) profile were assayed on a temporal basis. The results showed an increase in soil organic carbon (OC) content, total and mineralised N, P, and K, especially when the highest SMS dose was applied to soils. Repeated application caused OC content over time up to 2.3 times higher than initial content in the silty loam soil. This increase was not observed in sandy soil, possibly due to a higher bioavailability of OC, as indicated by the evolution of extractable humic acid/fulvic acid pools. In both soils, all biochemical parameters increased after amendment, being favoured both by the OC and by the presence of OF. Significant positive correlations were found between DHA, RES and BIO, and OC content especially in the first part and then levelled off after the second dose application. Total bacterial or fungal PLFAs patterns reflected the variation of BIO by SMS application. The higher growth of fungi vs. bacterial community in amended soils was recorded after the first SMS application, although the opposite effect occurred after the second application, with similar results in both soils. The findings indicate that the application of SMS or SMS + OF in vineyard soils could be an appropriate agronomic management practice for maintaining soil sustainability, although doses and application times of these amendments should first be evaluated depending on soil texture.
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•Effect of repeated application of organic-inorganic amendments was evaluated in vineyard soils.•SMS and SMS + OF wastes at two rates were studied as soil amendments.•Increase in nutrient content persisted over time favoured in amended soils at the highest dosage.•Biochemical parameters changes were mainly explained by the readily metabolised OC from SMS.•Optimisation of dosages and successive applications is essential to preserve soil sustainability.
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