Cr(VI) sorption/desorption on pine sawdust and oak wood ash

International Journal of Environmental Research and Public Health

DOI: 10.3390/ijerph120808849

The objective of this work was to study Cr(VI) sorption/desorption on two by-products from the wood industry: pine sawdust and oak wood ash. The retention/release experiments were carried out using standard batch-type trials. In the sorption-phase experiments, pine sawdust showed 23% sorption when a concentration of 100 mg Cr(VI)·L-1 was added, whereas sorption on oak wood ash was 17%. In the desorption-phase, chromium release was clearly higher from pine sawdust than from oak wood ash (98% and 66%, respectively). Sorption curves were well fitted to the Freundlich and Lineal models. In view of the results, both materials can be considered of very limited value to remove Cr from polluted soil and water, which can be of relevance regarding its appropriate use as biosorbents and recycled by-products.

Metalaxyl mobility in acid soils: Evaluation using different methods

International Journal of Environmental Science and Technology 

DOI: 10.1007/s13762-014-0612-1

In the present work, different methods were tested to evaluate the adsorption and desorption of metalaxyl in two acid soils with different organic carbon and clay contents. The three methods (batch, stirred flow chamber and column) that were examined produced similar findings when the two soils were compared: (a) the metalaxyl adsorption capacity was higher in the soil with higher organic matter and clay content, and (b) the soil with the lower organic matter and clay contents provided higher adsorption rate constants. In the two soils tested, the metalaxyl adsorbed in the soil was highly reversible. When only one soil was considered, the different methods yielded different results. The metalaxyl adsorption and its rate were higher with the stirred flow chamber than in the column experiments, and in the column experiments, the total metalaxyl adsorption and the rate of adsorption were higher than in the batch experiments. The percentages of metalaxyl desorbed from the soil were similar in the stirred flow chamber and column experiments, but in the batch experiments, the percentages were significantly lower. In the stirred flow chamber experiments, the desorption processes were faster than the adsorption processes, while in the column experiments, the adsorption and desorption processes exhibited similar rates.

Time evolution of the general characteristics and Cu retention capacity in an acid soil amended with a bentonite winery waste

Journal of Environmental Management

DOI: 10.1016/j.jenvman.2014.12.024

The effect of bentonite waste added to a "poor" soil on its general characteristic and copper adsorption capacity was assessed. The soil was amended with different bentonite waste concentrations (0, 10, 20, 40 and 80Mgha-1) in laboratory pots, and different times of incubation of samples were tested (one day and one, four and eight months). The addition of bentonite waste increased the pH, organic matter content and phosphorus and potassium concentrations in the soil, being stable for P and K, whereas the organic matter decreased with time. Additionally, the copper sorption capacity of the soil and the energy of the Cu bonds increased with bentonite waste additions. However, the use of this type of waste in soil presented important drawbacks for waste dosages higher than 20Mgha-1, such as an excessive increase of the soil pH and an increase of copper in the soil solution.

Heavy metals in pastureland soils situated in A Pastoriza (NW Spain) treated with cattle slurry and NPK fertilizers

Spanish Journal of Soil Science, 5, 154-164 (2015)

DOI: 10.3232/SJSS.2015.V5.N2.05

In Galicia (NW Spain), pasturelands cover a broad extension and are mainly used to feed cattle. Farms are managed in an intensive manner, using cattle slurry and inorganic fertilizers to increase pasture production, but also increasing risks of heavy metal pollution. In this work we studied the influence of fertilization practices on total concentrations and in-depth distribution of heavy metals and related elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) in two forest soils (SN1, SN2) and five pastureland soils (P1-P5) fertilized with cattle slurry and NPK, in a broadly exploded farmland area (A Pastoriza, Lugo). Soils SN2 and P4 were developed over slate, whereas soils SN1, P1, P2, P3 and P5 evolved on Candana quartzite. Forest soils presented acid pH (4.58-4.68), high Al saturation (75-90%), and low available P concentration (4.78-11.96 mg kg-1), whereas those parameters exhibited better scores in the pastureland soils, due to previous amendment and fertilization practices, thus giving pH 5.17-7.02, Al saturation 0.58-59.24%, and available P 5.24-42.07 mg kg-1. Regarding heavy metals, soil depth did not affect significantly to total concentrations, contrary to that happening with parent material, with higher As, Cu, Fe, and Ni concentrations found in soils over slate (possibly due to the presence of pyritic materials). In most cases, heavy metal total concentrations were lower than that considered as reference background levels for soils developed over each of the parent materials, and were always lower than that considered phyto-toxic. In this study, natural soils usually presented heavy metal total contents similar or even higher than that of the fertilized soils (unless Zn in the P4 pastureland), thus indicating that the spread doses of fertilizers did not influence significantly their concentration levels.

Profiling, distribution and levels of carcinogenic polycyclic aromatic hydrocarbons in traditional smoked plant and animal foods

Food Control, 59 (2016) 581–590

doi:10.1016/j.foodcont.2015.06.036

The purpose of this study was to evaluate the concentration of polycyclic aromatic hydrocarbons (PAH8 plus fluoranthene and pyrene) in “Pan de Cea” bread, “Pimentón de La Vera” paprika, “San Simón da Costa”, “Idiazábal” and “Humus” cheeses, and “Chorizo” garlic pork sausage. Results obtained showed that harmless low molecular weight compounds (Fluoranthene and Pyrene) represented the major contribution to the total PAHs. The most important PAHs according to the levels found were those in the 4 PAHs group (the rest of PAHs to add a total of 8 were contributing at very low levels). PAH4 and PAH8 levels showed percentages ranging from 6.0 to 7.0 % in bread, 16–17 % in paprika, 23–28 % in cheese and 20–24 % in meat sausages, respectively. B(a)P did not exceed the imposed limits in the EU. Bread showed the lower PAH concentration (3.4 μg/kg) followed by cheese (88 μg/kg), smoked sausage (1779 μg/kg) and paprika (9937 μg/kg). “Pimentón de la Vera” paprika is a condiment consumed in small quantities. The PAH profile had in common the decrease in PAH content as their molecular weight increased. These results showed that the contamination detected in “Pan de Cea” bread samples was very low, so that the consumption of this product does not pose a health risk. In cheese samples, the PAH contamination was detected meanly in rind, that accounted around the 100% of the total contamination. In meat sausages samples, the 90% of the total PAHs determined were accumulated in the casing. Considering the edible part, the PAH4 and B(a)P mean contents were below the limit established. Although, the highest PAH levels were detected in “Pimentón de la Vera” paprika, it should be pointed out that this product is a condiment consumed in small quantities and not in an everyday basis, it does not represent a risk for consumers. In cheese and meat sausage, according our estimates, the removal of the external part can be considered a good consumer practices to reduce the ingestion of PAHs.

A critical review about human exposure to Polychlorinated Dibenzo-p-Dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Biphenyls (PCBs) through foods

Critical Reviews in Food Science and Nutrition, 55 (11), 2015, 1590-1617

DOI:10.1080/10408398.2012.710279

Dioxins include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and part of polychlorinated biphenyls (PCBs). Only the compounds that are chlorinated at the 2,3,7, and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily; however their hydroxylated metabolites are detected in feces. They cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCDDs, PCDFs and PCBs on thyroid hormones, neurodevelopment and reproductive development were referenced. In addition, some studies of contamination of foods, bioaccumulation, dietary exposure assessment, as well as challenges of scientific research in these compounds were reviewed.

A critical review about the health risk assessment of PAHs and their metabolites in foods

Critical Reviews in food science and nutrition, 55 (10), 2015, 1383-1405

DOI:10.1080/10408398.2012.697497

Polycyclic aromatic hydrocarbons (PAHs) are a family of toxicants that are ubiquitous in the environment. These contaminants generate considerable interest, because some of them are highly carcinogenic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. Dietary intake of PAHs constitutes a major source of exposure in humans. Factors affecting the accumulation of PAHs in the diet, their absorption following ingestion, and strategies to assess risk from exposure to these hydrocarbons following ingestion have received very little attention. This review, therefore, focuses on concentrations of PAHs in widely consumed dietary ingredients along with gastrointestinal absorption rates in humans. Metabolism and bioavailability of PAHs in animal models and the processes, which influence the disposition of these chemicals, are discussed. Finally, based on intake, disposition, and tumorigenesis data, the exposure risk to PAHs from diet is presented. This information is expected to provide a framework for refinements in risk assessment of PAHs.

Toxicity evaluation of new agricultural fungicides in primary cultured cortical neurons

Environmental Research, 140, 2015, 37-44

doi 10.1016/j.envres.2015.03.013

Fungicides are crucial for food protection as well as for the production of crops of suitable quality and quantity to provide a viable economic return. Like other pesticides, fungicides are widely sprayed on agricultural land, especially in wine-growing areas, from where they can move-off after application. Furthermore, residues of these agrochemicals can remain on crops after harvest and even after some food processing operations, being a major exposure pathway. Although a relatively low toxicity has been claimed for this kind of compounds, information about their neurotoxicity is still scarce.

In the present study, nine fungicides recently approved for agricultural uses in the EU ― ametoctradin, boscalid, cyazofamid, dimethomorph, fenhexamid, kresoxim-methyl, mepanipyrim, metrafenone and pyraclostrobin ― have been evaluated for their toxicity in primary cultured mouse cortical neurons. Exposure to 0.1–100 µM for 7 days in vitro resulted in a dose-dependent toxicity in the MTT cell viability assay. Strobilurin fungicides kresoxim-methyl (KR) and pyraclostrobin (PY) were the most neurotoxic compounds (lethal concentration 50 were in the low micromolar and nanomolar levels, respectively) causing a rapid raise in intracellular calcium [Ca2+]i and strong depolarization of mitochondrial membrane potential. KR- and PY-induced cell death was reversed by the calcium channels blockers MK-801 and verapamil, suggesting that calcium entry through NMDA receptors and voltage-operated calcium channels are involved in KR- and PY-induced neurotoxicity. These results highlight the need for further evaluation of their neurotoxic effects in vivo.

Effects of sugar concentration processes in grapes and wine aging on aroma compounds of sweet wines—a review

Critical Reviews in Food Science and Nutrition, 55(8), 2015, 1053-1073

DOI 10.1080/10408398.2012.680524

Dessert sweet wines from Europe and North America are described in this review from two points of view: both their aroma profile and also their sensorial description. There are growing literature data about the chemical composition and sensory properties of these wines. Wines were grouped according to the production method (concentration of sugars in grapes) and to the aging process of wine (oxidative, biological, or a combination of both and aging in the bottle). It was found that wines natively sweets and wines fortified with liquors differ in their volatile compounds. Sensory properties of these wines include those of dried fruit (raisins), red berries, honey, chocolate and vanilla, which is contributing to their growing sales. However, there is still a need for scientific research on the understanding of the mechanisms for wine flavor enhancement.

Blending Local olive oils with Arbequina or Picual oils produces high quality, distinctive EVOOs

European Journal of Lipid Science and Technology. 2015

doi 10.1002/ejlt.201400357

Arbequina and Picual are the most common olive fruit varieties cultivated in Galicia (NW Spain). However, in recent years, the interest of oil producers in autochthonous Local olive fruits has increased substantially since its oil has differentiated and peculiar characteristics, especially with respect to the aromatic and phenolic composition. The blending of Local oil (in low percentages) with Arbequina or Picual oils is assessed in this study. Quality-related indices, fatty acid composition, as well as minor compounds, such as volatiles and phenolics, were determined for both monovarietal and blending oils. Results obtained showed that the blending has the advantage of producing high quality virgin olive oil with predictable phenolic and aromatic profiles.

Competitive adsorption/desorption of tetracycline, oxytetracycline and chlortetracycline on two acid soils: Stirred flow chamber experiments

Chemosphere, 134 (2015) 361-366

doi 10.1016/j.chemosphere.2015.04.098

The objective of this work was to study the competitive adsorption/desorption of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on two acid soils. We used the stirred flow chamber technique to obtain experimental data on rapid kinetic processes affecting the retention/release of the antibiotics. Both adsorption and desorption were higher on soil 1 (which showed the highest carbon, clay and Al and Fe oxides content) than on soil 2. Moreover, hysteresis affected the adsorption/desorption processes. Experimental data were fitted to a pseudo-first order equation, resulting qamax (adsorption maximum) values that were higher for soil 1 than for soil 2, and indicating that CTC competed with TC more intensely than OTC in soil 1. Regarding soil 2, the values corresponding to the adsorption kinetics constants (ka) and desorption kinetics constants for fast sites (kd1), followed a trend inverse to qamax and qdmax respectively. In conclusion, competition affected adsorption/desorption kinetics for the three antibiotics assayed, and thus retention/release and subsequent transport processes in soil and water environments.

Cr(VI) sorption/desorption on untreated and mussel-shell-treated soil materials: fractionation and effects of pH and chromium concentration

Solid Earth, 6, 373–382, 2015

doi 10.5194/se-6-373-2015

We used batch-type experiments to study Cr(VI) sorption/desorption on granitic material, forest soil, pyritic material, mussel shell, and on forest soil and granitic material amended with 12 t ha−1 (1.2 kg m−2) shell, considering the effects of varying Cr(VI) concentration and pH. Sequential extractions were carried out to fractionate adsorbed Cr(VI) and to determine the stability of Cr(VI) retention. The pyritic material had the highest Cr(VI) retention capacity, whereas the granitic material showed the lowest retention potential. When high Cr concentrations were added, some saturation of the adsorbent surfaces became apparent, but Cr release remained low. The highest Cr retention was achieved at a very acid pH value, with release progressively increasing as a function of increasing pH. The amendment with 12 t ha−1 mussel shell did not cause marked changes in Cr(VI) re- tention. Sorption data were satisfactory adjusted to the Fre- undlich model. Regarding Cr(VI) fractionation, the soluble fraction (weakly bound) was dominant in mussel shell and in the unamended and amended granitic material, whereas more stable fractions dominated in the pyritic material (resid- ual fraction) and in the forest soil (oxidizable fraction). In conclusion, the pyritic material presented the highest Cr(VI) retention capacity, while the retention was low and weak on the granitic material; mussel shell was not characterized by a marked Cr(VI) retention potential, and it did not cause re- markable increase in Cr(VI) retention when used to amend the granitic material or the forest soil.

A model to forecast the risk periods of Plantago pollen allergy by using the ANN methodology

Aerobiologia (2015) 31:201–211

DOI 10.1007/s10453-014-9357-z

Some biological particles present in the atmosphere, such as pollen grains, give rise to human health problems, allergies, and infections. In view of the recognized special allergenic ability of Plantago pollen grains, a model based on an artificial neural network (ANN) was developed in this work in order to forecast the Plantago airborne pollen concentration. The proposed model uses data from Plantago pollen and the main meteorological variables recorded during 16 years (1993–2008) in the city of Ourense (north- west Spain). Its accuracy was tested during the years 2009 and 2010 with a prediction horizon of 2 days in advance. The model was applied in the atmosphere of the city of Ourense (Spain). Obtained results show that ANN model provides good results against other classical mathematical methodologies, which do not convergence so well. The forecasted pollen concen- trations here are applied to allergology because they allow taking into account preventive measures in risk pollinosis suffers population.

Cleavage of carbofuran and carbofuran-derivatives in micellar aggregates

Progress in Reaction Kinetics and Mechanism, 40 (2015) 105-118

DOI: /10.3184/146867815X14259195615547

In recent years, the stability of carbamate pesticides have been studied by our research group in a wide range of biomimetic microheterogeneous media such as micelles or reverse micelles. These microheterogeneous media included different surfactant species and, hence, different self-assembled structures. In particular, basic hydrolysis of carbofuran and its derivatives have been analysed in the presence of anionic, cationic, non-ionic and reverse micelles. The results obtained from these physicochemical and kinetic studies, as well as a consistent comparison of them, are now summarised.

Evaluation of the effect of fenhexamid and mepanipyrim in the volatile composition of Tempranillo and Graciano wines

Food Research International

Volume 71, May 2015, Pages 108–117

doi:10.1016/j.foodres.2015.02.025

Grapes from Vitis vinifera var. Tempranillo and Graciano of La Rioja (North Central Spain) were vinified after addition of two fungicides (mepanipyrim and fenhexamid) at concentrations corresponding to their MRLs. These fungicides are commonly used in the vine growing to control botrytis disease. The fungicide effect throughout winemaking on the volatile composition and aroma profile of the final wines was evaluated, together with the level of fungicide residues in the final wines that were found to be safe for consumers. Concentrations of C13-norisoprenoids in Graciano wines obtained after the addition of both active substances showed the greatest variations with respect to control wine; whereas the concentration of volatile compounds in Tempranillo wines were seemingly unaffected by the presence of fungicide residues. On the other hand, the aroma profile of monovarietal red wines was evaluated by using odorant series which included volatile compounds with similar odour descriptors. In this sense, supplementation with the antifungals seemed to increase the OAV for the ripe fruit series with respect to the control wines in Graciano wines.

Perspectives on the use of by-products to treat soil and water pollution

Microporous and Mesoporous Materials

Volume 210, 1 July 2015, Pages 199–201

doi:10.1016/j.micromeso.2015.02.001

The use of modified by-products in pollution removal is conceptually very interesting, as shown in a paper by Peng et al. (2015) recently published in Microporous and Mesoporous Materials. However, we would like to stimulate a debate on the convenience of simultaneously continuing to research on the purging potential of raw by-products and waste materials.

Kinetics of tetracycline, oxytetracycline, and chlortetracycline adsorption and desorption on two acid soils

Environmental Science and Pollution Research

January 2015, Volume 22, Issue 1, pp 425-433

DOI 10.1007/s11356-014-3367-9

The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments. We used the stirred flow chamber (SFC) procedure to achieve this goal. All three antibiotics showed high affinity for both soils, with greater adsorption intensity for soil 1, the one with the highest organic matter and Al and Fe oxides contents. Desorption was always <15 %, exhibiting strong hysteresis in the adsorption/desorption processes. Adsorption was adequately modeled using a pseudo first-order equation with just one type of adsorption sites, whereas desorption was better adjusted considering both fast and slow sorption sites. The adsorption maximum (q max ) followed the sequence tetracycline > oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics on soils and other media, thus increasing knowledge on the behavior and evolution of these pharmaceutical residues in the environment.

Effect of crushed mussel shell addition on bacterial growth in acid polluted soils

Applied Soil Ecology

Volume 85, January 2015, Pages 65–68

doi:10.1016/j.apsoil.2014.09.010

We applied three different doses of crushed mussel shell (CMS) on two Cu-polluted acid soils to study the effect of these amendments on the growth of the bacterial community during 730 days. Soil pH increased in the short and medium term due to CMS addition. In a first stage, bacterial growth was lower in the CMS-amended than in the un-amended samples. Thereafter, bacterial growth increased slowly. The soil having the highest initial pH value (4.5) showed the first significant increase in bacterial growth 95 days after the CMS amendment. However, in the soil with the lowest initial pH value (3.8) bacterial growth increased significantly only after 730 days from the CMS addition. The highest dose of CMS caused that, at the end of the incubation period, pH value have increased 2 units, whereas bacterial growth was 4–10 times higher. In view of these results, CMS amendment could be considered as an agronomic sound practice for strongly acid soils (pH <4.5).

Adsorption, desorption and fractionation of As (V) on untreated and mussel shell-treated granitic material

Solid Earth, 6 (1) 337-346 (2015)

doi:10.5194/se-6-337-2015

As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the unamended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always <19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH <6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreased as pH increased. Desorption varying pH was always <26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). The granitic material did not show high As(V) retention capacity, which could facilitate As(V) transfer to water courses and to the food chain in case of As(V) compounds being applied on this material; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

Liquid chromatography–mass spectrometry method development for monitoring stress-related corticosteroids levels in pig saliva

Journal of Chromatography B

Volume 990, 15 May 2015, Pages 158–163

doi:10.1016/j.jchromb.2015.03.021

Biochemical response stressors results in an increase of adrenocortical activity. Before knowing the corticosteroid levels in saliva in a stressful situation, baselines salivary levels should be established. A method for simultaneous determination of five corticosteroids was developed, validated and applied to pig saliva at farms. The method employs solid-phase extraction (SPE) coupled with clean-up extraction step using silica cartridge in the same step followed by liquid chromatography/tandem mass spectrometry (LC–MS/MS), using electrospray ionization (ESI) in positive mode. The overall method quantification limits range from 0.050 to 0.30 μg/L for the enrichment of 1.0 mL saliva samples and analyte recoveries are between 60 and 90% (RSD < 11%). Some factors studied were: pig sex, breeds, and time at farm. The analytical method clearly shows that CRL and CRS levels of, respectively, 3.0 and 4.0 μg/L in saliva can be indicative of maxima non-stress levels in different pig breeds at farm.