Organic contaminants occurring in reclaimed water can be incorporated in soil, where they can interact with humic compounds or anthropogenic organic matter depending on their physicochemical properties. In the soil water, a fraction of these contaminants can be biodegraded, particularly in the rhizosphere, where the process is enhanced by root exudates. Another fraction can be uptaken by plants and translocated by xylem. Once incorporated in the plant, a fraction of the incorporated contaminant is metabolized, while the rest remains unaltered. Three stages can be distinguished in the metabolization process: (1) oxidation, (2) conjugation, and (3) accumulation in the vacuole or cell wall.
BACKGROUNDThe formation of struvite (MgNH4PO4 6H(2)O) from digested slurry is an opportunity to recover nutrients as a slow-release fertilizer. A series of batch and continuous experiments were conducted to assay the influence of operational parameters, total solids and organic matter content on the quality and size of struvite crystals formed. Finally, the agronomic bioavailability of struvite was assessed in a greenhouse experiment.; RESULTSIn terms of process conditions an optimum pH of 9 was found, while changes in temperature (from 25 degrees C to 36 degrees C) showed to exert no influence whatsoever. On the other hand, though the presence of Na+ didn't affect the efficiency, high amounts of Ca2+ decreased the percentage of Mg2+ and NH4+ removed. CO2 stripping presented a reduction in the reagents required (NaOH) to raise the pH, with a similar removal efficiency and good quality of the struvite obtained. Nevertheless, the presence of organic matter resulted in a reduction on the size of struvite crystals. Agronomic assays showed that struvite P availability is similar to that of synthesis ammonium phosphate fertilizers.; CONCLUSIONSThe results point to struvite precipitation as a good strategy to recover nutrients from digested manure and to improve nutrient management. (c) 2014 Society of Chemical Industry
To assess risks of cultivation of genetically modified crops (GMCs) on non-target arthropods (NTAs), field tests are necessary to verify laboratory results and in situations where exposure pathways are very complex and cannot be reproduced in the laboratory. A central concern in the design of field trials for this purpose is whether the tests are capable of detecting differences in the abundance or activity of NTAs in a treated crop in comparison with a non-treated comparator plot. The detection capacity of a trial depends on the abundance and variability of the taxon, the values assumed for type I (alpha) and II (beta) errors, and the characteristics of the trial and statistical design. To determine the optimal trial layout and statistical analysis, 20 field trials carried out in Spain from 2000 to 2009 to assess risks of GMCs on NTAs were examined with alpha and beta set at 0.05 and 0.20, respectively. In this article we aim to determine the optimal number of sampling dates during a season, or longitudinal samples, in the design of field trials for assessing effects of GM maize on NTAs, and the ones that contribute most to achieving detectable treatment effects (d(c)) less than 50% of the mean of the control. Detection capacities are a function of the number of individual samples taken during the season but a high number of samples is rarely justified because gains of repeated sampling can be relatively low. These gains depend primarily on field tests relative experimental variability in individual samplings (i.e. experimental variability relative to the mean of the control in each sampling date) which in turn depends on the sampling method (visual counts, pitfall traps or yellow sticky traps) and the density (or abundance) of the taxon in question. Taxa showing more density (or abundance) have less relative experimental variability. The smaller the experimental variability, the lower the profit of increasing the number of sampling dates. Sticky traps have a good effect detection capacity and need very few sampling dates, whereas visual counts and pitfall traps have a poorer effect detection capacity and need more individual samples to achieve d(c) values lower than 50%. In maize field trials, it is recommended to concentrate sampling efforts in certain growth stages; the optimal ones for achieving an acceptable detection capacity are variable but, in general, samples in the first half of the season render better detection capacity than samples in the second half.
Interest in identifying pools of antibacterial-resistance genes has grown over the last decade, with veterinary antibiotics (VAs) receiving particular attention. In this paper, a mesoscale study aimed at evaluating the vertical transport of common VAs-namely, fluoroquinolones, tetracyclines, sulfonamides, and lincosamides in agricultural soil subjected to drip irrigation-was performed under greenhouse conditions. Accordingly, leachates of cropped and uncropped soil, amended with swine-slurry leading to 19-38 mu g kg(-1) (dry mass) antibiotics in the soil, were analyzed over the course of the productive cycle of a lettuce (42 days) with three sampling campaigns (N=24). High lincomycin (LCM) concentrations (30-39 mu g L-1) were detected in the leachates collected from the swine-slurry-amended soil. The highest LCM mass recovered in the leachates (30.1 +/- 1.63 %) was obtained from cropped experimental units. In addition, the LCM leaching constant and its leaching potential as obtained from the first-order model were higher in the leachates from the cropped experimental units. Lower concentrations of sulfadimethoxine were also detected in leachates and in soil. Enrofloxacin and oxytetracycline occurred only in soil, which is consistent with high soil interaction.
La fracción orgánica de los residuos
municipales (FORM) comprende residuos
procedentes de hogares particulares
y residuos similares de otros establecimientos
que los municipios
recogen junto con la basura doméstica.
Estos residuos constituyen entre el 30 y
50% de la masa total de los residuos sólidos
Reclaimed water can be contaminated with several organic microcontaminants derived from human activities (e.g. pharmaceutical and personal care products (PPCPs). These contaminants can be risky to human health and environment, where they can move to different environmental compartments. For that reason, their determination, for example in food, becomes necessary to evaluate their exposure for risk assessment studies.
The aim of the present study is to evaluate the uptake of selected PPCPs by lettuce (Lactuca sativa, L) from irrigation water in a greenhouse experiment and correlate the uptake with their physico-chemical properties. A mesocosm study under greenhouse conditions with pearlite and sand (2:1; v:v) as a growing medium and Lactuca sativa watered with rainwater at four levels of concentrations of pollutants (10, 25, 50 and 100 ng•L-1) is used to study the fate of the selected PPCPs. Therefore, the concentration of those microcontaminants in soils, leaves and roots were determined using a gas chromatography (GC) and ultraperformance liquid chromatography (UPLC) coupled to tandem mass spectrometry (MS/MS).
Most of the studied PPCPs were found at different levels in leaves and roots. Carbamazepine was found at higher concentrations in leaves than other PPCPs in the four concentrations evaluated. Translocation factors (TSCF) were determined and they showed that Carbamazepine (TSCF>1) has an active uptake mechanism while the other PPCPs show a TSCF<1 which means they have a passive uptake mechanism based on diffusion.
Finally, statistical analysis of the obtained data will be performed in order to study the TSCF and bioaccumulation factor of microcontaminants correlated to their physico-chemical properties (water solubility, log Kow, log Dow, pKa).
Recovery of nutrients from the OFMSW is a relevant topic as evidenced by the European initiative \”End
of Waste\”. Following this guideline, the Ecoparc 2 of Montcada i Reixac, belonging to the Metropolitan Area
of Barcelona, submits the OFMSW to anaerobic digestion and then the digestate is separated mechanically,
fisrt by pressing and then by centrifugation. The solid of press (Sp) and the solid of centrifugue (Sc) are com-
posted together (CSp+Sc) and used as organic fertilizer. There are alternatives to the current treatment of
the OFMSW as: (1) direct use of Sc as fertilizer, (2) composting of Sc (CSc) and (3) composting of Sp (CSp).
This paper focuses on analyzing the recovery of nutrients
La recuperación de nutrientes en el tratamiento de la FORM es un tema relevante en Europa tal como se recoge en la iniciativa "End of Waste" (IPTS , 2012). Se ha estudiado la recuperación de nutrientes en el Ecoparc 2 a partir del proceso del tratamiento de la FORM . El tratamiento consiste en
digestión anaerobia, separación mecánica del digerido mediante prensado (Sp), centrifugado (Sc) ) del resiy compostaje de los sólidos obtenidos mezclados con poda , para obtener un compost comerc ial (Ccae mejorar mercial) con partículas menores a 10 mm. Los resultados indican que en el Ccamercial se recuperó un 28 % del N total entrante al proceso de compostaje.
The parasitism (Hymenoptera, Braconidae, Aphidiinae) of alfalfa aphids (Hemiptera, Aphididae) was determined during three crop growing seasons. The highest rates of parasitism of Acyrthosiphon pisum Harris and of Therioaphis trifolii Monell occurred during the first-second and the fourth alfalfa intercuts, respectively. The landscape surrounding the fields affected only parasitism rates of A. pisum. During the second intercut the forest area had a negative influence on parasitism rates, whereas the bordering surfaces of alfalfa and winter cereals had a positive influence. Positive correlations were found between the rates of parasitism of A. pisum and the rate of aphid population increase in the first intercut. By contrast, negative correlations were found in the second intercut, when the aphid population peaked, suggesting that parasitoids contribute to the regulation of the aphid. This study stresses that regulation of alfalfa aphids cannot be explained solely on the basis of one functional group of natural enemies.
When assessing the benefits and risks of transgenic crops, one consideration is their relative effects on non-target arthropod (NTA) abundance and functions within agroecosystems. Several laboratory and field trials have been conducted in Spain since the late 1990s to assess this issue. A consideration in the design of field trials is whether it is necessary to sample most NTAs living in the crop or only representative taxa that perform main ecological functions and have a good capacity to detect small changes in their abundance. Small changes in the field abundance of an effective representative taxon should be detectable using standard experimental protocols. The ability of a species to reveal differences across treatments may be analysed by examining the detectable treatment effects for surveyed non-target organisms. Analysis of data from several NTAs recorded in 14 field trials conducted over 10 years using complete block designs allowed us to select a number of representative taxa capable of detecting changes in the density or activity of arthropod herbivores, predators, parasitoids and decomposers in transgenic and non-transgenic maize varieties. The most suitable NTA as representative taxa (with detectable treatment effects below 50%) included leafhoppers among arthropod herbivores, Orius spp., Araneae, and Carabidae among predators, chalcidids, particularly the family Mymaridae, among parasitoids and Chloropidae as decomposer. Details of sampling techniques for each sampled taxa and their advantages and disadvantages are discussed. It is concluded that abundance of taxa is the most influential factor determining their capacity to detect changes caused by genetically modified varieties.
Hurtado, C.; Rivas, D.; Domínguez, C.; Cañameras, N.; Comas, J.; Bayona, J.M EuCheMS International Conference on Chemistry and the Environment Presentation's date: 2013-06 Presentation of work at congresses
Borgia, C.; García, M.; Li, T.; Gómez, H.; Comas, J.; Connor, D.; Mateos, L. Agricultural water management Vol. 121, p. 19-26 DOI: 10.1016/j.agwat.2013.01.002 Date of publication: 2013-04 Journal article
Two Macrolophus species, M. melanotoma (= M. caliginosus) and M. pygmaeus, have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants (Dittrichia viscosa and tomato) through crossing experiments
Ramírez, M.; Pujola, M.; Quemada, M.; Jarauta-Bragulat, E.; Comas, J.; Bonmatí, A. Soil Science Society of America journal Vol. 75, num. 3, p. 940-948 DOI: 10.2136/sssaj2010.0307 Date of publication: 2011-06 Journal article
Mateos, L.; Lozano, D.; Baba , A.; Gómez, H.; Comas, J.; Connor, D. Agricultural water management Vol. 97, num. 6, p. 901-909 DOI: 10.1016/j.agwat.2010.01.021 Date of publication: 2010-06 Journal article
Julia, M.; Pujola, M.; Silvestre, G.; Ramírez, M.; Rubio, P.; Flores, J.; Comas, J.; Bonmatí, A. RAMIRAN 2010. Treatment and use of organic residues in agriculture: challenges and opportunities towards sustainable management Presentation of work at congresses
Ramírez, M.; Roig, G.; García, K.; Ramos, E.; Cabré, M.; Picas, J.A.; Comas, J.; Pujola, M. International Workshop on Anaerobic Digestion of Slaughterhouse Waste p. 195-199 Presentation of work at congresses