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This study investigated the sanitary quality of digestates resulting from the mesophilic anaerobic digestion (AD) of urban and agricultural organic wastes (OWs). 40 sanitary indicators, including pathogenic bacteria, antimicrobial resistance genes, virulence factor genes, and mobile genetic elements were evaluated using real-time PCR and/or droplet digital PCR. 13 polycyclic aromatic hydrocarbons (PAHs) and 13 pharmaceutical products (PHPs) were also measured. We assessed agricultural OWs from three treatment plants to study the effect of different AD processes (feeding mode, number of stages, pH), and used three laboratory-scale reactors to study the effect of different feed-supplies (inputs). The lab-scale reactors included: Lab1 fed with 97% activated sludge (urban waste) and 3% cow manure; Lab2 fed with 85% sludge-manure mixture supplemented with 15% wheat straw (WS); and Lab3 fed with 81% sludge-manure mixture, 15% WS, and 4% zeolite powder. Activated sludge favored the survival of the food-borne pathogens Clostridium perfringens and Bacillus cereus, carrying the toxin-encoding genes cpe and ces, respectively. Globally, the reactors fed with fecal matter supplemented with straw (Lab2) or with straw and zeolite (Lab3) had a higher hygienization efficiency than the reactor fed uniquely with fecal matter (Lab1). Three pathogenic bacteria (Enterococcus faecalis, Enterococcus faecium, and Mycobacterium tuberculosis complex), a beta-lactam resistance gene (bla TEM), and three mobile genetic elements (intI1, intI2, and IS26) were significantly decreased in Lab2 and Lab3. Moreover, the concentrations of 11 PAHs and 11 PHPs were significantly lower in Lab2 and Lab3 samples than in Lab1 samples. The high concentrations of micropollutants, such as triclosan, found in Lab1, could explain the lower hygienization efficiency of this reactor. Furthermore, the batch-fed reactor had a more efficient hygienization effect than the semi-continuous reactors, with complete removal of the ybtA gene, which is involved in the production of the siderophore yersiniabactin, and significant reduction of intI2 and tetO. These data suggest that it is essential to control the level of chemical pollutants in raw OWs to optimize the sanitary quality of digestates, and that adding co-substrate, such as WS, may overcome the harmful effect of pollutants.
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Recycling organic wastes into farmland faces a double challenge: increasing the carbon storage of soil while mitigating CO2 emission from soil. Predicting the stability of organic matter (OM) in wastes and treatment products can be helpful in dealing with this contradiction. This work proposed a modeling approach integrating an OM characterization protocol into partial least squares (PLS) regression. A total of 31 organic wastes, and their products issued from anaerobic digestion, composting, and digestion-composting treatment were characterized using sequential extraction and three-dimension (3D) fluorescence spectroscopy. The apportionment of carbon in different fractions and fluorescence spectra revealed that the OM became less accessible and biodegradable after treatments, especially the composting. This was proven by the decrease in CO2 emission from soil incubation. The PLS model successfully predicted the stability of solid digestate, compost, and compost of solid digestate in the soil by using only the characterized variables of non-treated wastes. The results suggested that it would be possible to predict the stability of OM from organic wastes after different treatment procedures. It is helpful to choose the most suitable and economic treatment procedure to stabilize labile organic carbon in wastes and hence minimize CO2 emission after the application of treatment products to the soil.
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Dióxido de Carbono , Compostaje , Suelo/química , Carbono , Residuos SólidosRESUMEN
Microplastic (MP) input into agroecosystems is of particular concern as their sources are diverse (mulching films, biosolid application, wastewater irrigation, flooding, atmospheric input, road runoff). Compost application, which is needed to sustain soil ecosystem services in the context of a circular economy, may be a source of microplastics. The aim of this study was to evaluate how different composts derived from urban wastes impact the nature and quantity of coarse (2-5 mm) microplastics (CMP) in soils, using a long-term field experiment in France. Composts resulting from different levels of urban waste sorting were investigated. Our approach included the isolation of microplastics from composts and amended soils followed by their characterization using pyrolysis GC/MS spectrometry. We found that coarse microplastic concentrations varied from 26.9 to 417 kg per hectare depending on the compost type, after 22 years of bi-annual application. These values may be higher than for conventional agricultural practices, as application rate was twice as high as for normal practices. Composts made from municipal solid waste were by far the organic amendments leading to the highest quantity of plastic particles in soils, emphasizing the urgent need for limiting plastic use in packaging and for improving household biowaste sorting. Our results strongly suggest that standards regulating organic matter amendment application should take microplastics into account in order to prevent contamination of (agricultural) soils. Moreover, although no impacts on the soil bio-physico-chemical parameters has been noted so far. However, given the huge microplastic inputs, there is an urgent need to better evaluate their effect on soil functioning.
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Compostaje , Contaminantes del Suelo , Suelo/química , Microplásticos , Plásticos , Ecosistema , Contaminantes del Suelo/análisisRESUMEN
Anaerobic digestion is an increasingly widespread process for organic waste treatment and renewable energy production due to the methane content of the biogas. This biological process also produces a digestate (i.e., the remaining content of the waste after treatment) with a high fertilizing potential. The digestate composition is highly variable due to the various organic wastes used as feedstock, the different plant configurations, and the post-treatment processes used. In order to optimize digestate spreading on agricultural soils by optimizing the fertilizer dose and, thus, reducing environmental impacts associated to digestate application, the agronomic characterization of digestate is essential. This study investigates the use of near infrared spectroscopy for predicting the most important agronomic parameters from freeze-dried digestates. A data set of 193 digestates was created to calibrate partial least squares regression models predicting organic matter, total organic carbon, organic nitrogen, phosphorus, and potassium contents. The calibration range of the models were between 249.8 and 878.6 gOM.kgDM-1, 171.9 and 499.5 gC.kgDM-1, 5.3 and 74.1 gN.kgDM-1, 2.7 and 44.9 gP.kgDM-1 and between 0.5 and 171.8 gK.kgDM-1, respectively. The calibrated models reliably predicted organic matter, total organic carbon, and phosphorus contents for the whole diversity of digestates with root mean square errors of prediction of 70.51 gOM.kgDM-1, 34.84 gC.kgDM-1 and 4.08 gP.kgDM-1, respectively. On the other hand, the model prediction of the organic nitrogen content had a root mean square error of 7.55 gN.kgDM-1 and was considered as acceptable. Lastly, the results did not demonstrate the feasibility of predicting the potassium content in digestates with near infrared spectroscopy. These results show that near infrared spectroscopy is a very promising analytical method for the characterization of the fertilizing value of digestates, which could provide large benefits in terms of analysis time and cost.
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Nitrógeno , Espectroscopía Infrarroja Corta , Anaerobiosis , Biocombustibles , Carbono , Nitrógeno/análisis , Fósforo , PotasioRESUMEN
Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFAS) are increasingly reported in terrestrial and aquatic environments, but their inputs to agricultural lands are not fully understood. Here, we characterized PFAS in 47 organic waste products (OWP) applied in agricultural fields of France, including historical and recent materials. Overall, 160 PFAS from 42 classes were detected from target screening and homologue-based nontarget screening. Target PFAS were low in agriculture-derived wastes such as pig slurry, poultry manure, or dairy cattle manure (median ∑46PFAS: 0.66 µg/kg dry matter). Higher PFAS levels were reported in urban and industrial wastes, paper mill sludge, sewage sludge, or residual household waste composts (median ∑46PFAS: 220 µg/kg). Historical municipal biosolids and composts (1976-1998) were dominated by perfluorooctanesulfonate (PFOS), N-ethyl perfluorooctanesulfonamido acetic acid (EtFOSAA), and cationic and zwitterionic electrochemical fluorination precursors to PFOS. Contemporaneous urban OWP (2009-2017) were rather dominated by zwitterionic fluorotelomers, which represented on average 55% of ∑160PFAS (max: 97%). The fluorotelomer sulfonamidopropyl betaines (X:2 FTSA-PrB, median: 110 µg/kg, max: 1300 µg/kg) were the emerging class with the highest occurrence and prevalence in contemporary urban OWP. They were also detected as early as 1985. The study informs for the first time that urban sludges and composts can be a significant repository of zwitterionic and cationic PFAS.
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Compostaje , Fluorocarburos , Animales , Biosólidos , Bovinos , Estiércol , Aguas del Alcantarillado/química , Porcinos , ResiduosRESUMEN
Further characterization to properly assess the fate of organic matter quality during anaerobic digestion and organic carbon mineralization in soils is required. Organic matter quality based on its accessibility and complexity was employed to successfully classify 28 substrate/digestate pairs through principal components and hierarchical clustering analysis. The two first components explained 58.02% of the variability and four main groups were separated according to the feedstock type. A decrease in the accessibility (16-66%) and an increase in the complexity (34-98%) of the most accessible fractions was noticed. Besides, an increase of non-biodegradable compounds (17-66%) was globally observed after anaerobic digestion. The observed trends in the conversion of organic matter during anaerobic digestion have allowed to fill the gap in the modeling of the anaerobic digestion process chain. Indeed, partial least squares regressions have accurately predicted the organic matter quality of digestates from their inputs (R2 = 0.831, Q2 = 0.593) although the digester operational conditions (temperature and hydraulic retention time) were non-explicative enough. As a novel approach, the predicted digestate quality was used to feed a partial least squares regression model previously developed to predict organic carbon mineralization in soil. The combined models have predicted experimental organic carbon mineralization in soil (R2 = 0.697) with a model quality similar to the model for organic carbon mineralization in soil (R2 = 0.894). This is the first study that has successfully conceived an additional step in the prediction of organic matter fate from raw substrate before anaerobic digestion to soil carbon mineralization.
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Agricultura , Suelo , Anaerobiosis , CarbonoRESUMEN
Even though organic waste (OW) recycling via anaerobic digestion (AD) and composting are increasingly used, little is known about the impact of OW origin (fecal matters and food and vegetable wastes) on the end products' bacterial contents. The hypothesis of a predictable bacterial community structure in the end products according to the OW origin was tested. Nine OW treatment plants were selected to assess the genetic structure of bacterial communities found in raw OW according to their content in agricultural and urban wastes and to estimate their modifications through AD and composting. Two main bacterial community structures among raw OWs were observed and matched a differentiation according to the occurrences of urban chemical pollutants. Composting led to similar 16S rRNA gene OTU profiles whatever the OW origin. With a significant shift of about 140 genera (representing 50% of the bacteria), composting was confirmed to largely shape bacterial communities toward similar structures. The enriched taxa were found to be involved in detoxification and bioremediation activities. This process was found to be highly selective and favorable for bacterial specialists. Digestates showed that OTU profiles differentiated into two groups according to their relative content in agricultural (manure) and urban wastes (mainly activated sludge). About one third of the bacterial taxa was significantly affected by AD. In digestates of urban OW, this sorting led to an enrichment of 32 out of the 50 impacted genera, while for those produced from agricultural or mixed urban/agricultural OW (called central OW), a decay of 54 genera over 60 was observed. Bacteria from activated sludge appeared more fit for AD than those of other origins. Functional inferences showed AD enriched genera from all origins to share similar functional traits, e.g., chemoheterotrophy and fermentation, while being often taxonomically distinct. The main functional traits among the dominant genera in activated sludge supported a role in AD. Raw OW content in activated sludge was found to be a critical factor for predicting digestate bacterial contents. Composting generated highly predictable and specialized community patterns whatever the OW origin. AD and composting bacterial changes were driven by functional traits selected by physicochemical factors such as temperature and chemical pollutants.
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Many studies have assessed the potential of agricultural practices to sequester carbon (C). A comprehensive evaluation of impacts of agricultural practices requires not only considering C storage but also direct and indirect emissions of greenhouse gases (GHG) and their side effects (e.g., on the water cycle or agricultural production). We used a high-resolution modeling approach with the Simulateur mulTIdisciplinaire pour les Cultures Standard soil-crop model to quantify soil organic C (SOC) storage potential, GHG balance, biomass production and nitrogen- and water-related impacts for all arable land in France for current cropping systems (baseline scenario) and three mitigation scenarios: (i) spatial and temporal expansion of cover crops, (ii) spatial insertion and temporal extension of temporary grasslands (two sub-scenarios) and (iii) improved recycling of organic resources as fertilizer. In the baseline scenario, SOC decreased slightly over 30 years in crop-only rotations but increased significantly in crop/temporary grassland rotations. Results highlighted a strong trade-off between the storage rate per unit area (kg C ha-1 year-1 ) of mitigation scenarios and the areas to which they could be applied. As a result, while the most promising scenario at the field scale was the insertion of temporary grassland (+466 kg C ha-1 year-1 stored to a depth of 0.3 m compared to the baseline, on 0.68 Mha), at the national scale, it was by far the expansion of cover crops (+131 kg C ha-1 year-1 , on 17.62 Mha). Side effects on crop production, water irrigation and nitrogen emissions varied greatly depending on the scenario and production situation. At the national scale, combining the three mitigation scenarios could mitigate GHG emissions of current cropping systems by 54% (-11.2 from the current 20.5 Mt CO2 e year-1 ), but the remaining emissions would still lie far from the objective of C-neutral agriculture.
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Gases de Efecto Invernadero , Agricultura , Carbono , Productos Agrícolas , Francia , Efecto Invernadero , Gases de Efecto Invernadero/análisis , SueloRESUMEN
Microorganisms in soil are known to be a source and a sink of volatile organic compounds (VOCs). The role of the microbial VOCs on soil ecosystem regulation has been increasingly demonstrated in the recent years. Nevertheless, little is known about the influence of the microbial soil community structure and diversity on VOC emissions. This novel study analyzed the effect of reduced microbial diversity in soil on VOC emissions. We found that reduced levels of microbial diversity in soil increased VOC emissions from soils, while the number of different VOCs emitted decreased. Furthermore, we found that Proteobacteria, Bacteroidetes and fungi phyla were positively correlated to VOC emissions, and other prokaryotic phyla were either negatively correlated or very slightly positively correlated to VOCs emissions. Our interpretation is that Proteobacteria, Bacteroidetes and fungi were VOC producers while the other prokaryotic phyla were consumers. Finally, we discussed the possible role of VOCs as mediators of microbial interactions in soil.
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Microbiota , Microbiología del Suelo , Suelo/química , Compuestos Orgánicos Volátiles/análisis , Bacteroidetes/aislamiento & purificación , Bacteroidetes/metabolismo , Hongos/aislamiento & purificación , Hongos/metabolismo , Proteobacteria/aislamiento & purificación , Proteobacteria/metabolismo , Compuestos Orgánicos Volátiles/químicaRESUMEN
Anaerobic conditions mobilize phosphorus (P) in soils and sediments. The role of anaerobic microsites in well-drained soil on P migration is unknown. This study aimed to identify mechanisms that control field-scale vertical P mobility as affected by organic fertilizers that may trigger variable redox conditions. Soils were sampled at different depths in a well-drained Luvisol after 19 years of application of organic fertilizers. The concentrations of P and manganese (Mn) in 0.45-µm-filtered extracts (10-3 M CaCl2) of field-moist soil samples were strongly correlated (r = + 0.95), and both peaked in and below the compacted plough pan, suggesting that reductive processes mobilize P. Waterlogged soil incubations confirmed that anaerobic respiration comobilizes Mn and P and that this leads to the release of colloidal P and iron (Fe). The long-term applications of farmyard manure and immature compost enhanced the concentrations of Mn, Fe, and aluminum (Al) in the soil solution of subsurface samples, whereas less such effect was found under the application of more stable organic fertilizers. Farmyard manure application significantly enhanced soil P stocks below the plough layer despite a small P input. Overall, multiple lines of evidence confirm that anaerobic respiration, sparked by labile organic matter, mobilizes P in this seemingly well-drained soil.
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Fósforo , Suelo , Agricultura , Anaerobiosis , Fertilizantes/análisis , Manganeso/análisis , EstiércolRESUMEN
Organic waste products (OWP) application to crop lands makes possible nutrients recycling. However, it can result in long-term accumulation of trace elements (TE) in soils. The present study aimed at (i) assessing the impact of regular applications of urban composts and manure on the TE contents of topsoils and crops in a long-term field experiment, (ii) comparing the TE mass balances with the stock variations of TE in soils, and (iii) proposing a prospective evaluation of this practice, based on estimated soil safe threshold values and simulations of soil TE accumulation for 100 years. In the long-term field experiment, physico-chemical properties and TE contents (Cd, Cr, Cu, Hg, Ni, Pb and Zn) have been measured in OWP, soils, plants and leaching waters for the period 1998-2015, and used for mass balance calculations and long-term simulations of TE accumulations. The composts of green wastes and sludge (GWS) and of municipal solid waste (MSW) were the OWP with the largest TE contents, while the farmyard manure tended to have the lowest. Repeated application of OWP led to significant accumulation of Zn and Cu in the topsoil layer (not for Cr, Cd, Hg, Ni, Pb), especially with GWS, without overpassing calculated protective threshold values. No effect of repeated application of OWP has been observed on TE contents in grains (wheat, maize, barley). The positive mass balance has been dominated by the input flux of TE through OWP and resulted in the observed increases of soil stocks for Cu and Zn. Prospective simulation of soil content evolution until 2100 showed that soil content reached 0.4 mg Cd kg-1 soil (GWS, MSW), 38 mg Cu kg-1 soil (GWS) and 109 mg Zn kg-1 soil (GWS), which remained lower than protective threshold values.
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Compostaje , Metales Pesados , Contaminantes del Suelo , Suelo/química , Oligoelementos , Animales , Bovinos , Estiércol , Metales Pesados/análisis , Metales Pesados/química , Estudios ProspectivosRESUMEN
The simultaneous fate of organic matter and 4 endocrine disruptors (3 polycyclic aromatic hydrocarbons (PAHs) (fluoranthene, benzo(b)fluoranthene, and benzo(a)pyrene) and nonylphenols (NP)) was studied during the anaerobic digestion followed by composting of sludge at lab-scale. Sludge organic matter was characterized, thanks to chemical fractionation and 3D fluorescence deciphering its accessibility and biodegradability. Total chemical oxygen demand (COD) removal was 41% and 56% during anaerobic digestion and composting, respectively. 3D fluorescence highlighted the quality changes of organic matter. During continuous anaerobic digestion, organic micropollutants' removal was 22 ± 14%, 6 ± 5%, 18 ± 9%, and 0% for fluoranthene, benzo(b)fluoranthene, benzo(a)pyrene, and nonylphenols, respectively. Discontinuous composting allowed to go further on the organic micropollutants' removal as 34 ± 8%, 31 ± 20%, 38 ± 10%, and 52 ± 6% of fluoranthene, benzo(b)fluoranthene, benzo(a)pyrene, and nonylphenols were dissipated, respectively. Moreover, the accessibility of PAH and NP expressed by their presence in the various sludge organic matter fractions and its evolution during both treatments was linked to both the quality evolution of the organic matter and the physicochemical properties of the PAH and NP; the presence in most accessible fractions explained the amount of PAH and NP dissipated.
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Biodegradación Ambiental , Compostaje , Hidrocarburos Policíclicos Aromáticos/análisis , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/análisis , Benzo(a)pireno , Análisis de la Demanda Biológica de Oxígeno , Fraccionamiento Químico , Fluorenos , Eliminación de Residuos LíquidosRESUMEN
Recycling organic residues in agrosystems presents several benefits but faces the question of contaminants, among them a few trace metals which eventually accumulate in soils following regular applications of organic waste products (OWP) and represent an ecological risk. The increase of total trace metal contents in amended topsoils can be predicted by a mass balance approach, but the evolution of their available fractions is a more intricate issue. We aimed at modelling this evolution by using the dataset of a long-term field experiment of OWP applications (manure and three urban waste composts). Two operationally-defined fractions of 6 trace metals have been quantified in the OWP and amended topsoils between 2002 and 2015: the soluble and potentially available metals, extracted in 0.01â¯M CaCl2 and 0.05â¯M EDTA solutions, respectively. The potentially available metals have progressively increased in amended topsoils, at rates depending on elements and types of OWP. For Zn, these increases corresponded in average to inputs of potentially available Zn from OWP. But the soil stocks of potentially available Cu increased faster than from the inputs of EDTA-extractable Cu, showing linear regression slopes between 1.4 and 2.5, depending on OWP type. The influence of OWP has been provisionally interpreted in the light of their efficiency to increase soil organic matter and their inputs of reactive oxides. Soluble copper has increased with repeated amendments. But soluble cadmium, nickel and zinc have generally decreased, as they are influenced by changing soil variables such as pH and organic matter. Statistic models were used to unravel the relationships between soluble and EDTA-extractable metals and other soil variables. For Cu, the most satisfactory models just relate soluble and potentially available Cu. Developing such models could contribute to predict the long-term effects of a precise scenario of agricultural OWP recycling upon available trace metals in soils.
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Volatile Organic Compounds (VOCs) are reactive compounds essential to atmospheric chemistry. They are mainly emitted by living organisms, and mostly by plants. Soil microbes also contribute to emissions of VOCs. However, these emissions have not yet been characterised in terms of quality and quantity. Furthermore, long-term organic matter amendments are known to affect the microbial content of soils, and hence the quantity and quality of VOC emissions. This study investigates which and how much of these VOCs are emitted from soil amended with organic waste products (OWPs). Four OWPs were investigated: municipal solid waste compost (MSW), green waste and sludge co-compost (GWS), bio-waste compost (BIOW) and farmyard manure (FYM). These OWPs have been amended every two years since 1998 until now at a rate of ~4â¯tCâ¯ha-1. A soil receiving no organic inputs was used as a reference (CN). VOCs emissions were measured under laboratory conditions using a Proton Transfer Reaction-Quadrupole ion guide Time of Flight-Mass Spectrometry (PTR-QiToF-MS). A laboratory system was set up made of two Pyrex chambers, one for samples and the second empty, to be used as a blank. Our results showed that total VOC emissions were higher in BIOW than in MSW. Further findings outlined that the most emitted compounds were acetone, butanone and acetaldehyde in all treatments, suggesting a common production mechanism for these compounds, meaning they were not affected by the OWP amendment. We isolated 21 VOCs that had statistically different emissions between the treatments and could therefore be considered as good markers of soil biological functioning. Our results suggest that organic matter and pH jointly influenced total VOC emissions. In conclusion, OWPs in soil affect the type of VOC emissions and the total flux also depends on the pH of the soil and the quantity of organic matter.
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Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Compuestos Orgánicos Volátiles/análisis , Residuos/análisis , Eliminación de Residuos , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
A new model that was able to simulate the behaviours of polycyclic aromatic hydrocarbons (PAH) during composting and after the addition of the composts to agricultural soil is presented here. This model associates modules that describe the physical, biological and biochemical processes involved in PAH dynamics in soils, along with a module describing the compost degradation resulting in PAH release. The model was calibrated from laboratory incubations using three 14C-PAHs, phenanthrene, fluoranthene and benzo(a)pyrene, and three different composts consisting of two mature and one non-mature composts. First, the labelled PAHs were added to the compost over 28days, and spiked composts were then added to the soil over 55days. The model calculates the proportion of biogenic and physically bound residues in the non-extractable compartment of PAHs at the end of the compost incubation to feed the initial conditions of the model for soil amended with composts. For most of the treatments, a single parameter set enabled to simulate the observed dynamics of PAHs adequately for all the amended soil treatments using a Bayesian approach. However, for fluoranthene, different parameters that were able to simulate the growth of a specific microbial biomass had to be considered for mature compost. Processes that occurred before the compost application to the soil strongly influenced the fate of PAHs in the soil. Our results showed that the PAH dissipation during compost incubation was higher in mature composts because of the higher specific microbial activity, while the PAH dissipation in amended soil was higher in the non-mature compost because of the higher availability of PAHs and the higher co-metabolic microbial activity.
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Recycling organic waste products in agriculture is a potential route for the dispersion of pharmaceutical residues in the environment. In this study, the concentrations of thirteen pharmaceuticals and the personal care product triclosan (PPCPs) were determined in different environmental matrices from long-term experimental fields amended with different organic waste products (OWPs), including sludge, composted sludge with green wastes, livestock effluents and composted urban wastes applied at usual agricultural rates. PPCP concentrations were different in OWPs, varying from a few micrograms to milligrams per kilogram dry matter or per litre for slurry. OWPs from sludge or livestock effluents primarily contained antibiotics, whereas composted urban wastes primarily contained anti-inflammatory compounds. PPCP contents in soils amended for several years were less than a few micrograms per kilogram. The most persistent compounds (fluoroquinolones, carbamazepine) were quantified or detected in soils amended with sludge or composted sludge. In soils amended with composted municipal solid waste, carbamazepine was quantified, and fluoroquinolones, ibuprofen and diclofenac were sometimes detected. The small increases in fluoroquinolones and carbamazepine in soils after individual OWP applications were consistent with the fluxes from the applied OWP. The measured concentrations of pharmaceuticals in soil after several successive OWP applications were lower than the predicted concentrations because of degradation, strong sorption to soil constituents and/or leaching. Dissipation half-lives (DT50) were approximately 750-2500, 900 and <300days for fluoroquinolones, carbamazepine and ibuprofen, respectively, in temperate soils and <350 and <80days for fluoroquinolones and doxycycline, respectively, in tropical soils. Detection frequencies in soil leachates were very low (below 7%), and concentrations ranged from the limits of detection (0.002-0.03µg/L) and exceptionally to 0.27µg/L. The most frequently detected pharmaceuticals were carbamazepine and ibuprofen. Based on the risk quotient, the estimated ecotoxicological risks for different soil organisms were low.
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Cosméticos/análisis , Monitoreo del Ambiente , Preparaciones Farmacéuticas/análisis , Contaminantes del Suelo/análisis , Residuos/análisis , Agricultura , Ecotoxicología , Estiércol , Aguas del Alcantarillado , SueloRESUMEN
Organic wastes are potential sources of both energy as well as crop production fertilizers. Correlations and models, involving organic matter characterization, have been previously described by several authors although there is still a lack in knowledge on the potential of simultaneous predictions of methane and organic fertilizer quality to optimize the wastes treatments. A methodology combining chemical accessibility and fluorescence spectroscopy was used to characterize 82 different organic wastes. Characterization data were compared with the biochemical methane potential (BMP), and with the biodegradable organic carbon obtained by soil incubation (C_bio). High correlations values were observed (R2 of 0.818 for BMP and 0.845 for C_bio). Model coefficients highlighted the differences and similarities between anaerobic and aerobic soil biodegradation, suggesting that anaerobic recalcitrant molecules could enhance soil fertility. This is a first step in the development of a tool for optimising both types of valorisation according to agrosystem needs and constraints.
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Biodegradación Ambiental , Fertilizantes , Metano , Carbono , SueloRESUMEN
Pharmaceuticals can enter the environment when organic waste products are recycled on agricultural soils. The extraction of pharmaceuticals is a challenging step in their analysis. The very different extraction conditions proposed in the literature make the choice of the right method for multi-residue analysis difficult. This study aimed at evaluating, with experimental design methodology, the influence of the nature, pH and composition of the extraction medium on the extraction recovery of 14 pharmaceuticals, including 8 antibiotics, from soil and sewage sludge. Preliminary experimental designs showed that acetonitrile and citrate-phosphate buffer were the best extractants. Then, a response surface design demonstrated that many cross-product and squared terms had significant effects, explaining the shapes of the response surfaces. It also allowed optimising the pharmaceutical recoveries in soil and sludge. The optimal conditions were interpreted considering the ionisation states of the compounds, their solubility in the extraction medium and their interactions with the solid matrix. To perform the analysis, a compromise was made for each matrix. After a QuEChERS purification, the samples were analysed by online SPE-UHPLC-MS-MS. Both methods were simple and economical. They were validated with the accuracy profile methodology for soil and sludge and characterised for another type of soil, digested sludge and composted sludge. Trueness globally ranged between 80 and 120 % recovery, and inter- and intra-day precisions were globally below 20 % relative standard deviation. Various pharmaceuticals were present in environmental samples, with concentration levels ranging from a few micrograms per kilogramme up to thousands of micrograms per kilogramme. Graphical abstract Influence of the extraction medium on the extraction recovery of 14 pharmaceuticals. Influence of the ionisation state, the solubility and the interactions of pharmaceuticals with solid matrix. Analysis of different soils and organic waste products.
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Preparaciones Farmacéuticas/aislamiento & purificación , Aguas del Alcantarillado/análisis , Contaminantes del Suelo/aislamiento & purificación , Suelo/química , Extracción en Fase Sólida/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Acetonitrilos , Cromatografía Líquida de Alta Presión/métodos , Monitoreo del Ambiente/métodos , Concentración de Iones de Hidrógeno , Límite de Detección , Preparaciones Farmacéuticas/análisis , Contaminantes del Suelo/análisis , Solventes , Espectrometría de Masas en Tándem/métodos , Contaminantes Químicos del Agua/análisisRESUMEN
The fate of organic matter during anaerobic digestion of sewage sludge was studied in batch systems thanks to a sequential chemical fractionation of the particulate phase coupled to fluorescence spectroscopy. Polycyclic Aromatic Hydrocarbons (PAHs) distribution within the organic pools was characterized from their analysis in the residual fraction after each extraction. Both methods were combined to understand the link between PAHs presence in organic pools and their spectral characterization after extraction. Two batch systems (sludge and inoculum mixture) were set up to study the impact of PAHs spiking on their fate and distribution. The sequential fractionation allowed us to extract and characterize about 50% of total Chemical Oxygen Demand. Moreover, fluorescence spectroscopy helped us to understand the organic pools evolution: the most easily extracted pools composed of protein-like molecules were highly degraded meaning that chemical accessibility mimics the bioaccessibility to degrading microorganisms. PAHs were present in all pools of organic matter but native PAHs were mainly present in low accessible (hardly extractable) fractions and during anaerobic digestion, they accumulated in the non-accessible (non extractable) fraction. Spiked PAHs were more dissipated during anaerobic digestion since spiking made them present in more accessible fractions. During the anaerobic digestion, contrary to native PAHs, spiked ones relocated toward less accessible organic fractions confirming the ageing phenomenon. PCA analysis showed that, in spiked mixture, PAHs presence in organic pools is linked to both PAHs physical-chemical properties and quality/quantity of the associated organic pools.