Academic literature on the topic 'Composti organici persistenti'
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Journal articles on the topic "Composti organici persistenti"
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Barcauskaitė, Karolina. "Gas chromatographic analysis of polychlorinated biphenyls in compost samples from different origin." Waste Management & Research: The Journal for a Sustainable Circular Economy 37, no. 5 (February 17, 2019): 556–62. http://dx.doi.org/10.1177/0734242x19828156.
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Depending on the origin, the compost produced may contain not only nutrients but also pollutants, such as heavy metals and persistent organic pollutants. It is very important to determine them in soil-improving substances, because persistent organic pollutants show environmental toxic, cancerogenic, mutagenic effects and do not decompose for a long time. The aim of this study was to determine seven polychlorinated biphenyls concentrations in different kinds of composts produced in Lithuania and to evaluate the appliance of these composts in agricultural land. First, before routine analysis was done a gas chromatography with electron-capture detector method was developed. In this study 145 samples of green waste, sewage sludge, cattle manure, food waste, mixed municipal waste, digestate and composts made from mixed municipal waste after mechanical–biological treatment were analysed. Obtained results show that 28% of investigated cattle manure composts (CMCs) and 10.5% of food waste composts (FWCs) were free from polychlorinated biphenyls. Other kinds of composts investigated in this study (green waste compost (GWC), sewage sludge compost (SSC), mixed municipal waste compost (MMWC), mixed municipal waste compost after mechanical biological treatment (MMWCABMT) and digestate (DIG)) were contaminated 100% with polychlorinated biphenyls. Despite the fact that polychlorinated biphenyls were forbidden 25 years ago, their concentration varied from 2.70 to 163.7 µg kg−1 in different kinds of composts produced in Lithuania. According to get an increasing average amount of Σ7 polychlorinated biphenyls, Lithuanian composts were distributed as follows CMC > GWC > DIG > FWC > SSC > MMWCABMT > MMWC.
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Marsh, Lurline, Corrie Cotton, Elizabeth Philip, Salina Parveen, and Fawzy Hashem. "(300) Safety and Productivity of Cool-season Salad Greens Grown in Soils Amended with Composts." HortScience 41, no. 4 (July 2006): 1023C—1023. http://dx.doi.org/10.21273/hortsci.41.4.1023c.
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Excessive amounts of poultry waste on the Delmarva Peninsula of the United States, coupled with the availability of yard waste, may be potential inexpensive nutrient sources for growing vegetables. However, these composts may contain unsafe microorganisms. This study, therefore, was conducted to determine the presence and persistence of biological agents in soil treated with poultry compost and yard waste. Tatsoi [Brassica rapa (Narinosa Group)] and spinach (Spinacia oleracea L. `F415' and `Seven R') were planted under a high tunnel to extend their fall growing season. Samples of soil–compost mixture and original poultry compost were collected once a month for 4 months. Escherichia coli O157:H7 in the samples was determined by enrichment and immunomagnetic separation, and was not detected in any of the soil-mixtures. However, this bacterium was detected in the original poultry compost in very low numbers. Plant leaves were harvested periodically. Results showed that tatsoi plants significantly produced larger leaves and higher fresh weight in soils amended with organic compost with the tendency for yield to increase with the increase in harvest date. Generally, the organic amendments did not influence size and total fresh weight of spinach leaves, although earlier harvests tended to produce significantly larger leaves and higher fresh weight.
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Heckman, Katherine, Dorisel Torres, Christopher Swanston, and Johannes Lehmann. "Carbon and nitrogen molecular composition of soil organic matter fractions resistant to oxidation." Soil Research 55, no. 8 (2017): 809. http://dx.doi.org/10.1071/sr16182.
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The methods used to isolate and characterise pyrogenic organic carbon (PyC) from soils vary widely, and there is little agreement in the literature as to which method truly isolates the most chemically recalcitrant (inferred from oxidative resistance) and persistent (inferred from radiocarbon abundance) fraction of soil organic matter. In addition, the roles of fire, fuel type and soil morphology in the preservation of PyC are not yet defined. In an attempt to elucidate the importance of oxidative recalcitrance, fuel type and soil morphology to the persistence of soil organic matter, we examined two strongly contrasting soils using a variety of PyC isolation techniques coupled with quantifications of the molecular structure and mean residence time of the isolated organic materials. Surface and subsurface soil samples were examined from a Red Chromosol soil and a Black Vertosol soil. The δ13C values suggest that PyC in the Red Chromosol was sourced from eucalyptus, whereas PyC in the Black Vertosol was formed from grass. Soils were sieved at 53µm, treated with hydrofluoric acid to remove organics associated with mineral surfaces, then subjected to three common ‘PyC isolation’ treatments: chromic acid, photo-oxidation and chromic acid followed by photo-oxidation. Molecular structure of the organic residues remaining after each treatment was quantified by solid-state 13C cross polarisation magic angle spinning nuclear magnetic resonance and near edge X-ray absorption fine structure spectroscopy, and the mean residence time of the organic residues was estimated based on radiocarbon abundance. In all cases, treatment with chromic acid followed by photo-oxidation isolated the smallest proportion of organic matter (5–10% of <53µm C) which also had the longest mean residence time (estimated 600–3460 years). Additionally, molecular structure measurements indicated that this fraction was not composed solely of aromatic compounds, suggesting a non-homogenous source for the most oxidative-resistant fraction of soil organic matter.
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Bünemann, E. K., G. D. Schwenke, and L. Van Zwieten. "Impact of agricultural inputs on soil organisms—a review." Soil Research 44, no. 4 (2006): 379. http://dx.doi.org/10.1071/sr05125.
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External agricultural inputs such as mineral fertilisers, organic amendments, microbial inoculants, and pesticides are applied with the ultimate goal of maximising productivity and economic returns, while side effects on soil organisms are often neglected. We have summarised the current understanding of how agricultural inputs affect the amounts, activity, and diversity of soil organisms. Mineral fertilisers have limited direct effects, but their application can enhance soil biological activity via increases in system productivity, crop residue return, and soil organic matter. Another important indirect effect especially of N fertilisation is soil acidification, with considerable negative effects on soil organisms. Organic amendments such as manure, compost, biosolids, and humic substances provide a direct source of C for soil organisms as well as an indirect C source via increased plant growth and plant residue returns. Non-target effects of microbial inoculants appear to be small and transient. Among the pesticides, few significant effects of herbicides on soil organisms have been documented, whereas negative effects of insecticides and fungicides are more common. Copper fungicides are among the most toxic and most persistent fungicides, and their application warrants strict regulation. Quality control of organic waste products such as municipal composts and biosolids is likewise mandatory to avoid accumulation of elements that are toxic to soil organisms.
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Scott, Andrew, Yuan-Ching Tien, Craig F. Drury, W. Daniel Reynolds, and Edward Topp. "Enrichment of antibiotic resistance genes in soil receiving composts derived from swine manure, yard wastes, or food wastes, and evidence for multiyear persistence of swine Clostridium spp." Canadian Journal of Microbiology 64, no. 3 (March 2018): 201–8. http://dx.doi.org/10.1139/cjm-2017-0642.
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The impact of amendment with swine manure compost (SMC), yard waste compost (YWC), or food waste compost (FWC) on the abundance of antibiotic resistance genes in soil was evaluated. Following a commercial-scale application of the composts in a field experiment, soils were sampled periodically for a decade, and archived air-dried. Soil DNA was extracted and gene targets quantified by qPCR. Compared with untreated control soil, all 3 amendment types increased the abundance of gene targets for up to 4 years postapplication. The abundance of several gene targets was much higher in soil amended with SMC than in soil receiving either YWC or FWC. The gene target ermB remained higher in the SMC treatment for a decade postapplication. Clostridia were significantly more abundant in the SMC-amended soil throughout the decade following application. Eight percent of Clostridium spp. isolates from the SMC treatment carried ermB. Overall, addition of organic amendments to soils has the potential to increase the abundance of antibiotic resistance genes. Amendments of fecal origin, such as SMC, will in addition entrain bacteria carrying antibiotic resistance genes. Environmentally recalcitrant clostridia, and the antibiotic resistance genes that they carry, will persist for many years under field conditions following the application of SMC.
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Mentag, Rachid, Isabelle Duchesne, and Jacques-André Rioux. "Leaching and Persistence of Oxidiazon in Several Organic-based Substrates." HortScience 30, no. 4 (July 1995): 818F—818. http://dx.doi.org/10.21273/hortsci.30.4.818f.
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The objective of this study was to determine the persistence and leaching of the herbicide oxadiazon in five substrates. The substrate mixtures consisted of the following: peatmoss, compost, and sand in the following proportions: 1:1:0, 3:3:2, 1:1:2, 1:1:6, and 0:0:1 in 5-liter containers. Rates of oxadiazon used were 4 and 8 kg a.i./ha on two separate split-split plots. Each experimental design had three factors: five substrates, four harvest times (24 h; 1, 2, and 3 months) and five soil depths (0–2, 2–4, 4–6, 6–8, 8– cm). Only herbicide persistence and leaching from the various substrates were investigated in this experiment; therefore, we did not remove plant material. Substrate oxadiazon residues were determined by gas chromatography analysis, and it was shown that leaching was more evident in media with a lower percentage of organic matter. In addition, oxadiazon did not leach below 4 cm in conventional substrate (1 peatmoss: 1 compost: 1 sand, respectively). The persistence of oxadiazon was affected by soil composition and herbicide persisted more in substrates with great percentage of organic matter.
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Lü, Xing Dong, Xiao Hua Liu, and Guo Sheng Gai. "Study of Organic Modification for SrAl2O4:Eu2+, Dy3+ Phosphors." Advanced Materials Research 58 (October 2008): 169–75. http://dx.doi.org/10.4028/www.scientific.net/amr.58.169.
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Methylaminopropyltrimethoxysilane (MAPS) coupling agent was used to pre-modify SrAl2O4:Eu2+, Dy3+ phosphors, and then graft methylmethacrylate (MMA) on SrAl2O4:Eu2+, Dy3+ phosphors. IR, SEM and TEM measurements showed that there is an organic encapsulation film composed of silane modified poly(methylmethacrylate) (PMMA) on phosphor surface. This organic film encapsulated on phosphor surface like dense reticulation with a thickness of 20-30 nm. The water resistance and oil absorption measurements and persistent luminescent properties showed that after being encapsulated, SrAl2O4:Eu2+, Dy3+ phosphors has much better water resistance and lower oil absorption with little loss of persistent phosphorescence. The emission intensity and afterglow lifetime of the encapsulated phosphors were reduced to 93% and 95% of the originals, respectively.
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Farrick, Kegan K., Zakiya Akweli, and Mark N. Wuddivira. "Influence of manure, compost additions and temperature on the water repellency of tropical soils." Soil Research 56, no. 7 (2018): 685. http://dx.doi.org/10.1071/sr17303.
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Soil water repellency is a major concern in many systems as it substantially reduces infiltration and enhances surface runoff. While it is recognised that repellency is affected by the soil organic matter in natural ecosystems, the impact of manure and compost additions on the development and persistence of repellency in agroecosystems, particularly in the tropics, is poorly understood. We therefore examined the impact of different manure, compost additions and temperature on soil water repellency of tropical soils. We monitored the change in repellency in a Cambisol (Talparo – clay loam), Acrisol (Piarco – silt loam) and Arenosol (Arena – loamy sand), amended with three different manure and compost combinations at three different concentrations and four temperatures. Water repellency was the strongest among soils with higher clay content, which was likely due to the higher levels of organic matter observed in the clay loam. The cattle manure produced the most severe repellency despite having the lowest total organic carbon, whereas the sugarcane bagasse produced the lowest repellency. The increases in temperature had the strongest influence on repellency in sandy soils. Our results strongly support the findings of other studies that the quality of the organic material is more important than the total organic carbon in controlling the severity of repellency. This exploratory work also highlighted the importance of plant compost in reducing the level of repellency caused by cattle manure while still having a positive influence on the nutrient status of soils.
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Sumekar, Yayan, Denny Kurniadie, Dedi Widayat, and Anni Yuniarti. "Effectiveness and Persistence of Metsulfuron-Methyl Herbicide in Rice Fields with Compost Organic Materials." Asian Journal of Plant Sciences 20, no. 4 (April 15, 2021): 609–19. http://dx.doi.org/10.3923/ajps.2021.609.619.
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Urra, Alkorta, and Garbisu. "Potential Benefits and Risks for Soil Health Derived From the Use of Organic Amendments in Agriculture." Agronomy 9, no. 9 (September 12, 2019): 542. http://dx.doi.org/10.3390/agronomy9090542.
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The use of organic amendments in agriculture is a common practice due to their potential to increase crop productivity and enhance soil health. Indeed, organic amendments of different origin and composition (e.g., animal slurry, manure, compost, sewage sludge, etc.) can supply valuable nutrients to the soil, as well as increase its organic matter content, with concomitant benefits for soil health. However, the application of organic amendments to agricultural soil entails a variety of risks for environmental and human health. Organic amendments often contain a range of pollutants, including heavy metals, persistent organic pollutants, potential human pathogens, and emerging pollutants. Regarding emerging pollutants, the presence of antibiotic residues, antibiotic-resistant bacteria, and antibiotic-resistance genes in agricultural amendments is currently a matter of much concern, due to the concomitant risks for human health. Similarly, currently, the introduction of microplastics to agricultural soil, via the application of organic amendments (mainly, sewage sludge), is a topic of much relevance, owing to its magnitude and potential adverse effects for environmental health. There is, currently, much interest in the development of efficient strategies to mitigate the risks associated to the application of organic amendments to agricultural soil, while benefiting from their numerous advantages.
Dissertations / Theses on the topic "Composti organici persistenti"
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Brunello, Mirco <1986>. "Studio della contaminazione chimica della Laguna di Thi Nai (Vietnam Centrale) mediante analisi di composti organici persistenti (POPs) in campioni di sedimento." Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/1929.
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L' obiettivo del lavoro di tesi è lo studio della contaminazione chimica della laguna di Thi Nai (Vietnam centrale) mediante l'analisi di policlorobifenili (PCB) e di polibromodifenileteri (PBDE) in campioni di sedimento e di suolo prelevati dall'area perilagunare nel giugno 2010. L'area della provincia di Binh Dinh, in cui è situata la laguna oggetto di studio, è interessata infatti da una fase di accelerato sviluppo agricolo ed industriale, essendo una delle aree chiave designate a guidare lo sviluppo socio-economico del Vietnam centrale.La metodologia analitica adottata ha previsto l'estrazione dei contaminanti dai campioni di sedimento mediante un sistema automatico di estrazione accelerata con solvente (PSE) , la purificazione degli estratti mediante utilizzo di sistemi automatizzati (Power Prep), ed infine l' analisi strumentale mediante gascromatografia accoppiata a spettrometria di massa a bassa e ad alta risoluzione (HRGC-LRMS, HRGC-HRMS). Sono stati analizzati 15 campioni superficiali e 7 campioni di suolo.I livelli di contaminazione più elevati sono stati riscontrati in campioni provenienti dalle vicinanze del centro città e della zona industriale, con una prevalenza di pattern a basso livello di clorurazione/bromurazione. I valori più elevati di concentrazione totale di PCB e PBDE riscontrati nei suoli e nei sedimenti (18,6 ng/g e 6,40 ng/g rispettivamente per quanto riguarda i PCB, 4,02 ng/g e 9,62 ng/g rispettivamente per quanto riguarda i PBDE), sono valori tipici di aree costali caratterizzate da un basso impatto antropico, probabilmente a causa di efficienti processi di risospensione e/o rimozione degli inquinanti.
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Capriglia, Lorenzo. "Studi sul bioaccumulo di microinquinanti organici ed inorganici tramite Mytilus galloprovincialis in prossimità di un sito costiero contaminato." Doctoral thesis, Università degli studi di Trieste, 2009. http://hdl.handle.net/10077/3165.
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2007/2008Durante i tre anni di dottorato sono stati sviluppati degli strumenti utili a definire e ad interpretare il quadro ambientale associato alla presenza sul territorio di sorgenti secondarie non puntiformi come i siti inquinati ubicati sulla linea di costa. A tal fine sono stati ottimizzati e validati 2 metodi veloci e precisi per la determinazione rispettivamente di 51 PCB e 13 pesticidi organoclorurati sui mitili umidi e 12 pesticidi organoclorurati sui mitili liofilizzati. Inoltre sono stati sviluppati degli schemi interpretativi da applicare a risultati sperimentali mediante approfondimenti sugli aspetti fisiologici dei mitili, in termini di ciclo iproduttivo, abitudini alimentari e sistemi enzimatici. Lo studio si è basato su un sito contaminato reale, denominato Acquario, ubicato presso la costa muggesana del Golfo di Trieste; la contaminazione è stata provocata dalla realizzazione di un terrapieno di colmata di circa 28.000 m2, ideato per uno stabilimento balneare; l’imbonimento, eseguito con del terreno inquinato, ha provocato la contaminazione delle acque di falda e del sedimento limitrofo. L’attività di mitilicoltura prospiciente il sito stesso, aggrava la già complessa situazione, introducendo la delicata variabile alimentare/sanitaria nella definizione di un quadro ambientale. In convenzione con l’amministrazione comunale competente, è stato pianificato un monitoraggio per valutare il bioaccumulo su mitili di contaminanti eventualmente rilasciati dal sito inquinato fronte mare. La strategia di monitoraggio è strutturata nei seguenti punti: - Innesto di mitili “puliti” - Campionamento mensile dei mitili - Pulizia, apertura e omogeneizzazione dei campioni - Conservazione in congelatore dei campioni - Analisi per la valutazione del bioaccumulo - Interpretazione dei dati ottenuti Il monitoraggio ha coperto un periodo di 15 mesi. I 2 punti in cui sono collocate le reste hanno le seguenti coordinate: Punto A: 2421130 5051578 (13°43,916’ E, 45°36,631’ N) Punto B: 2420518 5051182 (13° 43,450’ E, 45°36,412’N) I campionamenti mensili sono stati effettuati con la collaborazione del personale del Servizio Territoriale del Dipartimento Provinciale di Trieste dell’ARPA FVG. Inizialmente, il monitoraggio è stato pianificato sui contaminanti massicciamente presenti nel terrapieno, quali IPA (Idrocarburi Policiclici Aromatici) e metalli pesanti (piombo e mercurio). Successivamente ci siamo concentrati anche su altri contaminati organici quali i PCB (PoliCloroBifenili) e pesticidi organoclorurati. Le analisi di tredici IPA (fluorene, fenantrene, antracene, fluorantene, pirene, benzo[a]antracene, crisene, benzo[b]fluorantene, benzo[k]fluorantene, benzo[a]pirene, dibenzo[a,h]antracene, benzo[g,h,i]perilene e indeno[1,2,3-cd]pirene) sono state effettuate previa estrazione dai mitili con il sistema microsoxhlet, mediante HPLC con rivelatore fluorimetrico. Le analisi di PCB e pesticidi organoclorurati sono state condotte mediante una metodica rapida messa a punto durante la tesi, senza pretrattamento spinto del campione, solvent free e completamente automatizzata tramite la tecnica HS-SPME (Head Space-Solid Phase MicroExtraction) associata alla gas cromatografia con spettrometria di massa. L’analisi impiegata è definita dalle operazioni di seguito descritte: in una vial vengono aggiunti 1 g di mitili freschi con 3 g (NH4)2SO4 e 5 ml di una soluzione al 5% di H2SO4. La vial così preparata viene incubata per 15 minuti sotto agitazione continua alla temperatura di 105°C. In seguito la fibra SPME viene esposta per 40 minuti nello spazio di testa, per consentire l’adsorbimento dei composti in fase vapore; tale operazione viene effettuata sempre a 105°C. La fibra SPME, in copolimero polidimetilsilossano/divinilbenzene (PDMS/DVB) con uno spessore di 65 μm, viene in seguito desorbita termicamente nell’iniettore del gas-cromatografo alla temperatura di 270°C per “liberare” le sostanze e consentire l’analisi cromatografica. L’analisi è completamente automatizzata grazie al sistema GC/MS Agilent (6890/5973) con autocampionatore per SPME Gerstel. Le tarature sono state effettuate mediante l’applicazione di uno spike (o fortificazione). Dodici dei 51 PCB analizzati sono diossina simili; le concentrazioni di tali PCB sono state convertite mediante opportuni fattori di tossicità equivalente (TEF) in equivalenti di tossicità di diossina (TEQ), per confrontare il dato ottenuto con il limite previsto dalla normativa vigente. I pesticidi determinati con la presente analisi sono i seguenti: l’esaclorobenzene, l’eptacloro epossido, l’aldrin, l’endrin, il dieldrin, gli isomeri alfa e gamma del clordano, gli isomeri e metaboliti del DDT (o,p’ DDE, p,p’ DDE, o,p’ DDD, p,p’ DDD, o,p’ DDT, p,p’ DDT). Inoltre è stata messa a punto un’altra analisi sempre in modalità SPME sui seguenti pesticidi organoclorurati: eptacloro epossido, aldrin, endrin, dieldrin, gli isomeri alfa e gamma del clordano e gli isomeri e metaboliti del DDT (o,p’ DDE, p,p’ DDE, o,p’ DDD, p,p’ DDD, o,p’ DDT, p,p’ DDT). L’ottimizzazione ha coinvolto i seguenti parametri: tipo di attacco, temperatura di incubazione/estrazione, tempo di estrazione, tipologia di fibra SPME. La metodica messa a punto è costituita dai seguenti punti: in una vial vengono aggiunti 0,1 g di mitili liofilizzati con 1 g di acetato di sodio e 8 ml di acqua. La vial così preparata viene incubata per 15 minuti, sotto agitazione continua alla temperatura di 130°C. In seguito, la fibra SPME viene esposta per 40 minuti nello spazio di testa, per consentire l’adsorbimento dei composti in fase vapore; tale operazione viene effettuata sempre a 130°C. La fibra SPME, in (PDMS/DVB), viene in seguito desorbita termicamente nell’iniettore del gas-cromatografo alla temperatura di 270°C. Le analisi relative al piombo sono state condotte previa mineralizzazione su 5 g di mitili con 25 ml di acido nitrico seguiti da 5 ml di acido perclorico. La mineralizzazione viene effettuata applicando una rampa di temperatura che mantiene il sistema a 110°C per 1 ora e, in seguito, a 130°C per 2 ore. L’analisi strumentale viene eseguita con il sistema Perkin Elmer 800, cioè assorbimento atomico (AAS)/fornetto di grafite. Per quanto concerne il mercurio, la mineralizzazione viene effettuata a caldo per 30 minuti a riflusso (per evitare perdite del mercurio volatile) con 10 ml di miscela solfonitrica 1÷1. L’analisi strumentale viene successivamente condotta con il sistema a vapori freddi di idruri con AAS (3100 PE). I risultati ottenuti non hanno evidenziato degli sforamenti ai limiti di legge previsti per i mitili quale alimento per benzo[a]pirene, PCB “diossina simili”, piombo, mercurio (regolamento 1881/2006) e pesticidi organoclorurati (D.M. 27/08/2004). I risultati sono di seguito riassunti - i pesticidi organoclorurati analizzati sono sotto i rispettivi limiti di rilevabilità. - il mercurio non presenta bioaccumulo, oscillando su valori che normalmente vengono riscontrati nei mitili del golfo di Trieste. - i valori di piombo presentano una situazione di modesto, ma graduale bioaccumulo - dai dati preliminari dei PCB si evince uno scarso bioaccumulo indice, comunque, della presenza di tali composti nel golfo. - per quanto concerne gli IPA totali, si può evidenziare un bioaccumulo, pur a valori inferiori alle soglie di criticità, soprattutto in certi mesi dell’anno. Tale bioaccumulo, infatti, non si presenta come un aumento costante, ma varia, in prima analisi, con un andamento non prospettato all’inizio di tale studio di monitoraggio. Il bioaccumulo è soprattutto a carico degli IPA più leggeri. - L’eventuale rilascio di contaminanti dal sito inquinato, inteso come sistema terreno/falda/sedimenti quale sorgente secondaria di emissione, sebbene non abbia compromesso la qualità del prodotto ittico durante il periodo di studio, ne ha caratterizzato il profilo dei contaminanti. Questa considerazione è evidente soprattutto per gli IPA, il cui profilo, sbilanciato verso la frazione più pesante, è influenzato dalla distribuzione di tali contaminanti in sedimenti, terreni e falde. In seguito a queste prime conclusioni, abbiamo valutato l’attività di monitoraggio su scala mensile, visualizzando gli andamenti mese per mese per il bioaccumulo degli analiti. Gli andamenti mensili di PCB e, soprattutto, di IPA non evidenziano un progressivo bioaccumulo, ma sono caratterizzati dalla presenza di minimi e massimi assoluti e relativi. Per le due classi di composti organici i massimi sono individuabili nel periodo estivo (che si protrae fino ad ottobre ‘06) e nel periodo gennaio-febbraio ‘07, mentre i minimi sono identificabili nei periodi primaverili ‘06-‘07 e nel periodo novembre-dicembre ’06. L’andamento del piombo,invece, nonostante alcune oscillazioni, è contrassegnato da un graduale, ma modesto bioaccumulo. Il mercurio non presenta bioaccumulo, mentre le concentrazioni dei pesticidi analizzati sono inferiori ai rispettivi LOD. La ciclicità nel trattenere e rilasciare soprattutto i contaminanti organici trova conferme in letteratura scientifica. Si è intrapreso, quindi, un percorso interpratativo che, mediante approfondimenti relativi alla biochimica e alla fisiologia dei mitili, ha fatto luce sulle possibili cause di tale ciclicità, come le abitudini alimentari che variano durante l’anno, e il sistema enzimatico, dal carattere stagionale, che può detossificare i livelli di contaminazione accumulati. Il tutto sembra correlato con l’andamento del ciclo riproduttivo, il quale ha una nota cadenza stagionale. Sulla base di queste considerazioni viene proposto uno schema che semplifica il complicato quadro generale e che giustifica l’andamento di massimi e minimi ottenuto nella campagna di monitoraggio.
XXI Ciclo
1979
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Gasull, Panadès Magda. "Anàlisi de la contaminació de la població general per compostos tòxics persistents i d’alguns dels seus efectes adversos per a la salut." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/669588.
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L’objectiu principal de la recerca realitzada és analitzar la contaminació de la població general per compostos tòxics persistents (CTPs) i estudiar la relació de les concentracions corporals d’aquests contaminants amb alguns dels seus possibles efectes adversos en la salut humana. La tesi aporta dades i coneixement sobre la contaminació per CTPs de la població general a Catalunya i a la ciutat de Barcelona. Es basa per una banda en una mostra de participants de l’Enquesta de Salut de Catalunya i, per l’altra, en una mostra de participants de l’Enquesta de Salut de Barcelona; són dos dels tres únics estudis sobre CTPs a nivell espanyol lligats a enquestes de salut o nutricionals i amb dades representatives de la població general. En la tesi s’apliquen noves formes de presentar i analitzar els resultats d’aquest tipus d’estudis a través de corbes de distribució poblacional i d’indicadors com el ‘nombre de compostos detectats a altes concentracions’, el qual també s’aplica en aquesta tesi a les dades disponibles de l’enquesta de salut dels Estats Units (l’anomenada NHANES). Aquesta enquesta recull periòdicament una àmplia quantitat de dades de biomonitorització ambiental representatives de la població general d’Estats Units. La tesi també analitza les relacions entre les concentracions sèriques de CTPs i la salut autopercebuda, la prevalença de diabetis tipus 2, prediabetis i de fenotips metabòlics alterats en persones amb sobrepès i obesitat i, per primer cop, en persones amb pes normal. A més, té en compte marcadors poc utilitzats en aquest context com és la proteïna C-reactiva. Les troballes plantegen noves hipòtesis que poden ser analitzades en estudis amb dissenys prospectius longitudinals, els quals poden incloure a més altres contaminants i factors rellevants. El coneixement generat pot ser utilitzat tant alhora d’avaluar l’impacte i els efectes de la contaminació de la població per CTPs, com alhora d’avaluar l’impacte de les polítiques públiques i privades que es puguin realitzar per reduir-la.The main aims of the research are to analyse the contamination of the general population by persistent toxic pollutants (PTS), as well as to study the relation between body concentrations of such compounds and some their possible adverse health effects. The thesis provides data and knowledge about the contamination by PTS of the general population of Catalonia and of the city of Barcelona. On one hand, it is based on a sample of participants of the Catalan Health Interview Survey, and in the other, on a sample of participants of the Barcelona Health Survey; these are two out of the three only studies on PTS in Spain linked to health or nutritional surveys and with representative data of the general population. New ways to present and analyse the results of this type of studies are applied in the thesis through population distribution curves and indicators such as the ‘number of compounds detected at high concentrations’, which is also computed in this thesis for the available data of the United States’ health survey (the so called NHANES). This survey periodically collets a wide quantity of environmental biomonitoring data representative of the general population of the United States. The thesis also analyses the relationships between serum concentrations of PTS and self-rated health, the prevalence of type 2 diabetes, prediabetes, and unhealthy metabolic phenotypes in overweight and obese individuals and, for the first time, in normal weight subjects. Moreover, markers not much used in this context, such as C-reactive protein, are considered. Findings suggest new hypotheses to be analysed in prospective longitudinal studies considering also other contaminants and relevant factors. The knowledge provided can be used when assessing the impact and effects of the population contamination by PTS, and also when assessing the impact of the public and private polices aimed to reduce such contamination.
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Tran, Dao. "Identifying risks associated with organic soil amendments: microbial contamination in compost and manure amendments." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/27364.
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The application of animal manures to agricultural land as a soil organic amendment has been identified as an important route by which foodborne pathogens can enter the human food chain. Knowledge of the presence and incidence of key foodborne pathogens in manure is a vital first step in the establishment of sound and effective guidelines for management and prevention of contamination by manure. The work described in this thesis attempts to determine the persistence of pathogens when raw manures are directly applied to agricultural soils, and treated under thermophilic composting conditions. Results from this study indicated that the current conditions suggested by typical food safety guidelines are sufficient to reduce the population of enteric bacteria to levels that minimise risks associated with culturable cells in raw manure and finished compost. However, E. coli cells have the potential to enter a viable but non-culturable (VBNC) state and are undetected by culture-based monitoring methods, thus providing a false impression of the innate risk of the product. Prc, bamB and tolA, which are responsible for stabilising the cell membrane, were found to be essential genes required for surviving heat treatment at 55°C. In addition, the presence of relA and oxyR suggested that E. coli may use the VBNC state as an adaptive strategy for long-term survival to withstand multiple stresses, including heat stress. Entering the VBNC state with a strengthen cell envelope may help E. coli to survive prolonged heating during standard composting conditions. Successful resuscitation from the VBNC state was achieved in the presence of cell-free supernatant from actively growing E. coli MG1655. These results underline the importance of considering VBNC cells when evaluating the sanitary effect of the composting process. VBNC cells in composts could facilitate the persistence of pathogens in manure-amended soil and thus pose a risk of microbial contamination of fresh produce.
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Almeida, Fernanda Vasconcelos de. "Bases tecnico-cientificas para o desenvolvimento de criterios de qualidade de sedimentos referentes a compostos organicos persistentes." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249634.
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Orientador : Wilson de Figueiredo JardimTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Doutorado
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Sawka, Corinne. "Contamination des logements français en composés organiques semi-volatils en phase particulaire." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1B033/document.
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Les composés organiques semi-volatils (COSV) font l’objet d’une attention croissante depuis une dizaine d’années. Utilisés dans de nombreux produits et matériaux du quotidien, ils sont émis dans les bâtiments par dispersion lors de l’usage, par évaporation ou abrasion. Du fait de leurs caractéristiques physico-chimiques, ces composés se répartissent à la fois dans l’air, en phases gazeuse et particulaire, et dans les poussières déposées au sol, sur le mobilier et les objets. Compte tenu du temps passé par la population dans les bâtiments, en particulier par les populations sensibles comme les enfants, les femmes enceintes et les personnes âgées, l’exposition à ces substances mérite d’être documentée, tenant compte des voies d’exposition en jeu : inhalation, ingestion et contact cutané. La thèse a porté sur les COSV présents en phase particulaire dans les logements. L’objectif de la thèse visait à exploiter les mesures de 66 COSV dans les particules en suspension de diamètre inférieur à 10 µm (PM10) et de 48 COSV dans les poussières au sol de taille inférieure à 100 µm considérées comme étant celles adhérant à la peau. Ces mesures ont été réalisées dans le cadre de deux campagnes nationales : la campagne « Logements » de l’Observatoire de la qualité de l’air intérieur conduite en 2003-2005 et l’enquête Plomb-Habitat dont les prélèvements ont eu lieu en 2008-2009. Une hiérarchisation des molécules jugées prioritaires au regard de leur impact sanitaire potentiel avait permis au préalable d’établir la liste des COSV à mesurer. L’exploitation de ces données de contamination a notamment porté sur l’identification d’éventuelles spécificités françaises au regard des molécules en présence et/ou des concentrations mesurées. Elle a permis de mettre en lumière un ensemble de facteurs déterminants de l’exposition (influence de la taille des particules, du type de poussières collectées, de leur bioaccessibilité), qui ne sont pas toujours considérés et qui limitent par ailleurs la comparabilité des résultats. Les concentrations mesurées ont aussi permis d’évaluer rétrospectivement la hiérarchisation sanitaire et d’en confirmer la pertinence. Les concentrations des COSV quantifiés à la fois dans l’air et au sol ont été mises en perspective afin d’examiner dans quelle mesure les particules en suspension et les poussières déposées sont similaires en termes de concentrations et de mélanges de COSV en présence. Enfin, l‘estimation des doses d’exposition aux COSV à partir d’équations simples, de variables humaines d’exposition et des données de contamination a permis une première évaluation des contributions respectives de l’inhalation et de l’ingestion aux expositions domestiques des enfants et adultes à ces composés en phase particulaireSemi-volatile organic compounds (SVOCs) refer to a broad spectrum of molecules from different chemical families that have numerous properties. They can be used as pesticides, plasticizers, flame retardants, surfactants, lubricants, etc. Consequently, they are introduced in numerous applications in buildings or used daily by the entire population. Once emitted through evaporation or abrasion in the indoor environment or introduced from the outdoors, their chemical or biological degradation is limited, and they persist indoors. This persistence also explains why some SVOCs that were banned a few years ago are still detected in the air and dust inside buildings. In indoor environments, SVOCs are divided between the gas phase, airborne particles, and dust settled on floors and surfaces. SVOCs are of concern due to their established or suspected health effects and their widespread exposure through different environmental media and pathways. The objective of the thesis was to study the concentrations of 66 SVOCs on airborne particles (PM10) and 48 SVOCs in settled dust in two samples of dwellings randomly selected across France. PM10 were sampled during the nationwide housing survey carried out by the French Observatory of indoor air quality in 2003-2005. The dust samples were collected from vacuum cleaner bags during a nationwide survey carried out in French dwellings where at least one child aged 6 months to 6 years lived (2008-2009). The SVOCs to be analyzed had prior been selected using a ranking method based on their toxicity and indoor concentrations. The data analysis focused in particular on the identification of French specificities in terms of detected molecules and measured concentrations. It highlighted some determinants of exposure, e.g., influence of particle size, type of dust collected, dust bioaccessibility, which are not always considered and limit the comparability of results. The measured concentrations were also used to assess the health ranking implemented prior to this work and to confirm its relevance. The concentrations measured both in the air and in settled dust were compared to study the similarities in terms of concentrations and SVOC mixtures. Finally, the exposure doses to SVOCs were calculated for both a child and an adult to assess the respective contributions of inhalation and ingestion to these compounds in particulate phase in dwellings
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Torres, Ronaldo José. "Efeitos da dragagem sobre a qualidade de sedimentos contaminados do canal do porto de Santos : biodisponibilidade e toxicidade de metais e compostos orgânicos persistentes." Universidade Federal de São Carlos, 2007. https://repositorio.ufscar.br/handle/ufscar/6128.
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Previous issue date: 2007-10-19Financiadora de Estudos e Projetos
Contaminated sediments is a worldwide problem, and mobilization of contaminants is one of the most critical issue in environmental risk assessment when dredging projects are concerned. Considering this, we decided to investigate if and how toxic metals and persistent organic compounds such as PAH and PCB are mobilized during dredging operations in the Port of Santos channel (São Paulo State, SE Brazil) in an attempt to assess changes in bioavailability and toxicity of those contaminants. Samples were collected in the dredging site before dredging, in the dredge s hopper (suction hopper dredge) and in the disposal site and its surroundings. Metals and persistent organic compounds were extracted from sediment samples according to USEPA methods for environmental samples. Ecotoxicological assessment was done on bulk sediment samples and in its pore water and elutriate. Results have shown that bulk sediments from the dredging sites are moderately contaminated with As, Pb and Zn and most severely with Hg, as well as had relatively high PCBs and PAHs concentrations (0,8 mg kg-1 for total Hg and 470 μg kg-1 for total PAHs, for example). These results have also shown a 50% increase in the total PAHs concentration in total suspended solids of the water samples collected inside of the dredge s hopper (679 μg kg-1 total PAHs on the total suspended solids against 479 μg kg-1 on bulk sediments from the channel collected on Alemoa terminal). This finding is of great concern as these data refer to the dredge overflow water which is pumped back to the ecosystem during dredging operations. Toxicity tests done with bulk sediment using the amphipod Tiburonella viscana did not show any toxicity, but the tests with the larvae of the sea urchin Lytechinus variegatus showed toxicity to the interstitial waters and elutriates of samples collected in the channel (dredging site), disposal site (sea site) and dredge´s hopper. In this study we also compared the obtained results to the widely used sediment quality guidelines (ERL and ERM), and to a sediment quality assessment scheme (based on various lines of evidence), as well as, to the Brazilian National Council for the Environment resolution called CONAMA 344/04. It can be seen in the results obtained in microcosm experiments (laboratory) that some organic compounds, mainly fluoranthene and pyrene, can be released from the sediments to the water. Such release was detected in the analysis of these compounds adsorbed in semi-permeable membranes (SPMDs) used in these tests. We hope that the results of this study will be used in the future to support a better planning of management strategies in dredging operations and sediment disposal in marine environment in Brazil.
Este trabalho visa avaliar os impactos causados pelas atividades de dragagem sobre a qualidade dos sedimentos do canal do Porto de Santos, priorizando o levantamento de dados tendo em vista o entendimento das alterações da partição, biodisponibilidade e toxicidade de contaminantes decorrentes destas atividades. Esta avaliação foi realizada através da determinação da concentração de contaminantes químicos (nutrientes, metais e compostos orgânicos xenobióticos) dos sedimentos (fração fracamente ligada), de suas águas intersticiais e elutriatos, e também, através de uma avaliação ecotoxicológica. As amostras foram coletadas nos sítios de dragagem (previamente à mesma) em cinco pontos do canal (dois próximos ao Terminal da Alemoa, dois no Terminal de Conteineres e um em frente ao Armazém 23), na draga após a dragagem (no interior da cisterna) e no sítio de disposição (antes e após a abertura da cisterna do navio). Os metais e os compostos orgânicos foram extraídos de acordo com os métodos da USEPA com extração por ácido nítrico e peróxido de hidrogênio para metais e ácido nítrico, sulfúrico e permanganato de potássio para mercúrio e com mistura hexano/acetona em ultra-som para compostos orgânicos. Os metais são determinados por espectrofotometria de absorção atômica e os compostos orgânicos são determinados por cromatografia gasosa acoplada a espectrometria de massas. Os resultados obtidos foram comparados a diferentes valores-guia de qualidade de sedimentos e aos critérios numéricos para a avaliação e classificação da qualidade de sedimentos a serem dragados que constam da Resolução CONAMA Nº 344/04. A partir dos resultados alcançados, foi possível constatar a contaminação do sítio de estudo por compostos orgânicos (como PAH e n-alcanos) e por metais (como Cd, Cr, Cu, Ni, Pb e Zn) e pelo semimetal As em níveis moderados e uma contaminação mais acentuada por Hg. As concentrações dos sedimentos do terminal da Alemoa estiveram na ordem de 470 μg kg-1 para PAH totais e 0,8 mg kg-1 para Hg total, sendo que este último violou os níveis 1 e 2 da Resolução CONAMA Nº 344/04. Nos testes de toxicidade, embora nos testes realizados com anfípodos (Tiburonella viscana), o sedimento integral em si não tenha se mostrado tóxico, suas águas intersticiais e elutriatos mostraram-se tóxicas nos testes realizados com larvas de ouriços (Lytechinus variegatus). Pôde-se, também, observar que o material particulado suspenso, coletado no interior da cisterna da draga, apresenta uma concentração maior destes elementos comparando-se ao sedimento original (679 μg kg-1 de PAH totais nos sólidos totais suspensos contra 479 μg kg-1 nos sedimentos do canal coletados no terminal da Alemoa) e, como durante a dragagem este material retorna ao ambiente através do overflow (eliminação da água excedente da cisterna da draga), é de se esperar um impacto negativo causado pelo retorno desses particulados e contaminantes ao ambiente. A partir dos experimentos de microcosmos desenvolvidos, pôde-se constatar que alguns compostos orgânicos, em especial fluoranteno e pireno, são liberados do sedimento para a coluna d'água, fato constatado pelo aumento da concentração desses compostos adsorvidos nas membranas semi-permeáveis (SPMDs) empregadas para tal fim, técnica esta, que poderia ser empregada em programas de monitoramento de atividades de dragagem. Espera-se que, de alguma forma, este trabalho possa contribuir, no futuro, a um melhor planejamento de estratégias de manejo e de tomada de ações para operações de dragagem e disposição de material dragado no ambiente marinho no Brasil.
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Mousset, Emmanuel. "Integrated processes for removal of persistent organic pollutants : soil washing and electrochemical advanced oxidation processes combined to a possible biological post-treatment." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1130/document.
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Les sols contaminés par les polluants organiques hydrophobes tels que les Hydrocarbures Aromatiques Polycycliques (HAPs) constituent un problème majeur puisqu'ils sont difficilement éliminés et leurs impacts toxicologiques restent significatifs. Comme alternative aux procédés thermiques et physiques traditionnels, les procédés de lavages de sol in situ et ex situ apparaissent être une solution envisageable et efficace et particulièrement pour les fortes pollutions. Cependant, le traitement des solutions fortement chargées de lavages de sol est une autre barrière à surmonter. Une nouvelle approche combinée est proposée pour répondre à ce problème: les procédés de lavages de sol in situ/ex situ combinés à un Procédé Electrochimique d'Oxydation Avancée Electrochimique (PEOA) avec possibilité de recirculer l'effluent (pour réutiliser l'agent extractant) et/ou de combiner avec un post-traitement biologique (pour minimiser le coût énergétique).L'efficacité d'extraction de l'agent extractant tel que l'hydroxypropyl-beta-cyclodextrine (HPCD) est comparé au traditionnel tensioactif non-ionique dénommé Tween 80, dans les solutions synthétiques et réelles de lavages de sol. Une nouvelle méthode sensible d'analyse du Tween 80, basée sur la fluorescence, est développée pour suivre l'oxydation du Tween 80. Deux PEOAs sont comparés : l'électro-Fenton (EF) et l'oxydation anodique (OA). Les anodes de platine (Pt) (dans le procédé EF) et de diamant dopés au bore (BDD) (dans les deux procédés) sont respectivement utilisées pour étudier la recirculation des effluents et la possibilité d'une combinaison avec un post-traitement biologique. Concernant la réutilisation des agents extractants, l'évolution de la biodégradabilité des solutions et l'énergie consommée (en kWh (kg COT)-1) pendant les PEAOs testés, l'HPCD est trouvée être plus avantageuse que le Tween 80. En revanche, en terme d'efficacité d'extraction, de coût des agents extractants et d'impact sur la respirométrie du sol, le Tween 80 paraît être plus avantageux. En prenant en compte tous ces avantages et inconvénients, le Tween 80 pourrait être retenu comme la meilleure solutionSoils contaminated by hydrophobic organic pollutants like polycyclic aromatic hydrocarbons (PAHs) are a common concern since they are extremely difficult to remove and their potential toxicological impacts are significant. As an alternative to traditional thermal or physical treatments, soil washing and soil flushing processes appear to be conceivable and efficient approaches, especially for higher level of pollution. However, the treatment of highly loaded soil washing/flushing solutions is another challenge to overcome. In that way, a new integrated approach is suggested: soil washing/flushing processes combined to an electrochemical advanced oxidation process (EAOP) in a combination with a recirculation loop (to save extracting agents) and/or a biological post-treatment step (to minimize energy cost).Extraction efficiency of the extracting agent like hydroxypropyl-beta-cyclodextrin (HPCD) is compared to the traditional non-ionic surfactant Tween 80 in synthetic and real soil washing solutions. A new simple fluorescent sensitive and selective quantification method is developed to monitor Tween 80 oxidation. Two EAOPs were compared: electro-Fenton (EF) and anodic oxidation (AO). Platinum (Pt) (in EF process) and boron doped diamond (BDD) (in both treatment) anodes are the respective electrodes employed to recycle effluents and to consider a biological post-treatment, respectively. Regarding the extracting agent recovery, the biodegradability evolution of effluent and the energy consumption (in kWh (kgTOC)-1) during EAOP, HPCD is more advantageous than Tween 80. However, in terms of extraction efficiency, costs of extracting agents and impact on soil respirometry, Tween 80 is much more efficient. By considering all these advantages and drawbacks, Tween 80 could still appear to be the best option
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Valvi, Damaskini 1983. "Effects of endocrine disrupting chemicals on childhood growth and obesity : evidence from the Spanish INMA Birth Cohort Study." Doctoral thesis, Universitat Pompeu Fabra, 2014. http://hdl.handle.net/10803/320194.
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Acumulada evidencia en estudios experimentales sugiere que la exposición a contaminantes capaces de interrumpir el sistema endocrino podría alterar las vías moleculares de los procesos de regulación hormonal y epigenética que están involucrados en el desarrollo del tejido adiposo y la homeostasia energética, lo que incrementaría la susceptibilidad de los individuos a ser obesos. La evidencia de esta emergente “Hipótesis de los Obesógenos Ambientales” en estudios humanos es escasa y se basa mayoritariamente en datos transversales. Por este motivo, el objetivo principal de la presente tesis fue evaluar los efectos de la exposición prenatal a compuestos orgánicos persistentes (COPs) y a los compuestos orgánicos no persistentes, BPA y ftalatos, en el crecimiento y la obesidad durante la infancia. Los datos que se utilizaron en esta tesis provienen del estudio poblacional de cohortes de nacimiento en España “Infancia y Medio Ambiente”-INMA. Los hallazgos sugieren que la exposición prenatal a COPs, ftalatos y de forma menos evidente a BPA, podrían influir en el crecimiento y la obesidad durante la infancia y que el sentido de estas asociaciones puede diferir según el contaminante y el sexo del niño.A growing body of experimental evidence suggests that exposure to endocrine disrupting chemicals during the critical windows of development may alter the molecular pathways that underlie the hormonal and epigenetic regulation of adipose tissue development and energy homeostasis and thus, may increase individuals susceptibility towards obesity. Human evidence supporting this emerging “Environmental Obesogen Hypothesis” is still scarce and largely relies on cross-sectional data. Thus, the main scope of the present thesis was to prospectively evaluate the influences of prenatal exposures to persistent organic pollutants (POPs) and the non-persistent organic pollutants, BPA and phthalates, on childhood growth and obesity. Data used in this thesis come from the population-based INMA-“INfancia y Medio Ambiente” Birth Cohort Project in Spain. Findings suggest that prenatal exposures to POPs, phthalates and less clearly BPA may influence childhood growth and obesity and that the direction of the effects may differ according to the chemical tested and child sex.
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Soukarieh, Banan. "Monitoring des HAPs et des PCBs dans le sol et les sédiments au Liban. Implantation d'une méthode optimisée et validée d'extraction et d'analyse." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0357.
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Actuellement, le public et surtout dans les pays industrialisés est de plus en plus conscient du fait que la dégradation de l’environnement peut dépasser les avantages du progrès rapide dans les domaines industriels et technologiques et que des dommages sérieux et irréversibles peuvent être imposés aux futures générations. L'occurrence des POPs dans l'environnement, qui résulte essentiellement des activités anthropogéniques, est l'une des préoccupations permanentes chez les scientifiques. Ces composés ont été trouvés dans toutes les matrices environnementales telles que l'air, le sol, l'eau et les sédiments et en raison de leurs propriétés lipophiles, ils risquent de rebondir dans la chaîne alimentaire humaine. Durant cette dernière décennie, le Liban a connu une grande explosion démographique qui a été accompagnée par des activités anthropogéniques diverses. La dégradation de la qualité de l’environnement est bien ressentie par la population locale et les conséquences sur la santé humaine sont lourdes et affreuses. Les travaux de cette thèse ont permis d’évaluer concrètement l’effet de POPs sur la qualité de l’environnement au Liban, ces travaux ont abouti à la détermination des niveaux de quelques POPs les plus globalement étudiés tels que les HAPs, les PCBs et les OCPs dans les différents compartiments environnementaux au Liban. A cette fin, des protocoles d'analyse comprenant une méthode GC/MS pour la séparation et la détection des HAPs, une méthode UAE pour l'extraction des HAPs à partir du sol et des sédiments et une méthode SPE pour l'extraction des HAPs à partir de l'eau ont été développés. Ces méthodes ont été ensuite appliquées pour évaluer les niveaux de 17 HAPs dans des sols de différents usages et pour étudier la distribution de HAPs dans la phase aqueuse et les sédiments sur les côtes libanais et dans des rivières côtières et internes. Les principaux résultats ont montré que les niveaux de contamination des sols par les HAPs décroissent dans l’ordre suivant: industriels, urbains, transport et agricoles et que les sols industriels et urbains étaient 777 et 256 fois plus toxiques que les sols ruraux de référence selon l'approche TEF. De plus, l'eau et les sédiments des sites côtiers affectés par l'industrie et le transport maritime ont montré une contamination plus élevée par les HAPs. Certains échantillons de sédiments ont montré des niveaux de quelques HAPs individuels supérieures à l'ERL, ce qui pourrait occasionnellement provoquer des effets écologiques négatifs. Les travaux de cette thèse incluent aussi la détermination des niveaux des PCBs et des OCPs dans les sédiments de la rivière Litani qui est une source d’une grande préoccupation environnementale actuelle au LibanCurrently, the public and especially in industrialized countries is increasingly aware that environmental degradation can outweigh the benefits of rapid progress in the industrial and technological fields and that serious and irreversible damage can be imposed on the future generations. The occurrence of POPs in the environment, which results mainly from anthropogenic activities, is one of the permanent concerns of scientists. These compounds have been found in all environmental matrices such as air, soil, water and sediments and because of their lipophilic properties, they are likely to rebound in the human food chain. During the past decade, Lebanon has experienced a large population explosion that has been accompanied by various anthropogenic activities. The degradation of the quality of the environment is felt by the local population and the consequences for human health are heavy and horrendous. The work of this thesis allowed to evaluate concretely the effect of POPs on the quality of the environment in Lebanon, this work led to the determination of the levels of some POPs most widely studied such as PAHs, PCBs and OCPs in the different environmental compartments in Lebanon. To this end, analytical protocols including a GC/MS method for the separation and detection of PAHs, a UAE method for the extraction of PAHs from soil and sediments and an SPE method for the extraction of PAHs from water were developed. These methods were then applied to evaluate the levels of 17 PAHs in soils of different uses and study the distribution of PAHs in the aqueous phase and sediments on the Lebanese coasts and in coastal and inner rivers. The main results showed that soil contamination levels by PAHs decreased in the following order: industrial, urban, transport and agricultural and that industrial and urban soils were 777 and 256 times more toxic than rural reference soils according to the TEF approach. In addition, water and sediments from coastal sites affected by industry and shipping have shown higher contamination by PAHs. Some sediment samples showed concentrations of a few individual PAHs greater than the ERL, which could occasionally cause negative ecological effects. The work of this thesis also includes the determination of levels of PCBs and OCPs in the sediments of the Litani River which is a source of great environmental concern currently in Lebanon
Books on the topic "Composti organici persistenti"
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T, Fenge, Downie David Leonard, and Inuit Circumpolar Conference, eds. Northern lights against POPs: Combatting threats in the Arctic. Montreal: Published for the Inuit Circumpolar Conference Canada by McGill-Queen's University Press, 2003.
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2
Shukla, Vertika, and Narendra Kumar. Persistent Organic Pollutants in the Environment. Taylor & Francis Group, 2021.
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3
Kumari, Kanchan. Persistent Organic Pollutants: Gaps in Management and Associated Challenges. Taylor & Francis Group, 2021.
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Kumari, Kanchan. Persistent Organic Pollutants: Gaps in Management and Associated Challenges. Taylor & Francis Group, 2021.
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Persistent Organic Pollutants: Gaps in Management and Associated Challenges. CRC Press, 2021.
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Kumari, Kanchan. Persistent Organic Pollutants: Gaps in Management and Associated Challenges. CRC Press LLC, 2021.
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Shukla, Vertika, and Narendra Kumar. Persistent Organic Pollutants in the Environment: Origin and Role. Taylor & Francis Group, 2021.
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Persistent Organic Pollutants in the Environment: Origin and Role. Taylor & Francis Group, 2021.
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Shukla, Vertika, and Narendra Kumar. Persistent Organic Pollutants in the Environment: Origin and Role. Taylor & Francis Group, 2021.
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Mehmetli, Ebru, and Bogdana Koumanova. Fate of Persistent Organic Pollutants in the Environment. Springer, 2007.
Find full textBook chapters on the topic "Composti organici persistenti"
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Gaur, Nisha, Dhiraj Dutta, Aman Jaiswal, Rama Dubey, and Dev Vrat Kamboj. "Role and Effect of Persistent Organic Pollutants to Our Environment and Wildlife." In Persistent Organic Pollutants (POPs): Monitoring, Impact and Treatment [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101617.
Full textAbstract:
Persistent organic pollutants (POPs) are toxic substances composed of carbon-based chemical compounds and mixtures. In the recent times, persistent organic pollutants (POPs) came as a threat for the wildlife and environmental world. POPs are chemically stable, remain intact in the environment for long periods, are recalcitrant in nature, and are lipophilic in nature. Therefore, they accumulate in fatty tissue of living organisms and reside longer period of time finally affecting the human and wildlife. It is believed that approximately 90% of human beings are exposed to POPs from their diets that contain animal products. These foods lead to bioaccumulation in fat tissues that then cause health hazard. There are many studies such that its behavior in photocatalytic oxidation reactions are available; also many research studies are going to combat from these toxic substances. In this chapter, we will take you through how persistent organic pollutants are affecting our environment and wildlife and what are its roles.
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Rao, Vyshnavi V., Sonashree R., and Rashmi R. Halbavi. "Review on Plastic Waste Disposal and Role of Microorganisms in Bioremediation of Plastics." In Advances in Environmental Engineering and Green Technologies, 236–47. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4921-6.ch011.
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Plastics are the most commonly used polymers for conventional applications. Plastic wastes accumulating the environment are presenting an ever-increasing ecological threat. Low density polyethylene is major cause of long-term environmental pollution. An eco-friendly approach to resolve this ever-growing persistent menace is bioremediation. The diverse metabolic capability of microbes can be effectively exploited for breakdown of plastic wastes. Another approach is to synthesise biodegradable or organic plastics which is soluble in the natural environment. There are several advantages associated with these biodegradable plastics or plastic degrading microbes. They can be composted with organic wastes and returned to enrich the soil. Their use will not only reduce stress and loss of habitat of wild animals caused by dumping of conventional plastics but will also lessen the labor expenses for the removal of plastic wastes in the environment because they degrade naturally. This review describes bioremediation/biodegradation process, production, types of and advantages of bioplastics.
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Rao, Vyshnavi V., Sonashree R., and Rashmi R. Halbavi. "Review on Plastic Waste Disposal and Role of Microorganisms in Bioremediation of Plastics." In Research Anthology on Emerging Techniques in Environmental Remediation, 481–92. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-3714-8.ch025.
Full textAbstract:
Plastics are the most commonly used polymers for conventional applications. Plastic wastes accumulating the environment are presenting an ever-increasing ecological threat. Low density polyethylene is major cause of long-term environmental pollution. An eco-friendly approach to resolve this ever-growing persistent menace is bioremediation. The diverse metabolic capability of microbes can be effectively exploited for breakdown of plastic wastes. Another approach is to synthesise biodegradable or organic plastics which is soluble in the natural environment. There are several advantages associated with these biodegradable plastics or plastic degrading microbes. They can be composted with organic wastes and returned to enrich the soil. Their use will not only reduce stress and loss of habitat of wild animals caused by dumping of conventional plastics but will also lessen the labor expenses for the removal of plastic wastes in the environment because they degrade naturally. This review describes bioremediation/biodegradation process, production, types of and advantages of bioplastics.
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"of control. The state of Queensland has generous expertise in this area, with the CSIRO Division of Entomology – Lands Department group in Brisbane boasting spectacular success against Salvinia and Eichhornia, and near the reservoir at James Cook University a USDA unit was involved in successes with the Tennessee Valley Authority (TVA) (see Chapter 12) using a range of stem-boring and leaf-mining insects (Balciunas et al. 1993). One might consider the herbivorous grass carp Ctenopharyngodon idella, originally from China, more as a harvester than a biological control agent. This fish grazes on submerged weeds such as Hydrilla, Myriophyllum, Chara, Potamogeton and Ceratophyllum, and at stocking rates of 75 fish/ha control is rapidly achieved. Some introductions in the USA have resulted in removal of all vegetation (Leslie et al. 1987), and in the Australian context the use of sterile (triploid) fish (Cassani and Canton 1985) could be the only consideration. However, in view of the damage already done by grass carp to some inland waterways in Australia, it is suspected that this option would be greeted with horror. Mechanical control involves the physical removal of weeds from a problem area and is useful in situations where the use of herbicides is not practical or poses risks to human health or the environment. Mobile harvesters sever, lift and carry plants to the shore. Most are intended for harvesting submerged plants, though some have been designed or adapted to harvest floating plants. Handling the harvested weed is a problem because of their enormous water content, therefore choppers are often incorporated into harvesting machinery design. However, many mechanical harvesters have a small capacity and the process of disposing of harvested plant material is time-consuming. Any material that remains may affect water quality during the decay process by depleting the water of oxygen. Furthermore, nutrients released by decay may cause algal blooms (Mitchell 1978). Another disadvantage of mechanical removal is that disturbance often promotes rapid new growth and germination of seed, and encourages the spread of weed by fragmentation. Some direct uses of macrophytes include the following: livestock food; protein extraction; manufacture of yeast; production of alcohol and other by-products; the formation of composts, mulches and fertilizers; and use for methane generation (Williams 1977). Herbicides either kill on contact, or after translocation through the plant. Some are residual and retain their toxicity for a period of time. Where herbicides are used for control of plants, some contamination of the water is inevitable (Bill 1977). The degree of contamination depends on the toxicity of the material, its fate and persistence in the water, the concentration used and the main purpose served by the water. After chemical defoliation of aquatic vegetation, the masses of decaying organic debris produced can interfere with fish production. Several factors must be taken into account when selecting and adapting herbicides for aquatic purposes, including: type of water use; toxicity of the herbicide to humans, fish, stock, and wildlife; rate of disappearance of residues, species affected and duration of control; concentration of herbicide; and cost (Bill 1977). The TVA has successfully used EPA-approved herbicides such as Endothall, Diquat, Fluridone and Komeen against Hydrilla (Burns et al. 1992), and a list of approved." In Water Resources, 153–54. CRC Press, 1998. http://dx.doi.org/10.4324/9780203027851-40.
Full textConference papers on the topic "Composti organici persistenti"
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Duoyuan, Wang, Hu Lingzhi, He Huizhu, Zhao Lizeng, Mi Xin, and Ni Yuxin. "The New Systems of Organic Photon-gated Photochemical Hole Burning." In Persistent Spectral Hole Burning: Science and Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pshb.1991.fe12.
Full textAbstract:
Recent material research has been devoted to search for two-color or photon-gated photochemical hole burning mechanisms in inorganic as well as organic materials. A mechanism for photon-gated spectral hole burning by donor-acceptor electron transfer in a material composed of meso-tetra-p-tolyl-tetrabenzoporphyrinato)zinc (TZT) (Donor) with halomethanes(acceptor) in poly(methylmethacrylate) (PMMA) thin film at 1.4K was reported by Carter et al.[1]
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Kaarli, Rein, Peeter Saari, and Heiki Sõnajalg. "New Developments in Time-and-Space-Domain Holography and Shaping of Light Pulses by Spectral Hole-Burning Filters." In Persistent Spectral Hole Burning: Science and Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pshb.1991.thb3.
Full textAbstract:
Photochemically instable dye molecules in low-temperature polymers are distributed not only spatially in the medium but also spectrally along the axis of resonant optical transition frequencies and orientationally with reference to the polarization of the transition. Consequently, such composite organic materials -- spectral hole burning media1-4 -- can be considered as novel optical materials possessing not only three-dimensional photosensitivity but also sensitivity to the wavelength and polarization of the incident light.
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Tian, Mingzhen, Baozhu Luo, Wenlian Li, Shihua Huang, and Jiaqi Yu. "Persistent Photon-gated Spectral Holeburning In A New Donor-Acceptor Electron Transfer System." In Persistent Spectral Hole Burning: Science and Applications. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pshb.1991.fa7.
Full textAbstract:
Due to the interest in the frequency-domain optical storage application, recent researches on spectral holeburning concentrated on the two-colour photon-gated persistent holeburning[1,2]. Some organic systems have been investigated [3-7]. A representative one is TZT as a donor and CHCl3 as an acceptor in PMMA film undergoing donor-acceptor electron transfer, which offered a significant mechanism for persistent holeburning in organic system [4,5]. But there is an insurmountable problem in the system. As CHCl3 is volatile at room temperature, its concentration can not be controlled and the sample is difficult to further study. Here we report the holeburning system composed of metal-tetrabenzoporphyrin derivatives (MTBP) as the donors and a solid electron acceptor, p-hydroxybenzaldhyde (PHBA), which can easily be made into a stable "dry" film and in which the concentration of each component can be modified easily.
Reports on the topic "Composti organici persistenti"
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Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen, and Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils: Speciation, Transport, and Accumulation. United States Department of Agriculture, June 2011. http://dx.doi.org/10.32747/2011.7697103.bard.
Full textAbstract:
Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.