Cette thèse est centrée sur le bupirimate, utilisé dans la région de Souss Massa comme fongicide dans la culture de tomates et propose l'étude de différents aspects liés à son utilisation comme son élimination par voie électrochimique des effluents aqueux d'origine agricole et son impact environnemental dans l'atmosphère. L'étude de surveillance des résidus de pesticides sur les fruits de tomates dans cette région du Maroc proposée dans cette thèse montre que sur les 194 échantillons analysés, il y a présence de bupirimate (10%), endosulfan (7%), bifenthrine (4%), L. cyhalothrine (3%), iprodione (3%), procymidone (3%), deltamethrine (2%), tetradifon (2%), cypermethrine (1%), chlorothalonil (1%), tau-Fluvalinate (1%) et de composés dont les concentrations sont inférieures à la limite de détection (63%). Le bupirimate fortement utilisé, est donc susceptible de se retrouver dans les effluents de lavage agricole, d'où l'intérêt de l'étude de sa dégradation électrochimique en phase aqueuse. Nous avons ainsi mis en évidence que la cinétique de dégradation et les rendements de minéralisation de ce pesticide peuvent être significativement augmentés, par variation des différents paramètres expérimentaux (concentration de l'électrolyte, valeur du courant imposé, et température). Nous avons également déterminé au cours de ce travail que la constante cinétique d'oxydation du pesticide est de l'ordre de 109.10-4 min-1. Les analyses de DCO ont démontré que le taux de minéralisation par électrooxydation dépasse 70 %. Les résultats de l'étude de la minéralisation par la CPG montrent que la vitesse de l'électro-Dégradation du bupirimate est plus élevée que celle obtenue par la DCO. Le rendement d'élimination est de l'ordre de 86%. Ce résultat est confirmé par l'analyse UV. La réactivité hétérogène de bupirimate vis-À-Vis de l'ozone, en phase hétérogène, est également étudiée. Les résultats obtenus montrent que la valeur de la constante cinétique est de 3.07x10-18 cm3.molécules-1.s-1 vis-À-Vis de l'ozone. Cette valeur implique une durée de vie atmosphérique de l'ordre de quelques jours. Les spectres UV et la réactivité homogène vis-À-Vis des radicaux OH du 4-Méthylpyrimidine, de la pyrimidine, du pyrrole, et de la pyridine (produits gazeux attendus de la dégradation des pesticides), ont été déterminés. Les études cinétiques ont été réalisées dans plusieurs chambres atmosphériques. Les résultats obtenus montrent que pour les composés possédant des hétérocycles à 6 atomes, avec 1 ou 2 atomes d'azote, les constantes de vitesse avec le radical OH sont du même ordre de grandeur. La présence des atomes dans le cycle aromatique a un effet désactivant sur la réactivité de ces composés avec les radicaux OH. Par ailleurs, le composé hétérocyclique aromatique à 5 atomes est hautement plus réactif vis-À-Vis les radicaux OH. Les durées de vie atmosphériques de ces composés, déduites de nos mesures cinétiques et spectroscopiques montrent que ces espèces ont tendance à s'éliminer rapidement par les différentes voies photochimiques. / The research study discussed in this thesis concerns the determination of the kinetic rate constants of the electrochemical and heterogeneous degradations of bupirimate. In this study we report the atmospheric fate of four compound heterocyclique by ozone and OH-Radicals using the technique of a simulation chamber coupled to a different analytical system.194 samples tomato samples from an agricultural region of the souss (Agadir, Morrocco) were analyzed for bupirimate (10%) endosulfan (7%), bifenthrine (4%), L. cyhalothrine (3%), iprodione (3%), procymidone (3%), deltamethrine (2%), tetradifon (2%), cypermethrine (1%), chlorothalonil (1%), tau-Fluvalinate (1%) and the concentration of author compounds is less of limits of detection (63%).The electrochemical oxidation of bupirimate is examined by bulk electrolyses at boron doped diamond (BDD) electrode. The influence of operating conditions on the reaction trend is investigated and suitable conditions for oxidative demolition of Bupirimate are individuated. The study also presents the results from bupirimate oxidation at BDD and SnO2 anodes. The COD of bupirimate solution was observed to fall with the first-Order kinetics. We also determined during this work that the constant kinetics of pesticide is about 109.10-4 min-1. In this study, we highlighted that the kinetics of degradation and the outputs of mineralization of bupirimate could be significantly increased, by variation of the various experimental parameters (concentration of electrolyte, value of the imposed current, and concentration of pesticide). The results of mineralization showed that the speed of degradation of the bupirimate by proceeds electrochemical is higher, one has obtains an output of elimination of 84% by the analyses of chromatography.UV spectra and the homogeneous reactivity vis-À-Vis the OH group of 4-Methylpyrimidine, pyrimidine, pyrrole, and pyridine (gaseous products of expected degradation of pesticides), were determined. Kinetic studies were carried out in several atmospheric chambers. The results show that for compounds 6 atoms aromatic ring, with 1 or 2 nitrogen atoms, the rate constants with OH radicals are of the same order of magnitude. The presence of atoms in the aromatic ring has a deactivating effect on the reactivity of these compounds with OH radicals. Moreover, the heterocyclic aromatic having 5 atoms is more highly reactive with OH radicals. The atmospheric lifetimes of these compounds, derived from our spectroscopic and kinetic measurements show that these species tend to be eliminated rapidly by different photochemical ways.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Bumble bees provide valuable pollination services to many agricultural crops and wild flower species. Consequently, evidence that wild populations are in decline has caused widespread concern. Among multiple causal factors, some have singled out neonicotinoid pesticides as potentially a major contributor to these declines. Bumble bees are exposed to neonicotinoids, such as imidacloprid and thiamethoxam, whilst foraging for nectar and pollen from treated crops. For neonicotinoids to cause population decline, the typical residues that bumble bees encounter in the field (defined here as between 1–12 μg kg-1) should be capable of reducing colony success by detrimentally impacting demographically relevant endpoints such as reproduction and worker performance. Whether field-realistic neonicotinoids are capable of causing such effects is yet to be fully established. The overall aim of this thesis was to investigate the effects of field-realistic neonicotinoids on endpoints of demographic importance and improve understanding of the effect mechanisms of neonicotinoids in bumble bees. Laboratory experiments were conducted with Bombus terrestris L. exposed to dietary neonicotinoids up to 98 μg kg-1. Results showed that food consumption and production of brood (eggs and larvae) in queenless B. terrestris microcolonies were significantly reduced by the two highest concentrations of imidacloprid and thiamethoxam tested (39, 98 μg kg-1), but only imidacloprid produced a negative effect when concentrations were in the typical field-realistic range. Imidacloprid’s affect on microcolonies was mirrored in queenright colonies where field-realistic concentrations substantively reduced both feeding and brood production. It was postulated that the detrimental effects of imidacloprid on brood production emerge principally from nutrient limitation imposed by the failure of individuals to feed. Removing imidacloprid from the bees’ diet resulted in the recovery of feeding and brood production in queenright colonies, even when previously exposed to high doses (98 μg kg-1). Investigation into the effect mechanisms of imidacloprid in B. terrestris revealed that cytochrome P450 enzymes are not important for metabolism of the neonicotinoid in adult workers. A transcriptomic analysis indicated B. terrestris exhibit a general stress response to imidacloprid, characterised by the alteration in expression of genes involved in, for example, metabolism and storage of energy. The thesis findings raise further concern about the threat of imidacloprid to wild bumble bees. However, they also suggest that some demographically important endpoints are resilient to imidacloprid as a realistic pulsed exposure, and that bumble bees may be less sensitive to field-realistic concentrations of thiamethoxam. Further research, which is required to fully establish the demographic consequences for bumble bees of exposure to neonicotinoids, can be developed based on the foundation of work presented here.

A photolytic cell system suitable for the treatment of wastewater streams containing three pesticides, i) acephate, ii) glyphosate and iii) malathion is reported. The system is capable of destroying these three organic compounds, commonly present in wastewater streams originating from agrochemical industries in Malaysia, and can lead to complete mineralisation under the optimum conditions. The system is based on an advanced oxidation process and involves the production of hydroxyl free radicals in the presence of a UV source. The performance of the system, for the three pesticides, was optimised by investigating the effects of i) UV source, ii) pH of the solution, iii) initial concentration of the substrate, iv) addition of oxidants, v) hydrogen peroxide (H2O2) in the presence and absence of single and mixed metal ions. To monitor the degradation efficiency of the system, the residual concentrations of these organic compounds and metal ions were analysed using five analytical techniques i) total organic carbon (TOC), ii) high performance liquid chromatography (HPLC), iii) ion chromatography (IC), iv) UV/Visible spectroscopy (UV/Vis), and v) atomic absorption spectroscopy (AAS). The data show that the developed photolytic cell system is capable of achieving complete mineralisation of the three pesticides with the use of both 400 W and 600 W UV lamps. However, the 400W UV lamp was used, for economic reasons, to optimise the system for the remaining factors. Changes in the pH of aqueous solutions influenced the degradation efficiency and a complete degradation of the three pesticides was achieved at their self-pH values ranging from 5.0-5.5. The degradation of acephate increased and malathion decreased at their higher initial concentrations whereas no significant effect related to concentration was observed for glyphosate. Results show that the degradation followed a first order kinetics and the degradation rates were: malathion > acephate > glyphosate. The addition of 30 mg/L of H2O2 enhanced the degradation of the pesticides and after 5 hours irradiation these were 95.7%, 91.5% and 81.3% for malathion, acephate and glyphosate respectively. The presence of metal ions was observed to affect degradation (Table 1). With 5.0 mg/L of Fe(II) the degradation of all three pesticides increased, and in all cases acephate removal was improved. Removal of both malathion and glyphosate was negatively affected by copper, an effect that work with mixtures indicated was stronger than the positive effect of iron. The addition of H2O2, in the presence of single metal ions, increases the degradation. However, the addition of H2O2, in the presence of mixed metal ions, has no significant effect on the degradation of glyphosate and malathion. The effect of mixed metal ions on the three pesticides and the effect of Zn(II) ions on acephate and malathion are reported for the first time in this thesis. The developed photolytic cell system can be used for the treatment of wastewater streams originating from point sources, for example, agrochemical industries, under the optimum conditions. The synergistic combination of the developed system with the existing standard technologies is also proposed for the treatment of surface water at water treatment facilities in Malaysia. The application of the developed system can also be extended, with minimum modifications, for the treatment of wastewater streams originating from different manufacturing industries in Malaysia, for example, textile, paper/pulp, printing, coke, petroleum, paint, solvent, pharmaceuticals and wood-preserving chemicals. All these industries produce wastewater streams containing low concentrations of organic pollutants and heavy metal ions.

Pesticides including organophosphates (OPs) and carbamates (CBs) are widelyused to control undesirable pests. These compounds are neurotoxic and inhibithydrolysis of the neurotransmitter acetylcholine by acetylcholinesterase. Public healthconcerns have increased with the escalating usage of pesticides. Reliable monitoringprograms are required to detect and quantify pesticide exposure, as well as to promotean understanding of their neurotoxic properties. In this dissertation, both theanticholinergic (Part I) toxicity and neurotoxicity in neuroblastoma cells (Part II) ofpesticides were explored using mass spectrometry (MS). The high sensitivity andhigh-throughput of this technique renders it well-suited for proteomics analysis.Part I describes the study of butyrylcholinesterase (BChE) inhibition resultingfrom OP and CB exposure. The main hypothesis of Part I is that the specialmodification of BChE can provide the origin and extent of pesticide exposure. A novelmethod for detection and quantification of pesticide exposure was designed using aproteomics approach and equine BChE (eBChE) as a model system. The methodologyfeatured detection and analysis of phosphorylated or carbamylated peptides at theactive site serine residue. The developed technique was successfully applied towardsthe study of human BChE (hBChE) inhibition in vitro and in serum samples. Aspecially designed affinity column enabled an isolation of BChE from serum. EnrichedBChE was subjected to enzymatic digestion by a novel on-bead double digestionprotocol. LC/MS/MS was employed to produce a calibration system for the analysis ofhBChE inhibition, which was then applied towards quantification of the enzyme.Part II describes a proteomic study of the neurotoxicity in neuroblastoma cellscaused from chlorpyrifos (CPF), an organophosphate pesticide. The concerns of CPFexposure to pregnant women, infants and children are increasing due todevelopmentally neurotoxic effects of this chemical. The main hypothesis of Part II isthat CPF can cause protein alterations and these altered proteins can be detected usingproteomics. Systematic studies at subcellular levels evaluated proteome changes inSH-SY5Y cells exposed to CPF. Two-dimensional gel electrophoresis (2DE) wasapplied with MALDI-TOF-MS to analyze differential protein expression. Thirty sevencommon unique altered proteins were identified, which play important roles inmetabolic pathway.

While there is growing public concern over the safety of the food supply, few studies have contrasted varying perceptions of pesticide risk. This study assessed and contrasted perceptions of three groups of Oregon State University Extension Service clientele (home food preservers, Master Gardener volunteers, commercial growers) and factors influencing these perceptions. The impact of the pesticide risk perceptions on purchasing decisions and pesticide application practices was assessed. Two questionnaires were developed: one for home food preservers/Master Gardener volunteers and one for commercial growers. One hundred twenty-seven questionnaires were completed by a convenience sample of home food preservers (85% adjusted return rate) and 155 questionnaires were completed by randomly selected Oregon State University Master Gardener volunteers (81% adjusted return rate). A shortened version of the questionnaire was completed by 124 participants at the annual meeting of Willamette Valley Processed Vegetable Growers. Home preservers were 84% female (mean age=49 ± 14 years), volunteers were 50% female/50% male (mean age=56 ±14 years), and commercial growers were 95% male (mean age=42 ± 11 years). Three different measures of pesticide risk perceptions were used to test six hypotheses: Respondents rated 1) "eating foods produced using pesticides" as high, low, or no risk, and agreed/disagreed (on Likert scales) whether 2) "chemical residues remaining on produce are a major health concern," and 3) "children are at a greater risk for illness from pesticides than adults." Produce selection decisions, pesticide application practices, life stages, gender, media awareness, and knowledge of agricultural production techniques and practices were also assessed to determine their relationship with risk perceptions. Perceptions of risk varied among the three groups. Fifty-five percent of preservers rated "eating foods produced using pesticides" as a "high" risk compared to 34% of volunteers and 2% of growers. Thirty-four percent of preservers strongly agreed that "chemical residues remaining on produce are a major health concern" compared to 25% of volunteers and 7% of growers. Forty-six percent of preservers strongly agreed that "children are at a greater risk of illness from pesticides than adults" compared to 42% of volunteers. Fifty-two percent of growers strongly/ somewhat agreed that children are at no greater risk. Gender was significantly associated with respondents' perceptions. Eighty-nine percent of preservers rating the risk of "eating food produced using pesticides" as "high" were female as were 65% of volunteers. Female volunteers moderately agreed that "chemical residues remaining on produce are a major health concern" compared to males who tended to neither agree nor disagree. The presence of children living in the home was significantly related to the volunteers' perceptions that chemicals are a major health concern and that children are at greater risk. Preservers and growers' results indicated there were no significant differences. Awareness of pesticide reports in the media was measured by recall of four media events. Media awareness was significantly associated with preservers' perceptions that eating foods produced with pesticides was "high" risk and that children are at a greater risk for illness because of pesticide residues. There was no media association for either volunteers or growers. Influence of risk perceptions on produce purchase decisions was measured with a series of questions about past, present, and future purchases. Results indicated that volunteers' pesticide risk perceptions were significantly related to more produce selection decisions than were home food preservers. The risk perception measure that "chemical residues remaining on produce are a major health concern" was most significantly associated with purchase decisions for both preservers and volunteers. For preservers and volunteers there were significant relationships between all three measures of pesticide risk perceptions and three of the twelve purchase decisions tested. Those who perceived a higher risk were 1) more willing to pay a higher price for certified residue free produce, 2) more concerned about pesticide residues when buying imported produce, and 3) intended to purchase produce grown without synthetic pesticides even if it costs more. Knowledge of agricultural practices was measured by a set of five questions. Mean scores ranged from 0.9 ± 0.9 for preservers to 1.6 ± 1.0 for volunteers out of a possible 5.0. Volunteers' with higher scores were significantly more likely to agree that chemicals are a major health concern and that children are at a greater risk of illness from pesticide residues. No significant associations were seen for preservers. Pesticide application practices were significantly related to pesticide risk perceptions. Preservers and volunteers who generally perceived the risks as "high" reported not using pesticides. Preservers reporting changes in application practices moderately agreed chemical residues are a major health concern while volunteers' reporting changes in application practices strongly agreed that children are at higher risk than adults. Growers tended to disagree that pesticides are a major health concern and they were less concerned that children are at a greater risk from pesticides. The study concluded that the home food preservers and Master Gardener volunteers perceived the risks associated with pesticides and produce as much higher than commercial vegetable growers. This difference in perceptions is reflected in some of their produce selection decisions and pesticide application practices. Children living at home, gender, media awareness, and knowledge of agricultural practices were associated with the pesticide risk perceptions of these Extension clientele. Results suggest that educational programming to increase knowledge about pesticide usage in agricultural production is warranted. There is also a need to foster better communications among groups with differing points of views about pesticide residue risks. / Graduation date: 1994

Creatinine is a metabolic waste product, removed from the blood by the kidneys, and excreted in the urine. The measurement of creatinine is used in the assessment and monitoring of many medical conditions as well as in the determination or adjustment of absorbed dosage of pesticides. Earlier models to predict 24-hour urinary creatinine used ordinary least squares regression and assumed that the subjects' observations were uncorrelated. However, many of these studies had repeated creatinine measurements for each of their subjects. Repeated measures on the same subject frequently are correlated. Using data from the NIOSH-CDC "Pesticide Dose Monitoring in Turf Applicators" study, this thesis project built a model to predict 24-hour urinary creatinine using the Mixed Model methodology. A covariance structure, that permitted multiple observations for any one individual to be correlated, was identified and utilized. The predictive capabilities of this model were then compared to the earlier models investigated.

A aplicação de biocarvão ao solo tem sido divulgada como prática com vantagens agrícolas e ambientais. Devido à sua elevada reatividade, o biocarvão pode interagir com contaminantes orgânicos e inorgânicos do solo, diminuindo o potencial poluidor de elementos tóxicos e pesticidas. Contudo, a eficácia de herbicidas pré-emergentes pode ser anulada devido à presença de biocarvão no solo, o que impõe a necessidade de doses maiores e resulta no aumento do risco de contaminação ambiental. Adicionalmente, pode haver maior persistência de pesticidas no solo devido à retenção e menor disponibilidade das moléculas em solos com biocarvão. As reações que ocorrem entre o biocarvão e os pesticidas dependem das próprias características do solo e da molécula, além do tempo de interação com o solo (aging) e das propriedades intrínsecas ao biocarvão (biomassa de origem, T°C de pirólise e granulometria). O tebuthiuron e a hexazinona são herbicidas com elevado potencial de lixiviação e podem ter seu destino alterado em função da presença de biocarvão no solo. Estas moléculas possuem elevado tempo de meia-vida (t1/2) e biodegradam lentamente no ambiente edáfico. Assim, processos oxidativos avançados (POA) podem acelerar a decomposição dos herbicidas, sendo ainda uma maneira de integrar o biocarvão em processos químicos para a dissipação de poluentes. Objetivou-se avaliar os efeitos da aplicação de biocarvão na dinâmica dos herbicidas tebuthiuron e hexazinona em solos, tendo-se como objetivos específicos: i) verificar o comportamento sortivo desses herbicidas frente à aplicação de biocarvões produzidos a partir de diferentes matérias-primas e T°C de pirólise, incluindo a influência de fatores como o aging dos herbicidas no solo, tamanho das partículas do biocarvão e disponibilidade de carbono orgânico dissolvido (COD) no solo promovida pela adição do biocarvão; ii) avaliar se a interação entre os herbicidas e o biocarvão afeta a eficiência de controle de braquiária (Brachiaria decumbens); iii) analisar a influência do biocarvão na dissipação e lixiviação de tebuthiuron e hexazinona; e iv) identificar o potencial de uso do biocarvão em POA, como suporte para catalisadores metálicos heterogêneos e como fonte de ferro para reações de Fenton, bem como avaliar o desempenho destes materiais na catálise oxidativa de hidrocarbonetos e dos herbicidas. Experimentos de sorção, (verificando a influência de biocarvões de diferentes matérias-primas e T°C de pirólise, aging e granulometria, além da avaliação em solos de texturas contrastantes), bem como de dissipação e lixiviação foram conduzidos, utilizando-se herbicidas radiomarcados. Em paralelo, a liberação de COD pelos biocarvões e pelos solos foi quantificada, enquanto que um experimento de eficiência de controle sobre braquiária em casa de vegetação foi conduzido. Os biocarvões foram, ainda, avaliados quanto ao potencial de uso como suporte para catalisadores metálicos e para reações de Fenton, avaliando-se sua performance para a oxidação dos herbicidas e de hidrocarbonetos. Apesar de não alterar a classe de lixiviação de tebuthiuron e hexazinona em curto prazo, quando considerado o efeito do aging, a presença de biocarvão de palha de cana-de-açúcar 550°C (PC550) no solo, independentemente da granulometria, pode auxiliar no manejo de herbicidas com elevada mobilidade, especialmente em solos de textura arenosa e com baixo teor de carbono. Neste caso, o herbicida tebuthiuron teve sua classificação alterada de \"molécula lixiviável\" (Kd,app < 5,0 L kg-1) para \"molécula não-lixiviável\" (Kd,app > 5,0 L kg-1). No entanto, o biocarvão de dejeto de galinha 350°C (DG350) aumenta o COD do solo, resultando na diminuição da sorção dos herbicidas. A adição dos biocarvões PC550 e DG350 ao solo não modificam a eficiência de controle de braquiária por moléculas altamente solúveis. Doses a partir das doses recomendadas em campo promovem controle eficiente, independentemente da presença ou não de biocarvão no solo. Tebuthiuron e hexazinona são moléculas recalcitrantes no ambiente, sendo muito baixas suas taxas de mineralização e de dissipação, tanto na presença como na ausência dos biocarvões PC550 e DG350. A presença de biocarvão no solo pouco influenciou a dissipação dessas moléculas. Os biocarvões PC550 e DG350 diminuem o potencial de lixiviação da hexazinona no solo de textura areia franca, mas não afetam o movimento vertical do tebuthiuron nas mesmas condições. Apesar do menor potencial para degradação de tebuthiuron e hexazinona em relação à epoxidação de hidrocarbonetos, a inserção do biocarvão para a síntese de catalisadores mostrou-se eficiente e permitiu o emprego deste material em processos de catálise industrial e ambiental, podendo auxiliar para o manejo da remediação de poluentes e contribuindo para expandir o uso do biocarvão. / Biochar amendments to soil has been claimed as a practice with agricultural and environmental advantages. Due to its high reactivity, biochar can interact with organic and inorganic soil contaminants, reducing the pollution potential of toxic elements and pesticides. However, pre-emergent herbicides efficacy can be negatively affected by biochar additions to the soil, which may impose higher doses and increase the environmental contamination risk. In addition, there may be increasing in the pesticide\'s persistence due to retention and lower availability of the molecules induced by biochar amendment to the soil. The interactions between biochar and the pesticides depend on the characteristics of the soil and the herbicide itself, besides the aging and the biochar\'s properties (biomass, pyrolysis T°C and granulometry). Tebuthiuron and hexazinone are herbicides with leaching potential and may have their fate modified due to the presence of biochar in the soil. These molecules have a high half-life time (t1/2) and biodegrade slowly in the environment. Thus, advanced oxidative processes (AOP) can accelerate the decomposition of herbicides and can be a way of incorporate biochar in chemical processes towards pollutants dissipation. We aimed to evaluate the effects of biochar amendments on tebuthiuron and hexazinone dynamics in soils, and the specific objectives were: i) to verify the sorption behavior of these herbicides in response to biochar\'s amendment from different feedstock and pyrolysis T°C, including the influence of factors such as herbicide aging on the soil, biochar particle size and availability of dissolved organic carbon (DOC) in the soil promoted by biochar addition; ii) to evaluate if the interaction between the herbicides and the biochars affects braquiária (Brachiaria decumbens) control efficiency; iii) to analyze the biochars influence on the dissipation and leaching of tebuthiuron and hexazinone; and iv) to identify the potential use of biochar in AOP as heterogeneous metal catalysts support and as a source of iron for Fenton reactions, as well as to evaluate the performance of these materials in oxidative catalysis of hydrocarbons and herbicides. Sorption experiments, (checking the influence of biochars from different feedstocks and pyrolysis T°C, aging and granulometry, as well as accessing the differences among soil textures), and dissipation and leaching experiments were conducted using radiolabeled herbicides. In parallel, the release of DOC by the biochars and soils was quantified, whereas an experiment in a greenhouse for braquiária control was conducted. The biochars were also evaluated for use as metal catalysts supports and for Fenton reactions, evaluating their performance for herbicides and hydrocarbons oxidation. Although it does not change tebuthiuron and hexazinone leaching class in short term, when considering the aging, the sugarcane straw biochar pyrolyzed at 550°C (PC550), regardless of granulometry, may be useful in the management of high mobility herbicides, especially in sandy soils with low carbon content. In this case, tebuthiuron had its classification modified from \"leachable\" (Kd,app < 5.0 L kg-1) for \"non-leachable\" molecule (Kd,app > 5.0 L kg-1). However, the biochar from poultry manure pyrolyzed at 350°C (DG350) increases the DOC content in the soil, resulting in decreased sorption of the herbicides. The additions of PC550 and DG350 to the soil does not modify the control efficiency of braquiária by highly soluble molecules. Doses higher than the recommended ones promote efficient control, regardless of the presence or absence of biochar in the soil. Tebuthiuron and hexazinone are highly recalcitrant molecules in the environment, having low rates of mineralization and dissipation both in the presence or absence of the biochars PC550 and DG350. The biochar application to the soil barely influenced the herbicides dissipation. The biochars PC550 and DG350 decrease the leaching potential of hexazinone in the sandy soil, but do not affect tebuthiuron leaching in the same conditions. Despite the lower potential for tebuthiuron and hexazinone degradation in relation to the epoxidation of hydrocarbons potential, biochar insertion in the synthesis of catalysts has been proved to be efficient, allowing the use of these wastes in industrial and environmental catalysis processes for pollutants remediation purposes and helping to expand the biochar range of uses.

O objetivo do trabalho foi o de comparar a eficiência de aplicação de agroquímicos na cultura da soja utilizando diferentes pontas de pulverização para aplicações terrestres em alta velocidade. Foram avaliadas as pontas AXI 110 04 na velocidade de 15 km.h-1 (testemunha), APE Cinza, AXI 110 08, TD Hispeed 110 06 e AXI TWIN 120 06, todos na velocidade de deslocamento de 35 km.h-1. O volume de aplicação foi fixado em 120 L.ha-1. A eficiência de aplicação foi avaliada por dois métodos: Análise do percentual de cobertura utilizando marcador fluorescente e luz ultravioleta e análise de depósito através da recuperação e quantificação do corante azul brilhante FD&C N°1 por espectrofotometria. Ambas as analises foram feitas em amostras retiradas de três partes da planta: Superior, média e inferior. As pontas de pulverização mostraram padrões de cobertura e depósito diferenciados, de modo que na parte superior da planta, a cobertura foi favorecida por gotas mais finas e o depósito melhorado pelo uso de gotas médias. Nas demais partes da planta não houve diferença estatística entre os tratamentos tanto para cobertura quanto para depósito. A velocidade de deslocamento não interferiu na eficiência de aplicação para pontas com mesmo padrão de gota, permitindo o aumento da capacidade efetiva do pulverizador sem diminuição na qualidade da aplicação. / The aim of this study was to compare the efficiency of agrochemical application on soybean crop using different types of spray nozzles for ground applications in high travel speed. It was evaluated the nozzles AXI 110 04 with ground speed of 15 km.h-1 (reference), APE Grey, AXI 110 08, TD Hispeed 110 06 and AXI TWIN 120 06, all using travel speed of 35 km.h-1. The volume rate was fixed in 120L.ha-1. The application efficiency was evaluated by two different methods: Analysis of coverage area using fluorescent dye tracer and UV light and analysis of deposits through the recovery and quantification of bright blue tracer FD&C N°1 by Spectrophotometry. Both analysis were done in samples collected from three parts of the plant: Top, medium and bottom. The spray nozzles showed differences in coverage and deposit pattern, so in the top of the plant, the coverage was increased with smaller droplets and the deposit was increased with medium droplets. In the other parts of the plant, there was no statistical difference between the treatments both for coverage and deposit. The travel speed did not influence the application efficiency for droplet with the same droplet pattern, so it is possible to increase the effective capacity of the sprayer without decreasing the application quality.