Cette thèse vise à l'application d'un procédé électrochimique pour réaliser la destruction de composés organiques présents dans des effluents industriels avec pour objectif de réduire au maximum la pollution de ces effluents. La recherche s'est basée sur une étude approfondie d'un système d'électro-oxydation couplée où les composés organiques sont détruits, d'une part, par oxydation anodique sur une mousse de titane recouverte de SnO2-Sb2O3 et d'autre part, par oxydation indirecte à la cathode selon le mécanisme Electro-Fenton, avec un RVC (carbone vitreux réticulé) pour électrode, en présence de fer en solution et sous injection d'O2. Au cours de l'étude, basée essentiellement sur l'électrodestruction couplée et cathodique du phénol, on a analysé de manière systématique l'influence, sur l'efficacité de l'électro-oxydation, de paramètres électrochimiques (conductivité, densité de courant, pH, concentration en fer, débit d'injection de l'O2) et de paramètres physiques liés à la conception d'une cellule de type filtre-presse et à la nature tridimensionnelle des électrodes utilisées (épaisseur des électrodes, vitesse de circulation de l'électrolyte). Il en est ressorti un choix des conditions opératoires permettant de réduire, par électrodestruction cathodique, la DCO associée au phénol de 1.2 à 0.2 g/l pour une consommation énergétique de 7.7 kWh/m³. La technique électrochimique a également été utilisée pour détruire des composés organiques réfractaires présents dans divers effluents industriels. Les résultats obtenus ont montré l'efficacité de cette technique quelle que soit la concentration en DCO de l'effluent. Néanmoins, d'un point de vue économique, le système d'électro-oxydation couplé, optimisé dans cette thèse, ne peut être envisagé que pour traiter des effluents à débit limité si leur concentration en DCO est relativement élevée ou, au contraire, pour traiter des effluents à débit élevé (500 m³/j) ayant une DCO relativement faible (100 à 500 mg/l). Dans ce dernier cas, une diminution de la DCO de 75 à 92 % peut être obtenue pour une consommation énergétique moyenne de 1 kWh/m³.

Thèse (Ph. D.)--Université Laval, 2009. / Bibliogr. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Thèse (Ph. D.)--Université Laval, 2003. / Bibliogr.: f. 173-181. Publié aussi en version électronique.

La producción mundial de jugos cítricos concentrados se estima en 2,6 millones de toneladas. El jugo de naranja representa el 88% del total. El mercado es liderizado por Brasil con el 50% del volumen elaborado, seguido por EEUU con el 40%. En Bolivia el mercado de frutas se encuentra en continuo crecimiento, tanto para importación como para consumo interno. Actualmente se comercializan bebidas a base de jugo de frutas tanto de importación como de fabricación nacional, las mismas que son sometidas a control por los Organismos Oficiales (Ministerio de Salud y Deportes, y el Servicio Nacional de Sanidad Agropecuaria e Inocuidad Alimentaria - SENASAG) bajo la Normativa Nacional e Internacional reconocida como es la Norma Boliviana y el Codex Alimentarius, al igual que todos los productos alimenticios para garantizar su calidad e inocuidad. El análisis laboratorial se basa principalmente en las determinaciones de parámetros fisicoquímicos que necesitan ser complementados con otros métodos analíticos (como: la Cuantificación de Prolina por Espectrofotometría, Indice de Formol y Cuantificación de Pectinas) propuestos en éste trabajo, capaces de determinar la genuinidad de jugos de naranja presentes en el comercio de la ciudad de La Paz, y así colaborar con los Organismos de Control para cumplir a cabalidad con la responsabilidad de garantizar que los productos consumidos por nuestra población cumplen con lo declarado.

This work integrates environmental concerns, highlighting the commitment of universities to the community in finding sustainable balance within social, cultural and environmental. The harmfulness of occupational and environmental effluents in the laboratories of morphology is one of the clearest among the sectors of universities, enhanced by the elimination of a solution containing formaldehyde, characterized by high concentration of organic matter that causes a drastic reduction of oxygen in the aquatic environment. The morphological preservation can be accomplished by various methods, but surely the use of formaldehyde is still significant due to its efficiency and lower cost. The main focus of work is the search for relevant procedures in the laboratory so as to enable the reuse of these solutions containing formaldehyde, reducing the volume of wastewater pollution and the costs relating to the procedures for preservation of anatomical specimens. In the laboratory were analyzed six tanks that store human bodies, dogs and sheep, each containing approximately 1000 L of formaldehyde solution initially prepared at 10%. The characterization of the solutions obtained as parameters relevant to COD (chemical oxygen demand), ranging from 5222 mg/L and 8600 mg/L, and pH between 3.9 and 4.7 and total solids found up to 7,415 mg/L. Parameters such as N (total nitrogen) and oils and greases were also analyzed, and the concentration of formaldehyde and microbiological evaluation of the tanks. Purification processes were studied for these solutions, in order to enable their reuse, starting with the filtration of the solution, which turned out to be a quick process, but insufficient to result. We chose to add the distillation process, with temperatures ranging between 60-100◦C, was observed to be possible there use of formaldehyde solutions through tested processes. It was also found that the recycling process must be premised on the accuracy in the preparation of parts, quality control of the solution recommended in the routine, with optimum concentration of formaldehyde and pH to prevent growth of microorganisms, as well as the ideal base structure of the entire laboratory, allowing the occupational safety of its users. / O presente trabalho integra-se às preocupações ambientais, ressaltando o compromisso das universidades com a comunidade na busca de equilíbrio sustentável no âmbito social, cultural e ambiental. A nocividade ambiental e ocupacional dos efluentes nos laboratórios de anatomia é uma das mais nítidas entre os setores das universidades, intensificada pela eliminação da solução contendo formol, caracterizada pela alta concentração de matéria orgânica que provoca uma redução drástica de oxigênio presentes no ambiente aquático. A preservação morfológica pode ser realizada por vários métodos, mas sem dúvida o uso de formol ainda é significativo devido à sua eficiência e menor custo. O objetivo principal do trabalho é a busca de processos aplicáveis no laboratório, de modo a viabilizar a reutilização destas soluções contendo formol, reduzindo o volume de águas residuais poluidoras e os custos referentes aos procedimentos de conservação das peças anatômicas. No laboratório foram analisados seis tanques que armazenam peças humanas, de caninos e ovinos, cada um contendo aproximadamente 1000 L de solução de formaldeído inicialmente preparados a 10%. Na caracterização das soluções obteve-se como parâmetros relevantes a DQO (demanda química de oxigênio), com variação entre 5222 mg/L e 8600 mg/L, além do pH entre 3,9 e 4,7 e sólidos totais encontrados de até 7415 mg/L. Parâmetros como N (nitrogênio total) e óleos e graxas também foram analisados, além da concentração de formaldeído e acompanhamento microbiológico dos tanques. Foram estudados processos de purificação para estas soluções, de forma a possibilitar seu reuso, iniciando-se pela filtração da solução, a qual se mostrou ser um processo rápido, porém insuficiente para resultado esperado. Optou-se em agregar o processo de destilação, com temperaturas variando entre 60◦C e 100◦C, constatando-se ser possível o reaproveitamento do formol das soluções através dos processos testados. Verificou-se ainda que, o processo de reaproveitamento deve ter como premissas o rigor na preparação de peças, controle de qualidade da solução preconizada na rotina, com concentração ótima de formol e pH de modo a evitar crescimento de microorganismos, além da base ideal da estrutura de todo laboratório, permitindo a segurança ocupacional de seus usuários.

Submitted by RAFAEL AUGUSTO PINHOLATI EUGENIO null (rafael.pinholati@duratex.com.br) on 2016-12-06T23:33:20Z No. of bitstreams: 1 DISSERTAÇÃO RAFAEL - MESTRADO Rev 4.pdf: 3957807 bytes, checksum: 74c157bc6d300c719cca57459b4455da (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-09T12:54:47Z (GMT) No. of bitstreams: 1 eugenio_rap_me_bauru.pdf: 3957807 bytes, checksum: 74c157bc6d300c719cca57459b4455da (MD5) / Made available in DSpace on 2016-12-09T12:54:47Z (GMT). No. of bitstreams: 1 eugenio_rap_me_bauru.pdf: 3957807 bytes, checksum: 74c157bc6d300c719cca57459b4455da (MD5) Previous issue date: 2016-12-02 / O trabalho consistiu na produção de painéis de MDF (Medium Density Fiberboard) em escala laboratorial utilizando o adesivo PVA (Poliacetato de Vinila), variando suas concentrações e realizando misturas com a resina comumente empregada neste processo, o adesivo a base de uréia-fomaldeído, onde foi avaliado além das características físicas e mecânicas dos painéis produzidos, também teve o intuito de verificar o desprendimento de formaldeído para o ambiente quando aplicado juntamente com a resina uréia-fomaldeído, e a avaliação dos perfis de densidades dos traços. As amostras foram confeccionadas com fibra de eucalipto, onde as dosagens do adesivo PVA seguiram as seguintes proporções: 30%, 50% e 70%, e para efeito de comparação com as amostras produzidas com a mistura de PVA foram fabricadas provas em branco com 100% uréia-formaldeído. No total foram produzidas 16 amostras, quatro painéis de cada traço, e retirados os corpos de prova que posteriormente foram avaliados conforme a NBR 15316-2:2015 para as condições secas. Todos os insumos foram fornecidos pelo fabricante de painéis Duratex SA, e os testes foram realizados nos laboratórios da empresa. O adesivo PVA mostrou-se bastante favorável, apresentando grande compatibilidade com os demais componentes da formulação, apresentando potencial para fabricação de MDF. Diversos traços conseguiram atender os requisitos da norma, com destaque para módulo de ruptura (MOR), módulo de elasticidade (MOE), obtidos atraves do ensaio de flexão estática, e o teor de umidade. Houve também uma discreta redução na emissão de formol em dois traços (T3 e T4), e na avaliação dos perfis de densidade foi constatado que a formulação dos traços não impactou nas densidades médias da espessura dos painéis. / The work consisted in the production of MDF (Medium Density Fiberboard) in laboratory scale using PVA adhesive (Polyacetate Vinyl Chloride), varying their concentrations and performing mixtures with commonly used resin in this process, the adhesive base of ureafomaldehyde, which was evaluated in addition to the physical and mechanical characteristics of the panels produced, also aimed to check the formaldehyde release to the environment when applied together with resin urea-fomaldehyde, and evaluation of the densities of the features profiles. The samples were made from eucalyptus fibers where PVA adhesive doses followed the following proportions: 30%, 50% and 70%, and for the purpose of comparison with the samples produced with the mixture of PVA blank tests were made with 100 % ureaformaldehyde. In total, we produced 16 samples, four panels of each stroke, and removed the specimens which were then evaluated according to NBR 15316-2: 2015 for dry conditions. All inputs were provided by the panel manufacturer Duratex SA, and the tests were performed in the company's laboratories. PVA adhesive proved to be very favorable, with high compatibility with the other components of the formulation, with potential for the production of MDF. Many features were able to meet the standard requirements, particularly modulus of rupture (MOR), modulus of elasticity (MOE), obtained through the bending, and moisture content test. There was also a slight reduction in formaldehyde emissions by two dashes (T3 and T4), and evaluation of density profiles was found that the formulation of the traits did not affect the average thickness of the thickness of the panels.

L’objectif de ce travail consiste à recycler les boues secondaires (BS) et explorer leur potentiel comme co-adhésif de l’urée-formaldéhyde (UF) dans la fabrication des panneaux de particules. Nous avons posé l’hypothèse qu’il est possible de valoriser les BS comme co-adhésifs pour la fabrication de panneaux de particules. Deux approches ont été adoptées: La première consiste à évaluer les possibilités de modification de l’UF par l’ajout des BS pour synthétiser un nouvel adhésif. Les résultats ont montré que le temps de polymérisation de la résine est très court et nous avons conclu que cette approche n’est pas applicable à l’échelle industrielle. Bien que la première approche ait été rejetée, des conclusions peuvent en être tirées. Premièrement, les caractéristiques des BS varient avec le procédé papetier, l’usine d’origine et le temps d’échantillonnage. Deuxièmement, les thermogrammes d’analyses par calorimétrie différentielle à balayage (DSC) montrent que l’influence de la BS sur la cuisson de l’UF est importante. Troisièmement, les analyses de résonance magnétique nucléaire (RMN) montrent qu’il existe un rapport optimal entre la BS du procédé chimico-thermoméchanique provenant de Bowater (PCTM (B)) et l’UF. La deuxième approche consiste à introduire in-situ les BS dans les panneaux à différentes proportions. Cette approche est techniquement faisable et a été testée avec différents types de BS (PCTM, thermo-mécanique (PTM) et kraft). Un dispositif expérimental a été mis en place pour évaluer le potentiel des BS comme co-adhésifs. Les facteurs de variation choisis sont la teneur en UF (3 niveaux), la source des BS (3 sources) et la proportion des BS (3 proportions). Il existe un ratio optimal de BS/UF selon les valeurs des cohésions internes (CI) des panneaux d’essais préliminaires. L’ajout de BS dans les panneaux ne nuit pas à la CI et peut même en entrainer une amélioration dans certains cas. La plupart des propriétés mécaniques ne sont pas influencées négativement par l’ajout des BS. Par contre, la stabilité dimensionnelle en est affectée négativement. Le principal avantage de l’utilisation des BS est qu’elles permettent de minimiser l’empreinte écologique du procédé de fabrication tout en provoquant une diminution des émissions de formaldéhyde (EF) des panneaux. / The objective of this work is to recycle secondary sludge (SS) and explore its potential as co-adhesive for Urea-formaldehyde (UF) adhesives used in particleboard manufacturing. We hypothesized that it is possible to use the SS as co-adhesive for the manufacture of composite panels made of wood particles. First, we modified UF resin by the addition of SS to synthesize a new co-adhesive. The results of the first approach showed that the curing time of the resin is very short and it was concluded that this approach is not applicable on an industrial scale. Although the first approach is rejected, some conclusions can be drawn: 1) The characteristics of the SS vary with the papermaking process, the plant and the sampling time. 2) Dynamic scanning calorimetry (DSC) thermograms show that the influence of SS on UF cure is noticeable. 3) Nuclear magnetic resonance (NMR) showed that there is an optimal ratio between the chemi-thermo-mechanical pulping CTMP (B) SS and UF. The second approach is to add SS in-situ in the process of panel making in different proportions. This approach is technically feasible and has been tested with SS from the three different sources (TMP, CTMP and Kraft). Preliminary trials were done. Then, a final experimental dispositive was set up to evaluate the potential of SS from these different processes as co-adhesives. Factors are the UF resin content (3 levels), the SS source (3 sources) and the proportion of SS (3 proportions). There was an optimal ratio of SS/UF according to the values of internal bond (IB) of particleboards from the preliminary trials. SS cannot be used as an adhesive alone for particleboards. In general, results of this study indicated that the use of SS from three different pulping processes as co-adhesive have several advantages including the possibility of manufacturing particleboards at reduced urea formaldehyde (UF) resin content and wood particles content, value-added utilization of pulp and paper sludge and, especially, reduction in formaldehyde emissions. The reduction of formaldehyde emission with the recycling of SS as co-adhesive has the most significant environmental benefit.

L'objectif de cette recherche était de mettre au point une technique permettant la visualisation des résines aminoplastes sur et dans les fibres de bois de panneaux de moyenne densité (MDF). Cette technique devait à la fois permettre la mesure de la profondeur de pénétration des résines urée-formaldéhyde (UF) et urée-mélamineformaldéhyde (UMF) et l'évaluation de leur distribution sur la surface des fibres. Les systèmes d'encollages étudiés furent de type sec (mélangeur rotatif) et humide (mélangeur tubulaire). La présence de résine dans la paroi des fibres fut mise en évidence , par microscope confocal à balayage laser (MCBL) pour les deux systèmes. La pénétration de la résine peut être expliquée par la force d'ascension capillaire qui pousse les molécules de la résine dans les différents pores de la fibre lors de l'encollage. Les vitesses de pénétration n'ont pu être mesurées puisque les temps alloués aux mélanges furent suffisants pour que la pénétration soit maximale pour tous les échantillons. Nous avons remarqué que la profondeur de la pénétration dépend fortement du système d'encollage choisi. Le système d'encollage en ligne (tubulaire) présente l'avantage de mieux distribuer la résine sur la fibre avec une moyenne de 22% de la surface couverte. Cependant, l'humidité et la chaleur provoquent une pénétration plus importante de résine dans les parois cellulaires. Pour les mélangeurs humides, la profondeur maximale de pénétration correspond à l'épaisseur de la paroi cellulaire. La modélisation de la pénétration de la résine ne fut réalisée que pour les mélanges à sec où la profondeur moyenne de pénétration est de l'ordre d'un ou deux microns. En divisant cette profondeur par le temps de mélange le plus court, nous obtenons une approximation de la vitesse de pénétration. Les vitesses proposées par le modèle sont du même ordre de grandeur. Finalement, l'utilisation d'un microscope à force atomique (MFA) permit de visualiser la microstructure des fibres d'épinette préparées selon le procédé MDF. La paroi secondaire 1 (S1) et la lamelle moyenne (LM) sont très poreuses en comparaison avec la couche secondaire 2 (S2). Les pores de la paroi SI et de la LM sont de l'ordre de 20 nm en diamètre et sont le résultat d'une organisation aléatoire de petits agrégats de fibrilles. Les fibrilles de la paroi S2 forment des agrégats plus larges et enlignées selon l'axe longitudinal de la fibre. Les longs pores de cette paroi sont de l'ordre de 2-4 nm de large et ne peuvent être représentés par le MFA

La recherche dans le domaine de la prise en charge de la douleur, notamment chronique, a un besoind’innovation car les traitements disponibles à l’heure actuelle sont pour la plupart anciens et souventliés à des effets indésirables. Il est maintenant admis que les études précliniques de la douleur ont denombreuses limites : pertinence des modèles, utilisation d’une stimulation douloureuse surajoutée,détermination d’un simple seuil ou délai, prise en compte de la seule composante sensoridiscriminative…De ce fait, certaines molécules efficaces chez l’animal et donc prometteuses, n’ontpas eu les effets escomptés chez l’homme. La base de notre travail de recherche s’attache donc àproposer de nouvelles méthodes d’appréciation de la douleur chronique chez l’animal en prenant encompte ses aspects multidimensionnels. De nombreuses études ont mis en évidence une altération dela qualité de vie chez des patients atteints de douleur chronique. Cette altération se caractérisenotamment par des perturbations émotionnelles et cognitives. Ces paramètres ne sont pas toujours prisen compte chez l’animal dans l’évaluation de traitements antalgiques mais pourrdouleurnt amener denouvelles possibilités et perspectives précliniques. Notre travail a consisté à étudier l’impact de ladouleur sur les comportements spontanés (automatisation du test au formol), la composanteémotionnelle et les capacités cognitives chez le rongeur. Il a été complété par l’exploration du rôle del’amygdale dans les mécanismes impliqués dans ces modifications comportementales.L’amélioration du test au formol a été réalisée dans le but de visualiser au mieux les comportementsspécifiques observés lors d’une douleur aiguë de type inflammatoire. Notre adaptation a permis, chezles mêmes animaux, de pouvoir dissocier l’effet antalgique et l’effet sédatif d’une molécule à l’aided’une méthode automatisée plus rapide et moins subjective.Parallèlement, nous avons apprécié l’impact de la douleur chronique sur la composante émotionnelleet les performances cognitives dans deux modèles de douleur chronique (inflammatoire etneuropathique). Les animaux souffrant de douleur chronique inflammatoire présentent desperturbations plus importantes que les animaux neuropathiques, perturbations pouvant être amélioréespar un traitement pharmacologique. Des études mécanistiques utilisant des micro-injections demorphine au niveau de l’amygdale ont souligné une implication importante du complexe basolatéraldans ces composantes émotionnelles et cognitives de la douleur.Ces nouvelles approches comportementales pourrdouleurnt permettre de mieux caractériser l’impact globalde la douleur chronique chez l’animal et de compléter la batterie de tests couramment utilisés enpréclinique. Ceci pourrait déboucher sur une transposition plus réaliste des résultats obtenus chezl’animal à l’homme, et donc conduire à une meilleure prédictibilité clinique de l’efficacité destraitements. Enfin, la mise en évidence de nouvelles cibles thérapeutiques innovantes implique l’étudedes mécanismes responsables de ces altérations comportementales. / Research in the field of pain management, including chronic pain management, needs innovationbecause available treatments are mostly old and often associated with many side effects. It is now wellrecognized that preclinical studies on pain have many limitations: the relevance of the models, the useof imposed painful stimulations, determination of simple thresholds or delays, taking into account thesensory-discriminative component of pain alone… Indeed, some molecules that are efficient inanimals and that are considered as promising, didn’t have the desired effect in humans. Therefore, thebasis of our research aims to propose new methods to assess chronic pain in animals taking intoaccount its multidimensional aspects. Many studies have shown impaired quality of life in patientssuffering from chronic pain. This alteration is characterized by emotional and cognitive disturbances.These components of pain are not always taken into account in animal when studying analgesictreatments, but could bring new preclinical possibilities and perspectives. Our work consisted instudying the impact of pain on spontaneous behaviours (automated formalin test), emotionalcomponent and cognitive capacities in rodents. This work has been completed by the exploration ofthe role of the amygdala in the mechanisms underlying those behavioural modifications.Improvement of the formalin test was conducted in order to better visualize the specific behaviorsobserved during an acute inflammatory pain. Our adaptation has allowed dissociating the analgesicand sedative effect of a molecule in a same animal, using an automated method which is faster and lesssubjective than the manual method.In the meantime, we assessed the impact of chronic pain on the emotional and cognitive performancesin two models of chronic pain (inflammatory and neuropathic). Animals suffering from chronicinflammatory pain have more important impairments than animal suffering from neuropathic pain,impairments that can be improved with a pharmacological treatment. Mechanistic studies using microinjectionsof morphine in the amygdala have emphasized an important involvement of the basolateralcomplex in these emotional and cognitive components of pain.These new behavioural approaches may help better characterize the overall impact of chronic pain inanimals and complete the battery of tests commonly used in preclinical studies. This could lead to amore realistic transposition of the results obtained from animals to humans, and thus lead to betterpredictability for the clinical efficacy of treatments. Finally, the identification of new targets forinnovative therapies involves the study of mechanisms responsible for these behavioral impairments.

Dissertação(mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Aqüicultura, Instituto de Oceanografia, 2010. / Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2012-07-27T17:53:57Z No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2012-07-27T18:31:32Z (GMT) No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) / Made available in DSpace on 2012-07-27T18:31:32Z (GMT). No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) Previous issue date: 2010 / Considerando a importância da tainha Mugil platanus Günther, 1880 como fonte de alimento e alternativa de emprego para comunidades locais, este estudo objetiva estabelecer a fauna parasitária e a forma de utilização de M. platanus pelos parasitos, definir a toxicidade do formol e a concentração eficaz para erradicar ou mesmo minimizar a parasitose e, por último, verificar quais as lesões causadas pelo formol e/ou pelos parasitos em juvenis da tainha M. platanus. Quarenta juvenis de tainha M. platanus com peso 1 ± 0,26g e comprimento 4,1 ± 0,4cm foram coletados em arroio na Praia do Cassino, no município de Rio Grande - RS - Brasil. Os hospedeiros foram necropsiados e os ectoparasitos foram fixados em formol 5 %, corados, clarificados e posteriormente montados em lâminas permanentes com bálsamo do Canadá para identificação. Outros foram montados em meio de Grey-Wess para verificação de estruturas esclerotizadas. Os endoparasitos foram fixados em AFA e corados em carmim de Semichon, clarificados e posteriormente montados em lâminas permanentes com bálsamo do Canadá para identificação. Foram identificados Ligophorus cf. uruguayense (Monogenoidea: Ancyrocephalidae) e Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) nas brânquias. Foram reportados Digenea e Nematoda nos intestinos. A prevalência (P %) de L. cf. uruguayense foi 100 %, a intensidade de infestação (II) variou entre 2 e 110, a intensidade média de infestação (IMI) foi 23,4 e a abundância média (AX) foi 23,4. A prevalência (P %) de S. cf. platyorchis foi 10 %, a intensidade de infestação (II) variou entre 1 e 3, a intensidade média de infestação (IMI) foi 1,5 e a abundância média (AX) foi 0,15. A prevalência (P %) de Digenea foi 92,5 %, a intensidade de infecção (II) variou entre 1 e 40, a intensidade média de infecção (IMI) foi 2,67 e a abundância média (AX) foi 2,47. A prevalência (P %) de Nematoda foi 6,7 %, a intensidade de infecção (II) foi 1, a intensidade média de infecção (IMI) foi 1 e a abundância média (AX) foi 0,07. Os elevados índices de infestação por Monogenoidea e de infecção por Digenea apontam o potencial dano que estes parasitos podem representar nos cultivos. Para analisar a toxicidade do formol para M. platanus e a eficácia deste quimioterápico no controle de parasitos, foram realizados quatro experimentos. Os juvenis foram mantidos em béqueres de 1 L, densidade 8 peixes/ béquer, temperatura da água 21 °C, fotoperíodo 12 h, salinidade da água 5, aeração suave e constante e mantidos em jejum e em observação para análise da sobrevivência. Para determinar a toxicidade do formol aos juvenis foi realizado um teste de toxicidade aguda 96 h, em que os tratamentos foram um controle (sem adição de formol na água) mais 5 concentrações: T1 (5), T2 (8), T3 (15), T4 (30) e T5 (50) mg/L de formol em triplicata. Para verificar a eficácia no controle parasitário foi administrado um banho profilático de 1 h de formol, em que os tratamentos foram um controle (sem adição de formol na água) mais 5 concentrações: T1 (25), T2 (50), T3 (100), T4 (150) e T5 (200) mg/L de formol na água em triplicata. No teste letal de toxicidade aguda, não houve diferença significativa (P > 0,05) entre as réplicas e a temperatura (°C), salinidade, pH, O2 dissolvido na água (mg/L), amônia total (mg/L) e a concentração letal mediana a 50 % (CL50) em 96 h foi estimada em 20,77 mg/L de formol. No banho profilático com formalina durante 1 h, todos os tratamentos foram eficientes eliminando 100 % dos parasitos, exceto no tratamento com 25 mg/L, em que foram identificados L. cf. uruguayense em 13,33 % dos peixes. Houve 100 % de sobrevivência dos hospedeiros em todos os tratamentos, exceto na concentração 200 mg/L em que a sobrevivência foi 87,5 %. Banhos com 25 mg/L de formol durante 1 h são indicados para o controle de S. cf. platyorchis e 50 mg/L para o controle de L. cf. uruguayense, por possuir menor concentração de formol e alta sobrevivência dos peixes. Porém, nenhuma das concentrações testadas é eficiente no controle de endoparasitos. Por último, para determinar as lesões causadas nas brânquias de formol e/ou pelos Monogenoidea, três peixes de cada tratamento, provindos do banho profilático com formol para o controle de parasitoses foram encaminhados para análise histológica. Foi observado que o aumento da concentração de formol causou lesões mais graves nas brânquias. Foi observada hiperplasia leve nos animais mantidos como controle, desprendimento do epitélio respiratório no T2, hiperplasia moderada no T3, aumento da atividade opercular no T4 e necrose, natação errática e mortalidade no T5. Os resultados histopatológicos deste estudo mostram que banhos de 50 mg/L de formol durante 1 hora podem ser aplicados em juvenis de M. platanus para o controle de Monogenoidea, pois nesta concentração, as lesões histológicas causadas nos hospedeiros são leves e a sobrevivência dos juvenis é alta. / Considering the importance of mullet Mugil platanus Günther, 1880 as a food source and alternative employment for local communities, this study aims to establish the parasitic fauna and how M. platanus use by the parasites to define the toxicity of formaldehyde and the effective concentration to minimize or even eradicate the parasites and, lastly, to evaluate the damages caused by formaldehyde and/or parasites in the juvenile mullet M. platanus. Forty juvenile mullet M. platanus weighing 1 ± 0.26 g and length 4.1 ± 0.4 cm were collected in the stream at Cassino Beach, in Rio Grande - RS - Brazil. The hosts were necropsied and the parasites were fixed in 5 % formaldehyde, stained, clarified and subsequently mounted on permanent slides with Canada balsam for identification. Others parasites specimens were mounted in the middle of Gray-Wess to check sclerotic structures. The endoparasites were fixed in AFA and stained with carmine Semichon, clarified and subsequently mounted on permanent slides with Canada balsam for identification. It was identified Ligophorus cf. uruguayense (Ancyrocephalidae) and Solostamenides cf. platyorchis (Microcotylidae) in the gills. It was reported Digenea and Nematoda in the intestines. The prevalence (P %) of L. cf. uruguayense was 100 %, the intensity of infestation (II) ranged between 2 and 110, the average intensity of infestation (IMI) was 23.4 and average abundance (AX) was 23.4. The prevalence (P %) of S. cf. platyorchis was 10 %, the intensity of infestation (II) ranged between 1 and 3, the average intensity of infestation (IMI) was 1.5 and mean abundance (AX) was 0.15. The prevalence (P %) of Digenea was 92.5 %, the intensity of infection (II) ranged between 1 and 40, the average intensity of infection (IMI) was 2.67 and the average abundance (AX) was 2.47. The prevalence (P %) of Nematoda was 6.7 %, the intensity of infection (II) was 1, the mean intensity of infection (IMI) was 1 and mean abundance (AX) was 0.07. High levels of infestation Monogenoidea and infection Digenea point to the potential damage that these bodies may represent the cultures. To analyze the toxicity of formalin to M. platanus and efficacy of chemotherapy in the control of parasites, four experiments were conducted. Juveniles were kept in beakers of 1 liter, density 8 fish/beaker, water temperature 21 °C, 12 h photoperiod, water salinity 5, smooth and constant aeration and maintained at fasting and under observation for survival analysis. To determine the toxicity of formaldehyde was carried out acute toxicity test, in which the treatments were a control (no added formaldehyde in water) and 5 more concentrations: T1 (5), T2 (8), T3 (15), T4 (30) and T5 (50) mg/L of formaldehyde in triplicate. To verify the effectiveness of formaldehyde on parasite control was given a bath of 1 h of the substance in which the treatments were a control (no added formaldehyde in water) and 5 more concentrations of formaldehyde: T1 (25), T2 (50) , T3 (100), T4 (150) and T5 (200) mg/L of formaldehyde in water in triplicate. In the test lethal acute toxicity, no significant difference (P > 0.05) between treatment and temperature (°C), salinity, pH, dissolved O2 in water (mg/L), total ammonia (mg/L) and lethal concentration to 50 % of the sample (LC50) at 96 h was estimated to be 20.77 mg/L of formaldehyde. In the final bath of formaldehyde for 1 h, all treatments were efficient by eliminating 100 % of parasites, except for treatment with 25 mg/L, which were identified L. cf. uruguayense in 13.33 % of the fish. There was 100 % survival of the hosts in all treatments, except at the concentration 200 mg/L in which survival was 87.5 %. Baths with 25 mg/L formaldehyde for 1 h are indicated for the control of S. cf. platyorchis and 50 mg/L for the control of L. cf. uruguayense, because it has lower concentration of formaldehyde and high survival of fish. However, none of the concentrations tested is effective against endoparasites. Finally, to determine the damage caused by formaldehyde in the gills and/or the Monogenoidea, three fish per treatment, coming the final bath of formaldehyde to control parasitosis were sent for histological analysis. It was observed that increasing the concentration of formaldehyde caused more severe lesions in the gills. Mild hyperplasia was observed in animals kept as control, detachment of the respiratory epithelium in T2, moderate hyperplasia in T3, increased opercular activity in T4 and necrosis, erratic swimming and mortality in T5. Histopathological results of this study show that bath of formaldehyde at a concentration of 50 mg/L for 1 hour can be applied to juveniles of M. platanus to control Monogenoidea, because in this concentration, histological lesions caused in the host are lightweight and survival of juveniles is high.