O sistema estuarino Timonha / Ubatuba està localizado na divisa dos Estados do Cearà e PiauÃ, 500 km à noroeste de Fortaleza, nordeste do Brasil. A bacia hidrogrÃfica afluente ao sistema estuarino ocupa uma Ãrea de 2.165 km2. A porÃÃo norte està inserida em terrenos PaleozÃicos do Planalto da Ibiapaba, Embasamento Cristalino, FormaÃÃo Barreiras e depÃsitos QuatemÃrios enquanto que a porÃÃo sul està ~sentada sobre terrenos PrÃÂCambrianos com exumaÃÃes do GranitÃide Chaval. A procura por Ãreas para expansÃo da carcinicultura, crescimento urbano e desenvolvimento agroindustrial pode representar o comprometimento da saÃde desse ecossistema, considerado o maior do Estado do Cearà Estes impactos tendem a se incrementar com a construÃÃo e operaÃÃo do aÃude pÃblico ItaÃna, com capacidade de armazenamento de 77,5 milhÃes de m3, localizado 17 km à montante da Ãrea estuarina. A par destes problemas e considerando as hipÃteses de minimizÃÂlos ou elimina-Ios, este trabalho considerou os elementos estruturais, dinÃmicos e controladores do estado de evoluÃÃo atual do sistema estuarino, contribuindo com informaÃÃes Ãteis para o uso adequado e sustentÃvel da Ãrea. Os processos hidrodinÃmicos e sedimentolÃgicos estÃo subordinados, sobretudo, ao regime sazonal das precipitaÃÃes onde somam-se processos de assoreamento da foz pela deriva litorÃnea e oscilaÃÃo da marÃ. A construÃÃo do reservatÃrio implicou na reduÃÃo de 91% da descarga fluvial do rio Timonha apresentando atualmente, uma vazÃo de 5,6 X 108 m3 ao longo de um ano. A vazÃo regularizada nÃo à suficiente para promover os processos de mistura e diluiÃÃo de sais, contribuindo para inversÃo da salinidade no perÃodo e estiagem. No perÃodo chuvoso, a salinidade do rio Timonha aumenta progressivamente em direÃÃo ao mar com regimes oscilando do limnÃtico  0,5) ao euhalino (30,0 à 40,0). Na estiagem, o regime à tipicamente euhalino com fortes indÃcios de hipersalinizaÃÃo (> 40,0). No Ubatuba, o regime salino variou de polihalino (18,0 à 30,0) a euhalino entre os perÃodos de chuva e estiagem. Os estuÃrios sÃo do tipo 2a no perÃodo chuvoso e do tipo Ia no perÃodo de estiagem. O balanÃo de sal do rio Timonha no perÃodo de chuva foi de + 0,3 t enquanto que no perÃodo de estiagem foi 0,01. No Ubatuba o balanÃo referente ao perÃodo de chuva foi de - 0,1 t e na estiagem foi de - 0,2 1. A profundidade mÃdia do sistema à de 5m com mÃximas observadas no Ubatuba. O substrato à formado predominantemente por areias mÃdias e sedimentos bioclÃsticos. O total de sedimentos exportados para deriva litorÃnea, ao longo de um ano, foi de 250 t enquanto que a carga importada foi de 150 1. O volume do prisma de marà no Timonha foi de aproximadamente 3,6 x 107 m3 e no rio Ubatuba 4) x 107 m3. Considerando o modelo simplificado, o tempo de residÃncia do Timonha à de 1 dia no perÃodo de chuva e 5 dias no de estiagem No Ubatuba esse tempo à de 0,5 dia no perÃodo chuvoso e 2 dias na estiagem Considerando o tempo de residÃncia calculado para cada segmento dos canais estuarinos dos rios Timonha e Ubatuba observa-se que o modelo linear nÃo à o mais representativo para anÃlise da capacidade de diluiÃÃo do sistema. Com base no modelo segmentado, observa-se que, no Timonha, a Ãrea situada entre 3,7 km e 7,0 km de distÃncia do mar assume forte tendÃncia à retenÃÃo de Ãgua, com tempo de residÃncia equivalente à aproximadamente uma semana. Essa Ãrea parece ser a mais inadequada à recepÃÃo de descarga direta de efluentes. Em comparaÃÃo com outros estuÃrios tropicais, o sistema apresenta uma boa capacidade de diluiÃÃo e baixo tempo residÃncia. A ausÃncia de monitoramento para a correÃÃo das vazÃes liberadas pelo AÃude ItaÃna em perÃodos de estiagem prolongados e os processos de assoreamento da foz poderÃo representar os principais vetores de comprometimento da capacidade de suporte do estuÃrio.

Since the demand for fresh potable water increases every year, it is important to have future water demand strategies in place. People expect a secure, high quality, water supply and the water supply industry is governed by increasingly stringent water quality guidelines and legislation. The Cape Metropolitan Area (CMA) faces the challenge of an increasing demand for fresh water in excess of the existing supply. The City is responsible for the planning and development of the local water supply resources as well as managing the water demand in the CMA and to supplement the water supply to the City of Cape Town from local sources. The ‘Voëlvlei Augmentation Scheme’ was identified as one of the options to augment the water supply to the CMA. This option would involve pumping winter water from the Berg River via a pipeline to the Voëlvlei water treatment plant (WTP). The Voëlvlei WTP was designed to treat water from the adjacent Voëlvlei Dam. This Voëlvlei WTP raw water has a higher turbidity and a lower colour in comparison to the Berg River water. The plant’s treatment conditions were optimized to remove this high turbidity. The Voëlvlei WTP raw water also contains a relatively high manganese concentration and coagulation therefore occurs at a high pH with ferric sulphate to remove the manganese during the initial stages of the water treatment process. As the quality of the Berg River water is different to that of the Voëlvlei WTP raw water, it might not be possible to treat the Berg River water at the Voëlvlei WTP using the plants current treatment parameters. The Berg River water could possibly be blended with the Voëlvlei WTP raw water before treatment at the WTP. If the Berg River water, or its blends, could not be treated at the Voëlvlei WTP using the plants current treatment parameters, then this water would have to be pre-treated before entering the plant. Various forms of pre-treatment could be used, e.g., conventional water treatment using either aluminium or ferric sulphate as primary coagulants or ion-exchange water treatment using the MIEX® resin or even a combination of both. The main objective of this study was to determine a treatment strategy for the Berg River water at the Voëlvlei WTP. It is therefore important to determine if the Berg River water could be treated at the Voëlvlei WTP using the current treatment regime. Also, if the Berg River water should be blended with the Voëlvlei WTP raw water, this study would determine which blend would be the most suited for treatment at the Voëlvlei WTP. If the Berg River water could not be treated directly at the Voëlvlei WTP, a pre-treatment strategy for this water should be determined. The cost of pretreatment of the Berg River water as compared to the cost of direct treatment at the Voëlvlei WTP should also be evaluated. In order to determine the best treatment strategy for the Berg River water at the Voëlvlei WTP, it was important to sample the Berg River water and the Voelvlei WTP raw water at regular intervals over a period of at least a year to determine its quality and the impact of seasonal changes. Various laboratory physical (e.g., turbidity) and chemical (e.g., total alkalinity) analyses were conducted on the Berg River water and Voëlvlei WTP raw water to determine its quality. The experimental procedure focused mainly on the Jar test which simulates the coagulation, flocculation and sedimentation processes at the Voëlvlei WTP. Jar tests were conducted on the Berg River water and the Voëlvlei WTP raw water using ferric sulphate and aluminium sulphate as coagulants to determine the optimum pH and optimum coagulant dosage concentration for each coagulant. The Berg River water was also blended with the Voëlvlei WTP raw water in three different proportions and Jar tests were conducted on these blends using ferric sulphate as the coagulant at a coagulation pH of 5.0 and a Fe3+ dosage of 5.0 mg/L. Jar tests were also conducted on these blends with the Voëlvlei WTP treatment parameters using ferric sulphate as the coagulant at a coagulation pH of 9.2 and a Fe3+ dosage of 3.5 mg/L. The analytical results showed a similar pattern for the characterization of the Berg River water and the Voëlvlei WTP raw water. The iron and aluminium concentrations were consistently low during the summer months with significant increases during the winter months. There were no significant seasonal impact on the UV absorbance and colour. The Jar test results of the Voëlvlei WTP raw water and the Berg River water with ferric sulphate as the coagulant showed an optimum Fe3+dosage of 3.0 to 4.0 mg/L and 4.0 to 6.0 mg/L, respectively, with an optimum coagulation pH range of 6.6 to 9.5 and 5.0 to 10.0, respectively. The Jar test results of the Voëlvlei WTP raw water and the Berg River water with aluminium sulphate as the coagulant showed an optimum Al3+ dosage of 2.5 to 3.0 mg/L and 4.0 to 5.0 mg/L, respectively, with an optimum coagulation pH of 6.0 to 7.0 and 6.0, respectively. The Jar test results obtained for all 3 blends were similar to each other. The UV absorbance of the treated water was consistently below the operational specification, while the turbidities were inconsistent and did not always comply with the SANS 241:2006 Specification (Class I) for drinking water. The iron of the treated water was also consistently above the specified value of <0.200 mg/L. The Jar tests conducted on all 3 blends, with the Voëlvlei WTP treatment parameters, also yielded similar results. The UV absorbance of the treated water was consistently above the maximum operational specification of 0.100, while the turbidities were also consistently above the SANS 241:2006 Specification of <1 NTU. Both ferric sulphate and aluminium sulphate can be used as coagulants to treat the Berg River water, although ferric sulphate would be the preferred choice due to its wide coagulation pH range and also because of differences in their health effects. The Voëlvlei WTP coagulates at a pH of 9.2 to remove turbidity and any manganese that might be present in the raw water. The manganese would not be removed at the low coagulation pH of aluminium sulphate. The specified treatment parameters, including the Voëlvlei WTP treatment parameters, used in treating the raw water blends were not effective and further investigation and research is necessary to determine its optimum treatment parameters. This study concluded that the Berg River water cannot be effectively treated at the Voëlvlei WTP using the plants treatment parameters, even if it is blended with the Voëlvlei WTP raw water. Therefore, the best treatment strategy for the Berg River water at the Voëlvlei WTP would be pre-treatment of the water before entering the Voëlvlei WTP. Although there are various ways of pre-treating the Berg River water, this study has identified the following possible pre-treatment strategies:<ul><li>pre-treatment with ferric sulphate and lime</li><li> pre-treatment with ferric sulphate and lime in conjunction with MIEX® resin</li><li> pre-treatment with MIEX® resin only</li></ul> Further research and investigation would be necessary to determine the best pretreatment strategy in terms of cost and efficiency. The pre-treated Berg River water would have to pass through the Voëlvlei WTP treatment process (i.e. high coagulation pH) to remove any manganese that might be present in the water. It is recommended that more samples should be taken at various points along the Berg River upstream of the Voëlvlei WTP over a longer period of time to compare the quality of water at these points in the river and also to monitor the effect of various run-off sites. Further research and investigation is necessary to determine the optimum treatment parameters for the Berg River water when blended with the Voëlvlei WTP raw water. Other blending ratios, different to those used in this study, should also be investigated. A more in-depth investigation is also necessary to determine the actual capital and operational costs for the pre-treatment of the Berg River water. / Dissertation (MSc)--University of Pretoria, 2011. / Chemical Engineering / unrestricted

Das Wasser der Elbe auf der Höhe von Dresden enthält anorganische Kolloidpartikel, deren Partikelgrößenverteilung nahezu den gesamten kolloidalen Definitionsbereich (1 nm bis 1 µm) überstreicht und die vor allem aus sekundär ausgeschiedener amorpher Kieselsäure sowie aus Oxyhydroxiden des Fe, Al und Mn bestehen. Als wichtigstes Schwermetall führen sie Zn. Ihre Konzentration liegt unter 5×10-1 mg/l, um etwa Faktor 30 unter der Konzentration der Schwebstoffe des Elbwassers (Partikel >1 µm). Wegen ihrer hohen spezifischen Oberfläche sind die Kolloidpartikel als potentielle Träger für Schadstoffe trotz dieser geringeren Massekonzentration nicht gegenüber den Schwebstoffen zu vernachlässigen. Die in der Elbe gemessene Partikelgrößenverteilung ähnelt derjenigen, die zu einem früheren Zeitpunkt im Rhein gefunden worden war. Auch die chemische Zusammensetzung der Kolloidpartikel in der Elbe ist der der Partikel des Rheins ähnlich. Die Konzentration der Kolloidpartikel in der Elbe war aber um Faktor 5 bis 10 höher als im Rhein. Grund für letzteres ist wahrscheinlich der höhere Gehalt des Elbwassers an gelöstem Kohlenstoff (DOC). Im "Bulk" eines Flusses sind kolloidgetragene Schadstoffe - anders als schwebstoffgetragene - vermutlich fast genauso mobil wie echt gelöste. Unterschiede zwischen den Transportgeschwindigkeiten der kolloidgetragenen und der echt gelösten Spurenstoffe treten in bestimmten Situationen auf, in denen das Wasser den "Bulk" eines Flusses verlässt (Sickerbereich unter dem Fluss, Ästuar). Es werden Schlussfolgerungen über die Rolle von Kolloidpartikeln im Ökosystem eines Flusses gezogen und noch bestehende Forschungsdesiderate benannt.

Yes / This paper focuses on the dispute over river Cauvery in Southern India. Among the causes of river water disputes are contested property rights, difficulty in enforcing such rights, conflict of uses and a lack of willingness to compromise. A co-operative outcome in such cases depends on several factors: asymmetry of power in a triadic relationship between a federal government and two riparian states (one upstream and one downstream). Other factors influencing co-operation are the extent to which the claims of river waters can be elevated from those of immediate riparian peoples to those of an entire state; the dominance of a masculine paradigm towards 'taming' river waters using 'hard' investments rather than 'soft' and decentralised alternatives. On the basis of district level data, the importance of river Cauvery to the hydrology, economy and polity of the two contesting states is examined. This analysis helps us to appreciate why the two riparian state governments have limited room to manouvre. Drawing from two brief case studies of Murray Darling Basin and recent litigation in the USA, and other international experiences of river water treaties, the paper identifies various implications for the resolution of Cauvery and other river water disputes.

M. Tech. (Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / A novel technology in the treatment of river water, which involves an electrochemical treatment technique to produce domestic or drinking water is being investigated using aluminium and iron electrodes in an electrochemical circuit. Coagulation and flocculation are traditional methods for the treatment of polluted water. Electrocoagulation presents a robust novel and innovative alternative in which a sacrificial metal anode treats water electrochemically. This has the major advantage of providing mainly active cations required for coagulation and flocculation, without increasing the salinity of the water. Electrocoagulation is a complex process with a multitude of mechanisms operating synergistically to remove pollutants from the water. A wide variety of opinions exist in the literature for key mechanisms. A lack of a systematic approach has resulted in a myriad of designs for electrocoagulation reactors without due consideration of the complexity of the system. A systematic, holistic approach is required to understand electrocoagulation and its controlling parameters. An electrocoagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium and/or iron electrodes. The water to be treated (river water) was subjected to coagulation, by Al(III) and Fe(II) ions dissolved from the electrodes, resulting in floes floating after being captured by hydrogen gas bubbles generated at the cathode surfaces. Apparent current efficiencies for AI and Fe dissolution as aqueous Al(III) and Fe(II) species at pH 6.5 and 7.8 were greater than unity. This was due to additional chemical reactions occurring parallel with electrochemical AI and Fe dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation plus reduction) currents at both anodes and cathodes. Investigation results illustrate the feasibility of ferrous and aluminium ion electrochemical treatment as being a successful method of water treatment. Better results were achieved under conditions of relatively high raw water alkalinity, relatively low raw water turbidity, and when high mixing energy conditions were available.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-10-19T15:59:43Z No. of bitstreams: 1 2016 - Laryssa Cristina Medina Azevedo.pdf: 3869837 bytes, checksum: 508d4054394209403e14c50fc5d2bc4b (MD5) / Made available in DSpace on 2016-10-19T15:59:43Z (GMT). No. of bitstreams: 1 2016 - Laryssa Cristina Medina Azevedo.pdf: 3869837 bytes, checksum: 508d4054394209403e14c50fc5d2bc4b (MD5) Previous issue date: 2016-01-23 / Water quality is related to the anthropogenic impact on water resources and their availability, and this quality is regulated by the National Environmental Council - CONAMA, through resolutions 357 of 2005 and 396 of 2008, from the boundaries quality standards of water bodies. The materials of organic origin, including natural polymers have an inherent tendency to degradation. The presence of oxidizable or hydrolysable groups in the chains of these polymers, in addition to hydrophobicity and hydrophilicity characteristics and degree of conformational flexibility of the chain are factors that contribute to the biodegradation of the polymer. Water pollution by hydrocarbons, including biodegradable polymers, can be an environment conducive to the presence of potentially degrading microorganisms from a variety of recalcitrant molecules released in the middle. The combination of different types of environmental effects can cause slow or fast decay, which depends on the predominant factor or degrading agent (photochemical, thermal, chemical, hydrolysis, oxidation, biodegradation). This work was carried out an investigation into the quality of water facilities (river water - RW distilled water - DW and water with nutrients - NW) after the biodegradation of polymeric blends and composites containing low density polyethylene (LDPE), thermoplastic starch (TPS), chitosan (Ch) Coconut fiber (CF). The samples were subjected to biodegradation test water in these media for a period of fifty-two days. After the test period may be seen that mixtures of TPS/Ch and TPS/CF undergone the process of biodegradation, confirmed the almost complete loss of their mass, increased conductivity, in spite of the turbidity values and the consumed oxygen concentration, decrease in the last days of rehearsal. As expected mixtures containing LDPE (LDPE/TPS, LDPE/TPS/Ch and LDPE/TPS/CF) showed less weight loss, and lower turbidity and O2 consumption in the chemical degradation of organic matter. Comparing the results of different means water, as expected, the results conductivity and pH of the river water (RW) were higher than the values found for the water with nutrients (NW) and distilled water (DW). The turbidity values and concentration of O2 consumed in the COD for the different blends containing LDPE as shown depended on the diffusion of water in the various polymeric materials and consequently influence the first stage of biodegradation, i.e., water penetration into the material surface attack of the chemical bonds of the amorphous phase and converting long chain of biodegradable polymers into smaller pieces and eventually into soluble fragments / A qualidade da ?gua est? relacionada com o impacto antropog?nico sobre os recursos h?dricos e sua disponibilidade, e essa qualidade ? regulamentada pelo Conselho Nacional do Meio Ambiente ? CONAMA, atrav?s das resolu??es 357 de 2005 e 396 de 2008, a partir do quadro dos limites dos padr?es de qualidade dos corpos h?dricos. Os materiais de origem org?nica, incluindo pol?meros naturais t?m uma tend?ncia inerente para degrada??o. A presen?a de grupos oxid?veis ou hidrolis?veis nas cadeias desses pol?meros, al?m das caracter?sticas de hidrofilicidade e hidrofobicidade e o grau de flexibilidade conformacional da cadeia s?o fatores que contribuem para a biodegrada??o do pol?mero. A polui??o das ?guas por hidrocarbonetos, incluindo pol?meros biodegrad?veis, pode ser um ambiente prop?cio ? presen?a de microrganismos potencialmente degradadores de uma variedade de mol?culas recalcitrantes liberadas no meio. A combina??o de diferentes tipos de efeitos ambientais pode causar deteriora??o r?pida ou lenta, a qual depende do fator predominante ou do agente degradante (fotoqu?mica, t?rmica, qu?mica, hidr?lise, oxida??o, biodegrada??o). Neste trabalho foi realizada uma investiga??o da qualidade de meios h?dricos (?gua de rio ? AR, ?gua destilada ? AD e ?gua com nutrientes ? AN) ap?s o ensaio de biodegrada??o de blendas e comp?sitos polim?ricos contendo polietileno de baixa densidade (PEBD), amido termopl?stico (TPS), quitosana (Q) e fibra de coco (FC). As amostras foram submetidas ao ensaio de biodegrada??o nestes meios h?dricos pelo per?odo de cinquenta e dois dias. Ap?s o per?odo de ensaio pode-se verificar que as misturas de TPS/Q e TPS/FC sofreram o processo de biodegrada??o, confirmado pela quase total perda de suas massas, aumento da condutividade, apesar dos valores de turbidez e da concentra??o de oxig?nio consumido, diminu?rem nos ?ltimos dias de ensaio. Como esperado as misturas contendo PEBD (PEBD/TPS, PEBD/TPS/Q e PEBD/TPS/FC) apresentaram menor perda de massa, al?m de menor turbidez e consumo de O2 na degrada??o qu?mica da mat?ria org?nica. Comparando os resultados dos diferentes meios h?dricos, como j? era esperado, os resultados valores de condutividade e pH da ?gua de rio (AR) foram maiores do que os valores encontrados para a ?gua com nutrientes (AN) e ?gua destilada (AD). Os valores de turbidez e DQO, para as diferentes misturas contendo PEBD, como mostrado, dependeram da difus?o da ?gua nos diferentes materiais polim?ricos e consequentemente influenciaram na primeira fase da biodegrada??o, isto ?, penetra??o da ?gua na superf?cie do material, ataque das liga??es qu?micas da fase amorfa e convers?o das longas cadeias doe pol?meros biodegrad?veis em partes menores, e, eventualmente, em fragmentos sol?veis

The intent of this thesis is to compare contingent valuation methods (CVM) and travel cost methods (TCM) to estimate consumer surplus for boaters and anglers in northern Utah. TCM results are about three times that of CVM. Several limitations are noted, specifically that CVM solicits given willingness to pay (WTP for specific reservoir sites. TCM analyzes aggregated trips to reservoirs with a wide array of site characteristics.

Diploma work that deals with topic of "Anti - flood measures on chosen parts of the Novohradka river" is divided into theoretical and practical treatise. Theoretical treatise contains specific section that deals with laws relating to flood solutions and general part that explains flood as such and everything it involves. Practical part sums up concrete proposed anti - flood measures but it also mentions personal suggestions and evaluations of so far executed measures. This work should especially attract attention of general public and representatives of interested parties.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-08-12T12:35:52Z No. of bitstreams: 1 Narciso Silva Leite Junior.pdf: 964909 bytes, checksum: d234d1169d74d0400bfd6c1088a39c58 (MD5) / Made available in DSpace on 2016-08-12T12:35:52Z (GMT). No. of bitstreams: 1 Narciso Silva Leite Junior.pdf: 964909 bytes, checksum: d234d1169d74d0400bfd6c1088a39c58 (MD5) Previous issue date: 2012-02-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Atlantic forest is the biome with the greatest concentration of endemic species in the world and is under severe threat of extinction. In the group of vertebrates amphibians occupy a prominent place in the number of endemism, with more than half of all species as being unique to that biome. The study was conducted in the Reserva Estadual de Gurjaú (RESG), which is located south of the city of Recife, within the limits of three municipalities (Jaboatão dos Guararapes, Cabo de Santo Agostinho and Moreno). The RESG has a total area of 1,077.10 ha, of which 400 ha are made up of forest areas. Since its inception Pernambuco is administered by the Company of Water and Sanitation (COMPESA), which has a treatment plant installed in the reserve while eliminating its chemical waste downstream of water intake. The frogs during their life cycle are subject to exposure in various types of environment, opposite as important bioindicators of polluted areas and environmentally abused. In order to confirm the harmful effect of disposing of waste in the environment, between January and December 2004 were collected weekly by active search in a 1km stretch of the River Gurjaú, 500m and 500m upstream and downstream of the point of eliminating pollutants. The results show that the 25 species listed for the RESG, six were seen near the river, namely: Hypsiboas semilineatus (Spix, 1824), Leptodactylus gr. marmoratus (Steindachner, 1867), Scinax x-signatus (Spix, 1824), Lithobates palmipes (Spix, 1824), Leptodactylus vastus (Spix, 1824) and Pseudopaludicola gr. falcipes (Hensel, 1867). Comparing the frequency of species in sampling sites with data from biochemical analysis of the water, we can conclude that the discharge of waste made COMPESA characterized by a potentially harmful action to the environment. / Os anfíbios anuros durante seu ciclo de vida estão sujeitos a exposição em diversos tipos de ambientes, contracenando como importantes bioindicadores de áreas poluídas e ambientalmente agredidas. No grupo dos vertebrados, os anfíbios ocupam lugar de destaque em relação ao número de endemismo, apresentando mais de metade do total de espécies como sendo exclusivas do bioma brasileiro mata atlântica. Objetivando confirmar o efeito nocivo da eliminação dos dejetos no ambiente, entre janeiro e dezembro de 2004 foram realizadas coletas semanais por busca ativa, em uma extensão de um (1) km à margem do Rio Gurjaú, sendo 500m a montante e 500m a jusante do ponto de eliminação dos poluentes. O trabalho foi desenvolvido na Reserva Estadual de Gurjaú (RESG), que está localizada ao sul da cidade do Recife, dentro dos limites de três municípios (Jaboatão dos Guararapes, Cabo de Santo Agostinho e Moreno). A RESG possui uma área total de 1.077,10 ha, dos quais 400 ha são compostos por áreas de floresta. Desde a sua criação é administrada pela Companhia Pernambucana de Saneamento e Águas (COMPESA), a qual possui uma estação de tratamento instalada na reserva, que elimina seus dejetos químicos a jusante da captação de água. Os resultados mostram que das 25 espécies listadas para a RESG, seis foram observadas nas proximidades do rio, a saber: Hypsiboas semilineatus (Spix, 1824), Leptodactylus gr. marmoratus (Steindachner, 1867), Scinax x-signatus (Spix, 1824), Lithobates palmipes (Spix, 1824), Leptodactylus vastus (Spix, 1824) e Pseudopaludicola gr. falcipes (Hensel,1867). Comparando a frequência das espécies nos pontos amostrados com os dados de análises bioquímicas da água, podemos concluir que a descarga de resíduos efetuada pela COMPESA caracteriza-se uma ação potencialmente danosa ao ambiente.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / In recent years, the use of synthesis routes with low environmental impact has emerged as a differential and is widely proposed by the scientific community for the production of various materials. In this scenario, modified sol-gel processes have gained evidence for using alternative agents in place of the metal alkoxides employed in the conventional method. The route of synthesis proposed in this work is one of the slopes of the modified sol-gel, as it explores the complexing capacity of the natural organic matter (NOM) contained in river water for the production of nanomaterials. The present work deals with the development of this new route of ecologically friendly synthesis for the production of neodymium doped pure yttrium oxide nanoparticles. Y2O3 (or yttria) has some particularly interesting physical and chemical properties for numerous technological applications such as wide band gap, low phonon energy, high thermal stability, and is still considered an excellent host matrix for rare earth ions. Calcination temperature, concentration and pH of the initial solution were the parameters investigated initially. Through the XRD measurements it was found that the single crystalline phase was obtained at the temperature of 450 º C for all pure samples, without significant influences of pH and concentration. Samples doped with Nd3+ were calcined at 450, 700 and 1000º C. Samples with estimated crystallite sizes between 10 and 25 nm were obtained. The diffraction patterns of these samples did not show secondary phases related to the dopant, confirming that it was suitably incorporated in the matrix. The fluorescence emission spectra showed higher intensity at concentrations of 0.5 and 1 mol% of Nd3+. On the other hand, the samples with concentrations of 2 and 3 mol% of Nd3+ presented low luminescent intensity due to the processes of cross relaxation and excitation migration. Influence of crystallite size on luminescent intensity was also observed. The samples with smaller sizes, calcined at 450º C, presented low emission intensity due to the high concentration of adsorbed OH radicals, representing a channel of fluorescent suppression in nanoparticles. Through the heat treatment carried out at low temperatures, the suppression effects caused by the hydroxyls were reduced, allowing the obtainment of nanoparticles of Y2O3: Nd3+ with higher luminescent efficiency and reduced particle sizes. / Nos últimos anos, o uso de rotas de síntese com baixo impacto ambiental vem despontando como um diferencial e sendo largamente proposta pela comunidade cientifica para a produção de vários materiais. Neste cenário, processos sol-gel modificados tem ganhado evidência por utilizar agentes alternativos em substituição aos alcóxidos metálicos empregados no método convencional. A rota de síntese proposta neste trabalho é uma das vertentes do sol-gel modificado, pois explora a capacidade de complexação da matéria orgânica natural (MON) contida em água de rio para a produção de nanomateriais. O presente trabalho aborda o desenvolvimento dessa nova rota de síntese ecologicamente amigável para a produção de nanopartículas de óxido de ítrio puro e dopado com neodímio. O Y2O3 (ou ítria) apresenta algumas propriedades físicas e químicas particularmente interessantes para inúmeras aplicações tecnológicas como band gap largo, baixa energia de fônons, alta estabilidade térmica, e ainda é considerada uma excelente matriz hospedeira para íons terras-raras. Temperatura de calcinação, a concentração e pH da solução inicial foram os parâmetros investigados inicialmente. Através das medidas de DRX constatou-se que a fase cristalina única foi obtida na temperatura de 450º C para todas as amostras puras, sem influências significativas do pH e da concentração. As amostras dopadas com Nd3+ foram calcinadas em 450, 700 e 1000º C. Foram obtidas amostras com tamanhos de cristalito estimados entre 10 e 25 nm. Os padrões de difração destas amostras não apresentaram fases secundárias relacionadas ao dopante, confirmando que este foi adequadamente incorporado na matriz. Os espectros de emissão fluorescente revelaram maior intensidade nas concentrações de 0,5 e 1 mol% de Nd3+. Por outro lado, as amostras com concentrações de 2 e 3 mol% de Nd3+ apresentaram baixa intensidade luminescente devido aos processos de relaxação cruzada e migração de excitação. Influência do tamanho de cristalito na intensidade luminescente também foi observada. As amostras com menores tamanhos, calcinadas a 450º C, apresentaram baixa intensidade nas emissões devido à alta concentração de radicais OH adsorvidos, que representam um canal de supressão fluorescente em nanopartículas. Através do tratamento térmico realizado posteriormente a baixas temperaturas, os efeitos de supressão causados pelas hidroxilas foi reduzido, possibilitando a obtenção de nanopartículas de Y2O3:Nd3+ com maior eficiência luminescente e tamanhos reduzidos de partículas.