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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

OPEN STORMWATER SYSTEMS FOR REDUCTION OF HEAVY METALS : AN EVALUATION OF COMMONLY USED DIMENSIONING METHODS

Jönsson, Johan January 2018 (has links)
In Östersund there are a few stormwater ponds and oil separation units   connected to the stormwater network, but mostly there is no systems for   filtration of stormwater before it is released into a nearby lake which acts   as Östersund’s source of drinking water. In the Industrial area in Lugnvik there   is an oil separation unit connected to the stormwater network but no other   means of filtration. This study will be conducted as a case study for the   industrial part of catchment area 6 of the municipality of Östersund’s   stormwater system, where this area acts as an example to apply the   dimensioning methods on. Aside from grease (O/G) residues that might be   removed by the oil separation unit, pollutants such as heavy metals,   nutrients and suspended solids (SS) are present in the area. Which will make   its way to the lake trough the existing stormwater system. One way to   filtrate stormwater is to construct an open vegetated stormwater system,   where the water is filtered as it passes through the vegetation and/or   infiltrates to the ground and/or trough sedimentation. The purpose of this study is to evaluate some commonly used for Sweden   relevant methods for dimensioning open stormwater systems. The evaluation is   to see if the methods result in a system size that would give a satisfactory   removal of heavy metals, or if the methods is not suitable to use for   dimensioning a vegetated stormwater system if the purpose is to remove heavy   metals. The study should give answers to if currently and commonly used   methods for dimensioning open stormwater systems is suitable to use for   dimensioning of open vegetated stormwater systems by relating the results to   real examples when the purpose of the open stormwater system is to reduce   heavy metal concentrations. Further, the study shall help to identify   important factors that regulates the removal rate of heavy metals as well as   determine what particle size that should be targeted to reach a satisfactory   removal rate of heavy metals. A conclusion if   the dimensioning methods is suitable to use or not is difficult to draw as   the size of the system depends on what values that are used to calculate the   stormwater flow. Therefore, there is a large variation in the resulting   system size. To add to this uncertainty, the projection that is based on   measurements on real systems is not accurate as this only use the size of the   system in relation to the size of the impervious catchment area as a factor   for heavy metal removal. In reality this is not the case, which is indicated   by the R2-values of these projections. Other factors that in this study is   confirmed to have an impact on the removal rate is particle size, surface   load/flow, and in the case of vegetated filter strips the slope of the   filter. The particle size that should be targeted is likely within the range   of 45-65 μm. / <p>20181116</p>
282

Nturlig förekomst av arsenik, bly och kadmium i enskilda dricksvattenbrunnar i norr- och västerbotten : Samband med jordarter. identifiering av riskområden samt följder av klimatförändringar

Hanna, Åbrink January 2018 (has links)
Clean and healthy drinking water is fundamental to human health. If the water comes from household drinking water wells, the quality of the water should be ensured by the property owner. Arsenic, lead and cadmium are substances that can cause health problems in elevated drinking water levels, making it important to control its occurrence. Several municipalities around the Skelleftefältet area in Norr- and Västerbotten County have been identified with elevated levels of these elements and the source is assumed to be the sulfide rich bedrock that dominates the area. This report aimed to investigate whether there was a correlation between elevated levels of arsenic, lead, and cadmium and soils. There was also reason to investigate future risk areas with increased erosion due to climate changes. Data from a total of 435 drinking water wells were gathered from Skellefteå and Piteå municipality and then compared with the soil at the sampling point. Wells within a radius of 1 km from areas with ravines or landslides were identified as risk areas. The result showed that about 14 % of the identified drinking water wells had elevated levels of arsenic. The concentrations in the samples and the soil types at the sampling points varied, and a correlation between a certain soil and elevated level could not be ensured. A few sampling points were identified in erosion-sensitive areas which are at major risk of major risk of increased mobility of metals.
283

RESPONSES OF HYLA CHRYSOSCELIS TO SUBLETHAL METAL MIXTURES UNDER INCREASING TEMPERATURES: IMPLICATIONS FOR THE EFFECTS OF CLIMATE CHANGE ON AMPHIBIANS

Hallman, Tyler Andrew 01 August 2012 (has links)
Amphibian populations are rapidly declining worldwide. Although individual factors may have large local influences, worldwide declines are attributed to interacting global stressors including rising temperatures and environmental pollutants. Globally, water temperatures closely track rising air temperatures and increase the metabolic rates of aquatic ectotherms, changing the rates of uptake, biotransformation, and excretion of contaminants, such as metals. To test how interactions of multiple, chronic stressors affect amphibian growth, I exposed Cope's gray treefrogs (Hyla chrysoscelis) in an outdoor mesocosm facility to three temperature regimes (ambient, ambient +1.5 oC, ambient +2.5 oC) in filtered lake water amended with mixtures of cadmium, copper, and lead ranging from 3.7 to 26.7 risk quotients (relative to the chronic concentration criteria protective of freshwater organisms). Temperature shifts and sublethal metals concentrations significantly affected the energetics of tadpoles as assessed by non-parametric and parametric analyses. Regression analyses indicated no significant relationship between temperature and time to forelimb emergence at the three lowest metals concentrations, but the relationship was parabolic at the three highest concentrations, indicating a differential effect of temperature across a gradient of water quality. The concept that tadpoles increase developmental rates to escape unfavorable aquatic conditions was supported at each temperature by shortened time to forelimb emergence (Gosner Stage 42) at the second highest metals concentration. This response, however, was overwhelmed by the energetic costs associated with the highest concentration and the highest temperature. Moreover, these parabolic relationships match predictions based on species specific thermal windows and pejus temperatures. My findings indicate that global warming may affect contaminated waters to a greater extent than pristine aquatic ecosystems, and that the primary effect may be diminished pejus and critical thermal maximum temperatures, and a narrowing of the species' thermal window.
284

EXPOSURE OF WINTERING SCOTERS TO SUBLETHAL INORGANIC CONTAMINANTS IN PUGET SOUND, WASHINGTON

Behnke, Jessica Lynn Hallman 01 December 2015 (has links)
North American scoter populations have declined by approximately 60% over the last 30-50 years. Prior studies of other sea duck species suggest that trace elements can have deleterious effects on overall body condition. For surf scoters (Melanitta perspicillatta) and white-winged scoters (Melanitta fusca), this study tested the following hypotheses: (1) Trace element accumulation differs among seasons, locations, and species; (2) Increased trace elements in tissues correlate with declines in body condition; (3) Surf scoters that shift their feeding to a higher trophic level in spring bioaccumulate higher levels of trace elements; and (4) Selenium and mercury co-accumulate in a 1:1 molar ratio. To test these hypotheses, cadmium (Cd), mercury (Hg), and selenium (Se) in livers and kidneys were collected from adult male surf scoters and white-winged scoters in December 2005 and March 2006 from three locations in Puget Sound, Washington. Trace elements in surf scoters differed among locations, and seasons. Se and Cd in liver and kidney explained 21% of the variance in a matrix of body condition factors in surf scoters. In white-winged scoters, body condition differed between March and December, but trace elements in tissues did not, indicating that contaminants did not explain changes in condition. Thus, hypotheses 1 and 2 received partial support while hypothesis 3 did not. Finally, Se and Hg did not covary in either the kidney or liver of either species (hypothesis 4). Compared to other marine birds, scoters in this study contained low contaminant levels. Nonetheless, inorganic contaminants explained substantial variation in body condition of surf scoters, and potentially contribute to their population declines. These findings suggest that inorganic contaminants, particularly Cd, should be considered in assessing habitat quality for sea ducks.
285

Síntese de sílica mesoporosa SBA 15 funcionalizada para teste de sorção de metais pesados / Synthesis of mesoporous silica SBA-15 functionalized by sorption test for heavy metals

Uchôa, Antonia Flávia Justino January 2011 (has links)
UCHÔA, Antonia Flávia Justino. Síntese de sílica mesoporosa SBA 15 funcionalizada para teste de sorção de metais pesados. 2011. 93 f. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2011. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-05-31T18:58:05Z No. of bitstreams: 1 2011_dis_afjuchoa.pdf: 3021135 bytes, checksum: 8f8b06b80d3524ad7b692c83e1473bef (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-31T23:20:34Z (GMT) No. of bitstreams: 1 2011_dis_afjuchoa.pdf: 3021135 bytes, checksum: 8f8b06b80d3524ad7b692c83e1473bef (MD5) / Made available in DSpace on 2016-05-31T23:20:34Z (GMT). No. of bitstreams: 1 2011_dis_afjuchoa.pdf: 3021135 bytes, checksum: 8f8b06b80d3524ad7b692c83e1473bef (MD5) Previous issue date: 2011 / SBA-15 Mesoporous silica functionalized with amine (– NH2) hat been prepared in this work for the purpose of the development of heavy metals adsorbents from wastewater. The functionalization with organic groups has been performed by two different methods, post-synthesis and co-condensation. In this work, the matrix was prepared by co-condensation. Two organic groups were selected to be incorporated with specific reactions sites containing amino groups, cysteine (HS–CH2–CH(NH2)–COOH) and phenylisotiocianate (C6H5–NCS). The materials were characterized by X-ray Diffraction at low angle (XRD), Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM), Nuclear Magnetic Resonance Solid State (NMR), Nitrogen adsorption-desorption (BET), Thermal Analysis (TG/DTG) and Spectroscopy of the Infrared (FT-IR). The hybrid material SBA 15_NH2 exhibit BET surface area of 451 m2/g and total pore volume 0,15 cm3/g. FT-IR, NMR, TG confirmed the incorporation of organic groups, cisteine and phenylisotiocianate in the materials. The analysis indicated that all synthesized materials showed hexagonal structure, characteristic of mesoporous materials like SBA-15 with good ordering of the pores, high surface area and narrow pore size distribution. All modified samples were subjected of sorption processes of Cu+2. The maximum adsorption capacity was 21 mg/g for the material modified with phenylisotiocianate. The Langmuir isotherm model fitted well to the experimental data together of pseudo-second order model kinetic process of adsorption. The results suggest that these materials can be used as adsorbents to remove trace metal ions in contaminated aqueous systems. / Sílicas mesoporosas do tipo SBA-15 funcionalizadas com amino (–NH2) foram preparadas para o desenvolvimento de adsorventes de metais pesados em águas residuais. A funcionalização com grupos orgânicos tem sido realizada por dois métodos distintos, pós-síntese e co-condensação. Neste trabalho a matriz foi preparada por co-condensação e dois grupos orgânicos foram selecionados para serem incorporados aos sítios de grupos amino: cisteína (HS–CH2–CH(NH2)–COOH) e fenilisotiocianato (C6H5–NCS). Os materiais foram caracterizados por difração de raios X em baixo ângulo (DRX), Microscopia Eletrônica de Varredura (MEV), Microscopia Eletrônica de Transmissão (MET),RMN no estado sólido, Adsorção-dessorção de nitrogênio, análise térmica (TG/DTG) e Espectroscopia na Região do Infravermelho (FT-IR). O material híbrido SBA-15_NH2 exibiu área superficial BET de 451 m2/g e volume total de poros de 0,15 cm3/g. FT-IR, RMN no estado sólido e TG/DTG confirmaram a incorporação das cadeias orgânicas da cisteína e fenilisotiocianato nos materiais. As análises indicaram que todas as amostras sintetizadas apresentaram estrutura hexagonal, característica dos materiais mesoporosos do tipo SBA-15, com boa ordenação dos poros, elevada área superficial e estreita distribuição de tamanhos de poros. Todas as amostras modificadas foram submetidas a processos de sorção de íons Cu2+. A capacidade de adsorção máxima foi de 21 mg/g para o material modificado com fenilisotiocianato. A isoterma de Langmuir ajustou-se melhor aos dados experimentais e associado com o modelo de pseudo-segunda ordem descreveu bem o processo cinético de adsorção. Os resultados sugerem que esses materiais podem ser usados como adsorventes para remoção de íons de metais traços em sistemas aquosos contaminados.
286

Determination of physiochemical properties and metal levels in soil, water, and plant from Alice landfill site

Maphuhla, N G January 2017 (has links)
The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
287

Avaliação do cádmio (Cd), chumbo (Pb), níquel (Ni) e zinco (Zn) em solos e plantas às margens de uma rodovia de tráfego intenso de veículos

Duarte, Rogéria Pãodian Saez [UNESP] January 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T21:02:59Z : No. of bitstreams: 1 duarte_rps_dr_botfca.pdf: 516578 bytes, checksum: 5840441c30c909288128b3d89d91d484 (MD5) / O presente trabalho objetiva detectar a presença dos metais pesados – Cádmio (Cd), Chumbo (Pb), Níquel (Ni) e Zinco (Zn) – em estruturas biológicas como solos e plantas, em regiões consideradas como de risco para ocorrência desses elementos, provenientes da poluição ambiental emitida pelo tráfego de veículos automotores. As amostras foram coletadas ao longo de três locais do Estado de São Paulo, localizados ao longo da Rodovia Presidente Dutra, sentido São Paulo - Rio de Janeiro (km 183 - Fazenda São Judas Tadeu; km 156 - Base da Polícia Federal de São José dos Campos e Km 87 - Posto de Pedágio Moreira César). A primeira amostragem ocorreu em agosto de 1999, a segunda amostragem, em abril de 2000 e a terceira amostragem, em novembro de 2000. Para o presente estudo foram coletadas amostras de plantas e solos provenientes das margens e da “ilha” (sistema de separação de um lado do outro das pistas) da rodovia, totalizando 324 amostras, a saber: 216 amostras de solos em profundidade (0, 0-10 e 10- 20cm, no perfil do solo) e em distância da margem da rodovia (10, 20 e 30m) de cada local ao longo da rodovia; 108 amostras de plantas nos pontos de amostragem de solo na “ilha” e à distância da rodovia (15 e 30m da margem asfáltica). Para a obtenção dos extratos das amostras de solos, utilizou-se a extração por DTPA (ácido dietilenotriaminopentaacético + CaCl2 + trietanolamina), com agitação mecânica em bloco digestor; as amostras de plantas foram submetidas à digestão ácida com solução nítrico-perclórica (HNO3 + HClO4). Os extratos obtidos dos tratamentos químicos empregados nas amostras foram levados para a leitura em Espectrofotômetro de Absorção Atômica... . / The present study aims at detecting the presence of heavy metals – Cadmium (Cd), Lead (Pb), Nickel (Ni) and Zinc (Zn) – in biological structures such as soil and vegetation, in regions considered as risk-areas for the occurrence of these elements, which originate from environment pollution from automobile fuel-combustion. Samples were collected in the vicinity of three locations in São Paulo State, along the Presidente Dutra Highway, on the São Paulo – Rio de Janeiro direction (São Judas Tadeu Farm, at km 183; Federal Police Office at São José dos Campos, at km 156; and Moreira César Toll Plaza, at km 87). The first sample collection took place in August 1999; the second one, in April 2000; and the last one occurred in November 2000. For this study, plant and soil samples were collected from the highway margins and median strips (system of separation of both sides of the lanes), in a total of 324 samples, organized as follows: 216 controlled-depth (0, 0-10 and 10-20cm-deep, at the soil’s profile) and controlled-distance from the margins (10, 20 and 30m) soil samples, at each location along the highway; 108 plant samples collected at the distance-controlled points of soil in the median strips collection (15 and 30m from highway margin). The extraction by DTPA (dietiletriaminopentaacetic acid + CaCl2 + trietanolamin) was used, for soil sample extracts with mechanical agitation in digesting block; plant samples were subjected to acid digestion with nitric-percloric solution (HNO3 + HClO4). Atomic Absorption Spectrofotrometrer for readings. Were used for extracts. Biological monitoring of the exposition does not exclude environmental monitoring, for both processes are valid and provide independent data which may, all in all, assess the exposition to toxic agents and their potential effects to human health and the environment... (Complete abstract, click electronic address below).
288

Monitoring heavy metals in private drinking water near industrial activity in Kosovo

Jansson, Victoria January 2018 (has links)
Exposure to heavy metals around the world is practically unavoidable due to their extensive use and spread in the environment. This is especially critical due to the metals’ toxicity and detrimental effects on human health. Rural inhabitants in less developed countries in Europe near industrial local polluters are especially exposed. Leachates from industrial wastes may add heavy metal pollution to surrounding groundwater aquifers. Both industrial pollution and rain runoff poses extensive risks for private wells. These wells provide a large part of the drinking water supplies for Kosovo’s inhabitants. The aim of this study is to investigate how a nickel (Ni) refining industry’s slag hill is affecting the drinking water quality in surrounding neighbours private drinking water supplies. To do this 10 samples with increasing distance from the industrial slag hill were collected and analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chromium (Cr), Ni and lead (Pb) were below guideline and limit values in the well water drinking supplies. Rain runoffs increased the concentrations of aluminium (Al), Ni and Pb, in wells where rainwater leaked in. This was however not the case for Cr. Highest Cr concentrations were found in clear (unpolluted by rain runoff) well waters, southeast of a local open pit mining area. This study shows that the Ni refinery and slag hill do not currently risk contaminating local drinking water wells above guideline and limit values. However, there are indications that local mining activity may pose a larger risk concerning Cr leakage to the private wells. Further groundwater monitoring is needed focusing on this area to investigate potential and actual sources of pollution.
289

Tissue variability in the infaunal bivalve Axinopsida serricata (Lucinacea: Thyasiridae) exposed to a marine mine-tailings discharge; and associated population effects

Bright, Doug Arthur 22 June 2018 (has links)
Axinopsida serricata (Bivalvia) is abundant in coastal waters of British Columbia subjected to natural and anthropogenic disturbance. To investigate the monitoring potential of histological lesions, field populations were sampled in Holberg Inlet and Quatsino Sound, British Columbia, from benthic habitats affected by the submarine discharge of copper-mine tailings, and from a reference site in Mill Bay, Saanich Inlet. Based on a quantitative analysis of the digestive gland, ctenidia, kidney, gonad and stomach, the relationship between histological variation and site, size, season, sex and parasitism was explored. The relationship between occurrence of histological lesions in this species and further ecological consequences of mine-tailings discharge was also explored by comparing population characteristics of clams living in deposited tailings with clams from the reference site. Between-sample differences were observed in the structure of digestive tubule digestive cells, digestive ducts, ctenidial frontal cells, laterofrontal cells, and abfrontal mucocytes, kidney concretions, and stomach epithelial cells. The pattern of differences in tissue structure between samples reflected proximity of the collection site to the mine-tailings discharge and seasonally-dependent reproductive activity. Simultaneous examination of six of the tissue variables (using a principal components analysis) showed that clams collected from three stations in Lower Holberg Inlet which were in closer proximity to the tailings discharge pipe were distinguishable from clams collected from the reference site, upper Holberg Inlet, and Quatsino Sound. Tissue structural variability in A. serricata was not influenced by sex, or ectoparasitism by a flagellate. Tissue variables were not causally related to clam size (and thus of age and duration of exposure). In spite of the notorious natural plasticity of molluscan tissues, the variability can be partitioned to provide a very effective interpretation of exposure to stressors. Based on an increased abundance in degraded habitats, A. serricata, and the superfamily Lucinacea in general, have been described as r-selected or opportunistic species. An investigation of life-history traits showed that A. serricata has a maximum longevity of five years or longer, exhibits sporadic growth primarily in the summer months, and is an iteroparous, gonochoristic broadcast spawner with gamete release occurring primarily in November. The observed life span of the clam and presence of ova which are very large (maximum diameter is approximately 100 μm) and yolk-rich for a broadcast spawner are somewhat at odds with the contention that A. serricata is an r-selected species. Tissue variations which occurred in the digestive tubules and ctenidia with increased incidence and severity closer to the tailings discharge pipe are similar to histopathological effects in molluscs as described by others. However, there is no evidence that tissue lesions in A. serricata negatively affect fecundity, growth, or abundance. The sub-population sampled closest to the discharge pipe is in a state of decline, but this is due to the absence of recruitment since 1986, rather than increased mortality in the established population. The apparent decoupling of tissue-level and population-level effects may be due to a time lag in manifestation of decreased fitness at the population level, selection of stress-tolerant individuals in response to the stressor, a strategy of neglect of somatic maintenance and repair, or some other mechanism. It is possible that A. serricata and other small Thyasirids have an evolutionary history which provides pre-adaptation to environmental stressors. / Graduate
290

Resíduos de mineração e metalurgia: efeitos poluidores em sedimentos e em espécie biomonitora - Rio Ribeira de Iguape - SP / Residues of mining and metallurgy: pollutant effect in sediments and biomonitor organism - River Ribeira de Iguape

Valeria Guimarães 10 May 2007 (has links)
Por aproximadamente 40 anos, o Rio Ribeira de Iguape recebeu resíduos da mineração: rejeitos das plantas de concentração mineral (enriquecidos em Cu, Cr, Pb, Ag e Zn) e escórias de uma unidade de metalurgia (enriquecidas em Cu, Zn, Cr, Fe, Pb e As), produzidos e descartados pela empresa Plumbum S/A, localizada em Adrianópolis (Paraná). Para verificar a contribuição destes resíduos na contaminação deste rio, como também identificar a possibilidade de depuração natural ou não no mesmo, definiu-se a necessidade de avaliar três compartimentos: resíduos, sedimentos e organismo biomonitor. Nas amostras de resíduos foram realizadas caracterizações físicas e químicas, nos sedimentos foram realizadas análises químicas, granulométricas e algumas amostras investigadas por MEV/EDS e no biomonitor (molusco Asiático da espécie Corbicula fluminea) foram realizadas análises químicas dos tecidos e das carapaças. Estas análises indicaram a existência de elevados teores de Pb nos resíduos da mineração, os quais ultrapassaram os valores deste metal estabelecidos na norma NBR 10.005 da ABNT. Nesta comparação, os rejeitos do concentrado da Mina do Rocha ultrapassaram em 32 vezes, os da Plumbum em 41 vezes e as escórias em 34 vezes, os limites estabelecidos por tal norma, sendo assim classificados como pertencentes à Classe I ? perigosos. Destes resíduos o mais problemático atualmente é o rejeito da Plumbum, por apresentar granulometria fina, pH mais baixo, apresentar maior teor de Pb no teste de lixiviação, além de estar depositado muito próximo de uma das margens do Rio Ribeira de Iguape. A interação destes resíduos com o sistema aquático foi verificada a partir da detecção de Pb, Zn, Cu nos sedimentos. Os sedimentos depositados em bancos de areia e os estuarinos exibiram maiores teores para Pb (média de 135,00 mg/kg para os depósitos em bancos de areia e 124,00 mg/kg para os estuarinos) e Zn (média de 112,62 mg/kg para os depositados em bancos de areia e de 133,00 mg/kg para os estuarinos). Em todos os tipos de sedimentos foi constatado que o local de coleta que exibiu teores mais elevados para os metais de estudo foi em Iporanga, secundariamente na Ilha do Caranguejo na região do Mar Pequeno, a sul de Iguape. Nos sedimentos em suspensão, as análises em MEV/EDS exibiram a presença de grãos de escória, indicando que estes ainda hoje, estão interagindo com este ambiente e sendo transportados. Esta comprovação, só foi possível, de fato, a partir das análises de tecidos e de carapaças da espécie Corbicula fluminea, os quais demonstraram estar havendo interação dos metais pesados provenientes dos resíduos com a biota deste sistema aquático. Nos tecidos deste biomonitor foram detectados em média 23,99 ?g/g de Cu, 144,21 ?g/g de Zn, 0,71 ?g/g de Cd, 2,41 ?g/g de Pb e 7,11 ?g/g de Cr. Destes metais, o mais preocupante é o Pb, ele apresenta concentrações mais elevadas que os relatados em outros estudos para este mesmo bivalve e também, ultrapassa o valor de referência da ANVISA (2,00 ?g/g) para a concentração deste metal pesado em peixes e produtos de pesca para consumo. Além dos tecidos, as carapaças deste biomonitor, também estão concentrado estes metais pesados. De modo geral, concluiu-se que o Rio Ribeira não está sofrendo processos naturais de depuração e que ainda hoje representa um problema ambiental, pois os metais estão migrando ao longo do curso da drenagem e neste processo sendo biodisponibilizados, o que pode vir a gerar transferência e acumulação na cadeia trófica. / For approximately 40 years, Ribeira de Iguape River received mining wastes (enriched in Cu, Cr, Pb, Ag and Zn) and metallurgical slags (enriched in Cu, Zn, Cr, Fe, Pb and As), produced and discharged by Plumbum S/A, a company located in Adrianópolis (Paraná). In order to verify the contribution of these residues in the river contamination and natural purification the compartments of mining residues, sediments and bioindicator organisms were evaluated. Physical and chemical characterizations were realized in the residues samples; while chemical analyses, grain size evaluation and MEV/EDS were carried out in sediments. Asiatic clam (Corbicula fluminea) was taken as a bioindicator, through chemical analyses of its tissues and shells. The results showed high Pb levels, being classified as Class 1 ? dangerous - by ABNT, norm NBR 10,005, once the limited levels were exceeded by Rocha wastes (32x), Plumbum wastes (41x) and slags (34x). The Plumbum waste is currently the most problematic, as it is made of fine grain, lower pH, higher Pb level detected in the extraction test and is deposited very close to the draining site. The interactions of these residues with the aquatic system was verified through Pb, Zn, Cu detection in the sediments. Pb and Zn levels were, respectively, 135.00 mg/kg and 112.62 mg/kg in the sand banks deposits, and 124.00 mg/kg and 133.00 mg/kg in the estuaries deposits, with prominent metal levels in Iporanga and, secondary, in Crab Island, region of the Small Sea, south of Iguape. MEV/EDS analyses carried out in suspended sediments showed the presence of slags grains, suggesting that still nowadays they are transported and interact with the environment, once they have been detected in tissues and shells samples of Corbicula fluminea. In the tissues of this bioindicator, there were detected average levels of 23.99 ?g/g of Cu, 144.21 ?g/g of Zn, 0.71 ?g/g of Cd, 7.11 ?g/g of Cr and 2.41 ?g/g of Pb; making evident that this last value is strongly high and over the ANVISA reference (2.00 ?g/g) for fish and other consumption products. The results suggest that natural processes of Ribeira de Iguape River are not sufficient for its purification, keeping metals\' transport and bioavailability, which can accumulate in the trophic chain, representing a serious environmental problem.

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