Cleber Pinto da Silva

Bioconcentration and bioaccumulation of metal in freshwater Neotropical fish Geophagus brasiliensis.

From the concentration in water and sediments, bioconcentration and bioaccumulation of copper (Cu), manganese (Mn), zinc (Zn), iron (Fe), cobalt (Co), cadmium (Cd), chrome (Cr), silver (Ag), lead (Pb), nickel (Ni), aluminum (Al), and arsenic (As) were determined in the gills, liver, and muscles of Geophagus brasiliensis in the Alagados Reservoir, Ponta Grossa, Paraná, Brazil. Metals were quantified through AAS, and a study was carried out on the existing relations between metal and body weight, size, and genre of this species. The level of metal in the water of the reservoir was lower than the maximum set forth in the legislation, except for that of Cd and Fe. In sediments, Cu, Cd, Cr, and Ni presented concentrations above the threshold effect level (TEL). Pb and Cr were above the limits for the G. brasiliensis. The tendency of metals present in the muscles of G. brasiliensis was Al > Cu > Zn > Fe > Co > Mn > Cr > Ag > Ni > Pb > Cd > As. In the gills, it was Al > Fe > Zn > Mn > Co > Ag > Cr > Ni > Cu > As > Pb > Cd, and the liver presented Al > Cu > Zn > Co > Fe > Mn > Pb > Ag > Ni > Cr > As > Cd. The bioconcentration and bioaccumulation of metal in the tissues follow the global tendency liver > gills > muscle. The statistical analysis did not point to significant differences in the metal concentration and body weight, size, and gender of the species in the three tissues under analysis.

Environmental pollution by heavy metals in the São João River basin, southern Brazil

Environmental pollution tends to reduce the quality of water sources around the world. Thus, there is a clear need for strategic assessments of conditions that negatively affect river basins. The São João River basin is located in a strategic conservation area due to the abounding water resources and biodiversity, but is strongly affected by anthropic activity. In this study, eight metals were evaluated (Cu, Mn, Fe, Zn, Cr, Co, Cd and Pb) in sediment and water from ten different points in the São João water basin. The São João basin pollution was evaluated through the geoaccumulation index (Igeo), ecological risk potential (ERP) and degree of pollution (Dp). The most toxic metals found in sediments were Cr (3.1–10.7), Cd (2.1–5.5) and Pb (5.0–28.1) in µg g−1. In the water samples, the most toxic metals were Cr (3.7–33.2), Cd (6.3–14.2) and Pb (5.0–57.5) in µg L−1. The Igeo presented indices between 2 and 3 in 80% of the samples, indicating significant pollution in the sediment. In 40% of the points sampled, the ERP values indicated severe risk for the ecosystem. In 30% of the water samples, the Dp values were over 40, indicating the highest pollution level. The results reveal that the use of land and water in the São João water basin without proper care might represent considerably high ecological and sanitary risk.

Translocation of metal ions from soil to tobacco roots and their concentration in the plant parts

This paper presents a study on the translocation factors (TFs) and bioconcentration factors (BCFs) of copper (Cu), manganese (Mn), zinc (Zn), cobalt (Co), chromium (Cr), cadmium (Cd), lead (Pb), iron (Fe), nickel (Ni), and arsenic (As) ions in roots, stems, and leaves of tobacco. The results revealed that during the tobacco growth, the roots are able to increase the sensitiveness of the physiological control, reducing the translocation of the metals Ni (0.38) and Pb (0.48) to the leaves. Cd and Zn presented factors TF and BCF >1 in the three tissues under analysis, which indicates the high potential for transportation and accumulation of these metals in all plant tissues. The TF values for Cr (0.65) and As (0.63) revealed low translocation of these ions to the aerial parts, indicating low mobility of ions from the roots. Therefore, tobacco can be considered an efficient accumulator of Ni, Cr, As and Pb in roots and Cd and Zn in all plant parts.

AVALIAÇÃO DA BIOACUMULAÇÃO DE METAIS EM Cyprinus carpio PELA INTERAÇÃO COM SEDIMENTO E ÁGUA DE RESERVATÓRIO

Bioaccumulation of Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn was determined in the gills and liver of Cyprinus carpio and related to concentrations in the sediment and water of the Alagados Reservoir, Ponta Grossa/Parana. Cd and Fe exceeded the legal limit for water. Fe was the most abundant metal in the reservoirs water and sediment. The metals in the sediment were below the level of probable adverse effects on biota. There were no significant differences between sampling sites for water and sediment. Liver and gills had higher concentrations of Al, Fe and Zn, with a significant increase in Al (P > 0.05) compared to the increase in weight and size of the specimens. Statistically, gills showed higher concentrations of Al, Cd, Co, Cr, Mn and Zn and liver higher concentrations of Cu and Fe. Co, Cu, Fe, Mn and Zn showed significant differences (P < 0.01) between the organs. The bioaccumulation factors (BAF) showed that the interaction of water with gills promotes greater accumulation of metals in this organ. Despite the low concentrations in the reservoir, bioaccumulation of metals in gills and liver of C. carpio occurs by its interaction with contaminated water and sediment, respectively.

Determination of Metal Ions in Contraband Cigarettes in Brazil

In Brazil, one out of each four cigarettes consumed by the smokers is smuggled. These cigarettes do not go through quality control and can present potential risk to their consumers. In this study, the flame atomic absorption spectrometry (FAAS) of metal ions Cu, Mn, Zn, Co, Cr, Cd, Pb, Fe, Ag and Ni was carried out in cigarettes of 18 different brands, which are the most smuggled into the country. The results obtained revealed that in all 18 brands of cigarettes analyzed, the values of metal ions under study appeared in higher concentrations when compared to similar studies found in the literature, with values up to eleven times higher for very toxic metals such as Cr, Ni, Cd and Pb.

Treatment of smuggled cigarette tobacco by composting process in facultative reactors

This paper presents a study on the degradation of smuggled cigarette tobacco combined with domestic organic waste and sawdust or wood chips, using facultative reactor. Four reactors with different amounts of residue were assembled. For the study of the quality of the compost obtained, physicochemical, phytotoxicity and microbiological analyses were carried out. The mixture with wood chips presented the best temperature conditions and pH variation optimizing the degradation. The final germination index (GI) values of all treatments were above the recommended GI value (50%) and the final C/N ratio between 8 and 13 indicated a mature compost. The concentration of metals under study was below the limit allowed for the commercialization. The composting carried out in all facultative reactors provided ideal conditions for the total sterilization of the final compost. Therefore, the treatment of smuggled cigarettes through facultative reactors was efficient to produce stable and mature compost.

Composting of smuggled cigarettes tobacco and industrial sewage sludge in reactors: Physicochemical, phytotoxic and spectroscopic study

The maturity of smuggled cigarette tobacco (SCT) and industrial sewage sludge (ISS) compost during composting in reactors was evaluated through physicochemical, phytotoxic and spectroscopic parameters. The temperatures reached peaks above 52 °C in the three reactors and were enough to achieve the stability of the compounds. The electric conductivity was in the optimal interval for farming uses and the pH alkaline band was favorable to produce inorganic nitrogen. The reduction in the C∕N ratio and the increase in cation exchange capacity (CEC) indicated an increase in the compost humification. After 120 days, the seed germination index (SGI) reached 95 % in reactor 3. In the three treatments, the reduction in E2/E6 and E4/E6 ratios (UV/Vis), the increase in humification indices, obtained through FTIR and the aromatic carbon resonance (13C NMR) indicated a high degree of aromaticity. The composting process in reactors was efficient to degrade different proportions of SCT and ISS, resulting in mature composts.

Development, validation and matrix effect of a QuEChERS method for the analysis of organochlorine pesticides in fish tissue

ABSTRACT This study aims to develop and validate a method to determine OCPs in fish tissues, minimizing the consumption of sample and reagents, by using a modified QuEChERS along with ultrasound, d-SPE and gas chromatography with an electron capture detector (GC-ECD), refraining the pooling. Different factorial designs were employed to optimize the sample preparation phase. The validation method presented a recovery of around 77.3% and 110.8%, with RSD lower than 13% and the detection limits were between 0.24 and 2.88 μgkg−1, revealing good sensitiveness and accuracy. The method was satisfactorily applied to the analysis of tissues from different species of fish and OCPs residues were detected. The proposed method was shown effective to determine OCPs low concentrations in fish tissues, using small sample mass (0.5 g), making the sample analyses viable without the need for grouping (pool).

PROPOSTA DE ENSINO PARA MÉTODOS DE SEPARAÇÃO DE MISTURAS BASEADA NA RESOLUÇÃO DE PROBLEMAS E SUAS RELAÇÕES COM OS ESTILOS DE APRENDIZAGEM DOS ALUNOS DOI: 10.5212/Publ.Exatas.v.18i1.0001

O ensino de Quimica enfrenta algumas dificuldades em relacao a aprendizagem de conceitos teoricos. Para tentar reverter essa situacao, foi aplicada e analisada uma proposta de ensino baseada na metodologia de resolucao de problemas conceituais envolvendo separacoes de misturas. A proposta foi realizada com 25 alunos do Ensino Medio de uma escola publica da cidade de Ponta Grossa. Os conteudos foram aplicados e, posteriormente, realizou-se uma analise por meio de questoes abertas e fechadas tendo como referencia o metodo psicometrico proposto por Felder e Silverman (1988) para estilos de aprendizagem. Verifi couse que a proposta atende os requisitos basicos exigidos pelo MEC, pois trabalha com estilos de aprendizagem variados, o que nao ocorre pelas propostas didaticas tradicionais.