Integrated assessment of metal contamination in sediments from two tropical estuaries

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da contaminação por elementos metálicos dos sedimentos do Estuário Santos - São Vicente

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluating and classifying contaminated areas based on loss functions using annealing simulations

This paper presents a methodology based on geostatistical theory for quantifying the risks associated with heavy-metal contamination in the harbor area of Santana, Amapa State, Northern Brazil. In this area there were activities related to the commercialization of manganese ore from Serra do Navio. Manganese and arsenic concentrations at unsampled sites were estimated by postprocessing results from stochastic annealing simulations; the simulations were used to test different criteria for optimization, including average, median, and quantiles. For classifying areas as contaminated or uncontaminated, estimated quantiles based on functions of asymmetric loss showed better results than did estimates based on symmetric loss, such as the average or the median. The use of specific loss functions in the decision-making process can reduce the costs of remediation and health maintenance. The highest global health costs were observed for manganese. (c) 2008 Elsevier B.V. All rights reserved

Calagem e adubação com vermicomposto de lixo urbano na produção e nos teores de metais pesados em alface

Foram realizados dois experimentos em casa de vegetação para avaliar o efeito da adição de um vermicomposto oriundo de lixo urbano e da calagem na matéria seca e na concentração de metais pesados na parte aérea de plantas de alface cv. Mesa 659. em um dos ensaios, foi usado um Latossolo Vermelho distroférrico e, em outro, um Argissolo Vermelho-Amarelo eutrófico. O delineamento experimental de cada experimento foi em blocos ao acaso, em esquema fatorial 5 x 5, com quatro repetições, combinando-se calagem para elevar a saturação por bases a 40; 50; 60; 70 e 80%, e o equivalente a 0; 25; 50; 75 e 100 t ha-1 de vermicomposto. Uma única aplicação de vermicomposto de lixo urbano, em doses acima de 50 t ha-1, limitou a produção de alface nos dois tipos de solos. Mesmo estas doses que restringiram a produção da alface, não a tornaram imprópria para consumo humano do ponto de vista da concentração de metais pesados.

Utilização da geoestatística na quantificação do risco de contaminação por metais pesados, na área portuária de Santana-Amapá

Pós-graduação em Geociências e Meio Ambiente - IGCE

Mucorales de solo contaminado com metais pesados na região do pólo cerâmico de Santa Gertrudes, SP: ocorrência e capacidade de biossorção de chumbo e zinco

Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC

NUTRITIONAL STATUS AND LEVELS OF HEAVY METALS IN LETTUCE PLANTS FERTILIZED WITH ORGANIC COMPOUNDS

The use of organic compounds has been a good option to reduce spending on fertilizers, and gain increased productivity in the cultivation of lettuce. However, given the wide variety of raw materials used in the preparation of organic compounds, studies are needed to evaluate its effects on the release of essential nutrients to plants and on the release of contaminants such as heavy metals. The aim of this study was to evaluate the mineral nutrition and heavy metal contamination of lettuce in soils treated with doses and types of compost. The experiment was conducted in a greenhouse in randomized blocks in factorial scheme 5x4, with five types of organic compounds and four nitrogen levels (0, 35, 70 and 140 kg ha(-1) of N), with four replications. In general, the doses of the compounds were not enough to provide the necessary quantity of nutrients to the lettuce, with the exception of nitrogen. There was no increase in levels of heavy metals in the soil above that allowed by Brazilian legislation. Furthermore, compounds based on manure plus grass, and commercial compound caused increases in Zn concentration in plants at levels above the recommended for consumed.

Diagnose foliar da cultura da soja em função da aplicação superficial de lodos de esgoto e resíduos industriais sob diferentes doses em sistema plantio direto

The application of industrial and municipal waste in the soil may be recommended by your corrective and fertilizer value, giving the great potential for agricultural reuse, improves physical, chemical and biological soil properties and helps to reduce the consumption of fertilizers and correctives, without contamination by heavy metals. This study aimed to evaluate the absorption of nutrients and potentially toxic elements, and their effect on the development of soybean (Glycine max (L.) Merrill) grown under No-Tillage system (NT). The work was developed in the field, at the Experimental Farm Lageado - FCA / UNESP, Botucatu (SP) in an Oxisol under tropical climate of altitude. The experimental design was randomized blocks, factorial 4x4+1, with four replications. The treatments consisted of four residues: two sewage sludge, one centrifuged and treated with quicklime (LC) and a biodigester (LB) and two industrial wastes: steel slag (E) and lime mud (Lcal) , applied in dosages of 0, 2, 4 and 8 Mg ha-1. The surface application of LC, LB, Lcal and E residues in soil under NT favored the development of soybean, with no heavy metal contamination, given the current legislation.

Selenium and sulfur: mitigation in plant stresses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil

Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecem) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments. (C) 2012 Elsevier Ltd. All rights reserved.

A Comparison of Deep Drawing and Ironing of Metal Alloy Strip Produced conventionally and Non-conventionally via Semi Solid Material Processing

A semi solid thin strip continuous casting process was used to obtain 50%wt Pb/50%wtSn strip by single and twin roll processing at speed of 15 m/min. A 50%wt Pb/50%wtSn plate ingot was also cast for rolling conventionally into strips of 1.4 mm thickness and 45 mm width for comparison with those achieved non-conventionally. This hypoeutectic alloy has a solidification interval and fusion temperature of approximately 31 degrees C and 215 degrees C respectively. The casting alloy temperature was around 280 degrees C as measured by a type K immersion thermocouple prior to pouring into a tundish designed to maintain a constant melt flow on the cooling slope during semi solid material production. A nozzle with a weir ensures that the semi solid material is dragged smoothly by the lower roll, producing strip with minimum contamination of slag/oxide. The temperatures of the cooling slope and the lower roll were also monitored using K type thermocouples. The coiled semi solid strip, which has a thickness of 1.5 mm and 45 mm width, was rolled conventionally in order to obtain 1.2 mm thick strip. The coiled thixorolled strip had a thickness of 1.2 mm and achieved practically the same width as the conventional strips. Blanks of 40 mm diameter were cut from the strips in a mechanical press, ready for deep drawing and ironing for mechanical characterization. All the strips achieved from non-conventional processing had the same mechanical performance as those achieved conventionally. The limiting drawing ratio (LDR) achieved was approximately 2.0 for all strips. Microscopy examination was made in order to observe phase segregation during processing.

Differential/combined effect of water contamination with cadmium and nickel on tissues of rats

The contamination of water by metal compounds is a worldwide environmental problem. Concentrations of metals are widely related to biochemical values which are used in disease diagnosis due to environmental toxicity. The acute combined effects of cadmium and nickel on biochemical parameters were determined and compared with those of Cd2+ or Ni2+ alone in rats. Male adult rats were given drinking solutions of CdCl2 [Cd(II) cation, 100 mg/liter] or NiSO4 [Ni(II) cation, 100 mg/liter]. For the combined treatment, the animals (Ni+Cd) received both Ni(II)) cation (100 mg/liter) and Cd(II) cation (100 mg/liter). Nickel treatment induced increased alanine transaminase (ALT) activity and hepatotoxicity, but not renal injury. In contrast, cadmium exposure produced hepatic, renal and myocardial damage, characterized by increased creatinine, total and direct bilirubin concentrations and increased ALT and lactate dehydrogenase (LDH) activities. The combined effect Ni-Cd is less toxic than cadmium alone, suggesting antagonism between these toxicants. The toxicity of nickel and cadmium, alone and in combination, decreased Cu-Zn superoxide dismutase (SOD) activity and increased lipoperoxide formation. (C) 1998 Elsevier B.V. Ltd. All rights reserved.