Tratamento estatístico dos parâmetros da qualidade das águas da bacia do alto curso do Rio das Velhas

Water quality was monitored at the upper course of the Rio das Velhas, a major tributary of the São Francisco basin located in the state of Minas Gerais, over an extension of 108 km from its source up to the limits with the Sabara district. Monitoring was done at 37 different sites over a period of 2 years (2003-2004) for 39 parameters. Multivariate statistical techniques were applied to interpret the large water-quality data set and to establish an optimal long-term monitoring network. Cluster analysis separated the sampling sites into groups of similarity, and also indicated the stations investigated for correlation and recommended to be removed from the monitoring network. Principal component analysis identified four components, which are responsible for the data structure explaining 80% of the total variance of the data. The principal parameters are characterized as due to mining activities and domestic sewage. Significant data reduction was achieved.

Geoquímica de fósforo como indicadora da qualidade ambiental e dos processos estuarinos do Rio Jaguaribe - costa nordeste oriental brasileira

Phosphorus geochemistry as a proxy of environmental estuarine processes at the Jaguaribe River, Northeastern Brazil. Sedimentation of different phosphorus geochemical fractions can characterize the natural or anthropogenic processes dominant in the watershed. Selective chemical extraction of different phosphorus geochemical forms in estuarine sediments showed the predominance of inorganic over organic forms suggesting an increase in inorganic phosphorus input from anthropogenic sources. Local hydrochemistry favors the dominance of inorganic ferric and carbonatic phosphorus. Ongoing changes in the estuarine throphy, from mesothrophic to euthrophic, may decrease the immobilization of these forms, increasing dissolved phosphorus and favoring euthrophy. Detritic phosphorus suggests a fluvial origin of this fraction and acts as a tracer of river influence upon the estuary.

Avaliação do efeito da piscicultura em sistemas aquáticos em Assis e Cândido Mota, São Paulo, por indicador de qualidade da água e análise estatítica multivariada

In this work, the impact of fish farming activities on the Queixada, Macuco and Pari-Veado Rivers in the Paranapanema watershed was evaluated. Physical, chemical and microbiological parameters were quantified in these aquatic systems followed by application of multivariate statistical analysis (MSA) and water quality index (WQI) tools. Watersheds where fish farming activities are predominant presented WQI > 52 indicating good quality, whereas MSA demonstrated bad quality for these aquatic bodies. The results showed that the degradation in this watershed follows the fish farming activity. The MSA index is more restricted than the "National Foundation Sanitation" (NFS) index routinely used to infer water quality.

Efeito da presença e concentração de compostos carbonílicos na qualidade de vinhos

Studies on identification of compounds that make up the aroma and flavor in wines involve research evaluating mainly the influence of terpenes, esters, lactones and alcohols upon these sensory characteristics. However, carbonylic compounds (CC) play an important role concerning the substances that impact aroma to these drinks. Their origin is reported to be linked to the grape's chemical composition, must fermentation or micro-oxidation occurring during storage in barrels. Some CCs, like E-ionone, E-damascenone, siryngaldehyde, can contribute a pleasant aroma and improve the wine quality whereas others are responsible for unpleasant characteristics (acetaldehyde, furfural, 5-hydroxy-methyl furfural, diacetil, E-non-2-enal, etc). A fraction of CCs present is associated with bisulfite ions in the form of hydroxyalkylsulfonic acids. Some of them are stable and play an important role in determining wine quality. The reaction involving the formation of this aduct commonly occurs with CCs of low molar mass, such as formaldehyde and acetaldehyde. The reaction involving CCs with more than three carbon atoms demands further studies.

Avaliação da qualidade do corpo hídrico do rio Tibagi na região de Ponta Grossa utilizando análise de componentes principais (PCA)

The aim of this paper was to evaluate alterations in the quality of the water of the Tibagi River caused by the urban and industrial activities in the region of Ponta Grossa. The study involved the monitoring of physico-chemical and microbiological parameters of the water body, which were evaluated by a principal components analysis routine. Sample collections were carried out monthly during one year (October of 2005 to September of 2006), at 3 sampling points: upstream and downstream of the industrial district and downstream from the city of Ponta Grossa. The principal components analysis showed the effect of point sources associated with industrial activity, which contribute to the rise of total concentration of amoniacal nitrogen and the reduction of dissolved oxygen in the studied region.

Indicadores químicos de qualidade da matéria orgânica de solo da sub-bacia do Rio das Mortes sob manejos diferenciais de cafeeiro

This work evaluated the chemical quality of organic matter (OM) of a Brazilian Oxisol cultivated with coffee plants, under organic and conventional managements. Total organic C (TOC), light fraction C (LF-C) and C in humic (HA-C) and fulvic (FA-C) acids fractions was measured. Amongst the evaluated indexes, TOC and LF-C discriminated better OM attributes as a function of management. The stratification ratio (TOC5-10cm/TOC10-20cm) did not show differences between the systems studied. The organic system can contribute to the sustainability of coffee plantations in Brazil, because it maintains the chemical attributes of OM closer to the indexes verified under forest conditions.

Parâmetros bioquímicos foliares das espécies Licania tomentosa (Benth.) e Bauhinia forficata (Link.) para avaliação da qualidade do ar

Foliar analysis of biochemical parameters were carried out in order to investigate the influence of air pollutants on two tropical tree species (Licania tomentosa (Benth.) and Bauhinia forfícata (Link.)). Special attention was given to tropospheric ozone due to the fact that concentration levels in the region were found to be up to 140 µg m-3 for a 4 h average time, which is well above the value that can cause injuries to orchides and tobacco (59 µg m-3). Other pollutants such as nitrogen and sulphur oxides were measured and their ambient concentrations were also associated to biochemical alterations in the investigated species.

Efeitos dos escoamentos urbanos e rurais na qualidade das águas do córrego verruga em vitória da conquista - Bahia, Brasil

This study examined the spatial and temporal variations of 13 physico-chemical parameters in water and sediment samples collected along the rural and urban section of Verruga Stream. The metal concentrations were determined by FAAS. The conductivity and the concentration of Na+, Cl-, and Ca2+ showed the largest variations in the urban area demonstrating that these parameters are appropriate indicators of urban contamination. The application of cluster and principal component analysis showed that the Cd2+ and Mn2+ are associated with the use of fertilizers in the rural area.

Métodos de extração e qualidade da fração lipídica de matérias-primas de origem vegetal e animal

Methodologies of extraction of lipids from chicken breast and oats flakes were evaluated: Soxhlet, Folch et al., Bligh & Dyer and Hara & Radin. For chicken breast, the methods Soxhlet, Folch et al. and Bligh & Dyer presented the highest yields in total lipids. With oat flakes, the methods Soxhlet and Bligh & Dyer presented higher yields than the Hara & Radin and Folch et al. The Soxhlet method affected the quality of the lipid fraction in both samples. Extracted lipid components were separated by thin layer chromatography, the chloroform-methanol based was more efficient to extract the neutral and polar lipids.

Estudo da especiação de arsênio inorgânico e determinação de arsênio total no monitoramento ambiental da qualidade de águas subterrâneas

This work reports an alternative, fast and robust method, for the determination of total As, As(III) and As(V) by HG-AAS without the use of prereductants. The method is based on the different rates of arsine formation of the inorganic As species and the effect of As(III) in the signal obtained for total As. Groundwater and mineral spiked waters were used to sample preservation evaluation. The method was validated by the determination of As in SRM 1640 and used in the determination of total As and its inorganic species in groundwater samples collected from mines in the Iron Quadrangle - MG.

Biodiesel: parâmetros de qualidade e métodos analíticos

The establishment of quality standards for biodiesel was a key step to win the confidence of the market and the automotive industry, thus ensuring the success of the new fuel. In this review are presented standard methods and other analytical methods suggested for analysis of biodiesel. The methods of analysis were divided into groups according to information that may be provided on the contaminants from the raw material of the production process, the molecular structures of biodiesel and its degradation during storage.

Avaliação da qualidade de sedimentos - estudo de caso: sub-bacia do Ribeirão Espírito Santo, afluente do Rio São Francisco

This study evaluated the environmental impact resulting from surface water and sediment contamination by metals in a watershed affected by a tailing basin that controls effluents coming from a zinc-ore beneficiation plant. The studies combined assessments of sediment chemistry (exceedances of sediment quality guidelines), benthic assemblage structure and acute and chronic ecotoxicity. The results showed that the levels of metal contamination in sediments are not yet enough to cause deleterious effects to the biota. However, the ecotoxicity tests indicated the occurrence of chronic effects, demonstrating that other factors, as the use of fertilizers, could also be a source of contamination.

A qualidade de água como indicador de uso e ocupação do solo: bacia do Gama - Distrito Federal

The spread of Brasília isn't accompanied by correct support of land occupation, situation that is reflected in water quality. Under the optics of land use and occupation, working with multivariate statistics as main tool, water physical and chemical quality of Gama Catchment were assessed. During two years samples were collected and analyzed for 24 parameters. The statistical analysis showed the influence of civil buildings, agricultural activities and the best statistical parameters to a quickly assessment: nitrate, ammonia, suspended solids and aluminium.

Avaliação e identificação de parâmetros importantes para a qualidade de corpos d'água no semiárido baiano. Estudo de caso: bacia hidrográfica do rio Salitre

Objective of this work was identifying superficial water quality parameters, significant to semi-arid hydrographic basins, minimizing costs of water monitoring. The Salitre river basin, an important sub-basin of the São Francisco river, was used as a case study. STD, Cl-, DO, BOD, pH, NO3-, PO4(3-), Al, Cu, Fe, Mn, Ni and Pb were considered the most significant parameters, with concentration levels found in some stretches of the basin not compliant with the current legislation. Some of the Salitre river basin sediments may represent a risk to the quality of the water body in relation to levels of nickel and zinc.

Uso de CLAE no controle de qualidade em produtos comerciais de Nim: reprodutibilidade da ação inseticida

The Neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides. However, the efficiency in field of products like neem oil can be committed because they have not been observed reproductive content of secondary metabolic like azadirachtin. Based on reverse-phase high-performance liquid chromatography (HPLC) a new method was developed to permit the rapid quantitative analysis of azadirachtin from seeds, extracts and oil of Neem. In the present study it was evaluated the azadirachtin quantitative variation among various Neem's extracts and seeds showing the importance of quality control for reproduction of the insecticide efficiency, using S. frugiperda as target insect.