Diagnóstico ambiental de metais e organoclorados em córregos adjacentes a áreas de cultivo de cana-de-açúcar (Estado de São Paulo, Brasil)

Sugar cane cultivation in the State of São Paulo has expanded in the last years, with an annual production of 200•10(6) t in an area of 2.5• 10(6) hectares. The use of herbicides, pesticides and fertilizers in sugar cane plantations, together with deforestation of riparian vegetation, have caused impacts on the hydric resources of the adjacent areas. The aim of this work is to evaluate the influence of sugar cane plantations on streams in the central region of the State of São Paulo, studying 16 organochlorinated compounds and 7 metals (Cu, Fe, Cd, Zn, Mn, Cr and Ni) found in the sediments of 11 streams. The results show that there is a higher concentration of metals and organochlorinated compounds in streams without riparian vegetation when compared to forested areas.

Uso de lodo de estação de tratamento de água centrifugado em matriz de concreto de cimento portland para reduzir o impacto ambiental

An alternative application of the humid sludge from the Passaúna WTP, located in Curitiba's metropolitan area, is proposed for concrete structures, partially replacing aggregates and cement. For the investigation, a reference concrete and four concrete mixtures with sludge were produced, and from these, two mixtures, containing 4% and 8% of sludge (m/m), were analyzed by different techniques: X ray fluorescence, X ray diffraction, thermo-gravimetric analysis, physicochemical analysis, compressive strength, etc. The properties were evaluated and the results indicate that the mixtures can be applied in different situations as cast structures for construction of concrete walls. Mixtures with more than 4% of sludge are restricted to applications where the workability of the concrete is not required, such as for residential pavements, sidewalks and stepping floors.

Monitoramento atmosférico passivo de SO2, NO2 e O3 em áreas urbanas e de influência industrial como prática de química ambiental para alunos de graduação

This study is a result of undergraduate student participation in the Environmental Chemistry discipline provided by the Chemistry Institute/UFBA. The students were involved in the development of passive samplers, a project of the LAQUAM (Environmental Analytical Chemistry Laboratory). The students' residences and other neighborhoods were used to create a passive sampling network, allowing the measurement of atmospheric levels of pollutants in urban areas and in those under industrial influence. The assembly of the passive samplers, including impregnation of filters and chemical analysis were part of the students' practice tasks. The results were analyzed taking into consideration the Brazilian legislation.

Método multirresíduo para monitoramento de contaminação ambiental de pesticidas na região de Bauru (SP) usando mel como bio-indicador

The presence of residues of the major groups of pesticides (organohalogen, organophosphorous, pyrethroids and organonitrogen) in representative samples of honey produced in Bauru (state of São Paulo, Brazil) was investigated from 1999 through2004. A multiresidue method was applied to honey samples to determine 48 pesticides with recoveries ranging from 76 to 95%. The limits of detection found were lower than 10 µg/kg for GC-MS-SIM. The results indicated that most pesticides found in the samples belonged to the organohalogen and organonitrogen groups. Residues of malathion were detected in almost all of the samples in high concentration.

Alquilbenzeno sulfonato linear: uma abordagem ambiental e analítica

The environmental impact of detergents and other consumer products is behind the continued interest in the chemistry of the surfactants used. Of these, linear alkylbenzene sulfonates (LASs) are most widely employed in detergent formulations. The precursors to LASs are linear alkylbenzenes (LABs). There is also interest in the chemistry of these hydrocarbons, because they are usually present in commercial LASs (due to incomplete sulfonation), or form as one of their degradation products. Additionally, they may be employed as molecular tracers of domestic waste in the aquatic environment. The following aspects are covered in the present review: The chemistry of surfactants, in particular LAS; environmental impact of the production of LAS; environmental and toxicological effects of LAS; mechanisms of removal of LAS in the environment, and methods for monitoring LAS and LAB, the latter in domestic wastes. Classical and novel analytical methods employed for the determination of LAS and LAB are discussed in detail, and a brief comment on detergents in Brazil is given.

Ecomateriais: desenvolvimento e aplicação de materiais porosos funcionais para proteção ambiental

Fundamental aspects of the conception and applications of ecomaterials, in particular porous materials in the perspective of green chemistry are discussed in this paper. General recommendations for description and classification of porous materials are reviewed briefly. By way of illustration, some case studies of materials design and applications in pollution detection and remediation are described. It is shown here how different materials developed by our groups, such as porous glasses, ecomaterials from biomass and anionic clays were programmed to perform specific functions. A discussion of the present and future of ecomaterials in green chemistry is presented along with important key goals.

Avaliação de contaminação ambiental causada por poluentes orgânicos persistentes utilizando simulação computacional

Environmental concern is growing in the current days and there is global agreement to banish production and use of persistent organic pollutants (POP). The synthetic insecticides chlordecone and mirex, classified as POPs, have similar structures and they are potentially toxic. This work uses properties and physicochemical constants related to the pesticides and computational simulation to evaluate the leach phenomenon and persistency in soil. The largest tendency of persistence of the compound is found to be in the surface of soil, but even low concentration in water represents a high risk due to bioaccumulation in adipose tissue.

Avaliação do impacto da agricultura em áreas de proteção ambiental, pertencentes à bacia hidrográfica do rio ribeira de iguape, São Paulo

In order to ascertain the impact of agricultural activities on water quality of the Ribeira de Iguape River Basin in the state of São Paulo, surface water areas for catchment and drinking water have been characterized. The sampling period covered March/2002 - February/2003 and January/2004 at 10 different catchment points. SPE-LC-UV/Vis was used to monitor various pesticide classes such as carbamates, triazines and nitroanilines. The results revealed that water quality is associated with seasonal variation. Of 152 samples analyzed, only 24% showed the presence of pesticides, particulary during the wet season. High variability in pH, turbidity and color were observed.

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.

Un método de bajo costo para la determinación de cobre a nivel de vestigios en matrices de interés ambiental por espectrofotometría en fase sólida (EFS)

A method for determining copper by solid phase spectrophotometry (SPS) was optimized using the Doehlert design. Copper(II) was sorbed on a styrene-divinylbenzene anion-exchange resin as a Cu(II)-1-(2-pyridylazo)-2-naphthol (PAN) complex, at pH 7.0. Resin phase absorbances at 560 and 800 nm were measured directly. The detection limit was found to be 2.5 µg L-1. The relative standard deviation on ten replicate determinations of 10 µg Cu(II) in 1000 mL samples was 1.1%. The linear range of the determination was 5.0-100 µg L-1. The method was applied successfully to the determination of Cu(II) in natural water and vegetable samples.

A gestão integrada de resíduos sólidos urbanos - perspectiva ambiental e económico-energética

The importance of urban solid waste integrated systems is characterized by the several components of these systems, which are, basically, formed by physical, chemical and biological methods. This article, characterizes these methods and, which is also important, identifies the several and potential environmental impacts of those techniques. It's also extremely important to make a study of the economic rentability of those infrastructures and, also, characterize the quantitative energetic contributions of some components of these systems. This study was analysed and their results are presented in this article.

Educação ambiental nas escolas da região de Ribeirão Preto (SP): concepções orientadoras da prática docente e reflexões sobre a formação inicial de professores de química

During short courses, 95 secondary school teachers from 49 state schools and 421 students from the Ribeirão Preto region (in Sao Paulo state, Brazil, with a population of 530,000) were asked to fill in different questionnaires. The points raised in the teacher's questionnaire were used as a guide to establish a continuous dialogue during the short courses. Most of the schools claimed to have some kind of environmental education (EE). Based on the questionnaires and dialogues we analyzed how the teachers' perceptions on EE reflect on the views secondary students hold about their own responsibility for preserving the environment. The role of universities in the preparation of chemistry teachers capable of effectively approaching EE is also discussed.

Ambiental volatile organic compounds in the megacity of São Paulo

In order to characterize the composition of the main urban air organic compounds in the megacity of Sao Paulo, analysis of samples collected during the winter of 2003 downtown was carried out. The samplings were performed on the roof of a building in the commercial center of São Paulo. Hydrocarbons and carbonyls compounds were collected on August 4, 5 and 6. Comparing to previous data, the concentration of hydrocarbons presented no decrease in the concentration, except for the aldehydes, which decreased when compared to previous data. Among the HCs species analyzed, the highest concentrations observed were those of toluene (7.5 ± 3.4 ppbv), n-decane (3.2 ± 2.0 ppbv), benzene (2.7 ± 1.4 ppbv) and 1,3,5-trimethylbenzene (2.2 ± 1.5 ppbv).

Experimento didático sobre cromatografia gasosa: uma abordagem analítica e ambiental

This paper describes an experiment to teach the principles of gas chromatography exploring the boiling points and polarities to explain the elution order of a series of alcohols, benzene and n-propanone, as well as to teach the response factor concept and the internal standard addition method. Retention times and response factors are used for qualitative identification and quantitative analysis of a hypothetical contamination source in a simulated water sample. The internal standard n-propanol is further used for quantification of benzene and n-butanol in the water sample. This experiment has been taught in the instrumental analysis course offered to chemistry and oceanography students.