Objective: to determine the influence of air pollutants on the rainwater. Methods: use of wet deposition in a long-term study conducted in the state of Acre, in Western Amazon, from 2005 to 2010. One hundred and eightyfive rainy events were monitored to determine the pH value, the electrical conductivity and the concentration of total organic carbon. The atmospheric aerosol load was measured by solar photometry whereas the water vapors, temperature, winds and rains were monitored to observe weather conditions. Results: the pollutant concentration, depending on the aerosol optical depth, varied from very high values of 3 and 4 during the dry season, to very low values of about 0.08 during the rainy season. Twenty five percent of rainfalls were acidic with pH ranging 3 to 4.7, being 5.4 the average value. The electrical conductivity values were generally lower than 10 µS cm-1. The total organic carbon reached relatively high values of 20 to 30 mg L-1. Conclusions: in the dry season, the forest fires are responsible for high degree of air pollution, but the situation changes in the rainy season when the environment is clean because of the wet deposition. During the dry season, the air aerosol load increases 40 times if compared to the environmental conditions in the dry season. Therefore, more efficient control measures are needed to stop environmental degradation in the Amazon as well as a systematic monitoring of the air pollution for the benefit of human health and other forms of life.

Objetivo: determinar la influencia de contaminantes atmosféricos sobre el agua de lluvia. Métodos: utilización de la deposición húmeda en un estudio de largo plazo, realizado en el Estado de Acre, Amazonia Occidental, 2005-2010. Se monitorearon 185 eventos de lluvia, se determinó en ellos el pH, la conductividad eléctrica y la concentración de carbono orgánico total. Se monitoreó la carga de aerosoles atmosféricos mediante fotometría solar y las condiciones meteorológicas a través de mediciones del vapor de agua, temperatura, vientos y lluvias en su comportamiento estacional. Resultados: la concentración de contaminantes según la profundidad óptica de aerosoles varió desde valores muy altos, entre 3 y 4 durante la seca, hasta valores muy bajos, aproximadamente de 0,08, durante la estación lluviosa. El 25 % de las lluvias fue ácida con pH entre 3 y 4,7 y un promedio de 5,4. Los valores de conductividad eléctrica generalmente fueron inferiores a 10 µS cm-1. El carbono orgánico total alcanzó valores relativamente altos, entre 20 y 30 mg L-1. Conclusiones: durante la seca los incendios forestales responden por la alta contaminación de la atmósfera, que queda limpia durante la estación lluviosa por efecto de la deposición húmeda. Durante la seca la carga de aerosoles atmosféricos aumenta en más de 40 veces, en comparación con el estado de la atmósfera en la estación lluviosa. Son necesarias medidas más eficientes de control de la degradación ambiental en la Amazonia y de monitoreo sistemático de la contaminación de su atmósfera, en beneficio de la salud humana y de otras formas de vida.

Objective: to determine the influence of air pollutants on the rainwater. Methods: use of wet deposition in a long-term study conducted in the state of Acre, in Western Amazon, from 2005 to 2010. One hundred and eightyfive rainy events were monitored to determine the pH value, the electrical conductivity and the concentration of total organic carbon. The atmospheric aerosol load was measured by solar photometry whereas the water vapors, temperature, winds and rains were monitored to observe weather conditions. Results: the pollutant concentration, depending on the aerosol optical depth, varied from very high values of 3 and 4 during the dry season, to very low values of about 0.08 during the rainy season. Twenty five percent of rainfalls were acidic with pH ranging 3 to 4.7, being 5.4 the average value. The electrical conductivity values were generally lower than 10 µS cm-1. The total organic carbon reached relatively high values of 20 to 30 mg L-1. Conclusions: in the dry season, the forest fires are responsible for high degree of air pollution, but the situation changes in the rainy season when the environment is clean because of the wet deposition. During the dry season, the air aerosol load increases 40 times if compared to the environmental conditions in the dry season. Therefore, more efficient control measures are needed to stop environmental degradation in the Amazon as well as a systematic monitoring of the air pollution for the benefit of human health and other forms of life.

Objetivo: determinar la influencia de contaminantes atmosféricos sobre el agua de lluvia. Métodos: utilización de la deposición húmeda en un estudio de largo plazo, realizado en el Estado de Acre, Amazonia Occidental, 2005-2010. Se monitorearon 185 eventos de lluvia, se determinó en ellos el pH, la conductividad eléctrica y la concentración de carbono orgánico total. Se monitoreó la carga de aerosoles atmosféricos mediante fotometría solar y las condiciones meteorológicas a través de mediciones del vapor de agua, temperatura, vientos y lluvias en su comportamiento estacional. Resultados: la concentración de contaminantes según la profundidad óptica de aerosoles varió desde valores muy altos, entre 3 y 4 durante la seca, hasta valores muy bajos, aproximadamente de 0,08, durante la estación lluviosa. El 25 % de las lluvias fue ácida con pH entre 3 y 4,7 y un promedio de 5,4. Los valores de conductividad eléctrica generalmente fueron inferiores a 10 µS cm-1. El carbono orgánico total alcanzó valores relativamente altos, entre 20 y 30 mg L-1. Conclusiones: durante la seca los incendios forestales responden por la alta contaminación de la atmósfera, que queda limpia durante la estación lluviosa por efecto de la deposición húmeda. Durante la seca la carga de aerosoles atmosféricos aumenta en más de 40 veces, en comparación con el estado de la atmósfera en la estación lluviosa. Son necesarias medidas más eficientes de control de la degradación ambiental en la Amazonia y de monitoreo sistemático de la contaminación de su atmósfera, en beneficio de la salud humana y de otras formas de vida.

A remediação de uma amostra de Latossolo Vermelho-Amarelo contaminado artificialmente com petróleo (5.000 mg kg-1) foi estudada comparando diferentes oxidantes químicos: KMnO4 0,10 mol L-1; K2S2O8 0,10 mol L-1; H2O2 0,10 mol L-1; H2O2/Fe2+ 0,10/0,080 mol L-1 (reação de Fenton); e H2O2/Fe2+/UV 0,10/0,080 mol L-1 (reação de foto-Fenton). A remediação foi praticamente completa aos 30 min para o processo de foto-Fenton (99 %). Todos os outros oxidantes não atingiram essa taxa de dissipação até 180 min. O processo em que se usou H2O2 0,10 mol L-1 (70,51 %) foi o de menor eficiência. A adição de íons Fe aumentou a taxa de dissipação para 86,98 % (H2O2/Fe2+ 0,10/0,080 mol L-1). Os métodos convencionais apresentaram taxas de dissipação de 76,58 % (KMnO4 0,10 mol L-1) e 93,85 % (K2S2O8 0,10 mol L-1).

The possibilities of remediation of a Latossolo Vermelho Amarelo artificially contaminated with oil (5,000 mg kg-1) were investigated. Different remediation methods with chemical oxidants were compared: KMnO4 0.10 mol L-1; K2S2O8 0.10 mol L-1; H2O2 0.10 mol L-1; H2O2/Fe2+ 0.10/0.08 mol L-1 (Fenton's reaction) and H2O2/Fe2+/UV 0.10/0.08 mol L¹ (photo-Fenton reaction). The remediation was practically complete (99 %) after 30 min of the photo-Fenton process. No other oxidant reached this dissipation rate after 180 min. The remediation was least efficient with 0.10 mol L-1 H2O2 (70.51 %). The addition of iron ions increased the dissipation rate to 86.98 % (H2O2/Fe2+ 0.10/0.08 mol L-1). The conventional methods reached rates of 76.58 % (KMnO4 0.10 mol L-1) and 93.85 % (K2S2O8 0.10 mol L-1).

O objetivo deste trabalho foi obter compostos orgânicos similares aos encontrados na matéria orgânica da terra preta de índio (TPI) por meio de procedimento de funcionalização química de carvão ativado, bem como determinar a ecotoxicidade desses compostos. A partir do estudo da matéria orgânica de TPI, um modelo orgânico foi proposto e uma tentativa de reproduzi-lo foi descrita. Realizou-se a oxidação de carvão ativado pelo uso de hipoclorito de sódio em diferentes concentrações. Recorreu-se à ressonância magnética nuclear para verificar se os espectros dos produtos formados eram similares aos de ácidos húmicos de TPI. A similaridade dos espectros indicou que os produtos obtidos eram estruturas aromáticas policondensadas, com grupos carboxílicos: um condicionador de solo capaz de contribuir com a fertilidade do solo e com a sustentabilidade de seu uso. Um teste ecotoxicológico com Daphnia similis foi realizado nas frações mais solúveis (ácidos fúlvicos) do condicionador obtido. Cloretos de arila foram formados durante a síntese dos compostos orgânicos a partir do carvão funcionalizado e parcialmente removidos por meio de um processo de purificação. Contudo, é provável que algum cloreto de arila tenha permanecido no produto final, já que o teste ecotoxicológico indicou moderada toxicidade do condicionador obtido.

The objective of this work was to obtain organic compounds similar to the ones found in the organic matter of anthropogenic dark earth of Amazonia (ADE) using a chemical functionalization procedure on activated charcoal, as well as to determine their ecotoxicity. Based on the study of the organic matter from ADE, an organic model was proposed and an attempt to reproduce it was described. Activated charcoal was oxidized with the use of sodium hypochlorite at different concentrations. Nuclear magnetic resonance was performed to verify if the spectra of the obtained products were similar to the ones of humic acids from ADE. The similarity between spectra indicated that the obtained products were polycondensed aromatic structures with carboxyl groups: a soil amendment that can contribute to soil fertility and to its sustainable use. An ecotoxicological test with Daphnia similis was performed on the more soluble fraction (fulvic acids) of the produced soil amendment. Aryl chloride was formed during the synthesis of the organic compounds from activated charcoal functionalization and partially removed through a purification process. However, it is probable that some aryl chloride remained in the final product, since the ecotoxicological test indicated that the chemical functionalized soil amendment is moderately toxic.

Room-temperature phosphorimetry was used to quantify trace levels of chrysene in sugar-cane spirits and in fish bile. A selective phosphorescence enhancer (AgNO3) and synchronous scanning allowed the detection of ng amounts of chrysene. Accuracy (113 ± 17%) and selectivity was evaluated using the CRM-NIST-1647d - Priority Pollutant Polycyclic Aromatic Hydrocarbons in acetonitrile. Analysis of sugar-cane spirit samples enabled recovery of 108 ± 18% which agreed with the one achieved using HPLC. Method's uncertainty was equivalent to 3.4 ng of the analyte, however, the analyte pre-concentration (SPE) improved sensibility and minimized the relative uncertainty. Characterization and homogeneity studies in fish bile were also performed.

Estudou-se a desinfecção de águas de abastecimento por fotocatálise heterogênea usando um reator de fluxo em um sistema composto por uma placa de vidro com TiO2 P 25 (Degussa) imobilizado e luz solar como fonte de radiação. Foram utilizados dois modos de operação do reator: passagem única e recirculação. Os experimentos foram conduzidos utilizando inicialmente uma água preparada em laboratório e posteriormente água coletada em poços e lagos de uma região próxima à Campinas, SP. Estudou-se a influência de fatores, tais como, o modo de operação do reator, a cor e turbidez da água, os quais influenciam significativamente na eficiência fotocatalítica de descontaminação e, portanto, na viabilidade da aplicação do processo. Em dias ensolarados, alcançou-se uma redução na carga bacteriológica de cerca de 100% do valor inicial de Escherichia coli (2 <FONT FACE=Symbol>´</FONT> 10³ NMP per 100 mL) para soluções de água sintética, e, 80% do valor inicial de Escherichia coli (16.6 to 22.2 <FONT FACE=Symbol>´</FONT> 10³ MPN per 100 mL) para água in natura, através da fotocatálise heterogênea usando TiO2.

TiO2-assisted heterogeneous photocatalysis and photolysis were evaluated for the disinfection of water samples using a glass reactor with immobilized TiO2 (catalyst), solar light and E. coli as an indicator microorganism of the efficiency of disinfection. Parameters such as color and turbidity of the water, level of coliform bacteria (by the Colilert® method), inclination angle of the solar reactor, solar light intensity, flow rate and retention time were controlled during the experiments. Two different operational modes were used for the solar reactor: single pass mode and recirculation mode. First, synthetic water was used in the disinfection tests as a model system; second, tests were conducted using natural samples specifically groundwater collected from a lake and a well. In bacterial suspensions in synthetic water in the absence of color and turbidity, heterogeneous photocatalysis was responsible for the reduction of approximately 100% of the initial concentration of E. coli. Only a 56.5% reduction was obtained by photolysis during the same solution recirculation time, which indicated a better efficiency using the catalyst. From the natural samples, total inactivation was not achieved in the studied cases. However, photocatalysis using TiO2/solar light was shown to be quantitatively efficient in the destruction of the total coliforms in water, reaching values up to around 80% inactivation in natural waters with initial levels of total coliforms ranging from 16.6 to 22.2<FONT FACE=Symbol>´</FONT>10³ MPN per 100 mL.

Conventional technology used in the treatment of wastewater has been pointed as a major environmental problem for sustainable development, since minimization is not addressed accordingly. Advanced oxidation processes (AOP), based on the formation of hydroxyl radical (•OH), a powerful oxidant agent, have been considered to be a potential technology for the destruction of many toxic compounds. Photocatalysis using solar light, an AOP, has been studied for nearly 20 years and recently attracted great interest as a clean-up technology. However, solar detoxification processes have not yet achieved commercial success. This article presents an overview of reaction mechanisms at the surface of semiconductors used as photocatalysts (specially TiO2), when heterogeneous photocatalysis is used to remove hazardous compounds from contaminated sites.