The present study aimed to propose a new cause of odorous compounds release, i.e., the presence of antibiotics in water bodies and its toxicity to cyanobacteria, known to be the main producer of geosmin (GEO) and 2-methylisoborneol (2-MIB). Therefore, a literature review was carried out regarding the problems caused by antibiotics in aquatic environment, including cyanobacterial blooms and GEO and 2-MIB release. In addition, a bibliometric analysis was performed using the VOSviewer software based on the results obtained from the Web of Science (WOS) database. This review aims to build a scientific understanding of the problem, presenting interesting points that converge with the proposed association. It is worth mentioning that no work has been found in the literature that has proposed this relationship. Thus, based on the bibliographic survey, observations and information acquired in recent years about cyanobacterial blooms and environmental contamination by pharmaceutical drugs, one of the main causes of an earthy and musty flavour and odour in a drinking water supply is the toxicity imposed by the presence of antibiotics in aquatic environments on cyanobacteria.

Abstract Glyphosate affects ecosystems due to exposure of non-target crops and is a persistent contaminant at low concentrations. The application of palygorskite to reduce glyphosate contamination in Brazil is an environmentally friendly way to remediate impacted areas. This research evaluated palygorskite application for glyphosate adsorption present in a synthetic effluent. Palygorskite samples were ore dressed by wet granulometric classification and wet magnetic separation and submitted to organophilization with cetyltrimethyl ammonium bromide solutions at concentrations of 0.01, 0.1, 1.0 and 1.5% (w/w), and the organo-palygorskite was applied in glyphosate adsorption tests. After ore dressing there was an increase in its cation exchange capacity from 19 to 41 meq 100 g-1 and the surface area was 149 g m-2. The 1.0% organo-palygorskite adsorbed about 86% of glyphosate from synthetic aqueous effluent. Based on this high adsorption yield, the organo-palygorskite is a potential adsorbent for remediation of effluents containing the toxic herbicide glyphosate.

ABSTRACT The objective of this work was to investigate the adsorptive potential of a previously benefited and characterized brazilian montmorillonite sample, regarding amoxicillin trihydrate removal, a zwitterionic species, present in aqueous solutions. 500 mg capsule of antibiotic was properly characterized by XRD, FTIR, SEM/EDS and surface charge measurement through Zeta potential. Amoxicillin aqueous solution and supernatants from adsorption essays were characterized by Molecular Absorption Spectrophotometry in Ultraviolet-Visible Region (UV/VIS), from 200 to 400 nm. Three investigative essays were performed, varying montmorillonite mass (0.050, 0.525 and 1.000 g) and contact time between substances (10, 95 and 180 min). Amoxicillin sample is crystalline, morphologically prismatic, essentially composed of carbon, nitrogen, sulfur, hydrogen and oxygen. Its zwitterionic character was confirmed by Zeta potential, presenting positive (pH 2 to 4), relatively neutral (pH 4 to 6), and negative (above pH 6) surface charges. Test results indicated that the highest removals (21.4 and 41.8 %) were for the largest clay mineral masses (0.525 and 1.000 g, respectively), with pHs close to amoxicillin pka1 (2.68). Larger clay mineral masses have more adsorbent sites, which, associated with components opposite charges in desired pH range, promote a greater interaction. Thus, brazilian montmorillonite can promote amoxicillin removal from aqueous solutions.

Resumo Objetiva-se, aqui, avaliar o efeito do manejo do fogo nas transformações das propriedades físicas (granulometria e porosidade), químicas (matéria orgânica e pH) e mineralógica do solo. O estudo foi desenvolvido no distrito de São Pedro da Serra - Nova Friburgo/RJ, área de predomínio da agricultura de corte e queima, com presença de relevo formado por vertentes íngremes e vales encaixados. A região apresenta um clima Tropical de Altitude, caracterizado por verões quentes e chuvosos e invernos amenos e secos. A precipitação média anual é de 1.279 mm, sendo os meses mais chuvosos de novembro a março, e os meses mais secos de maio a agosto, marcando o período sazonal de chuvas (verão) e secas (inverno). Foram coletadas amostras deformadas e indeformadas de solo nas profundidades de 0-5cm, 5-10cm e 10-15cm, em uma área de incêndio (INC - fogo de alta intensidade) e outra com a presença de uma agricultura tradicional de corte e queima (CO - fogo de baixa intensidade). Conclui-se que as propriedades físicas, químicas e mineralógicas do solo têm respostas distintas à perturbação gerada pelo fogo. Os resultados indicam que a área onde ocorreu incêndio (INC), apresenta hidrofobicidade acompanhada de maiores valores de microporosidade. Já no sistema tradicional de corte e queima (CO) há maior percentual de macroporos. Os resultados sugerem que a agricultura tradicional de corte e queima foi o sistema que menos alterou as propriedades do solo.

Abstract The objective of this study was to evaluate the effect of fire on the transformation of the soil’s physical (granulometry and porosity), chemical (organic matter and pH) and mineralogical properties in an area where slash-and-burn farming predominates. The study was conducted in the district of São Pedro da Serra, municipality of Nova Friburgo, Rio de Janeiro state, Brazil, with relief formed by steep slopes interspersed with valleys. The region has a Tropical Altitude Climate, characterized by hot, rainy summers and mild, dry winters. The average annual rainfall is 1.279 mm, with the wettest months from November to March, and the driest months from May to August, marking the seasonal rainy (summer) and dry (winter) period. We collected deformed and undeformed soil samples at three depths (0-5 cm, 5-10 cm and 10-15 cm), in two areas, one that had been subject to high-intensity fire (HIF) and the other where traditional slash-and-burn agriculture is practiced (S&B), with low-intensity fire. The physical, chemical and mineralogical properties of the soil had distinct responses to the disruption caused by fire of varying intensity. In the HIF area, the soil was hydrophobic, accompanied by smaller pore size (microporosity). In the S&B area, in contrast, the soil had a greater percentage of macropores. The results suggest that slash-and-burn agriculture, where there are fallow intervals, less severely affects the soil properties.

ABSTRACT Our previous work reported that palygorskite has potential for application as metal cations adsorbent due to its chemical and mineralogical properties. In this work, kinetic study and adsorption isotherms were performed in order to evaluate Pb (II) ions adsorption rate, maximum capacity and type of adsorption by using palygorskite as adsorbent. Adsorption tests were performed in batch, using pH of 5, 2 g of palygorskite, 40 mL of synthetic effluent solution and stirring for 1 hour. Kinetic experiments were performed using 34 mg L-1 of a lead synthetic effluent at same mass and pH conditions. Furthermore, after adsorption studies, the sample was characterized by X-ray fluorecence (XRF), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDS) analysis, in order to verify and understand the interaction of lead ions in palygorskite. The results demonstrated that palygorskite presented an equilibrium time of 10 min with 99.14% of removal, following pseudo-second order kinetic. The maximum adsorption capacity was 21.65 mg g-1 and Gibbs’ adsorption-free energy was -21.39 KJ mol-1, with Langmuir model being the most suitable for adjustment of the data. Thus, its presence was confirmed by characterization techniques, indicating that the metal is distributed homogeneously on palygorskite surface, proving its efficiency as lead ions adsorbent.

ABSTRACT The potential mobility of Cd, Cr, Cu, Ni, Pb and Zn in soils severely impacted by inadequate storage of industrial wastes in Rio de Janeiro State (Brazil) was evaluated by applying the Toxicity Characteristic Leaching Procedure (TCLP). This procedure allowed the estimation of toxicity risks for Cd, Cr and Pb. In a contamination hotspot within the study area, the following order of metal concentrations was observed: Pb > Zn > Cu > Ni > Cd > Cr, with significantly higher values than observed for a control site. Decades of soil exposure to wastes implied TCLP results for Pb above 300 mg/L in this hotspot, which exceed the TCLP regulatory threshold in two orders of magnitude, while Cd (up to 0.8 mg/L) and Cr (up to 0.3 mg/L) results were below the respective TCLP thresholds. Surface soil profile analysis (0-30 cm depth) indicates that Pb vertical migration occurs in the hotspot. TCLP concentrations of Pb were up to four orders of magnitude higher than the groundwater quality threshold preconized by Brazilian regulations for this metal (0.01 mg/L), suggesting that downward dispersion of large loadings of anthropogenic Pb is a major concern.

RESUMEN La movilidad potencial de Cd, Cr, Cu, Ni, Pb y Zn en suelos gravemente afectados por el almacenamiento inadecuado de desechos industriales en el estado de Río de Janeiro, Brasil, se evaluó mediante la aplicación del procedimiento de lixiviación con características de toxicidad (TCLP, por sus siglas en inglés). Este procedimiento permitió la estimación de riesgos de toxicidad para Cd, Cr y Pb. En una zona de alta contaminación dentro del área de estudio, se observó el siguiente orden de concentraciones de metales: Pb > Zn > Cu > Ni > Cd > Cr, con valores significativamente más altos que los observados para un sitio de control. Décadas de exposición del suelo a desechos implicaron resultados de TCLP para Pb por encima de 300 mg/L en esta zona, los cuales exceden el umbral regulatorio de TCLP en dos órdenes de magnitud, mientras que los valores de Cd (hasta 0.8 mg/L) y Cr (hasta 0.3 mg/L) estuvieron por debajo de los umbrales de TCLP respectivos. El análisis del perfil del suelo superficial (0-30 cm de profundidad) indica que la migración vertical de Pb se produce en la zona de alta contaminación. Las concentraciones de Pb obtenidas con el TCLP fueron hasta cuatro órdenes de magnitud más altas que el umbral de calidad del agua subterránea recomendado por las regulaciones brasileñas para este metal (0.01 mg/L), lo que sugiere que la dispersión descendente de grandes cargas de Pb antrópico es un problema importante.

RESUMO Áreas contaminadas por metais podem configurar sério risco à saúde pública e ao meio ambiente. Na década de 1980 foi instalado um pátio de estocagem provisória de resíduos industriais perigosos (CENTRES), no município de Queimados, Rio de Janeiro, o que causou um grande impacto ambiental ao solo da região. A legislação brasileira para o diagnóstico de áreas contaminadas limita a extração de metais em solos aos métodos recomendados pela United States Environmental Protection Agency (USEPA) 3050 e 3051A. Entretanto, muitos pesquisadores utilizam o método com água-régia para a extração de metais em solo, mas são escassos estudos que comparem as concentrações de metais extraídos por água-régia e USEPA 3051A. Logo, o objetivo deste trabalho foi avaliar se o método de extração de metais em solos por água-régia é estatisticamente diferente do método USEPA 3051A. Os resultados obtidos revelaram que as concentrações de Cd, Cr, Cu, Ni, Pb e Zn utilizando ambas as extrações (água-régia e USEPA 3051A) foram estatisticamente semelhantes. Também foi possível identificar que as concentrações de Cu, Ni, Pb e Zn foram superiores ao valor de investigação industrial, o que caracteriza essa área como altamente contaminada e solo classe 4.

ABSTRACT Metal contaminated areas lead to environmental and public health risks. In the 1980s, dangerous industrial waste storage was initiated in the CENTRES area in the municipality of Queimados, Rio de Janeiro, Brazil. The inadequate management of these wastes has promoted a large environmental impact to this region’s soils. The Brazilian legislation for diagnostics of contaminated areas limits the extraction of metals on soils to USEPA 3050-B and USEPA 3051-A methods. However, many researchers use the aqua regia method for extracting metals in soil, but there are few studies comparing concentrations of metals extracted by aqua regia and USEPA 3051A. Therefore, the objective of this work was to evaluate if the method of extracting metals in soils by aqua regia is statistically different from US EPA 3051A. The results showed that the Cd, Cr, Cu, Ni, Pb and Zn concentrations using both extractions were statistically similar. It was also observed that Cu, Ni, Pb and Zn concentrations were higher than the industrial investigation value which characterizes this area as highly contaminated and soil class 4.

Abstract Companies producing lead-acid batteries are required by law to recycle their battery scrap. The recycling can be performed by a pyrometallurgical process resulting in slags containing mainly lead and iron. A study was carried out with the aim of recovering the lead contained in this slag. This work has economic and environmental implications. Slag characterization was performed by X-ray diffraction, X-ray fluorescence and scanning electron microscopy (SEM). A laboratory-scale mechanical cell was used for flotation tests. The results showed that Pb-Fe selectivity is possible using ethyl xanthate as collector. The coke floats together decreasing concentrate grade. However, this is no problem because coke participates in the metallurgical process for the production of lead. A concentrate containing 22.9% Pb was obtained from a slag with 2.2% Pb. The process removes more than 99.6% of the iron contained. However, the recovery was only 19.0 %. Analyses from scanning electron microscopy detected the presence of lead inside the iron particles, limiting the possibility of lead recovery.

Atualmente, compósitos à base de polímero/carga mineral têm sido alvo de grande interesse, tanto em indústrias quanto em pesquisas acadêmicas, devido à melhora significativa nas propriedades dos materiais quando comparadas ao polímero virgem. O carbonato de cálcio (CaCO3) é um dos materiais mais abundantes do planeta e tem sido geralmente usado na obtenção de compósitos poliméricos. As propriedades de suas partículas (tamanho, forma e módulo) podem provocar um efeito significativo, especialmente no comportamento mecânico. As misturas PEAD/CaCO3 são amplamente usadas na indústria automotiva. No presente estudo, o efeito da incorporação de CaCO3 nas propriedades mecânicas e de escoamento destas misturas foi avaliado através de um planejamento fatorial simples de dois níveis, do tipo 2n, com n = 3 fatores: teor de carga; tamanho de partícula e velocidade de rotação da rosca. As variáveis de resposta analisadas foram: módulo de Young e resistência ao impacto e índice de fluidez (MFI). Os resultados mostraram que, dentro dos níveis estabelecidos, o fator que apresentou mais impacto nas variáveis de resposta foi o teor de carga mineral.

In recent years, polymer/mineral filler composites have attracted great interest, both in industries and academic researches, because they often show a remarkable improvement of materials properties when compared to virgin polymers. Calcium carbonate, CaCO3, is one of the most abundant materials on the planet and it has been often used to obtain polymer composites. The properties of its particles (size, shape and modulus) can provoke a significant effect, especially on mechanical behavior. HDPE/CaCO3 compounds are widely used in the automotive industry. In the present study, the effect of CaCO3 addition to the mechanical and flow properties of these compounds was evaluated using a simple 2n factorial design, with n = 3 factors: filler content; particle size and screw speed. The dependent variables analyzed were: Young modulus; impact strength and melt flow index (MFI). The results showed that the greatest impacts on the dependent variables were related to changes on mineral filler content.

Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.

Neste trabalho a função TCHZ (Modificada por Thompson-Cox-Hastings) foi usada para a análise das larguras integrais dos perfis das linhas de difração dos raios X de caulinitas através do método de ajuste Le Bail. Este método não requer informações estruturais, exceto dos parâmetros de rede aproximados e dos parâmetros de resolução instrumental. Esta técnica de refinamento faz parte do programa FullProf onde é conhecido como "Profile Matching". O método foi aplicado para dois casos de alargamento devido aos tamanhos de cristalitos e microdeformações da rede da caulinita de depósitos brasileiros, que passaram por beneficiamentos químico e físico. As amostras apresentam teores de Fe2O3 variando entre 1,55 (moderado) a 3,04% (alto). O refinamento através do método de Rietveld foi realizado com os dados de uma amostra de referência padrão do LaB6 para obter simultaneamente os parâmetros instrumentais e como uma maneira independente de validar os resultados obtidos pelo método "Profile Matching". Foi observado que o tamanho do cristalito decresce e a deformação cresce com o aumento do conteúdo de Fe2O3 (% em peso) na amostra. A forma Lorentziana dos alargamentos intrínsecos das linhas de difração é um forte indicador que são os pequenos tamanhos dos cristalitos a principal causa das imperfeições das amostras de caulinitas analisadas.

In this work, the modified Thompson-Cox-Hastings function (TCHZ) was used in the analisys of the integral breadths obtained from the broadned X ray diffraction line profiles. These set of X ray diffraction results were calculated from the "Le Bail" fitting method, which does not require any structural information, except unit cell and resolution instrumental parameters. The refinement used here is called ‘Profile Matching' in the FullProf, a program for Rietveld analysis. The method was applied in two case size-strain broadening of kaolinites from Brazilian deposits that after the treatment chemical and physical still had a content ranging between 1,55 % w/w (intermediate) to amount of 3,04% w/w (high) of structural and total iron. The Rietveld refinement was first performed by using the set of data from standard reference material LaB6to obtain all the instrumental parameters, simultaneously. This result has been used as an independent method to validate the results obtained by the ‘Profile Matching' method. It has been shown that the crystallite size decreasing and the strain increasing with Fe2O3 (% w/w) contents. The Lorentzian shape of the inherent widths of the lines diffraction is a strong indication that are the small crystallite size the main cause of the analysed kaolinites samples.

É conhecido da teoria da difração de raios X que os alargamentos das linhas de reflexões de uma amostra de pó estão associados com as imperfeições dos cristalitos, com os erros instrumentais e com efeitos da radiação utilizada. Nesse estudo, são separados os parâmetros microestruturais de duas amostras beneficiadas de caulinitas provenientes de depósitos brasileiros de diferentes regiões, usando o método de ajuste do perfil "Profile Matching", também conhecido como ajuste Le Bail, incorporado ao programa FullProf, que trata de difratogramas de raios X pelo método de Rietveld. O refinamento de Rietveld foi realizado com os dados de um material padrão LaB6, para obter os parâmetros da função instrumental e como uma forma de validar o método "profile matching". Uma função pseudo-Voigt modificada (TCHZ) foi usada para o ajuste dos perfis. Os valores das larguras integrais betah e dos parâmetros etah calculados pelo programa serviram de dados para a aplicação do "modelo" aqui denominado TCHZpV. Os resultados dos parâmetros microestruturais calculados pelos dois procedimentos foram, então, comparados com boa concordância, indicando que os tamanhos dos cristalitos constituem a maior fonte das imperfeições cristalinas das amostras de caulinita.

From the x-ray diffraction theory, we know that the broadening of the reflection lines obtained from a powder sample may be related to some imperfection of the crystallite. Such broadening effect may also be caused by instrumental failures and dispersion of the length of the radiation. In this study, the micro structural parameters of two improved samples of kaolinites were obtained through the method of fitting profiles. This method is also known as Le Bail fitting method and was embodied in the version of FullProf, a program of Rietveld analysis. The Rietveld refinement was performed with the data obtained from the standard reference material LaB6. This refinement led to a set of instrumental function parameters and the validation method of the results obtained by the profile matching method. A modified pseudo-Voigt function (TCHZ) was used to fit the profiles. The integral broadening and the parameters, bh and hh, respectively, were calculated from the program and used as data base for the TCHZpV "model". The results of the microstructural parameters computed by both methods match well, suggesting that the size of the crystallites is the major cause of the kaolinite crystalline imperfections.