Phosphate species can affect aquatic ecosystems, as excess of this nutrient can cause eutrophication, generating environmental impacts. Lamellar double hydroxides have shown promise in removing phosphate at low concentrations (10-50 mg L 1). In this context, lamellar double hydroxides were synthesized interspersed with nitrates and humic substances, searching for a new product that favors phosphorus adsorption. X-ray diffraction showed the presence of characteristic peaks of lamellar double hydroxides and thermogravimetric analysis showed the decomposition behavior of lamellar structure. The adsorption capacity occurred quickly (< 30 min), being more efficient for lamellar double hydroxides with NO3. The maximum adsorption capacity showed results of 35.03 and 44.20 mg g 1 for lamellar double hydroxides with humic substances and lamellar double hydroxides with NO3, respectively. The complexation capacity showed that pH directly influences complexation, being greater for lamellar double hydroxides with humic substances at pH 6.5. Thus, nanostructured materials with humic substances are promising for use in contaminant remediation and adsorption can be a fast and efficient technique for use in soil and water. ecosystems eutrophication impacts 1050 10 50 (10-5 1. . 1) context Xray X ray structure < ( 3 min, min , min) NO3 NO 3503 35 03 35.0 4420 44 20 44.2 respectively 65 6 5 6.5 Thus water 105 (10- 350 0 35. 442 4 2 44. 6. (10 (1

Polymers are options as antimicrobials for skin protection, antifouling surfaces, and fabrics. Here we analyzed the interaction of polymers based on poly(methacrylate) (PMMA) and poly((dimethylamino ethyl) methacrylate) (PDMAEMA) with model membranes and bacteria. We used the homopolymers PMMA, PDMAEMA, and the diblock copolymer(s) prepared with different PMMAm:PDMAEMAn ratios (m/n). The interactions of PDMAEMA and PMMAm-b-PDMAEMAn with large unilamellar vesicles (LUVs) prepared with phosphatidylcholine and phosphatidylglycerol at different pHs, were analyzed by nuclear magnetic resonance (NMR), dynamic light scattering, and zeta potential. These polymers promoted LUVs leakage of a fluorescent probe (5,6-carboxyfluorescein) localized exclusively in the internal aqueous compartment. Interestingly, all copolymers exhibit a bell-shaped pH dependence for the polymer-induced LUVs leakage. The interaction of the positively charged polymers and the pH effect was also demonstrated using giant unilamellar vesicles. These copolymers inhibited bacterial growth in the micromolar range and can be used to prevent bacterial growth on surfaces. protection surfaces fabrics polymethacrylate poly methacrylate poly(methacrylate PMMA (PMMA polydimethylamino dimethylamino ethyl (PDMAEMA bacteria copolymer s copolymer(s PMMAmPDMAEMAn PMMAm PDMAEMAn m/n. mn m/n . m n (m/n) PMMAmbPDMAEMAn b (LUVs pHs NMR, NMR , (NMR) scattering potential 5,6carboxyfluorescein 56carboxyfluorescein carboxyfluorescein 5,6 5 6 (5,6-carboxyfluorescein compartment Interestingly bellshaped bell shaped polymerinduced polymer induced (m/n (NMR 6carboxyfluorescein 56 5,

Biochar from slow pyrolysis under controlled conditions is favorable in the transformation of waste into materials that serve as soil conditioners, and/or environmental remediation. Thus, this work aimed to produce and characterize biochar from cassava waste under different temperature conditions and evaluate interactions with Ca2+ and Pb2+ for agricultural and environmental applications. To investigate the efficiency of the interaction of biochar with nutrients (Ca) and contaminants (Pb), the influence of pH and contact time were evaluated. There was an increase in pH, pHzpc (zero point charge), and condensed aromatic structures in BC, due to the increase in pyrolysis temperature. Also, biochar demonstrated a Pb2+ adsorbed amount of 2.03 to 2.37 mg g-1 and a Ca2+ release capacity of 0.655 to 0.765 mg g-1. In this way, biochar produced from residues of cassava waste can be a viable strategy to enhance agricultural production and reduce environmental contaminants.

The suspended particulate material (SPM) present in waters has fundamental importance for a better understanding of environmental behaviors of aquatic pollutants. This work determined the physicochemical parameters (pH, temperature, conductivity, total organic carbon and metals concentration) in water samples from Mundaú-Manguaba estuarine-lagoon system, Alagoas, Brazil. This work extracted and characterized the organic matter present in SPM in this estuary and studied the interaction of this organic matter with potentially toxic metals (Cd2+ and Pb2+). The results of the physical-chemical parameters evaluated showed influence of the tide and also of anthropic contributions close to the estuary. In fact, the lead concentrations determined (0.10-1.32 mg L-1) are well above that allowed by Brazilian legislation (< 0.010 mg L-1). The organic matter present in the SPM showed a high degree of humification being similar to the organic matter extracted from water and showed strong interaction by Pb2+ ions.

Este trabalho apresenta uma análise sistêmico-funcional de duas redações originadas do Exame de Redação Analítica da Universidade da Califórnia, escritas por aprendizes da lingua inglesa. A análise mostra as escolhas linguísticas utilizadas nessas duas redações, uma que recebeu uma nota alta e uma que recebeu uma nota baixa no exame. O artigo descreve algumas das escolhas gramaticais que são funcionais para a redação expositiva, divididas em três categorias principais: escolhas textuais, interpessoais e ideacionais. Depois dessa breve descrição é apresentada a análise das duas redações em termos desses recursos. O artigo mostra as diferenças entre as redações em termos das escolhas linguísticas usadas pelos dois autores. Algumas conclusões para a prática educacional e recomendações para educadores baseados na análise serão incluídas.

This article presents a systemic-functional linguistic analysis of two writing samples of the University of California Analytical Writing Placement (AWP) Examination written by English language learners (ELLs). The analysis shows the linguistic features utilized in the two writing samples, one that received a passing score and one that received a failing score. The article describes some of the grammatical resources which are functional for expository writing, which are divided under three main categories: textual, interpersonal, and ideational resources. Following this brief description is the analysis of both essays in terms of these resources.. The configuration of grammatical features used in the essays make up the detached style of essay 1 and the more personal style of essay 2. These grammatical features include the textual resources of thematic choices and development, clause-combining strategies (connectors), and lexical cohesion; interpersonal resources of interpersonal metaphors of modality; and ideational resources of nominalization and abstractions as ideational metaphors. Implications for educational practice and recommendations for educators based on the analysis are provided.

As elevadas concentrações de mercúrio em diferentes matrizes ambientais na Amazônia têm sido atribuídas a atividades mineradoras. Entretanto, altas concentrações de mercúrio também estão presentes no solo e na água em locais como a Bacia do médio Rio Negro, distantes de fontes emissoras antropogênicas. A região Amazônica é caracterizada por dois diferentes regimes sazonais, bem definidos em períodos de cheias e vazantes. O objetivo deste trabalho foi investigar as influências sazonais na interação entre mercúrio e substâncias húmicas aquáticas (AHS), que são os principais complexantes orgânicos naturais. Os resultados obtidos por análise estatística multivariada dos dados mostraram que as substâncias húmicas possuem diferentes características estruturais, dependendo do período sazonal. A capacidade das substâncias húmicas em formar complexos com Hg(II) não está diretamente relacionada ao seu teor de carbono, mas sim natureza e disponibilidade dos grupos funcionais presentes em sua estrutura. Os grupos funcionais carboxílicos e aromáticos estão diretamente relacionados maior capacidade de complexação de AHS por íons mercúrio.

High mercury concentrations in different environmental matrices in the Amazon have been attributed to mining activities. However, high concentrations of mercury are also present in the soil and water in places like in the middle of the Negro River Basin, which is far away from any anthropogenic emission sources. The Amazon region is characterized by two different regional seasons, with well-defined flood and low water periods. The objective of this work was to investigate the seasonal influences of the interaction between mercury and aquatic humic substances (AHS), which are the main agents of the natural organic complexation capacity. The results of the multivariate statistical analysis of the data showed that the humic substances had different structural characteristics, depending on each season. The ability of humic substances to form complexes with Hg(II) is not directly related to their carbon content, but to the nature and availability of the functional groups present in its structure. The functional groups are carboxylic and aromatic directly related to the higher complexation capacity of AHS by mercury ions.

Este artigo oferece um contexto histórico para as políticas educacionais recentes nos Estados Unidos, especialmente aquelas relacionadas à lei "No Child Left Behind" (NCLB). O artigo explica os efeitos dessas políticas com relação a um segmento da população que vem crescendo muito, os aprendizes de inglês - alunos que estão no processo de desenvolvimento de inglês como uma língua adicional. O texto explica muitas controvérsias e problemas relacionados ao uso de testes padronizados com essa população estudantil.

This article provides a historical context for current educational policies in the United States, especially those mandated by the No Child Left Behind Act (NCLB). The article explains the effects of these policies on a rapidly growing segment of the U.S. population, namely English Learners (ELs), students who are in the process of developing English as an additional language. It explains several of the controversies and concerns related to the use of standardized tests with this student population.

Interações entre substâncias húmicas aquáticas (SHA), de rios tropicais, e dois interferentes endócrinos (IE) foram estudados utilizando sistema de ultrafiltração em fluxo tangencial equipado com membrana de celulose de 1 kDa com a finalidade de separar os IE livres da fração ligada as SHA. A quantificação de 17α-etinilestradiol e bisfenol A foi realizada utilizando cromatógrafo a gás acoplado a espectrômetro de massas (GC-MS). O tempo de equilíbrio entre as SHA e IE foi de aproximadamente 30 min, e as capacidades complexantes do 17α-etinilestradiol e bisfenol A foram em torno de 18,53 e 2,07 mg g-1 de carbono orgânico total (COT), respectivamente. A maior interação das SHA ocorreu para 17α-etinilestradiol, em relação ao bisfenol A, devido a presença de hidrogênio na estrutura do 17α-etinilestradiol, que podem interagir com os grupos oxigenados presentes nas SHA. Os resultados indicam que as SHA podem influenciar fortemente no transporte e reatividade dos interferentes endócrinos presentes em sistemas aquáticos

Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17α-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17α-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g-1 TOC, respectively. The greater interaction of AHS with 17α-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17α-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems.

Neste trabalho, substâncias húmicas foram extraídas de amostras de água coletadas mensalmente na Bacia do Rio Negro-AM para estudar suas propriedades no ambiente amazônico e interações com íons mercúrio, considerando a influência da variação sazonal na sua formação. Os parâmetros razões atômicas C/H, C/N e C/O, grupos funcionais, radicais livres do tipo semiquinona, pH, índices pluviométricos e fluviométricos, concentrações de mercúrio foram interpretados por análise hierárquica de cluster (AHC) e análise de componentes principais (ACP). As análises estatísticas mostraram que, quanto maior o índice pluviométrico e menor o índice fluviométrico maior o grau de humificação das substâncias húmicas aquáticas. A seguinte ordem decrescente do grau de humificação das SHA coletadas mensalmente pode ser estabelecida: Nov/02 a Fev/03 > Mar/02 a Mai/02 > Jun/02 a Out/02. As maiores concentrações de mercúrio foram determinadas nas amostras mais humificadas, sugerindo que devido a rearranjos inter e/ou intramoleculares, quanto maior o grau de humificação maior a afinidade dos íons Hg(II) pelas substâncias húmicas aquáticas.

In this work, humic substances were extracted from water samples collected monthly from the Negro River basin in the Amazon state (Brazil) to study their properties in the Amazonian environment and interactions with the mercury ion considering the influence of seasonalness in this formation. The C/H, C/N and C/O atomic ratio parameters, functional groups, concentration of semiquinone-type free radicals, pH, pluviometric and fluviometric indices, and mercury concentrations were interpreted using hierarchical cluster analysis (HCA) and principal component analysis (PCA). The statistical analyses showed that when the pluviometric index was greater and the fluviometric index was smaller, the degree of humification of aquatic substances was greater. The following decreasing order of the degree of humification of the AHS collected monthly was established: Nov/02 to Feb/03 > Mar/02 to May/02 > Jun/02 to Oct/02. The greatest concentrations of mercury were detected in more humidified samples. These results suggest that due to inter and/or intra-molecular rearrangements, the degree of humification of aquatic humic substances is related to its affinity for Hg(II) ions.