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Milk is an important food in the human diet due to its physico-chemical composition; therefore, it is necessary to monitor contamination by toxic metals such as Pb. Milk sample slurries were prepared using Triton X-100 and nitric acid for direct analysis of Pb using graphite furnace atomic absorption spectrometry - GF AAS. After dilution of the slurries, 10.00µl were directly introduced into the pyrolytic graphite tube without use of a chemical modifier, which acts as an advantage considering this type of matrix. The limits of detection and quantification were 0.64 and 2.14µgl, respectively. The figures of merit studied showed that the proposed methodology without pretreatment of the raw milk sample and using external standard calibration is suitable. The methodology was applied in milk samples from the Guarapuava region, in Paraná State (Brazil) and Pb concentrations ranged from 2.12 to 37.36µgl.

ABSTRACT:The industrial swine production is characterized by generation of significant effluent amounts that require treatment. The most adopted practices by Brazilian swine farmers have been wastewater storage in lagoons and its subsequent use as a biofertilizer. Nutrient accumulation in soil and water creates the need for an effective management of these residues. The anaerobic digestion process is an important alternative and low-cost treatment for organic matter reduction. However, its efficiency is limited by the digester capacity of solid degradation, especially at low hydraulic retention times. Thus, the present study aimed to verify the behavior of an upflow anaerobic digester by increasing the organic loading rate. This was accomplished in three stages using, as a parameter, volatile solids at 0.5; 1.0 and 1.5 kgVS m -3 d -1, respectively. This digester model proved to be quite robust and effective in swine manure treatment, achieving high efficiency of volatile solid removal at all stages of the study (stage 1: 61.38%; stage 2: 55.18%; and stage 3: 43.18%). Biogas production was directly related to the increasing organic load, reaching 0.14, 0.85, and 0.86add. , respectively, with no significant difference (p<0.05) of biogas methane concentration among the studied stages (73.7, 75.0, and 77.9%).KEYWORDS: hydraulic retention time, biogas production, animal wastewater. TRATAMENTO DE EFLUENTE DA SUINOCULTURA UTILIZANDO PROGRESSÃO DE CARGA ORGÂNICA EM BIODIGESTOR ANAERÓBIO DE FLUXO ASCENDENTE RESUMO:A suinocultura industrial tem como característica a geração de significativas quantidades de efluente que necessitam de tratamento. O processo de biodigestão anaeróbia surge como uma alternativa importante, de baixo custo para o tratamento e eficiente na redução da matéria orgânica das águas residuárias da suinocultura. Porém os processos anaeróbios têm sua eficiência limitada, entre muitos aspectos, pela concentração de sólidos voláteis no biodigestor e sua capacidade de mineralização da matéria orgânica em função do tempo de retenção hidráulica. Diante disso, o presente estudo teve por objetivo verificar o comportamento de um biodigestor anaeróbio de fluxo ascendente, alimentado com dejetos de suínos, mediante progressão de carga de sólidos voláteis. O estudo foi realizado em três etapas, utilizando-se como parâmetro de sólidos voláteis a 0,5; 1,0 e 1,5 kgSV m -3 d -1 , respectivamente. Este modelo de biodigestor mostrou ser bastante eficaz e robusto no tratamento de efluentes da suinocultura, atingindo boa eficiência na remoção de sólidos voláteis em todas as etapas do trabalho (etapa 1: 61,38%, etapa 2: 55,18% e etapa 3: 43,18%). A produção de biogás teve relação direta com o aumento da carga orgânica, atingindo 0,14; 0,85 e 0,86 Nm 3 kgSV adic. , respectivamente, não havendo diferença significativa (p<0,05) na porcentagem de metano no biogás entre elas (73,7; 75,0 e 77,9%).

Summary: The complexation agents 2[‐bis‐(pyridylmethyl)aminomethyl]‐4‐methyl‐6‐formyl‐phenol (BPMAMFF) and 2‐[2‐(hydroxybenzyl)‐2‐(pyridylmethyl)aminomethyl]‐4‐methyl‐6‐formyl‐phenol (HBPAMFF) were immobilized on chitosan biopolymer in order to obtain new adsorbent materials for metal ions. The chitosan derivatives were characterized by IR spectroscopy, DSC, TGA, and CHN analysis. The characterization study proved that the chitosan surface was chemically modified with both complexing agents and however, it is expected that these modifications improve the selectivity for metal ions specific in relation to the chitosan.

The aim of this study was to impregnate the chelating agent 3,3-bis-N,N,bis-(carboxymethyl)aminomethyl-o-cresolsulfonephthalein in chitosan and to investigate the adsorption of Cu(II) ions. The chemical modification was confirmed by FTIR spectrometry, thermogravimetric analysis (TGA) and energy dispersive x-ray spectroscopy (EDX). The adsorption studies were carried out with Cu(II) ions in a batch process and were shown to be dependent on pH. The adsorption kinetics was tested using three models: pseudo first-order, pseudo second order and intraparticle diffusion. The experimental kinetics data were best fitted with the pseudo second-order model (R² = 0.999), which provided a rate constant, k2, of 1.21 x 10-3 g mg-1 min-1. The adsorption rate depended on the concentration of Cu(II) ions on the adsorbent surface and on the quantity of Cu(II) ions adsorbed at equilibrium. The Langmuir isotherm model provided the best fit for the equilibrium data in the concentration range investigated, with the maximum adsorption capacity being 81.0 mg of Cu(II) per gram of adsorbent, as obtained from the linear equation of the isotherm. Desorption tests revealed that around 90% of the adsorbed metal was removed, using EDTA solution as the eluent. This result suggests that the polymeric matrix can be reused

O uso de ácidos graxos, óleos de peixes como suplemento e peixes na alimentação humana têm sido objeto de inúmeras pesquisas nos últimos anos. Foram evidenciados os efeitos benéficos dos ácidos graxos polinsaturados (AGPI) de pescado nas populações que residem em área de pesca [14].Tem sido atribuída uma elevada importância nutricional aos ácidos da família ômega-3 (ou n-3), especialmente aos ácidos alfa-linolênico l8:3n-3 (LNA), eicosapentaenóico 20:5n-3 (EPA) e docosa-hexaenóico 22:6n-3 (DHA). Assim, inúmeras pesquisas surgiram sobre os ácidos graxos ômega-3 e, conseqüentemente, as indústrias alimentícias e farmacêuticas suplementaram alimentos e desenvolveram concentrados com ômega-3 em todo o mundo.Os resultados das pesquisas vêm confirmando que um aumento na ingestão de AGPI n-3 reduz a taxa total de colesterol no sangue. Além disso, estudos realizados com base em intervenções de dietas comprovaram que o consumo de AGPI e/ou óleos de pescado reduz fatores bioquímicos de risco associados a doenças cardiovasculares [9,27], psoríase [18], artrite e câncer [22,24,31] e pode estar envolvido na fertilidade humana [5].Pesquisadores acreditam que, atualmente as dietas de ácidos graxos ômega-3 e ômega-6 nos ocidentais apresentam razão n-6/n-3 de aproximadamente 20 a 30:1, valores muito elevados quando comparados com aqueles considerados ideais de 1 a 2:1 [25]. Os elevados valores da razão n-6/n-3 geraram um desbalanceamento de ácidos graxos no organismo humano e, provavelmente, contribuíram para o desenvolvimento de processos inflamatórios, desordem do sistema imune, hipertensão e disfunções neurológicas [14].Os ácidos alfa-linolênico 18:3n-3 (LNA) e linoléico 18:2n-6 (LA) são considerados ácidos graxos essenciais e precursores dos demais ácidos da família n-3 e n-6, respectivamente. O ácido LA pode ser encontrado em abundância nos óleos de milho, girassol, soja, dentre outros. Enquanto, o ácido LNA é encontrado em concentrações elevadas na semente de linho (Linum usitatissimum), a qual apresenta 32 a 38% de óleo e teores percentuais de LNA que variam de 44,6 a 51,5% do total dos ácidos graxos [3,4].No Brasil, nos últimos anos, ocorreu e continua ocorrendo um crescimento vertiginoso na criação e consumo de peixes em cativeiro. Isto ocorre devido a condições hidrográficas favoráveis, ao crescimento de pesque e (0,10,20, 30 days) with flaxseed oil (source of α-linolenic acid 18:3 n-3, LNA), in substitution to the sunflower oil. There were not significant differences among (P>0,05) the moisture, ash, protein, and total lipids values for the different treatments (times of supply). The values of total lipids found in the heads varied from 8.41 to 10.13%, and 27 fatty acids were found in these lipids in all treatments. The majority fatty acids were 18:2n-6, 18:1n-9 and 16:0. There was an increase in the LNA acid percentage values, in the omega-3 (n-3) sum, and a decrease of the n-6/n-3 reason, with significant differences among the treatment A (zero time) and other treatments that received flaxseed oil. There were not si...