Assessment of heavy metal residues in Brazilian poultry and swine tissue / Avaliação de resíduos de metais pesados em tecidos de aves e suínos

The aim of this study was to investigate the presence of arsenic, lead and cadmium residues in samples of liver, kidney and muscle of poultry and swine during the years from 2002 to 2008. A total of 1978 samples were analyzed: 1031 of poultry and 947 of swine from Brazilian slaughterhouses. The samples were analyzed at the National Agricultural Laboratory using the atomic absorption spectrometry technique. In poultry, the arsenic residues were detected in 53.6% of liver samples, although no results have exceeded the MRL. In kidneys, 39.7% of the samples showed measurable residues and there was no violation of the limits. Regarding lead, there were 5 contaminated liver samples and 24 contaminated kidney samples (1.5 and 3.6% respectively). In muscle tissue there was only one sample with residues...

Objetivou-se investigar a presença de resíduos de arsênico, chumbo e cádmio em amostras de fígado, rins e músculo de aves e suínos, durante os anos de 2002 a 2008. Um total de 1.978 amostras foi analisado: 1031 de aves e 947 de suínos provenientes de matadouros brasileiros. As amostras foram analisadas no Laboratório Nacional Agropecuário (Lanagro), sendo utilizada a técnica de espectrometria de absorção atômica. Em aves, os resíduos de arsênico foram detectados em 53,6% das amostras de fígado, embora sem exceder o LMR. Nos rins, 39,7% das amostras mostraram resíduos mensuráveis e não houve violação dos limites. Em relação ao chumbo, cinco amostras de fígado e 24 de amostras de rins estavam contaminadas (1,5 e 3,6%, respectivamente). No tecido muscular, houve apenas uma amostra com resíduos. Para o cádmio, 3,8% das amostras apresentavam valores abaixo do LMR. Resíduos de cádmio foram encontrados em 110 amostras de rins (16,3% testados), mas apenas uma ultrapassou o limite máximo permitido pela legislação nacional. Em suínos, resíduos de arsênico foram detectados em 15,3% das amostras de fígado, sem exceder o LMR. Nos rins, 14,2% das amostras apresentaram resíduos mensuráveis...

Equilibrium sorption isotherm studies of Cd(II), Pb(II) and Zn(II) ions detoxification from waste water using unmodified and EDTA-modified maize husk

The mobilization of heavy metals in the environment due to industrial activities is of serious concern due to the toxicity of these metals in humans and other forms of life. The equilibrium adsorption isotherms of Cd(II), Pb(II) and Zn(II) ions, detoxification from waste water using unmodified and EDTA-modified maize husk have been studied. Maize husk was found to be an excellent adsorbent for the removal of these metal ions. The amount of these metal ions adsorbed increased as the initial concentration increased. Also, EDTA-modification enhanced the adsorption capacity of maize husk due to the chelating ability of ethylenediamine tetra acetic acid (EDTA). Among the three adsorption isotherms tested, Dubinin-Radushkevich isotherm gave the best fit with R² value ranging from 0.7646 to 0.9988 and an average value of 0.9321. This is followed by Freundlich and then Langmiur isotherms. The sorption process was found to be mostly a physiosorption process as seen from the apparent energy of adsorption which ranged from 1.03 KJ/mol to 12.91 KJ/mol. Therefore, this study demonstrates that maize husk which is an environmental pollutant could be used to adsorb heavy metals and achieve environmental cleanliness.