Madson de Godoi Pereira

Vermicompost as a natural adsorbent material: characterization and potentialities for cadmium adsorption

Vermicompost (humic material) samples were submitted to characterization by infrared spectroscopy, X-ray diffractometry, thermogravimetric analysis, electron microscopy etc. In addition, its cation exchange capacity (CEC) was determined. Factorial experiments were designed in order to elucidate the interaction mechanisms between Cd2+ and the adsorptive sites of vermicompost. The maximum adsorptive capacity for cadmium was evaluated by a Langmuir isotherm. The characterization revealed that vermicompost exhibits high CEC values (ca. 72.9 meq per 100 g), high surface area (porous material), chelating groups and a maximum adsorptive capacity for Cd (38.6 mg g-1) at pH 5.0. This potential application was exploited in the analysis of synthetic and real (mineral water) samples with Cd concentrations of ca 5 mg L-1, requiring a preconcentration step. An enrichment factor of 100 was attained.

An Overview of the Environmental Applicability of Vermicompost: From Wastewater Treatment to the Development of Sensitive Analytical Methods

The use of vermicompost (humified material) for treating wastewaters, remediating polluted soils, improving agricultural productivity, protecting crop production, and developing sensitive analytical methods is reviewed here, covering the past 17 years. The main advantages of vermicompost, considering all applications covered in this paper, comprise (i) easy acquisition, (ii) low costs, (iii) structural, chemical, and biological characteristics responsible for exceptional adsorptive capacities as well as pollutant degradation, and (iv) the promotion of biocontrol. Specifically, for wastewater decontamination, a considerable number of works have verified the adsorption of toxic metals, but the application of vermicompost is still scarce for the retention of organic compounds. Problems related to the final disposal of enriched vermicompost (after treatment steps) are often found, in spite of some successful destinations such as organic fertilizer. For decontaminating soils, the use of vermicompost is quite scarce, mainly for inorganic pollutants. In agricultural productivity and biocontrol, vermicompost imparts remarkable benefits regarding soil aggregation, plant nutrition, and the development of beneficial microorganisms against phytopathogens. Finally, the use of vermicompost in sensitive analytical methods for quantifying toxic metals is the newest application of this adsorbent.

Bio-inspired gold microtubes based on the morphology of filamentous fungi

This communication describes a general method for templating fungal filaments with gold nanoparticles that results in a gold replica of filaments after calcination of the biological template.

Occurrence and Distribution of Polyphenolics in Species of Deguelia(Leguminosae)

The species of Deguelia (Papilonoidae Leguminose) genus are recognized for producing polyphenolic secondary metabolities that are predominantly classified as isoflavonoids. The study about the distribution of these secundary metabolities in species of Deguelia genus is very important for understanding the chemosystematic at genus level. Additionally, it has been reported that polyphenolics isolated from Deguelia present many desirable biological effects against human diseases and agricultural pests. Thus, this paper reviewed the occurrence and distribution of polyphenolics in species of Deguelia and evidenced the biological properties of these compounds.

Assessment of Physical-Chemical Characteristics of Water and Sediments from a Brazilian Tropical Estuary: Status and Environmental Implications

The environmental quality of the Jacuípe Rivers estuary (very important in northeastern Brazil) was assessed during 2007 and 2008. In water, concentrations (mg L−1) of NO2 − (<0.004 to 0.016), NO3 − (0.01 to 0.33), soluble PO4 3− (<0.02 to 0.22), dissolved oxygen (3.9 to 9.6), total contents (mg L−1) of Cd (<0.001), Cu (<0.01), Pb (<0.01), and Zn (<0.1), pH (5.60 to 8.00), and electrical conductivity (0.12 to 48.60 mS cm−1) agreed with environmental standards. In sediments, clay and total organic matter (%, m/m) varied, respectively, from 8.8 to 12.0 and from 1.1 to 8.8, while infrared, thermogravimetric profile, electronic micrograph, as well as X-Ray analyses showed desirable adsorptive characteristics. However, maximum exchangeable levels (mg kg−1) of Cd (1.3), Cu (44.6), Pb (35.7), and Zn (43.7) and their respective maximum pseudototal concentrations (mg kg−1): 19.4, 95.1, 68.2, and 30.3 were below the recommended limits. In this sense, it was possible to demonstrate good environmental preservation even with the growing number of industries and touristic activities in the evaluated estuarine area.

Cadmium and lead retention in fresh and rotten red meat

The metal sorption capacity in fresh and rotten red meat was evaluated for Cd2+ and Pb2+ ions at pH 6 and the process involved in the studied metal retention was discussed. For the experimental set, an eight channels multi-port selection valve was employed to mechanise the sample preparation. The cadmium and lead concentrations were determined by ICP-OES. A high retention (> 80%, m/m) of Cd2+ and Pb2+ ions, in fresh and rotten bovine muscle was found, indicating the potential contamination risks related to the consumption of meat submitted to inappropriate conditions of abattoir, handling, storage and commercialisation. Seventy per cent of the cadmium was released with the immersion of meat in acetic acid at 1% (v/v), revealing that cookery practices may act on contaminant sorptive processes in meat structure.