EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol). The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

MERCURY QUANTIFICATION IN SOILS USING THERMAL DESORPTION AND ATOMIC ABSORPTION SPECTROMETRY: PROPOSAL FOR AN ALTERNATIVE METHOD OF ANALYSIS

Despite the considerable environmental importance of mercury (Hg), given its high toxicity and ability to contaminate large areas via atmospheric deposition, little is known about its activity in soils, especially tropical soils, in comparison with other heavy metals. This lack of information about Hg arises because analytical methods for determination of Hg are more laborious and expensive compared to methods for other heavy metals. The situation is even more precarious regarding speciation of Hg in soils since sequential extraction methods are also inefficient for this metal. The aim of this paper is to present a technique of thermal desorption associated with atomic absorption spectrometry, TDAAS, as an efficient tool for quantitative determination of Hg in soils. The method consists of the release of Hg by heating, followed by its quantification by atomic absorption spectrometry. It was developed by constructing calibration curves in different soil samples based on increasing volumes of standard Hg2+ solutions. Performance, accuracy, precision, and quantification and detection limit parameters were evaluated. No matrix interference was detected. Certified reference samples and comparison with a Direct Mercury Analyzer, DMA (another highly recognized technique), were used in validation of the method, which proved to be accurate and precise.

Alternative genotyping method for the single nucleotide polymorphism A2959G (AF159246) of the bovine CAST gene

The objective of this work was to genotype the single nucleotide polymorphism (SNP) A2959G (AF159246) of bovine CAST gene by PCR-RFLP technique, and to report its use for the first time. For this, 147 Bos indicus and Bos taurus x Bos indicus animals were genotyped. The accuracy of the method was confirmed through the direct sequencing of PCR products of nine individuals. The lowest frequency of the meat tenderness favorable allele (A) in Bos indicus was confirmed. The use of PCR-RFLP for the genotyping of the bovine CAST gene SNP was shown to be robust and inexpensive, which will greatly facilitate its analysis by laboratories with basic structure.

2,4-dichlorophenoxyacetic acid as an alternative auxin for rooting of vine rootstock cuttings

Viticulture is an important agricultural activity in semiarid northeastern Brazil, and the quality and ease of vine propagation are very important in this context. This study evaluated the use of 2,4-dichlorophenoxyacetic acid (2,4-D) as an alternative to indolebutyric acid (IBA) in the rooting of vine rootstock cuttings. The trial was conducted at the Universidade Federal de Sergipe (São Cristóvão-SE) between January and March 2010 with cuttings of the rootstocks of 'IAC-766', 'IAC-572', and 'Paulsen 1103' treated with 2,4-D or IBA applied at concentrations of 0, 1000, 2000, or 3000 rng-L-1 for 5 s and planted in a field on washed sand. At 56 days after planting, the percentages of rooted, sprouted, callused, and dead cuttings were evaluated, and also the average number and length of the rooted cuttings. The results showed that 2,4-D was not superior to IBA in the characteristics wanted for the rooting process of the vine rootstock cuttings. The vine rootstocks showed potential for propagation by cutting without auxin application. It was observed that the high concentrations were the worst for the rooting of the cuttings.

Development and validation of an alternative titration method for the determination of sulfate ion in indinavir sulfate

A simple and rapid precipitation titration method was developed and validated to determine sulfate ion content in indinavir sulfate raw material. 0.1 mol L-1 lead nitrate volumetric solution was used as titrant employing potentiometric endpoint determination using a lead-specific electrode. The United States Pharmacopoeia Forum indicates a potentiometric method for sulfate ion quantitation using 0.1 mol L-1 lead perchlorate as titrant. Both methods were validated concerning linearity, precision and accuracy, yielding good results. The sulfate ion content found by the two validated methods was compared by the statistical t-student test, indicating that there was no statistically significant difference between the methods.

Electrocatalysis and electrocatalysts for low temperature fuel cells: fundamentals, state of the art, research and development

This article deals with electrocatalysis and electrocatalysts for low temperature fuel cells and also with established means and methods in electrocatalyst research, development and characterization. The intention is to inform about the fundamentals, state of the art, research and development of noble metal electrocatalysts for fuel cells operating at low temperatures.

Alternative technique for biodiesel quality control using an optical fiber long-period grating sensor

We report the use of an optical fiber sensor to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device is based on the long-period grating sensitivity to the surrounding medium refractive index, which leads to measurable modifications in the grating transmission spectrum. The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques of total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the proposed method.

70º aniversário do biodiesel em 2007: evolução histórica e situação atual no brasil

Periodically, during petroleum shortages, vegetable oils and their derivatives have been proposed as alternatives to petroleum diesel fuel. Different approaches have been proposed, including the use of pure vegetable oils (or blends) or their derivatives. Indeed, the use of fatty-acid methyl or ethyl esters (usually known as "biodiesel") produced by alcoholysis of triacylglycerides or esterification of fatty acids was initially proposed in Belgium 70 years ago, when the first world patent was deposited. Recently, foreign dependence on diesel fuel and the petroleum crisis have increased the discussion in Brazil on starting to use alternatives to diesel fuel, being biodiesel the alternative of choice for a large petroleum diesel substitution program.

Determination of Cd and Pb in fuel ethanol by filter furnace electrothermal atomic absorption spectrometry

A method was developed for quantification of Cd and Pb in ethanol fuel by filter furnace atomic absorption spectrometry. Filter furnace was used to eliminate the need for chemical modification, to stabilize volatile analytes and to allow the application of short pyrolysis step. The determinations in samples were carried out against calibration solutions prepared in ethanol. Recovery tests were made in seven commercial ethanol fuel samples with values between 90 and 120%. Limits of detection were 0.1 µg L-1 for Cd and 0.3 µg L-1 for Pb. Certified water samples (APS 1071, APS 1033, NIST 1643d, NIST 1640) were also used to evaluate accuracy and recoveries from 86.8% to115% were obtained.

Aproveitamento sustentável de biomassa e de recursos naturais na inovação química

Increased production of biomass is currently the only immediately accessible alternative for large-scale carbon sequestration and it can produce large amounts of food, fuel and raw materials for the chemical industry that can in turn growingly replace oil as a source of organic building blocks and also of hydrogen and sulfur. Development of processes for biomass and abundant minerals transformation into chemical raw materials should now benefit from large inputs from nanotechnologies, biotechnologies, information and micro-reactor technologies. Success in R&D&Innovation along this line can yield new products and processes needed to perform desirable functions within a sustainable development paradigm.

Biocombustíveis a partir de óleos e gorduras: desafios tecnológicos para viabilizá-los

Periodically, during petroleum shortage, fatty acids and their derivatives have been used as alternative fuels to those derived from petroleum. Different approaches have been proposed, including the use of neat fats and oils or their derivatives. Indeed, the utilization of biodiesel produced by alcoholysis of triacilglycerides or esterification of fatty acids, or hydrocarbons obtained from cracking of fatty materials were studied and used in several countries. Increasing concerns about energy security and climate changes have lead several countries, including Brazil, to start up biofuels programs. Different technologies are currently being developed in order to produce biofuels with economical feasibility. In this work are discussed alternative fatty raw-materials and processing technologies that are currently being studied in order to produce fuels suitable to sustainable substitute diesel fuel.

Pilhas de combustíveis microbianas utilizadas na produção de eletricidade a partir de rejeitos orgânicos: uma perspectiva de futuro

In this review is presented an innovative technology for use of animal and vegetable waste with high pollution levels in microbial fuel cell (MFC) as an alternative to waste remediation and simultaneously producing electricity and fertilizer for agriculture. A brief history of MFC, the studies about the electron transfer mechanisms, discussion of the biological nanowires in bacteria and the use of chemical mediators or carriers of electrons are explained. The factors influencing the performance of MFCs, the application in waste and sewage treatment and power generation are also discussed.

Diesel/biodiesel soot oxidation with ceo2 and ceo2-zro2-modified cordierites: a facile way of accounting for their catalytic ability in fuel combustion processes

CeO2 and mixed CeO2-ZrO2 nanopowders were synthesized and efficiently deposited onto cordierite substrates, with the evaluation of their morphologic and structural properties through XRD, SEM, and FTIR. The modified substrates were employed as outer heterogeneous catalysts for reducing the soot originated from the diesel and diesel/biodiesel blends incomplete combustion. Their activity was evaluated in a diesel stationary motor, and a comparative analysis of the soot emission was carried out through diffuse reflectance spectroscopy. The analyses have shown that the catalyst-impregnated cordierite samples are very efficient for soot oxidation, being capable of reducing the soot emission in more than 60%.

Chemical composition and antibacterial activity of essential oils from verbenaceae species: alternative sources of (E)-caryophyllene and germacrene-D

Volatile oils from the leaves of Verbenaceae species Aloysia virgata, Lantana camara, Lantana trifolia, Lantana montevidensis, Lippia brasiliensis and Lippia sericea were investigated for its chemical composition and antibacterial activity. The volatile oils were characterized by a high content of sesquiterpenes of which (E)-caryophyllene (10-35%), germacrene-D (5-46%) and bicyclogermacrene (7-17%) were the major components for all studied species. For the flowers, a higher concentration of monoterpenes was observed for the species L. camara, L. trifolia and L. brasiliensis. These compounds probably act as attractive to specific pollinators. The volatile oils from A. virgata was the most active, exhibiting moderate antimicrobial activity against the bacteria Staphylococcus aureus, Bacillus cereus and Escherichia coli.

Certified reference material to water content determination in bioethanol fuel

Bioethanol is a strategic biofuel in Brazil. Thus, a strong metrological basis for its measurements is required to ensure the quality and promote its exportation. Recently, Inmetro certified a reference material for water content in bioethanol. This paper presents the results of these studies. The characterization, homogeneity, short-term stability and long-term stability uncertainty contributions values were 0.00500, 0.0166, 0.0355 and 0.0391 mg g-1, respectively. The certificated value for water content of bioethanol fuel was (3.65 ± 0.11) mg g-1. This CRM is the first and up to now the unique in the world.