Subproduto da indústria de alumínio como amenizante de solos contaminados com cádmio e chumbo

Costa, Enio Tarso de Souza; Guilherme, Luiz Roberto Guimarães; Curi, Nilton; Oliveira, Luiz C.A.; Visioli, Elton Luiz; Lopes, Gertrudes Teixeira

doi:10.1590/s0100-06832008000600030

Cited by 14 publications

(6 citation statements)

References 28 publications

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“…40 They are clearly evident in the spectrum of the untreated crude waste (top), but are no longer observed in the spectrum of the product phase (bottom). Also, in the latter spectrum the aliphatic peaks at δ = 0.683, 0.694, 0.701, 0.711, 0.717, The 13 C NMR spectra of the crude vs. the product phase (Fig. 2) corroborate the results of the proton scans, as the peaks for glycerol (top, 13 a These values are within the generally accepted 0.4% error margin of the EA method.…”

Section: Organic Productssupporting

confidence: 69%

“…Also, in the latter spectrum the aliphatic peaks at δ = 0.683, 0.694, 0.701, 0.711, 0.717, The 13 C NMR spectra of the crude vs. the product phase (Fig. 2) corroborate the results of the proton scans, as the peaks for glycerol (top, 13 a These values are within the generally accepted 0.4% error margin of the EA method. In the following, analysis for nitrogen was therefore not carried out.…”

Section: Organic Productssupporting

confidence: 69%

“…6 A recent series of exhaustive reviews by Klauber et al provides up-to-date details about current disposal techniques and the associated advantages and disadvantages of the main methods, options for utilization, as well as details about the composition of this waste. [7][8][9][10] Examples of interesting initiatives to design an application and alternative use for Red Mud are the production of materials for civil construction, i.e., ceramics, brick and cement, 11,12 in the remediation of soils high in acidity, poor in iron or contaminated with heavy metals, 13 as an adsorbent for inorganic and organic compounds, 14 as a CO 2 sequestering agent, [15][16][17] or as a catalyst, as the metallic oxides typically present in Red Mud are known to have catalytic activity. 18,19 In particular, iron oxides (Fe x O y ) are known to be active catalysts for hydrogenation, ketonization, water-gas shift and Fisher-Tropsch reactions, titanium dioxide (TiO 2 ) has activity as a ketonization catalyst, while silicon (SiO 2 ), aluminum (Al 2 O 3 ), calcium (CaO) and sodium (Na 2 O) oxides are all known Brønstedt and/or Lewis acid/base active catalysts and/or catalyst supports.…”

Section: Red Mudmentioning

confidence: 99%

“…e 1.1 g of a solid organic recovered. 30.89, 30.92, 32.68, 33.08, 34.83) and are reduced to a small number of distinct and well defined peaks in the spectrum of the product phase (bottom, 13 C-NMR, 100 MHz, MeOD, δ = 14.49, 23.78, 30.52, 30.81, 33.11). The spectra of all other product phases were very similar to the ones shown here and are therefore well represented by the spectra in Fig.…”

Section: Organic Productsmentioning

confidence: 99%

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Synergistic co-processing of Red Mud waste from the Bayer process and a crude untreated waste stream from bio-diesel production

et al. 2013

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The production of the aluminum metal from bauxite ore and bio-diesel from triglyceride oils both generate large waste streams, and their management and valuation is therefore of great interest in Brazil and any other country with established or developing bio-fuel and aluminum industries. The integration of these two waste streams into the development of alternative technologies that utilize wastes as low-cost materials could potentially contribute to economic development as well as chemical sustainability and minimize the environmental and ecological impact of these industries. In this study, a crude untreated bio-diesel plant waste stream consisting of glycerol, methanol, free fatty acid salts and water was coprocessed with Red Mud, the highly alkaline by-product of bauxite refining through the Bayer Process, at elevated temperature and pressure (350 to 400 °C; 0-500 psi hydrogen gas) in an attempt to synergistically produce value-added products from these two waste streams. Comparative analysis between untreated and upgraded materials was performed by CHN EA, TGA, TPR, SEM, MS, FT-IR, Karl-Fischer-Titration, and 1 H/ 13 C NMR. The products obtained showed an increase in carbon and hydrogen content in both the organic product phase and the Red Mud catalyst recovered. Also observed in the organic phases was an increase in the paraffin content relative to starting material as determined by NMR with a concomitant reduction of the alcohol content confirming glycerol and methanol conversion. The Red Mud recovered after every upgrading reaction showed a change of color to dark gray to black, magnetic and amphiphilic properties, as well as a substantial decrease in its alkalinity and an increase in its carbon content. Catalyst recycling reactions were performed highlighting the possibility that the Red Mud could be reused as a catalyst promoting an increase in the observed crude glycerol conversion to paraffins potentially usable as a low-grade heavy fuel oil.Brazilian aluminum industry. According to ABAL (Brazilian Association of Aluminum), Brazil is the sixth largest primary aluminum producer in the world, exceeded only by China, Russia, Canada, United States and Australia. By extension, Brazil possesses the fifth largest bauxite deposits on the planet, is the fourth largest alumina producer and ranks fifth in exports of primary aluminum and its alloys. 1 Both the biodiesel and the aluminum industry generate a large amount of waste giving rise to increasing concerns over environmental impacts. In the production of aluminum, Red Mud is generated from the caustic soda digestion of bauxite ore to create pure alumina via the Bayer process. 2 The alumina production process used today is essentially the same as invented by Karl Bayer in 1887. Exploiting the amphoteric nature of Al 2 O 3 , it uses sodium hydroxide to selectively dissolve this oxide component of the bauxite ore as Na[Al(OH) 4 ]. This solution is then filtered. Concentrating it and adding lime (CaO) leads to the

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Section: Organic Productssupporting

confidence: 69%

Section: Organic Productssupporting

confidence: 69%

Section: Red Mudmentioning

confidence: 99%

Section: Organic Productsmentioning

confidence: 99%

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Synergistic co-processing of Red Mud waste from the Bayer process and a crude untreated waste stream from bio-diesel production

et al. 2013

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“…phenol [10] and dyes [11]) and inorganic compounds (e.g. phosphates and arsenic from acid drainage [12,13] and heavy metal from contaminated soils [14]). The controlled reduction of red mud with hydrogen was also used to produce active heterogeneous Fenton system for the oxidation of organic contaminants [15].…”

Section: Introductionmentioning

confidence: 99%

Production of nanostructured magnetic composites based on Fe0 nuclei coated with carbon nanofibers and nanotubes from red mud waste and ethanol

Oliveira

Tristão

Ardisson

et al. 2011

Applied Catalysis B: Environmental

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Mono- and Multielement Sorption of Trace Metals on Oxidic Industrial By-products

Costa

Guilherme

Lopes

et al. 2011

Water Air Soil Pollut

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Subproduto da indústria de alumínio como amenizante de solos contaminados com cádmio e chumbo

Cited by 14 publications

References 28 publications

Synergistic co-processing of Red Mud waste from the Bayer process and a crude untreated waste stream from bio-diesel production

Synergistic co-processing of Red Mud waste from the Bayer process and a crude untreated waste stream from bio-diesel production

Production of nanostructured magnetic composites based on Fe0 nuclei coated with carbon nanofibers and nanotubes from red mud waste and ethanol

Mono- and Multielement Sorption of Trace Metals on Oxidic Industrial By-products

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