Mineral Charcoal Research Articles

Identificação de adulterações no carvão ativado de osso utilizado na desfluoretação de águas subterrâneas por NIRS-PLS-DA

A desfluoretação de águas com excesso de íons fluoreto é fundamental para a saúde pública, visto que de acordo com a Portaria de Consolidação número 05 de 2017 do Ministério da Saúde, a ingestão de água com concentrações de flúor acima de 1,5 mg L-1, pode causar fluorose dentária em crianças. Dentre as técnicas empregadas para a desfluoretação, o método de adsorção usando carvão ativado de osso é um dos mais utilizados. Assim, esta pesquisa teve como objetivo determinar a eficácia do carvão ativado de osso bovino, bem como do carvão vegetal e mineral para a desfluoretação de água, utilizando ferramentas quimiométricas para identificar possíveis adulterações no carvão ativado de osso. Assim, um planejamento fatorial foi realizado para misturar três componentes e testes de adsorção. A espectroscopia no infravermelho próximo (NIRS, do inglês Near Infrared Spectroscopy) foi usada para construir um modelo de análise discriminante por mínimos quadrados parciais (PLS-DA, do inglês Discriminant Analysis by Partial Least Squares). Os resultados mostraram que o carvão ativado de osso é o material mais eficiente para desfluoretação, com capacidade de adsorção de 1,21 ± 0,06 mg g-1 (n = 3), significativamente superior à capacidade de adsorção do carvão vegetal e mineral (p < 0,05). Adulterações no carvão ativado de osso bovino foram identificadas por meio da análise discriminante, indicando que o NIRS-PLS-DA é uma alternativa eficiente para a caracterização e identificação desses adsorventes para sistemas de tratamento de água.

Hydrotreating of fast pyrolysis oil: A comparison of carbons and carbon-covered alumina as supports for Ni2P

Nickel phosphide is a promising material for substitution of metal nobles and sulfides catalysts in fast pyrolysis oil hydrotreating. In this study, we compared the effects of three different carbon supports for Ni2P on the catalyst activity and selectivity in hydrodeoxygenation (HDO) reactions. It was also evaluated the impacts of temperature and pressure on the quality of hydrotreated bio-oils. The experiments were carried out in a batch reactor at 150 °C and 250 °C while the pressure ranged from 50 to 100 bar. The results showed that Ni2P on activated carbon (AC) performed better at 150 °C than Ni2P on carbon covered alumina (CCA) and mineral charcoal (MC), producing bio-oils with lower oxygen content and higher heating value. At 250 °C, best results were obtained with Ni2P/CCA catalyst, giving bio-oils with lower O/C molar ratio and higher H/C molar ratio. Overall, hydrogenation reactions were favored at the higher temperature in all catalytic systems. TGA analysis indicated that coking tendency of hydrotreated bio-oils was influenced by their chemical composition and reaction temperature. In addition, catalyst characterization before and after reactions, revealed that carbon supported materials were more affected at 250 °C by pore blocking. XRD results also showed the presence of different Ni-phases after reaction, such as Ni12P5 and Ni, probably due to the loss of P by oxidation and/or formation of PH3.

Modifications of phosphorus in Latosol as a function of humic acids and acidity

ABSTRACT The effect of humic acids (HA) on phosphorus (P) availability is still contradictory; thus, it is necessary to identify the conditions that play a crucial role in this effect. The aim of this study was to investigate the effect of HA application, combined with doses of P, on the content of this nutrient in a Latosol with and without acidity correction. Two experiments were carried out, one with HA from peat and another with HA from mineral charcoal (leonardite). Doses of these acids (0; 1.12 and 5.62 mg C g-1 of soil) and P (26.2 and 104.7 mg P g-1 of soil, 1 and 4-fold higher than recommended, respectively) were tested at soil pH 4.5 and 7.0, in a three-factorial design. The soil was incubated for 20 days and the soil-P content was measured by Mehlich-1 and remaining-P tests. The effect of HAs on P availability varied with the P doses and soil acidity. Humic acids application increases P content in Latosol when P dose is higher than recommended and there is no acidity correction (pH 4.5). However, there is no effect of HAs application on soil-P content when applying the recommended amount of this nutrient, irrespective of the pH value.

Efeito de substâncias húmicas na cinética de absorção de potássio, crescimento de plantas e concentração de nutrientes em Phaseolus vulgaris L.

As substâncias húmicas podem influenciar direta ou indiretamente o metabolismo das plantas, alterando assim o seu crescimento. O objetivo deste trabalho foi avaliar o efeito de substâncias húmicas (SH) no crescimento e na concentração de nutrientes em plantas de feijão (Phaseolus vulgaris, L.) e nos parâmetros cinéticos de absorção de K. O experimento foi realizado em bancada de laboratório, com luz artificial. As plantas cresceram em vasos contendo solução nutritiva completa acrescida de cinco doses (0; 2,5; 5; 10; e 20 mg L-1 de C) de SH solúveis em meio alcalino (ácido húmico + ácido fúlvico), extraídos de amostra de carvão mineral da mina de Candiota, RS, da Companhia Riograndense de Mineração, num delineamento completamente ao acaso, com três repetições. Aos 28 dias de cultivo, foram avaliados parâmetros cinéticos de absorção de K, massa da parte aérea e da raiz seca, teores de N, P, K, Ca e Mg no tecido da parte área e as características morfológicas de raízes (comprimento, área e raio). Os resultados evidenciaram que a adição de SH extraída de carvão mineral estimulou o crescimento do feijão e afetou a cinética de absorção de K. A produção de massa da parte aérea seca das plantas mostrou resposta quadrática à adição de substâncias húmicas, atingindo valor máximo na dose equivalente a 11 mg L-1 de C, enquanto a massa das raízes secas aumentou linearmente em até 41 %, com as doses testadas. As características morfológicas de raiz e o estado nutricional das plantas não foram significativamente afetados pelas SH. Os parâmetros cinéticos de absorção de K, Imáx, Cmín e Km, decresceram linearmente com o aumento das doses de SH, causando redução na taxa de absorção de K nas concentrações deste nutriente na solução superiores a 10 μmol L-1.

The legacy of Charles Lyell: advances in our knowledge of coal and coal-bearing strata

Abstract On his travels in both Britain and North America Sir Charles Lyell paid particular attention to coalfields and their fossils. Understanding the formation of coal and associated rocks was the subject of several publications. In this contribution three aspects of this work are highlighted, all of which are the subject of ongoing modern research. Lyell was interested in modern analogues for the Carboniferous coal swamps and was amongst the first to suggest analogies with the mires of the eastern United States, such as the Dismal Swamps. A brief review of recent research on new modern analogues from Southeast Asia is presented. Lyell observed ‘mineral charcoal’ in some of the coals and noted its anatomical structure. Considerable advances in our understanding of the role of fires in terrestrial ecosystems and their potential as an agent of fossil preservation are addressed. One of Lyell’s most important palaeontological finds was of remains of the earliest reptiles (these proved to be amphibians but Sir William Dawson found reptiles subsequently) preserved in the Upper Carboniferous tree trunks at Joggins, Nova Scotia, Canada. Whilst this occurrence of reptiles is no longer the oldest, the reasons for the remarkable tetrapod occurrences in upright sandstone-filled lycophyte trees at Joggins are currently being investigated and recent progress is presented.

Observations on Fusain

Fusain, usually called carbonized wood or mineral charcoal and probably constituting a large part of the carbonaceous material, mentioned in lithologic descriptions, is a common constituent of sedimentary rocks and can be successfully used as a parameter in the interpretation of sedimentary environments associated with some of the stratigraphic-type oil pools. Two kinds of fusain are encountered in sedimentary rocks, that produced by charring during forest fires and that closely associated with coal. The light-weight, easily dispersible nature of this material makes the probability of its incorporation in sediments remote. Only as the result of critical entrapment processes will sufficient quantities of fusain be deposited with mineral clastics to result in a charcoal-r ch sediment, processes peculiar to environments associated with beach, bar, and lagoonal environments.

Stratigraphy of Some Lower Cretaceous Rocks of Black Hills Area

The Skull Creek shale, the Newcastle sandstone, and the lower part of the Mowry shale are considered to be Lower Cretaceous in age correlated by Foraminifera with rocks of Kansas, Oklahoma and Texas. Structural, mineralogical, and biological parameters indicate that the sandstone was deposited toward the close of the Lower Cretaceous as a chain of lenticular, discontinuous offshore bars rimming a low, forested landmass of smaller area than the present Black Hills. Periodic forest fires produced mineral charcoal which was incorporated in the sediments. Deposition of the offshore bars was synchronous only in the gross aspect, and their upper surfaces ranged from a few feet above to a few feet below sea-level with sufficient temporal and spatial expression to result in the existence of a brackish, lagoonal environment which supported specialized foraminiferal assemblages. Migration of these sand bodies occurred laterally and through time with resulting rapid lensing and interfingering conditions both parallel with and normal to the trend of the ancient shore line. The Newcastle sandstone and the lower part of the Mowry shale are considered subordinate to the Skull Creek formation and are assigned member rank.

The Nature and Origin of Fusain

Fusain, called also mineral charcoal, fossil charcoal, mother-of-coal, fusit, fusaine, and Faserkohle, has been known and variously interpreted since the early days of geology. Of the many early hypotheses concerning its nature and origin, three still have adherents. According to the first, known as the hypothesis, fusain is the product of the well known process of fungal decay known as dry-rot. Against this, it may be argued that dry-rot does not produce anything resembling fusain, and that fusain rarely if ever shows the least sign of the decay which attends dry-rot, but on the contrary is generally exquisitely preserved. The second or acid hypothesis postulates that fusain is derived from woody debris that lay at the surface of a swamp during times of evaporation, at which times the woody matter is supposed to have become impregnated and encrusted with concentrated humic solutions. These insoluble and poisonous humic concentrates, upon drying, might have hardened and protected the wood from further decay. Under the conditions postulated, however, no product resembling fusain, that is, having among other characters a pure carbon composition, is ever formed in modern swamps or bogs. Moreover, fusain is a stratified clastic sediment commonly occurring in thin even layers; quite the reverse of the highly irregular, hummocky, residual deposit which the hypothesis would lead one to expect. The third or charcoal hypothesis postulates that fusain is vegetable matter carbonized by fire. A number of objections have been made to this hypotheis but all of them seem to be readily answerable.

VII.— The Banded Constituents of Coal

1. The Physical Characteristics of the Banded Constituents. In the course of this paper it is proposed to describe what have become known to us within recent years as the banded constituents of bituminous coal. Prior to the year 1919, investigators into the constitution of coal were content to describe its appearance as bright or dull according to the predominance of the bright or dull layers in the specimens under examination. There were, however, in addition to these hard, bright and dull bands, varying lenticles of soft, black, charcoal-like substance to which specific names such as “mineral charcoal” and “mother of coal” had been applied. Another distinctive material forming part of some coal seams is cannel or “parrot” coal. This type of coal differs from the ordinary banded variety in its uniformity of texture, its satiny lustre and its marked conchoidal fracture. Its occurrence in coal seams is very uncertain and it is usually present in varying sized lenticular bands. In some publications it may be referred to as “boghead” coal owing to its similarity in appearance to the famous Torbanehill mineral. If a close inspection is made of a lump of ordinary bituminous coal, it will generally be found to consist of layers of materials whose power to reflect light varies considerably. There may be bands of bright, black, glassy lustre; bands of bright material which show minute striations; bands of dull, granular material; and, finally, lenticles of the soft, charcoal-like substance to which reference has already been made. It This 250-word extract was created in the absence of an abstract

X.—Investigation of the Banded Structure of a Fifeshire Coal Seam

It has long been known that a bituminous coal seam is not a homogeneous bed, but is made up of a number of parallel bands. For example, Karsten in 1826 observed and described three banded constituents of such a seam, viz. Faserkohle, Matt Coal, and Glanz Coal, corresponding respectively to mineral charcoal, dull coal, and bright coal, and he gave some chemical details of their composition. Bowman, 1841, stated “there is a peculiarity in the texture of coal which has not received the attention it deserves. If it be clearly examined it will be found to consist of a series of parallel horizontal layers varying in thickness, these laminæ being best observed in the cross fracture, and often exhibit considerable difference in compactness and lustre. This structure, though in coal seams indistinct, is so general that it seems to point to some law which the chemical geologist might advantageously investigate.” Again, Wethered in 1884 observed that a coal seam is separated by partings into many beds differing in quality as in structure while in 1885 he pointed out the advisability of studying the different bands of a seam, and of recording details of its dull and bright portions.

Notes on Prototaxites and Pachytheca , discovered by Dr. Hicks in the Denbighshire Grits of Coewen, N. Wales

Specimens of the first-mentioned fossil were kindly sent to me by Dr. Hicks, at my request, but unfortunately arrived when I was at my summer residence at Little Metis. Though without the means of examining them microscopically, I ventured to write, after studying them with a good pocket-lens, that they resembled Prototaxites , and could not be referred to Algae. The latter conclusion might appear rash; but there are, to the practised eye, indications in specimens of this kind which can scarcely deceive. The fibrous and highly carbonaceous nature of the darker specimens, and the silky and incoherent texture of the lighter-coloured ones, are characters never found in any fossil plants except those having durable woody tissues. Further, the occurrence of the material in angular fragments and in a condition approaching to that of the mineral charcoal of the Coal-measures, proves subaerial decay, little likely to have occurred in the case of aquatic plants. From the state of preservation of the specimens, I also inferred that, if really of the nature of Prototaxites , they might throw some additional light on its structure, as the specimens previously studied had been from entire trunks in a silicified state.

On the Structure and Affinities of Sigillaria, Calamities and Calamodendron

1. Sigillaria The difficulty of arriving at a correct knowledge of the structure of these curious trees is caused principally by the unequal durability of the different parts of the stem. It arises from this that some portions have usually perished, while others were in process of mineralization, and the portions which remain have in a great degree lost their original form and arrangement. The outer bark, while extremely durable, was too impenetrable to be preserved in any other way than as compact coal. The fibres Of the bark and of the woody axis are often mineralized or imperfectly preserved as mineral charcoal. The cellular portions of the bark and of the axis have usually entirely disappeared. Still, imperfectly preserved stems can be obtained in great abundance in any coal-field by those who are content to work on such unpromising material. Probably the finest specimen of a Sigillaria hitherto described is that of S. elegans , so admirably figured by Brongniart, and which has long served to give to the student of palæobotany his ideas of the structure of the genus. Unfortunately, however, Brongniart's specimen represents a small or young stem belonging to the somewhat aberrant subgenus Favularia ; so that it fails to give an adequate idea of the structure of the typical fossil Sigillariæ , which are much more common and important, at least in the coal-fields of Nova Scotia. The structure of these last, as observed in specimens obtained at the South Joggins, was, I believe, first described by me

On the Structure and Affinities of Sigillaria, Calamites , and Calamodendron

Abstract The object of this paper was to illustrate the structure and affinities of the genera above named, more especially with reference to the author's previous papers on the “Structures in Coal” and the “Conditions of Accumulation of Coal,” and to furnish new facts and conclusions as to the affinities of these plants. With reference to Sigillaria , a remarkably perfect specimen of the axis of a plant of this genus, from the Coal-field of Nova Scotia, was described as having a transversely laminated pith of the Sternbergia type, a cylinder of woody tissue, scalariform internally and reticulated or discigerous externally, the tissues much resembling those of Cycads. Medullary rays were apparent in this cylinder; and it was traversed by obliquely radiating bundles of scalariform vessels or fibres proceeding to the leaves. Other specimens were adduced to show that the species having this kind of axis had a thick outer bark of elongated or prosenchymatous cells. The author stated that Prof. Williamson had enabled him to examine stems found in the Lancashire Coal-field, of the type of Binney's Sigillaria vascularis , which differed in some important points of structure from his specimens; and that another specimen, externally marked like Sigillaria , had been shown by Mr. Carruthers to be more akin to Lepidodendron in structure. These specimens, as well as the Sigillaria elegans illustrated by Brongniart, probably represented other types of Sigillarioid trees; and it is not improbable that the genus Sigillaria, as usually understood, really includes several distinct generic forms. The author had recognized six generic forms in a previous paper and in his ‘Acadian Geology;’ but the type described in the present paper was that which appeared to predominate in the fossil Sigillarian forests of Nova Scotia, and also in the mineral charcoal of the coal-beds. This was illustrated by descriptions of structures occurring in erect and prostrate Sigillariæ , on the surface of Sternbergia -casts, and in the coal itself. The erect Calamites of the coal formation of Nova Scotia illustrate in a remarkable manner the exterior surface of the stems of these plants, their foliage, their rhizomata, their roots, and their habit of growth. Their affinities were evidently with Equisetaceæ as Brongniart and others had maintained, and as Carruthers and Schimper had recently illustrated. The internal structure of these plants, as shown by some specimens collected by Mr. Butterworth, of Manchester, and soon to be published by Prof. Williamson, showed that the stems were more advanced in structure than those of modern Equiseta , and enabled the author to explain the various appearances presented by these plants, when the external surface is preserved, wholly or in part, and when a cast of the internal cavity alone remains. It was further shown that the leaves of the ordinary Calamites are linear, angular, and transversely wrinkled, and different from those of Asterophyllites properly so called, though some species, as A. comosus , Lindley, are leaves of Calamites. The Calamodendra , as described by Cotta, Binney, and others, and further illustrated by specimens from Nova Scotia, and by several interesting and undescribed forms in the collection of Prof. Williamson, are similar in general plan of structure to the Calamites, but much more woody plants; and, if allied to Equisetaceæ, are greatly more advanced in the structure of the stem than the modern representatives of that order. Specimens in the collection of Prof. Williamson show forms intermediate between Calamites and Calamadendron , so that possibly both may be included in one family; but much farther information on this subject is required. The tissues of the higher Calamodendra are similar to those of Gymnospermous plants. The wood or vascular matter of the thin-walled Calamites consists of multiporous cells or vessels, in such species as have been examined. In conclusion, a Table was exhibited showing the affinities of Sigillariæ , on the one hand (through Clathraria and Syringodendron ) with Lycopodiaceæ, and on the other hand (through Calamodendron ) with Equisetaceæ; while in another direction they presented links of connexion with Cycads and Conifers.

Notice of the Discovery of a Reptilian Skull in the Coal of Pictou

T he reptilian specimen described by Prof. Owen (Quart. Journ. Geol. Soc. No. 38. p. 207. pl. 9) is the upper part of a head found by me in 1851, at the Albion Mines, in a heap of rubbish extracted from a band of carbonaceous clay iron-stone and coarse coal, occurring in the main coal-seam, about 5 feet below its roof, and known to the miners as the “ holeing-stone .” This band is marked No. 5 in the detailed section of the Albion main coal given by Mr. Poole and myself in the Geological Society's Journal, vol. x. p. 47. It varies in thickness in different parts of the mine, from 2 inches to about 18 inches; and it contains much coprolitic matter, and a few scales, teeth, and spines of fishes, as well as minute Spirorbis-like shells, similar to those found in the Joggins coal-measures attached to plants*. None of these fossils, however, are by any means abundant; and the vegetable remains contained in the “holeing-stone” have in general been reduced to the state of homogeneous coal, or of mineral charcoal. There can be little doubt that this remarkable band indicates a somewhat protracted submergence of the area of coal then accumulating under the waters of a lake or lagoon. As stated in a note which accompanied the specimen, when forwarded to the Geological Society in 1852, the matrix split in such a manner as to leave the upper part of the skull adhering to the larger portion of the block,

On the Structure of the Albion Coal-Measures, Nova Scotia

T he Coal-measures of the Albion Mines present some features very different from those observed in other parts of the coal-formation in Nova Scotia. This must he very evident to any one who compares the published sections and descriptions of the coal-measures of the South Joggins and Sydney, and those of the Pictou coal-field by Mr. Logan, Sir C. Lyell, and Mr. Dawson. Unfortunately the natural sections at Pictou are so imperfect, that the order of succession of the beds is much less fully known than at the other places referred to. Recent exploratory works, conducted by Mr. Poole, Superintendent of the Albion Mines, have, however, brought out some important facts which are exhibited in the Plan and sectional lists appended to this paper, to which these remarks relate, and with the aid of which I propose to state the more important points in which the Albion measures differ from the rocks of similar age in their vicinity, and, if possible, to indicate the causes of these differences. 1. The coal of the Albion Mines is somewhat peculiar in its structure and chemical composition. It is more highly laminated, abounds more in mineral charcoal, is more bituminous and much more free from sulphuret of iron, than the coals of other parts of Nova Scotia. I t has also white and very light ashes, and has a remarkable power of continuing in a state of combustion when covered with ashes, and of remaining alight until all the coaly matter