Identification Of Organic Matter Research Articles

Fluorescence Characteristics of Coalbed Methane Produced Water and Its Influence on Freshwater Bacteria in the South Qinshui Basin, China

Production of coalbed methane (CBM) resources commonly requires using hydraulic fracturing and chemical production well additives. Concern exists for the existence of chemical compounds in CBM produced water, due to the risk of environmental receptor contamination. In this study, parallel factor method analysis (PARAFAC), fluorescence index, and the fluorescence area integral methods were used to analyse the properties of CBM produced water sampled from Shizhuang Block (one of the most active CBM-producing regions in the Qinshui Basin). A culture experiment was designed to determine the effect of discharged CBM produced water on microorganisms in freshwater. Water quality analysis shows the hydrochemistry of most water samples as Na-HCO3 type produced water of CBM appears as a generally weak alkaline (pH 8.69 ± 0.185) with high salinity, high alkalinity, and a high chemical oxygen demand (COD) value. Three individual components were identified by using parallel factor method analysis as humic-like components (C1), fulvic-like components (C2), and amino acid-like substances (C3). The fluorescence characteristic index comprehensively explains that the fluorescent substances in CBM produced water has the characteristics of a low degree of humification and a high recent self-generating source. The region integration results of characteristic peaks show that tyrosine-like and tryptophan-like materials account for more than 67% of fluorescent substances in CBM produced water. The addition of produced water from coalbed methane promotes the growth of freshwater bacteria, and this process is accompanied by the decrease of the proportion of fulvic acid, humic acid, and the increase of the proportion of soluble microbial metabolites. This paper proposes a convenient method for organic matter identification of CBM produced water and provides some theoretical support and reference for the improvement of CBM water treatment and utilization.

Characterization of soil magnetic susceptibility: a review of fundamental concepts, instrumentation, and applications

The characterization of magnetic susceptibility (MS) has become an accepted technique in soil science. This review examines the concept of volume and mass-specific MS, magnetism, frequency dependence, and thermal behavior of MS, as they pertain to soil material. A comparison is presented of the two types of instrumentation for measuring soil MS, based on magnetic field and electromagnetic induction (EMI). These are discussed with respect to applications including magnetic granulometry, detection of pollutants, identification of organic matter, the delineation of drainage class, paleo-environmental studies, archaeology, as well as soil erosion and degradation. Instruments that use magnetic fields can precisely measure the MS of small amounts of soil, thinly deposited layers or soil exposures, but cannot effectively measure materials at distances ≥10 cm from the sensor. EMI instruments, instead, are capable of quickly measuring apparent MS of a finite volume of the soil, and are utilized in mapping of soil MS in agricultural and archaeological investigations; however, the measured apparent MS values need to be further processed to give the real volume MS values of soil layers/segments. Although both kinds of instruments are widely used in soil science, their measured data are not interchangeable. Future work should be conducted to increase the understanding of the comparability of these instruments to find better utility among soil scientists.

Color moment and gray level co-occurrence matrix in classification of soil organic matter for patchouli plantation

<span>Patchouli is one of the essential plants that have the most potential and widely cultivated in Indonesia. Patchouli is greedily absorbing soil nutrients and organic matter. Therefore, the selection of soil with high organic matter will maximize the patchouli’s productivity. This paper aims to facilitate soil’s organic matter identification by classifying soil image based on the combination of color and texture features. The color feature extraction was done using the Color Moments method and the texture feature was done using Gray Level Co-occurrence Matrix (GLCM) method. The selection of features was performed to obtain the best combination of color and texture features. The selected features then was used as input of classification by using Modified K-Nearest Neighbor (MKNN). The samples of soil that used as data were taken from several districts in Blitar, East Java province. The testing result of this research showed the highest accuracy of 93,33% by using 180 training data, and also particular color and texture feature combination.</span>

An approximation to the study of black pigments in Cova Remigia (Castellón, Spain). Technical and cultural assessments of the use of carbon-based black pigments in Spanish Levantine Rock Art

Spanish Levantine Rock Art is a unique pictorial expression within the prehistoric European context. Located in shelters in the inland regions of the Iberian Mediterranean basin, this art form, which must be necessarily studied in the frame of the process of neolithization of this territory, still lacks direct dating, and therefore its authorship is still open to debate.In this paper we present the first characterization of black pigments used in the Cova Remigia shelters in the Valltorta-Gassulla area (Castellón, Spain) by means of EDXRF spectrometry combined with SEM-EDS and Raman spectroscopy. Our aim is both to identify the raw material used for the preparation of black pigments and to make a first approach to the cultural choices involved in its use.The results are relevant for several reasons. Firstly, carbon-based black pigments have been identified for the first time in northern regions of Levantine rock art. Secondly, the recurrent use of black pigments in Cova Remigia questions the assumption of its restricted use in Spanish Levantine art. Thirdly, posterior repainting and graphic re-appropriation of black figures have been observed in Cova Remigia, giving rise to the combination of two colours, black and red, fact that is extremely rare in this rock art tradition. Finally, the identification of organic matter in the black pigments opens the possibility of radiocarbon dating.

Organic geochemistry of Upper Carboniferous bituminous coals and clastic sediments from the Lublin Coal Basin

Abstract Bituminous coals and clastic rocks from the Lublin Formation (Pennsylvanian, Westphalian B) were subjected to detailed biomarker and Rock-Eval analyses. The investigation of aliphatic and aromatic fractions and Rock-Eval Tmax suggests that the Carboniferous deposits attained relatively low levels of thermal maturity, at the end of the microbial processes/initial phase of the oil window. Somewhat higher values of maturity in the clastic sediments were caused by postdiagenetic biodegradation of organic matter. The dominance of the odd carbon-numbered n-alkanes in the range n-C25 to n-C31 , high concentrations of moretanes and a predominance of C 28 and C29 steranes are indicative of a terrigenous origin of the organic matter in the study material. This is supported by the presence of eudesmane, bisabolane, dihydro-ar-curcumene and cadalene, found mainly in the coal samples. In addition, tri- and tetracyclic diterpanes, e. g. 16β(H)-kaurane, 16β(H)-phyllocladane, 16α(H)-kaurane and norisopimarane, were identified, suggesting an admixture of conifer ancestors among the deposited higher plants. Parameters Pr/n-C17 and Rdit in the coal samples show deposition of organic matter from peat swamp environments, with the water levels varying from high (water-logged swamp) to very low (ephemeral swamp). Clastic deposits were accumulated in a flood plain environment with local small ponds/lakes. In pond/lake sediments, apart from the dominant terrigenous organic matter, research also revealed a certain quantity of algal matter, indicated, i.a., by the presence of tricyclic triterpanes C28 and C29 and elevated concentrations of steranes. The Paq parameter can prove to be a useful tool in the identification of organic matter, but the processes of organic matter biodegradation observed in clastic rocks most likely influence the value of the parameter, at the same time lowering the interpretation potential of these compounds. The value of Pr/Ph varies from 0.93 to 5.24 and from 3.49 to 22.57 in the clastic sediments and coals respectively. The microbial degradation of organic matter in both type of rocks and during early stages of diagenesis is confirmed by a high concentration of hopanes, the presence of drimane homologues, bicyclic alkanes and benzohopanes. Moreover, bacteria could also have been connected with the primary input of organic matter, which is shown by the presence of e.g. C30 neohop-13(18)-ene.

Identification of organic matter in lignite samples from basins in the Czech Republic: Geochemical and petrographic properties in relation to lithotype

Five Tertiary deposits in the Czech Republic were studied using coal petrological and organic geochemical methods. Coal samples were chosen to cover four lithotypes: xylite rich coal, matrix coal, liptobiolith, and sapropelic coal. Xylite rich and matrix coals are characterized by higher ulminite and densinite contents, and lower textinite and resinite contents. Sapropelic coals from the North Bohemian and Žitava basins are formed by large amount of ulminite and densinite, and a high proportion of liptodetrinite, sporinite and alginite that prevails in sapropelic shale from the Uhelná relic. The essential difference between sapropelic coal and liptobiolith coal consists of high contents of liptodetrinite, bituminite, resinite, inertinite, and lower contents of clay minerals in liptobioliths. The biomarker composition of the aliphatic fraction includes n-alkanes, and their distribution varied according to coal lithotype: long n-alkanes were dominant in liptobioliths, sapropelic coals and shale, the mid-chain n-alkanes prevailed in xylite rich coals, and the short-chain n-alkanes were abundant in matrix coals. The prevalence of diterpenoids represented by phyllocladane type compounds indicated the presence of gymnosperm vegetation. Molecular indicators for angiosperms, present mainly as oleanenes, were also recognized in the lignite samples. Hopanoids were represented mainly by 17α(H),21β(H)-homohopane and hop-17(21)-ene. The biomarker fingerprints and petrographic based indices show that the majority of the xylite rich, matrix and sapropelic coals and shale originated from mixed forests, formed by arborescent and herbaceous communities, aquatic plants and macrophytes, under wet and slightly dry and slightly oxic–anoxic conditions.

Relationship between soil composition and retention capacity of terbumeton onto chalky soils

Environmental context. The wide use of pesticides for pest and weed control contributes to their presence in underground and surface waters, which has led to a continuously growing interest in their environmental fate. Soils play a key role in the transfer of these compounds from the sprayer to the water as a result of their capacity to retain pesticides depending on the soil components. The knowledge of soil composition should enable one to predict pesticide behaviour in the environment. Abstract. Eight calcareous soils of Champagne vineyards (France) were studied to investigate the adsorption of the herbicide terbumeton (TER). A preliminary characterisation of the soil samples using X-ray diffraction (XRD), elemental and textural analyses, revealed a wide range of soil properties for the selected samples. The adsorption isotherms of TER were plotted for all samples. The determination of soil properties, which significantly correlated with the Kd distribution coefficient, allowed identification of organic matter and CaCO3 as the two main soil components that govern the retention of the herbicide. Organic matter was the predominant phase involved in the retention but its role was limited by the presence of calcite. Finally, the ratio of CaCO3 content to organic matter content was proposed as a useful parameter to predict the adsorption of terbumeton in chalky soils. The evolution of Kd as a function of this ratio was successfully described using an empirical model.

Microalgal lipid markers for paleoclimatic research

Primary producers, mainly represented in the marine environment by microalgae, synthesize a wide variety of lipid constituents, some of which are recognized as ‘biomarkers’ that can be used to identify sources of organic matter. Furthermore, as phytoplankton rapidly reflect climate variations, the identification of organic matter in sediments may help to understand present or ancient specific environmental conditions. To highlight differences in some lipid constituents (hydrocarbons, sterols and fatty acids) of different taxa of microalgae, we determined these compounds in the diatom Cylindrotheca closterium and dinoflagellate Scrippsiella trochoidea isolated from the Adriatic Sea and grown in batch cultures. Total lipids were extracted in chloroform-methanol and, after separation, analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The only hydrocarbons present in these species were cis-3,6,9,12,15,18-heneicosahexaene (HEH) and squalene. Analysis of sterols in C. closterium revealed that only 4-desmethylsterols were present. Conversely, in S. trochoidea, 2 different groups of sterols (4-desmethylsterols and 4a-methylsterols) were identified. Besides the fatty acid 16:0, which predominated in both species, high percentages of 16:1n-7 and 20:5n-3 were observed in C. closterium, whereas 18:4n-3 and 22:6n-3 were detected in S. trochoidea. Differences in lipid patterns were observed between C. closterium and S. trochoidea. These differences might help understand the Adriatic Sea Basin’s paleoclimatic history.

Organic matter identification in source and reservoir carbonate in the Lower Cretaceous Mauddud Formation in Kuwait

ABSTRACT The purpose of this study is to identify the source rock, reservoirs and nonproductive zones in the Lower Cretaceous Mauddud Formation in Kuwait, using geochemical methods. This formation is one of the major Cretaceous oil reservoirs. It is composed mainly of calcarenitic limestone interbedded with marl and glauconitic sands. Its thickness ranges from almost zero in the south to about 100 m (328 ft) in the north. A total of 99 core samples were collected from six oil fields in Kuwait: Raudhatain, Sabiriyah and Bahra in the north, and from the Burgan, Ahmadi and Magwa in the south. Well logs from these fields (gamma ray GR, sonic, resistivity, density) were correlated and used in the study. The core samples were screened for the amount and nature of the organic matter by Rock-Eval 6 pyrolysis (RE6) using reservoir mode. A set of samples was selected to study the properties of the organic matter including the soluble and insoluble organic parts. The geochemical characterisation was performed using different methods. After organic solvent extraction of rock samples, the solvent soluble organic matter or bitumen was characterised in terms of saturates, aromatics and heavy compounds (resins and asphaltenes). Then the hydrocarbon distribution of saturates was studied using gas chromatography (GC/FID) and gas chromatography-mass spectrometry (GC/MS) for tentative oil-source rock correlation. After mineral matrix destruction of previously extracted rocks, insoluble organic matter or kerogen was analysed for its elemental composition to identify kerogen type. The geology and the analytical results show similarities between the wells in the southern fields and the wells in the northern fields. Average Total Organic Matter (TOC) in the carbonate facies is 2.5 wt.% and the highest values (8.0 wt.%) are in the northern fields. The clastic intervals in the northern fields show higher total organic matter (1.3 wt.%) relative to the southern fields (0.6 wt.%). The total Production Index is higher in the carbonate (0.6) than the clastic section (0.3). This reflects the amount of extractable hydrocarbons, which are usually associated with the carbonate section in this formation, representing its reservoir section. Although the carbonate rocks are dominated by richer total organic matter, there are some intervals, with low total organic matter values (0.07 wt.%), representing its poor reservoir sections. The kerogen type varies between type II-III and III in the shales with a slightly better quality in the carbonate section. It is immature in almost all the studied fields. The composition of the rock extract has no relation with the rock type. Some sandstone show similar extract composition to the carbonate rocks in the reservoir intervals. The extracts from these intervals show different genetic nature than those in the shales. The maturity level in the reservoir extract is much higher than in the shale intervals. Thus, the oil accumulated in the reservoir might be largely related to migrated oil from a more mature source rock deposited in a clearly different environment than the associated shaly intervals. The best candidates being a more deeply buried Early Cretaceous Sulaiy Formation and Upper Jurassic Najmah Formation.

Identification of organic matter in thin section by staining and a study programme for carbonate rocks

ABSTRACT A method for the identification of organic material in thin section using biological stains is described and placed in context as part of a study programme for carbonate rocks.