Sample records for by-product gypsum produced

  1. Use of flue gas desulfurization (FGD) by-product gypsum on alfalfa

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    Stout, W.L.; Priddy, W.E. [USDA ARS, University Park, PA (United States)


    Subsoil acidity in northeast United States has been associated with decreased yield and decreased water and fertilizer nitrogen (N) utilization by forages. Surface applications of gypsiferous products has been shown to reduce subsoil acidity largely caused by high levels of soluble aluminium (Al). Our objective was to test the effectiveness and safety of using FGD gypsum to increase dry matter (DM) yields of alfalfa (Medicago sativa L.). Four and one-half, 9, and 18 mt/ha of either commercially available agricultural gypsum or two gypsum by-products were applied to a Rayne soil (fine-loamy, mixed, mesic Typic Hapludult) with a strongly acid subsoil. Agricultural and FGD gypsum increased alfalfa DM yields by as much as 21 and 14%, respectively. Correspondingly, in the subsoil, soluble Al decreased and calcium (Ca) content and Ca:Al ratio increased. Heavy metal concentrations in either the alfalfa or soils were not increased by any treatment. However, Si in the alfalfa grown at the highest treatments approached concentrations that are considered to be toxic to grazing animals.

  2. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 6, Field study conducted in fulfillment of Phase 3 titled. Use of FGD by-product gypsum enriched with magnesium hydroxide as a soil amendment

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    Bigham, J. M. [Ohio State Univ., Wooster, OH (United States). Ohio Agricultural Research Development Center; Soto, U. I. [Ohio State Univ., Wooster, OH (United States). Ohio Agricultural Research Development Center; Stehouwer, R. C. [Ohio State Univ., Wooster, OH (United States). Ohio Agricultural Research Development Center; Yibirin, H. [Ohio State Univ., Wooster, OH (United States). Ohio Agricultural Research Development Center


    A variety of flue gas desulfurization (FGD) technologies have been developed to meet environmental restrictions imposed by the federal Clean Air Act and its amendments. These technologies include wet scrubber systems that dramatically reduce sulfur dioxide (SO2) emissions. Although such systems are effective, they also produce large volumes of sludge that must be dewatered, stabilized, and disposed of in landfills. Disposal is an expensive and environmentally questionable process for which suitable alternatives are needed. Wet scrubbing of flue gases with magnesium (Mg)-enhanced lime has the potential to become a leading FGD technology. When combined with aforced oxidation system, the wet sludges resulting from this process can be modified and refined to produce gypsum (CaS04∙2H2O) and magnesium hydroxide [Mg(OH)2] of sufficient purity for beneficial re-use in the construction (wallboard) and pharmaceutical industries. The pilot plant at the CINERGY Zimmer Station near Cincinnati can also produce gypsum by-products formulated to contain varying amounts of Mg(OH)2- Such materials may have value to the agriculture, forestry, and lawn-care industries as soil "conditioners", liming agents, and nutritional supplements capable of supplying calcium (Ca), Mg, and sulfur (S) for plant growth. This report describes three field studies designed to evaluate by-product gypsum and Mg-gypsum from the Zimmer Station power plant as amendments for improving the quality of mine spoils and agricultural soils that were unproductive because of phytotoxic levels of dissolved aluminum (Al) and low pH. The technical literature suggests that gypsum may be more effective than agricultural limestone for ameliorating Al toxicity below the immediate zone of application. Such considerations are important for deep-rooted plant species that attempt to utilize water and nutrients occurring at depth in the spoil/soil.

  3. Reclamation of highly calcareous saline sodic soil using Atriplex halimus and by-product gypsum. (United States)

    Gharaibeh, M A; Eltaif, N I; Albalasmeh, A A


    The removal of sodium salts from saline soils by salt tolerant crops, as alternative for costly chemical amendments, has emerged as an efficient low cost technology. Lysimeter experiments were carried out on a highly saline sodic soil (ECe = 65.3 dS m(-1), ESP = 27.4, CEC = 47.9 cmole+ kg(-1), and pH = 7.7) and irrigated with canal water (EC = 2.2 dSm(-1), SAR = 4.8) to investigate reclamation efficiency under four different treatments: control (no crop and no gypsum application) (C), gypsum application equivalent to 100% gypsum requirement (G100), planting sea orach (Atriplex halimus) as phytoremediation crop (Cr), planting sea orach with gypsum application equivalent to 50% gypsum requirement (CrG50). Soil salinity (ECe) and exchangeable sodium percentage (ESP) were significantly reduced compared to the control. Average ESP and ECe (dS m(-1)) in the top layer were 9.1, 5.8 (control), 4.8, 3.7 (Cr), 3.3, 3.9 (CrG50), and 3.8, 3.1 (G100), respectively. Atriplex halimus can be recommended as phytoremediation crop to reclaim highly saline sodic clay loam soils.

  4. Study on the Possibility of Using Vine Stalk Waste ( Vitis Vinifera) for Producing Gypsum Particleboards (United States)

    Rangavar, H.; Khosro, S. Kh.; Payan, M. H.; Soltani, A.


    The objective of this study was the production of gypsum particleboards with vine stalk waste and the investigation of some physical and mechanical properties of the boards. For this purpose, boards were made from gypsum, oven-dried mass of vine stalk waste, and the white portland cement in various ratios. The thickness swelling and water absorption after 2 and 24 hours of immersion in water, the modulus of rupture, the modulus of elasticity, and the internal bond strength of the boards were determined according to the European Norms standard. The results show that, by selecting proper ratios between the constituents, particleboards with good physicomechanical properties can be produced.

  5. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 5, A laboratory greenhouse study conducted in fulfillment of Phase 2, Objective 2 titled. Use of FGD by-product gypsum enriched with magnesium hydroxide as a soil amendment

    Energy Technology Data Exchange (ETDEWEB)

    Yibirin, H. [Ohio State Univ., Wooster, OH (United States); Stehouwer, R. C. [Ohio State Univ., Wooster, OH (United States); Bigham, J. M. [Ohio State Univ., Wooster, OH (United States); Soto, U. I. [Ohio State Univ., Wooster, OH (United States)


    The Clean Air Act, as revised in 1992, has spurred the development of flue gas desulfurization (FGD) technologies that have resulted in large volumes of wet scrubber sludges. In general, these sludges must be dewatered, chemically treated, and disposed of in landfills. Disposal is an expensive and environmentally questionable process for which suitable alternatives must be found. Wet scrubbing with magnesium (Mg)-enhanced lime has emerged as an efficient, cost effective technology for SO2 removal. When combined with an appropriate oxidation system, the wet scrubber sludge can be used to produce gypsum (CaSO4-2H2O) and magnesium hydroxide [Mg(OH)2] of sufficient purity for beneficial re-use. Product value generally increases with purity of the by-product(s). The pilot plant at the CINERGY Zimmer Station near Cincinnati produces gypsum by products that can be formulated to contain varying amounts of Mg(OH)2. Such materials may have agricultural value as soil conditioners, liming agents and sources of plant nutrients (Ca, Mg, S). This report describes a greenhouse study designed to evaluate by-product gypsum and Mg gypsum from the Zimmer Station pilot plant as amendments for improving the quality of agricultural soils and mine spoils that are currently unproductive because of phytotoxic conditions related to acidity and high levels of toxic dissolved aluminum (Al). In particular, the technical literature contains evidence to suggest that gypsum may be more effective than agricultural limestone in modifying soil chemical conditions below the immediate zone of application. Representative samples of by-product gypsum and Mg(OH)2 from the Zimmer Station were initially characterized. The gypsum was of high chemical purity and consisted of well crystalline, lath-shaped particles of low specific surface area. By contrast, the by-product Mg(OH)2 was a high surface area material (50 m2 g

  6. Effect of the addition of by-product ash of date palms on the mechanical characteristics of gypsum-calcareous materials used in road construction (United States)

    Khellou, A.; Kriker, A.; Hafssi, A.; Belbarka, K.; Baali, K.


    The gypsum-calcareous materials, also known as the crusting tuff, are used in the pavement layers of low -traffic road and considered as the materials of first choice in the Saharan region of Algeria. The objective of this paper is to study the mechanical characteristics of tuff of Ouargla town that is situated in the Southeast of Algeria, by adding different percentage of ash resulted from the combustion of by-products of date palms, such as 4%, 8% and l2%, to the tuff. The results obtained have shown a remarkable improvement both in compressive strength at different ages and in the bearing index in the two cases immediate and after immersion in water. These characteristics of the mixture (tuff+ash) reach their maximum values at the 8% of ash addition.

  7. Compaction of FGD-gypsum

    NARCIS (Netherlands)

    Stoop, B.T.J.; Larbi, J.A.; Heijnen, W.M.M.


    It is shown that it is possible to produce compacted gypsum with a low porosity and a high strength on a laboratory scale by uniaxial compaction of flue gas desulphurization (FGD-) gypsum powder. Compacted FGD-gypsum cylinders were produced at a compaction pres-sure between 50 and 500 MPa yielding

  8. Gypsum karst in Great Britain

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    Cooper A.H.


    Full Text Available In Great Britain the most spectacular gypsum karst development is in the Zechstein gypsum (late Permian mainly in north-eastern England. The Midlands of England also has some karst developed in the Triassic gypsum in the vicinity of Nottingham. Along the north-east coast, south of Sunderland, well-developed palaeokarst, with magnificent breccia pipes, was produced by dissolution of Permian gypsum. In north-west England a small gypsum cave system of phreatic origin has been surveyed and recorded. A large actively evolving phreatic gypsum cave system has been postulated beneath the Ripon area on the basis of studies of subsidence and boreholes. The rate of gypsum dissolution here, and the associated collapse lead to difficult civil engineering and construction conditions, which can also be aggravated by water abstraction.

  9. Growth of indoor fungi on gypsum

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    Segers, Frank J J; van Laarhoven, Karel A; Wosten, Han; Dijksterhuis, Jan


    AIMS: To have a better understanding of fungal growth on gypsum building materials to prevent indoor fungal growth. METHODS AND RESULTS: Gypsum is acquired by mining or as a by-product of flue-gas desulfurization or treatment of phosphate ore for the production of fertilizer. Natural gypsum,

  10. Alfalfa Responses to Gypsum Application Measured Using Undisturbed Soil Columns

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    Rebecca Tirado-Corbalá


    Full Text Available Gypsum is an excellent source of Ca and S, both of which are required for crop growth. Large amounts of by-product gypsum [Flue gas desulfurization gypsum-(FGDG] are produced from coal combustion in the United States, but only 4% is used for agricultural purposes. The objective of this study was to evaluate the effects of (1 untreated, (2 short-term (4-year annual applications of gypsum totaling 6720 kg ha−1, and (3 long-term (12-year annual applications of gypsum totaling 20,200 kg ha−1 on alfalfa (Medicago sativa L. growth and nutrient uptake, and gypsum movement through soil. The study was conducted in a greenhouse using undisturbed soil columns of two non-sodic soils (Celina silt loam and Brookston loam. Aboveground growth of alfalfa was not affected by gypsum treatments when compared with untreated (p > 0.05. Total root biomass (0–75 cm for both soils series was significantly increased by gypsum application (p = 0.04, however, increased root growth was restricted to 0–10 cm depth. Soil and plant analyses indicated no unfavorable environmental impact from of the 4-year and 12-year annual application of FGDG. We concluded that under sufficient water supply, by-product gypsum is a viable source of Ca and S for land application that might benefit alfalfa root growth, but has less effect on aboveground alfalfa biomass production. Undisturbed soil columns were a useful adaptation of the lysimeter method that allowed detailed measurements of alfalfa nutrient uptake, root biomass, and yield and nutrient movement in soil.

  11. Alfalfa Responses to Gypsum Application Measured Using Undisturbed Soil Columns (United States)

    Tirado-Corbalá, Rebecca; Slater, Brian K.; Dick, Warren A.; Barker, Dave


    Gypsum is an excellent source of Ca and S, both of which are required for crop growth. Large amounts of by-product gypsum [Flue gas desulfurization gypsum-(FGDG)] are produced from coal combustion in the United States, but only 4% is used for agricultural purposes. The objective of this study was to evaluate the effects of (1) untreated, (2) short-term (4-year annual applications of gypsum totaling 6720 kg ha−1), and (3) long-term (12-year annual applications of gypsum totaling 20,200 kg ha−1) on alfalfa (Medicago sativa L.) growth and nutrient uptake, and gypsum movement through soil. The study was conducted in a greenhouse using undisturbed soil columns of two non-sodic soils (Celina silt loam and Brookston loam). Aboveground growth of alfalfa was not affected by gypsum treatments when compared with untreated (p > 0.05). Total root biomass (0–75 cm) for both soils series was significantly increased by gypsum application (p = 0.04), however, increased root growth was restricted to 0–10 cm depth. Soil and plant analyses indicated no unfavorable environmental impact from of the 4-year and 12-year annual application of FGDG. We concluded that under sufficient water supply, by-product gypsum is a viable source of Ca and S for land application that might benefit alfalfa root growth, but has less effect on aboveground alfalfa biomass production. Undisturbed soil columns were a useful adaptation of the lysimeter method that allowed detailed measurements of alfalfa nutrient uptake, root biomass, and yield and nutrient movement in soil. PMID:28696383

  12. Effects of gypsum on trace metals in soils and earthworms (United States)

    Mined gypsum has been beneficially used for many years as an agricultural amendment. Currently a large amount of flue gas desulfurization (FGD) gypsum is produced by removal of SO2 from flue gas streams when fuels with high S content are burned. The FGD gypsum, similar to mined gypsum, can enhance c...

  13. Growth of indoor fungi on gypsum. (United States)

    Segers, F J J; van Laarhoven, K A; Wösten, H A B; Dijksterhuis, J


    To have a better understanding of fungal growth on gypsum building materials to prevent indoor fungal growth. Gypsum is acquired by mining or as a by-product of flue-gas desulphurization or treatment of phosphate ore for the production of fertilizer. Natural gypsum, flue-gas gypsum and phosphogypsum therefore have different mineral compositions. Here, growth of fungi on these types of gypsum was assessed. Conidia of the indoor fungi Aspergillus niger, Cladosporium halotolerans and Penicillium rubens were inoculated and observed using microscopic techniques including low-temperature scanning electron microscopy. Elemental analysis of gypsum was done using inductively coupled plasma atomic emission spectroscopy and segmented flow analysis. Moisture content of the gypsum was determined using a dynamic vapour sorption apparatus. Aspergillus niger, C. halotolerans and P. rubens hardly germinated on natural gypsum and flue-gas gypsum. The latter two fungi did show germination, outgrowth, and conidiation on phosphogypsum, while A. niger hardly germinated on this substrate. Other experiments show that C. halotolerans and P. rubens can develop in pure water, but A. niger does not. The observations show that the lack of germination of three indoor fungi is explained by the low amount of phosphor in natural, flue-gas and laboratory-grade gypsum. Additionally, C. halotolerans and P. rubens can develop in pure water, while conidia of A. niger do not show any germination, which is explained by the need for organic molecules of this species to induce germination. Indoor fungal growth is a potential threat to human health and causes damage to building materials. This study possibly helps in the application of the right type of gypsum in buildings. © 2017 The Society for Applied Microbiology.

  14. Gypsum hydration: a theoretical and experimental study

    NARCIS (Netherlands)

    Yu, Qingliang; Brouwers, Jos; de Korte, A.C.J.; Fischer, H.B; Bode, K.A.


    Calcium sulphate dihydrate (CaSO4·2H2O or gypsum) is used widely as building material because of its excellent fire resistance, aesthetics, and low price. Hemihydrate occurs in two formations of α- and β-type. Among them β-hemihydrate is mainly used to produce gypsum plasterboard since the hydration

  15. Chitooligomers preparation by chitosanase produced under solid state fermentation using shrimp by-products as substrate. (United States)

    Nidheesh, T; Pal, Gaurav Kumar; Suresh, P V


    Solid state fermentation (SSF) conditions were statistically optimized for the production of chitosanase by Purpureocillium lilacinum CFRNT12 using shrimp by-products as substrate. Central composite design and response surface methodology were applied to evaluate the effect of variables and their optimization. Incubation temperature, incubation time, concentration of inoculum and yeast extract were found to influence the chitosanase production significantly. The R(2) value of 0.94 indicates the aptness of the model. The level of variables for optimal production of chitosanase was 32 ± 1°C temperature, 96 h incubation, 10.5% (w/v) inoculum, 1.05% (w/w) yeast extract and 65% (w/w) moisture content. The chitosanase production was found to increase from 2.34 ± 0.07 to 41.78 ± 0.73 units/g initial dry substrate after optimization. The crude chitosanase produced 4.43 mM of chitooligomers as exclusive end product from colloidal chitosan hydrolysis. These results indicate the potential of P. lilacinum CFRNT12 for the chitosanase production employing cost effective SSF using shrimp by-products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Hydrogeology of Gypsum formations

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    Klimchouk A.


    Full Text Available Detailed explanation of hydrogeological characteristics of gypsum aquifers is given in various situations: deep-seated karst-confined conditions, subjacent, entrenched and denuded karst types-semi-confined, phreatic and vadose conditions. The hydrogeological evolution of barren exposed gypsum karst and flow velocities in gypsum karst aquifers is also discussed.

  17. Hydrogeology of Gypsum formations


    Klimchouk A.


    Detailed explanation of hydrogeological characteristics of gypsum aquifers is given in various situations: deep-seated karst-confined conditions, subjacent, entrenched and denuded karst types-semi-confined, phreatic and vadose conditions. The hydrogeological evolution of barren exposed gypsum karst and flow velocities in gypsum karst aquifers is also discussed.

  18. Immobilized Sclerotinia sclerotiorum invertase to produce invert sugar syrup from industrial beet molasses by-product. (United States)

    Mouelhi, Refka; Abidi, Ferid; Galai, Said; Marzouki, M Nejib


    The fungus Sclerotinia sclerotiorum produces invertase activity during cultivation on many agroindustrial residues. The molasses induced invertase was purified by DEAE-cellulose chromatography. The molecular mass of the purified enzyme was estimated at 48 kDa. Optimal temperature was determined at 60 °C and thermal stability up to 65 °C. The enzyme was stable between pH 2.0 and 8.0; optimum pH was about 5.5. Apparent K(m) and V(max) for sucrose were estimated to be respectively 5.8 mM and 0.11 μmol/min. The invertase was activated by β-mercaptoethanol. Free enzyme exhibited 80 % of its original activity after two month's storage at 4 °C and 50 % after 1 week at 25 °C. In order to investigate an industrial application, the enzyme was immobilized on alginate and examined for invert sugar production by molasses hydrolysis in a continuous bioreactor. The yield of immobilized invertase was about 78 % and the activity yield was 59 %. Interestingly the immobilized enzyme hydrolyzed beet molasses consuming nearly all sucrose. It retained all of its initial activity after being used for 4 cycles and about 65 % at the sixth cycle. Regarding productivity; 20 g/l of molasses by-product gave the best invert sugar production 46.21 g/day/100 g substrate related to optimal sucrose conversion of 41.6 %.

  19. Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength (United States)

    Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed


    Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

  20. Flue gas desulphurisation gypsum as a raw material

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    Demmich, Joerg [Knauf Gips KG, Iphofen (Germany)


    For decades the use of wet desulphurisation processes with the production of FGD gypsum has been well-proven in the power industry around the globe. In the meantime the European gypsum industry has also adapted with additional investments to the processing of moist, finely divided FGD gypsum. However, it is extremely difficult at this point of time to give any corresponding long-term prognosis on the development of the environment and energy policy with respect to the long-term raw material supplies with FGD gypsum for the gypsum industry. Two very different scenarios are described leading to entirely different results regarding FGD gypsum production in Germany. One of the scenarios expects a substantial extension of renewable energies in Germany. According to that, this would lead to a considerable reduction of FGD gypsum quantities produced at least in Germany. (orig.)

  1. Dealing with gypsum karst problems: hazards, environmental issues, and planning


    Cooper, A.H.; Gutiérrez, F.


    Gypsum dissolves rapidly underground and at the surface, forming gypsum karst features that include caves, subsidence areas, and sinkholes. Mapping these landforms, understanding the gypsum karst and local hydrogeology, and producing sinkhole susceptibility and hazard maps are crucial for development and public safety. Situations that change the local hydrogeology, such as dams, water abstraction, or injection/drainage, can accelerate dissolution and subsidence processes, increasing the sever...

  2. Integrated biovalorization of wine and olive mill by-products to produce enzymes of industrial interest and soil amendments

    Energy Technology Data Exchange (ETDEWEB)

    Reina, R.; Ullrich, R.; García-Romera, I.; Liers, C.; Aranda, E.


    An integral and affordable strategy for the simultaneous production of lignin-modifying and carbohydrate active enzymes and organic amendment, with the aid of a saprobe fungus was developed by using olive oil and wine extraction by-products. The polyporal fungus Trametes versicolor was cultivated in soy or barley media supplemented with dry olive mill residue (DOR) as well as with grape pomace and stalks (GPS) in solid state fermentation (SSF). This strategy led to a 4-fold increase in the activity of laccase, the principal enzyme produced by SFF, in DOR-soy media as compared to controls. T. versicolor managed to secrete lignin-modifying enzymes in GPS, although no stimulative effect was observed. GPS-barley media turned out to be the appropriate medium to elicit most of the carbohydrate active enzymes. The reuse of exhausted solid by-products as amendments after fermentation was also investigated. The water soluble compound polymerization profile of fermented residues was found to correlate with the effect of phytotoxic depletion. The incubation of DOR and GPS with T. versicolor not only reduced its phytotoxicity but also stimulated the plant growth. This study provides a basis for understanding the stimulation and repression of two groups of enzymes of industrial interest in the presence of different carbon and nitrogen sources from by-products, possible enzyme recovery and the final reuse as soil amendments. (Author)

  3. Characterization of quality recycled gypsum and plasterboard with maximized recycled content

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    A. Jiménez-Rivero


    Full Text Available The quality of secondary materials is imperative to promote a circular economy. In order to improve the way in which the quality of recycled gypsum is assessed, European guidelines on recycled gypsum (RG quality criteria have been outlined in the framework of the Life+ Gypsum to Gypsum (GtoG project. Such GtoG guidelines, along with the European Standard on gypsum plasterboard EN 520, provided the basis for this study. During the GtoG project, gypsum recycling and plasterboard manufacturing processes were monitored by testing the gypsum feedstock and the plasterboard produced. The aim of this paper is to discuss the results obtained on relevant parameters that characterize gypsum as a secondary raw material, as well as the resulting product. The minimum requirements were fulfilled by 56% of the RG samples and 86% of the plasterboard with increased RG.

  4. Mechanism of gypsum hydration

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    Pacheco, G.


    Full Text Available There is an hypothesis that the mechanism o f gypsum hydration and dehydration is performed through two simultaneous phenomena. In this study we try to clear up this phenomenon using chlorides as accelerators or a mixture of ethanol-methanol as retarders to carry out the gypsum setting. Natural Mexican gypsum samples and a hemihydrate prepared in the laboratory are used. The following analytical techniques are used: MO, DRX, DTA, TG and DTG. In agreement with the obtained results, it can be concluded: that colloid formation depends on the action of accelerators or retarders and the crystals are a consequence of the quantity of hemihydrate formed.

    En el mecanismo de hidratación y deshidratación del yeso existe la hipótesis de que éste se efectúa por dos fenómenos simultáneos. Este estudio intenta esclarecer estos fenómenos, empleando: cloruros como aceleradores o mezcla etanol-metanol como retardadores para efectuar el fraguado del yeso. Se emplean muestras de yeso de origen natural mexicano y hemihydrate preparado en laboratorio; se utilizan técnicas analíticas: MO, DRX, DTA, TG y DTG. De acuerdo a los resultados obtenidos se puede deducir: que la formación del coloide depende de la acción de los agentes aceleradores o retardadores y que los cristales son consecuencia de la cantidad de hemihidrato formado.

  5. Strengthening of poor subsoil: utilization of power station gypsum and coal ash

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    Inamatsu, T.; Himiya, S.; Ariga, A.; Tokugawa, M.


    A current research theme in Japan is the utilisation of flue gas desulfurization gypsum and fly ash (produced as by-products at coal-fired power plants) for improving soil quality and cutting construction costs. In the present report, the authors outline a series of on-site experiments scheduled to be carried out in connection with the slope faces of embankments at the new site of Kanazawa University. The experiments are designed to clarify the best procedures for the use of mixtures of gypsum, fly ash, cement and lime in soil, so as to prevent collapse of slope faces constructed from poor subsoils. A second development target is to ensure that suitable plants can subsequently be grown on embankments built from strengthened soil.

  6. Gypsum speleogenesis: a hydrogeological classification of gypsum caves

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    José-María Calaforra


    Full Text Available This article reviews the state of the art of speleogenetic investigations in gypsum karsts from numerous studies carried out over the past 50 years in Spain. A classification of gypsum karsts is proposed based on the hydrogeological, tectonic and stratigraphic criteria that decisively control the evolution of gypsum karsts. In this respect, lithological aspects of Messinian and Triassic-Permian gypsum series in south-eastern Spain are considered, such as the alternation of rhythmic levels of marl and gypsum, as well as geodynamic aspects. The influence of the hydrogeological characteristics of evaporite aquifers on gypsum cave speleogenesis is discussed; this includes speleogenetic processes in confined, semi-confined or free aquifers controlled by regional and local base levels. Also, the importance of intense saline diapiric uplift is examined. To illustrate our classification, examples of gypsum caves developed in Spain are presented. Their similarities and differences with gypsum karsts in other regions (Italy, Ukraine, and USA are discussed. A first general division addresses: (1 caves controlled by stratigraphic factors and (2 caves controlled by tectonic factors. Several typologies can be described, including (A multilayer caves with confined hydrogeological origin, (B confined hypophreatic caves with linear or maze configurations, (C caves controlled by the variation or remanence of regional or local base-levels, and (D caves controlled by the halokinetic evolution of salt/gypsum diapirs. The proposed classification is flexible and adaptable to each case, because different genetic mechanisms can coincide in time and space. Likewise, most considerations stated in this work about gypsum karst are valid for speleogenesis in other rock types.

  7. Preparation of Waste GFRP Fiber Reinforced Gypsum Block with Water-resistant and Energy Storage Characteristics

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    Zhang Meng-Meng


    Full Text Available Gypsum block possesses good performances such as volume stability, lightweight and thermal insulation, is recognized as typical eco-friendly building material. However, its poor water resistance characteristics restrict the application. The semi-hydrated desulphurization gypsum is modified with steel slag, granulated blast-furnace and carbide slag (SGC composite powder as well as waste glass-reinforced plastic (GFRP fiber, aiming at producing water-resistant gypsum block. The proper mass proportioning of the modified gypsum block is obtained: semi-hydrated desulphurization gypsum 75%, SGC 25% and waste GFRP fiber 1.0%. The product is of softening coefficient of 0.84 and thermal flexural strength of 8.6 MPa. Phase change energy storage material (PCM is used to increase the energy saving characteristics of the block. Compared with ordinary gypsum walls, the modified gypsum block with CA-SA exhibits good energy storage property.

  8. The mechanical and physical properties of unfired earth bricks stabilized with gypsum and Elazığ Ferrochrome slag

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    İbrahim Türkmen


    Full Text Available During the last few years, an increasing interest has been appeared for earth as a building material. Earth-based materials have been studied because of energy efficiency and ecologically sustainability. The chromite deposits, 10% of the world reserves, are processed in Elazığ Ferrochrome Factory in Eastern of Turkey. Elazığ Ferrochrome slag (EFS as a by-product of the factory is produced roughly 50,000 tons in a year. The disposal, removal and storage of this by-product is a serious problem. Therefore, the utilization of this waste material in building applications is very important. The aim of this work is to investigate effects of gypsum and EFS additives on mechanical and physical properties of unfired earth brick (UEB materials in order to assess their potential advantages in building applications. The earth material was characterized by laboratory tests. Four different UEB samples were produced by using different compositions of earth, gypsum, EFS and straw fibers. Compressive strength, water absorption coefficient, drying shrinkage, ultrasonic pulse velocity (UPV and density of the prepared UEB samples were determined. The experimental findings have showed that the usage of gypsum and EFS in stabilizing process of UEBs was advantageous.

  9. Use of waste gypsum to replace natural gypsum as set retarders in portland cement. (United States)

    Chandara, Chea; Azizli, Khairun Azizi Mohd; Ahmad, Zainal Arifin; Sakai, Etsuo


    The present study is focused on clarifying the influence of waste gypsum (WG) in replacing natural gypsum (NG) in the production of ordinary Portland cement (OPC). WG taken from slip casting moulds in a ceramic factory was formed from the hydration of plaster of paris. Clinker and 3-5wt% of WG was ground in a laboratory ball mill to produce cement waste gypsum (CMWG). The same procedure was repeated with NG to substitute WG to prepare cement natural gypsum (CMNG). The properties of NG and WG were investigated via X-ray Diffraction (XRD), X-ray fluorescence (XRF) and differential scanning calorimetry (DSC)/thermogravimetric (TG) to evaluate the properties of CMNG and CMWG. The mechanical properties of cement were tested in terms of setting time, flexural and compressive strength. The XRD result of NG revealed the presence of dihydrate while WG contained dihydrate and hemihydrate. The content of dihydrate and hemihydrates were obtained via DSC/TG, and the results showed that WG and NG contained 12.45% and 1.61% of hemihydrate, respectively. Furthermore, CMWG was found to set faster than CMNG, an average of 15.29% and 13.67% faster for the initial and final setting times, respectively. This was due to the presence of hemihydrate in WG. However, the values obtained for flexural and compressive strength were relatively the same for CMNG and CMWG. Therefore, this result provides evidence that WG can be used as an alternative material to NG in the production of OPC.

  10. [Low molecular weight oxidation by-products produced during catalytic ozonation with ferric hydroxide of NOM fractions isolated from filtrated water]. (United States)

    Lu, Jin-Feng; Qiu, Jiao; Ma, Jun; Zhang, Tao; Chen, Zhong-Lin; Wang, Huan


    Natural organic matter (NOM) in a filtered river water from a water treatment plant was isolated and fractionated into six types of fractions. The aim of the work is to investigate the formation of the low molecular weight (LMW) oxidation by-products (i.e. aldehydes, ketones and ketoacids) after ferric hydroxide-catalyzed ozonation of individual NOM fractions. Results showed that catalytic ozonation could improve the reduction of the dissolved organic matter (DOC) and specific UV absorbance (SUVA) at 254 nm compared with ozonation alone. However, catalytic ozonation with ferric hydroxide could not produce less LMW oxidation by-products than ozonation. Hydrophobic neutral (HON) produced much higher yields of the LMW oxidation by-products than other fractions both during catalytic ozonation and ozonation alone, while the basic NOM fractions formed relatively lower productions of these by-products. Like the case of ozonation alone, the predominant contributors for the yields of aldehydes and ketoacids formed in catalytic ozonation were formaldehyde and pyruvic acid, respectively. Among these NOM fractions, HON produced the highest yields of the formaldehyde and pyruvic acid after catalytic ozonation. The yield of formaldehyde from HON was up to 71.6% of the total aldehydes and ketones, and the pyruvic acid concentration of HON was 78.6 microg/mg after catalytic ozonation. In addition, NOM fractions became more biodegradable after catalytic ozonation, because the percent of total LMW by-products carbon in the final DOC after catalytic ozonation was higher than ozonation alone.

  11. Use of municipal solid waste incineration bottom ash and crop by-product for producing lightweight aggregate (United States)

    Giro-Paloma, J.; Ribas-Manero, V.; Maldonado-Alameda, A.; Formosa, J.; Chimenos, J. M.


    Due to the growing amount of residues in Europe, it is mandatory to provide a viable alternative for managing wastes contributing to the efficient use of resources. Besides, it is also essential to move towards a low carbon economy, priority EU by 2050. Among these, it is important to highlight the development of sustainable alternatives capable of incorporating different kind of wastes in their formulations.Municipal Solid Waste Incineration (MSWI) is estimated to increase in Europe, where the accessibility of landfill is restricted. Bottom ash (BA) is the most significant by-product from MSWI as it accounts for 85 - 95 % of the solid product resulting from combustion. BA is a mixture of calcium-rich compounds and others silicates enriched in iron and sodium. In addition, it is categorized as non-hazardous waste which can be revalorized as secondary material in construction or civil engineering fields, previous weathering stabilization during 2 - 3 months. Taking into account the relative proportion of each size fraction and the corresponding material characterization, the content of glass (primary and secondary) is estimated to be around 60 wt%. Furthermore, as a renewable resource and according to waste management European policies, residual agricultural biomass has attracted attention in preparation of advanced materials for various applications, due to their low cost, abundance, and environment friendliness. Among this residual biomass, rice husk is a by-product of rice milling industry which has high content of silica and has been widely used in buildings as natural thermal insulation material.Weathered BA (WBA) with a particle size less than 30 mm was milled under 100 μm, mixed with 2.0 - 5.0 mm rice husk, formed into ball-shaped pellets and sintered by different thermal treatments, which remove the organic matter content generating a large porosity. Physico-chemical analysis and mechanical behavior of the manufactured lightweight aggregates were tested

  12. Chromatographic quantitation of some bioactive minor components in oils of wheat germ and grape seeds produced as by-products. (United States)

    Hassanein, Minar Mahmoud M; Abedel-Razek, Adel Gabr


    The objective of this work was to determine some beneficial and bioactive minor lipid components in wheat germ and grape seeds as a result of milling industry of wheat and pressing of grapes in wineries. Sterylglycosides (SG's) were isolated and fractionate into free and acylated SG's by TLC and were determine as their1-anthroylnitriles (1-AN) by HPLC. Moreover, 4-desmethylsterols were isolated, derivatized into their trimethyl silyl derivatives and analyzed by GLC. Tocopherols and tocotrienols were directly analyzed by HPLC. In addition, fatty acids composition by GLC was accomplished. The results were compared to three conventional edible oils, namely, corn, sunflower and cottonseed. It was found that the wheat germ oil (WGO) and grape seed oil (GSO) contained reasonable amounts of whole sterols. Sterylglycosides fraction (SG), which have not been evaluated, it was found that the two by-products contained high amounts of SG's and they were rich in free and acylated campe/stigma SG as well as free and acylated beta-sito SG. Total tocopherols and tocotrienols components were found in very high amounts in WGO (1300 ppm) and GSO (380 ppm). It is noteworthy to mention that GSO contained significant amounts of alpha- and gamma-tocotrienols which prevent cardiovascular diseases and contained reasonable amounts of alpha- and gamma-tocopherols. On the other side, it was found that WG and GS oils were enrich in linoleic acid (omega-6), while linolenic acid (omega-3) was present in higher quantity in WGO.

  13. Fate of Mercury in Synthetic Gypsum Used for Wallboard Production

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Sanderson


    This report presents and discusses results from the project 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production', performed at five different full-scale commercial wallboard plants. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capture of mercury in FGD systems. The objective of this study has been to determine whether any mercury is released into the atmosphere at wallboard manufacturing plants when the synthetic gypsum material is used as a feedstock for wallboard production. The project has been co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope included seven discrete tasks, each including a test conducted at various USG wallboard plants using synthetic gypsum from different wet FGD systems. The project was originally composed of five tasks, which were to include (1) a base-case test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5,could not be conducted as planned and instead was conducted at conditions similar to Task 3. Subsequently an opportunity arose to test gypsum produced from the Task 5 FGD system, but with an additive expected to impact the stability of mercury, so Task 6 was added to the project. Finally, Task 7 was added to evaluate synthetic gypsum produced at a power plant from an

  14. FGD gypsum as a raw material used in the gypsum industry. Variations in quality and quality problems, impact on the product, elimination of malfunction in the flue gas desulphurisation system (FGD)

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Harald [Knauf Gips KG, Iphofen (Germany). Project Synthetic Gypsum


    The major quantity of the FGD gypsum produced is used today as raw material in the gypsum industry for the production of gypsum-based building materials for interior partitioning. The common basis of the European gypsum industry and the coal-fired power stations is the FGD gypsum quality standards commonly developed. The compliance with the quality parameters plays an important role both as for the acceptance of FGD gypsum as product and for the downstream production processes as well. This paper describes the variations in and problems with the observation of the quality parameters, their impacts on the downstream production processes of the gypsum products as well as the remediation of the malfunctions in the FGD. (orig.)

  15. Fundamental and molecular composition characteristics of biochars produced from sugarcane and rice crop residues and by-products. (United States)

    Jeong, Chang Yoon; Dodla, Syam K; Wang, Jim J


    Biochar conversion of sugarcane and rice harvest residues provides an alternative for managing these crop residues that are traditionally burned in open field. Sugarcane leaves, bagasse, rice straw and husk were converted to biochar at four pyrolysis temperatures (PTs) of 450 °C, 550 °C, 650 °C, and 750 °C and evaluated for various elemental, molecular and surface properties. The carbon content of biochars was highest for those produced at 650-750 °C. Biochars produced at 550 °C showed the characteristics of biochar that are commonly interpreted as being stable in soil, with low H/C and O/C ratios and pyrolysis fingerprints dominated by aromatic and polyaromatic hydrocarbons. At 550 °C, all biochars also exhibited maximum CEC values with sugarcane leaves biochar (SLB) > sugarcane bagasse biochar (SBB) > rice straw biochar (RSB) > rice husk biochar (RHB). The pore size distribution of biochars was dominated by pores of 20 nm and high PT increased both smaller and larger than 50 nm pores. Water holding capacity of biochars increased with PT but the magnitude of the increase was limited by feedstock types, likely related to the hydrophobicity of biochars as evident by molecular composition, besides pore volume properties of biochars. Py-GC/MS analysis revealed a clear destruction of lignin with decarboxylation and demethoxylation at 450 °C and dehydroxylation at above 550 °C. Overall, biochar molecular compositions became similar as PT increased, and the biochars produced at 550 °C demonstrated characteristics that have potential benefit as soil amendment for improving both C sequestration and nutrient dynamics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Morphological biosignatures in gypsum: diverse formation processes of Messinian (∼6.0 Ma) gypsum stromatolites. (United States)

    Allwood, A C; Burch, I W; Rouchy, J M; Coleman, M


    The ∼5.3-6.0 million-year-old evaporitic gypsum deposits of Cyprus and Crete contain a variety of stromatolites that formed during the Messinian salinity crisis. We recognize four stromatolite morphotypes, including domical, conical, columnar, and flat-laminated structures. Observations of morphological and textural variations among the different morphotypes reveal significant diversity and complexity in the nature of interactions between microorganisms, gypsum deposition, and gypsum crystal growth. Nonbiological processes (detrital gypsum deposition, in situ crust precipitation, syntaxial crystal growth, subsurface crystal growth, and recrystallization) interacted with inferred microbial processes (including localized growth of biofilms, trapping and binding of grains in mats, nucleation of gypsum on cells) to produce distinct morphological-textural assemblages. Evidence for biological origins is clear in some stromatolite morphotypes and can come from the presence of microfossils, the spatial distribution of organic matter, and stromatolite morphology. In one stromatolite morphotype, the presence of the stromatolite, or the biota associated with it, may have determined the morphology of gypsum crystals. In some stromatolite morphotypes, definitive evidence of a microbial influence is not as clear. There are broad similarities between the Messinian gypsum stromatolites and carbonate stromatolites elsewhere in the geologic record, such as the formation of precipitated and granular layers; the development of domed, columnar, and conical morphotypes; the potential for microbes to influence mineral precipitation; and the recrystallization of deposits during burial. However, in detail the array of microbial-sedimentary-diagenetic process interactions is quite distinct in gypsiferous systems due to differences in the way gypsum typically forms and evolves in the paleoenvironment compared to carbonate. Unique aspects of the taphonomy of gypsum compared to carbonate

  17. Thermochemical reduction of pelletized gypsum mixed with ...

    African Journals Online (AJOL)

    This can facilitate recovery of treatment costs and prevention of environmental pollution from gypsum waste-dumps. Thermal reduction using rotary kilns to recover valuable materials from waste gypsum remains a critical and controversial process because of waste gypsum handling problems, environmental pollution due to ...

  18. Converting SDAP into gypsum in a wet limestone scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Fogh, F. [Faelleskemikerne, Elsamprojekt A/S, Fredericia (Denmark)


    The ELSAM power pool has an installed electrical capacity of approx. 5 GW{sub e}, mainly firing import coal. The major base load units are equipped with desulphurization units and three different desulphurization technologies are used: the wet limestone gypsum process, the spray dry absorption process and a sulphuric acid process. Gypsum and sulphuric acid are commercialized, whereas it has been difficult to utilize the spray dry absorption product (SDAP). The main constituents of SDAP are calcium sulphide, calcium chloride, hydrated lime and impurities mainly originating from fly ash. Sulphide can be oxidized into sulphate in acidic solution - the reaction is utilized in the wet limestone gypsum process - and the possibility of using any spare capacity in the wet limestone gypsum units to oxidize the sulphide content of SDAP into sulphate and produce usable gypsum has been investigated in the laboratory and in a 400 MW{sub e} equivalent wet limestone unit. The limestone inhibition effect of the addition of SDAP is currently being studied in the laboratory in order to determine the effect of different SDAP types (plant/coal sources) on limestone reactivity before further long-term full-scale tests are performed and permanent use of the process planned. (EG)

  19. Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: The Surface Topography. (United States)

    Khalaf, Salah; Ariffin, Zaihan; Husein, Adam; Reza, Fazal


    This study aimed to compare the surface roughness of maxillofacial silicone elastomers fabricated in noncoated and coated gypsum materials. This study was also conducted to characterize the silicone elastomer specimens after surfaces were modified. A gypsum mold was coated with clear acrylic spray. The coated mold was then used to produce modified silicone experimental specimens (n = 35). The surface roughness of the modified silicone elastomers was compared with that of the control specimens, which were prepared by conventional flasking methods (n = 35). An atomic force microscope (AFM) was used for surface roughness measurement of silicone elastomer (unmodified and modified), and a scanning electron microscope (SEM) was used to evaluate the topographic conditions of coated and noncoated gypsum and silicone elastomer specimens (unmodified and modified) groups. After the gypsum molds were characterized, the fabricated silicone elastomers molded on noncoated and coated gypsum materials were evaluated further. Energy-dispersive X-ray spectroscopy (EDX) analysis of gypsum materials (noncoated and coated) and silicone elastomer specimens (unmodified and modified) was performed to evaluate the elemental changes after coating was conducted. Independent t test was used to analyze the differences in the surface roughness of unmodified and modified silicone at a significance level of p silicone elastomers processed against coated gypsum materials (p silicone elastomers. Silicone elastomers with lower surface roughness of maxillofacial prostheses can be obtained simply by coating a gypsum mold. © 2014 by the American College of Prosthodontists.

  20. Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams (United States)

    Hladik, Michelle; Focazio, Michael J.; Engle, Mark


    Fluids co-produced with oil and gas production (produced waters) are often brines that contain elevated concentrations of bromide. Bromide is an important precursor of several toxic disinfection by-products (DBPs) and the treatment of produced water may lead to more brominated DBPs. To determine if wastewater treatment plants that accept produced waters discharge greater amounts of brominated DBPs, water samples were collected in Pennsylvania from four sites along a large river including an upstream site, a site below a publicly owned wastewater treatment plant (POTW) outfall (does not accept produced water), a site below an oil and gas commercial wastewater treatment plant (CWT) outfall, and downstream of the POTW and CWT. Of 29 DBPs analyzed, the site at the POTW outfall had the highest number detected (six) ranging in concentration from 0.01 to 0.09 μg L− 1 with a similar mixture of DBPs that have been detected at POTW outfalls elsewhere in the United States. The DBP profile at the CWT outfall was much different, although only two DBPs, dibromochloronitromethane (DBCNM) and chloroform, were detected, DBCNM was found at relatively high concentrations (up to 8.5 μg L− 1). The water at the CWT outfall also had a mixture of inorganic and organic precursors including elevated concentrations of bromide (75 mg L− 1) and other organic DBP precursors (phenol at 15 μg L− 1). To corroborate these DBP results, samples were collected in Pennsylvania from additional POTW and CWT outfalls that accept produced waters. The additional CWT also had high concentrations of DBCNM (3.1 μg L− 1) while the POTWs that accept produced waters had elevated numbers (up to 15) and concentrations of DBPs, especially brominated and iodinated THMs (up to 12 μg L− 1 total THM concentration). Therefore, produced water brines that have been disinfected are potential sources of DBPs along with DBP precursors to streams wherever these wastewaters are discharged.

  1. Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams. (United States)

    Hladik, Michelle L; Focazio, Michael J; Engle, Mark


    Fluids co-produced with oil and gas production (produced waters) are often brines that contain elevated concentrations of bromide. Bromide is an important precursor of several toxic disinfection by-products (DBPs) and the treatment of produced water may lead to more brominated DBPs. To determine if wastewater treatment plants that accept produced waters discharge greater amounts of brominated DBPs, water samples were collected in Pennsylvania from four sites along a large river including an upstream site, a site below a publicly owned wastewater treatment plant (POTW) outfall (does not accept produced water), a site below an oil and gas commercial wastewater treatment plant (CWT) outfall, and downstream of the POTW and CWT. Of 29 DBPs analyzed, the site at the POTW outfall had the highest number detected (six) ranging in concentration from 0.01 to 0.09 μg L(-1) with a similar mixture of DBPs that have been detected at POTW outfalls elsewhere in the United States. The DBP profile at the CWT outfall was much different, although only two DBPs, dibromochloronitromethane (DBCNM) and chloroform, were detected, DBCNM was found at relatively high concentrations (up to 8.5 μg L(-1)). The water at the CWT outfall also had a mixture of inorganic and organic precursors including elevated concentrations of bromide (75 mg L(-1)) and other organic DBP precursors (phenol at 15 μg L(-1)). To corroborate these DBP results, samples were collected in Pennsylvania from additional POTW and CWT outfalls that accept produced waters. The additional CWT also had high concentrations of DBCNM (3.1 μg L(-1)) while the POTWs that accept produced waters had elevated numbers (up to 15) and concentrations of DBPs, especially brominated and iodinated THMs (up to 12 μg L(-1) total THM concentration). Therefore, produced water brines that have been disinfected are potential sources of DBPs along with DBP precursors to streams wherever these wastewaters are discharged. © 2013.

  2. Nutritional and functional properties of fishmeal produced from fresh by-products of cod (Gadus morhua L.) and saithe (Pollachius virens). (United States)

    Ween, Ola; Stangeland, Janne K; Fylling, Turid S; Aas, Grete Hansen


    Fresh by-products of whitefish such as cod and saithe is processed to fishmeal (FM) on-board seagoing Norwegian trawlers. The aim of this study was to document the properties of whitefish FM (WFM) protein with respect to, physicochemical and bioactive properties. Analysis of the proximate composition of representative seasonal WFM batches show that the production is robust without much variance. The mean protein (61.9 ± 1.2), fat (8.9 ± 1.1%), moisture (5 ± 1.2%) and ash content (22.4 ± 0.8%), reflect the use of lean and bony raw-material. The WFM has a low content of free amino acids (0.7%) and biogenic amines (nutritionally essential amino acids. The WFM physicochemical properties was comparable to soy-bean meal (SBM) by analysis of solubility, water-holding capacity (WHC), the emulsion stability (ES). Proteolytic degradation of the WFM was used to demonstrate the presence of bioactive peptides with inhibiting activity against angiotensin-converting enzyme (ACE) activity, in vitro. Taken together, WFM produced from fresh by-products is an excellent protein source with attributes of interest beyond the aquafeed-market.

  3. Nutritional and functional properties of fishmeal produced from fresh by-products of cod (Gadus morhua L. and saithe (Pollachius virens

    Directory of Open Access Journals (Sweden)

    Ola Ween


    Full Text Available Fresh by-products of whitefish such as cod and saithe is processed to fishmeal (FM on-board seagoing Norwegian trawlers. The aim of this study was to document the properties of whitefish FM (WFM protein with respect to, physicochemical and bioactive properties. Analysis of the proximate composition of representative seasonal WFM batches show that the production is robust without much variance. The mean protein (61.9 ± 1.2, fat (8.9 ± 1.1%, moisture (5 ± 1.2% and ash content (22.4 ± 0.8%, reflect the use of lean and bony raw-material. The WFM has a low content of free amino acids (0.7% and biogenic amines (< 1000 mg/kg that confirm the high quality and freshness of the raw material. Amino-acid analysis identified the presence of all nutritionally essential amino acids. The WFM physicochemical properties was comparable to soy-bean meal (SBM by analysis of solubility, water-holding capacity (WHC, the emulsion stability (ES. Proteolytic degradation of the WFM was used to demonstrate the presence of bioactive peptides with inhibiting activity against angiotensin-converting enzyme (ACE activity, in vitro. Taken together, WFM produced from fresh by-products is an excellent protein source with attributes of interest beyond the aquafeed-market.

  4. Gypsum karst in the United States.

    Directory of Open Access Journals (Sweden)

    Johnson K.S.


    Full Text Available Gypsum is one of the most soluble of common rocks; it is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are found in limestones and dolomites. The four basic requirements for gypsum karst to develop are: (1 a deposit of gypsum; (2 water, unsaturated with CaSO4 (3 an outlet for escape of dissolving water; and (4 energy to cause water to flow through the system. Gypsum deposits are present in 32 of the 48 conterminous United States, and they underlie about 35-40% of the land area; they are reported in rocks of every geologic system from the Precambrian through the Quaternary. Gypsum karst is known at least locally (and sometimes quite extensively in almost all areas underlain by gypsum, and commonly extends down to depths of at least 30 m below the land surface. The most widespread and pronounced examples of gypsum karst are in the Permian basin of southwestern United States, but many other areas also are significant. Human activities may also cause, or accelerate, development of gypsum karst.

  5. Thermochemical reduction of pelletized gypsum mixed with ...

    African Journals Online (AJOL)


    Apr 3, 2015 ... The recovery of better quality waste gypsum during acid mine drainage (AMD) neutralization is one step closer to achieving downstream waste gypsum ... Thermal reduction using rotary kilns to recover valuable materials from waste ..... gold fields with special emphasis on acid mine drainage. Report.


    African Journals Online (AJOL)

    X-ray fluorescence analyzer (XRF) was employed in the analysis of some local and imported stocks of gypsum and limestone utilized by a leading cement manufacturing industry in Nigeria. In addition, the recycled dust standard reference samples were also analyzed along with the raw materials in question. The gypsum ...

  7. occurrence and geochemistry of nafada gypsum, north-eastern nigeria

    African Journals Online (AJOL)



    Mar 18, 2010 ... The container was placed in a. “HERZOG” palletizing machine for 10 seconds after which a pellet was produced. The procedure was repeated for each gypsum sample. Each pellet was analyzed for SiO2, Al2O3, CaO, MgO, SO3, K2O, Na2O,. MgCO3, combine water and purity, using X-ray spectrometer.

  8. Oxidation of North Dakota scrubber sludge for soil amendment and production of gypsum. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Moe, T.A.


    Cooperative Power`s Coal Creek Station (CCS) the North Dakota Industrial Commission, and the US Department of Energy provided funds for a research project at the Energy and Environmental Research Center. The goals of the project were (1) to determine conditions for the conversion of scrubber sludge to gypsum simulating an ex situ process on the laboratory scale; (2) to determine the feasibility of scaleup of the process; (3) if warranted, to demonstrate the ex situ process for conversion on the pilot scale; and (4) to evaluate the quality and handling characteristics of the gypsum produced on the pilot scale. The process development and demonstration phases of this project were successfully completed focusing on ex situ oxidation using air at low pH. The potential to produce a high-purity gypsum on a commercial scale is excellent. The results of this project demonstrate the feasibility of converting CCS scrubber sludge to gypsum exhibiting characteristics appropriate for agricultural application as soil amendment as well as for use in gypsum wallboard production. Gypsum of a purity of over 98% containing acceptable levels of potentially problematic constituents was produced in the laboratory and in a pilot-scale demonstration.

  9. Measurement of soil moisture using gypsum blocks

    DEFF Research Database (Denmark)

    Friis Dela, B.

    For the past 50 years, gypsum blocks have been used to determine soil moisture content. This report describes a method for calibrating gypsum blocks for soil moisture measurements. Moisture conditions inside a building are strongly influenced by the moisture conditions in the soil surrounding...... the building. Consequently, measuring the moisture of the surrounding soil is of great importance for detecting the source of moisture in a building. Up till now, information has been needed to carry out individual calibrations for the different types of gypsum blocks available on the market and to account...

  10. Use of Flue Gas Desulfurization (FGD) Gypsum as a Heavy Metal Stabilizer in Contaminated Soils (United States)

    Flue Gas Desulfurization (FGD) gypsum is a synthetic by-product generated from the flue gas desulfurization process in coal power plants. It has several beneficial applications such as an ingredient in cement production, wallboard production and in agricultural practice as a soil...

  11. Adsorption of phosphonates on gypsum crystals

    NARCIS (Netherlands)

    Weijnen, M.P.C.; Van Rosmalen, G.M.


    The absorption of phosphonate inhibitors at the crystal surface of gypsum has been determined from the decrease in phosphonate concentration of the bulk solution. The phosphonate was therefore oxidized to orthophosphate and spectrophotometrically determined as a molybdovanadophosphoric acid complex.


    Directory of Open Access Journals (Sweden)

    Guyumdzhjan Perch Pogosovich


    Full Text Available The study on the creation of composite materials based on peat use-cation gypsum binder with improved thermal characteristics which en-rectifying to apply it during the construction of various buildings.

  13. Evaluation of Synthetic Gypsum Recovered via Wet Flue-Gas Desulfurization from Electric Power Plants for Use in Foundries

    Directory of Open Access Journals (Sweden)

    R. Biernacki


    Full Text Available This article investigates possible use of waste gypsum (synthetic, recovered via flue-gas desulfurization from coal-fired electric powerplants, in foundries. Energy sector, which in Eastern Europe is mostly composed from coal-fired electric power plants, is one of the largestproducers of sulfur dioxide (SO2.In order to protect the environment and reduce the amount of pollution flue-gas desulfurization (FGD is used to remove SO2 fromexhaust flue gases of fossil-fuel power plants. As a result of this process gypsum waste is produced that can be used in practicalapplications.Strength and permeability tests have been made and also in-depth analysis of energy consumption of production process to investigateways of preparing the synthetic gypsum for casting moulds application. This paper also assesses the chemical composition, strength andpermeability of moulds made with synthetic gypsum, in comparison with moulds made with traditional GoldStar XL gypsum and withceramic molds. Moreover examination of structure of synthetic gypsum, the investigations on derivatograph and calculations of energyconsumption during production process of synthetic gypsum in wet flue-gas desulfurization were made.After analysis of gathered data it’s possible to conclude that synthetic gypsum can be used as a material for casting mould. There is nosignificant decrease in key properties, and on the other hand there is many additional benefits including low energy consumption,decreased cost, and decreased environmental impact.

  14. Gypsum karst of the Baltic Republics

    Directory of Open Access Journals (Sweden)

    Paukstys B.


    Full Text Available The Baltic Republics of Estonia, Latvia and Lithuania have karst areas developed in both carbonate and gypsiferous rocks. In the north, within the Republic of Estonia, Ordovician and Silurian limestones and dolomites crop out, or are covered by glacial Quaternary sediments. To the south, in Latvia and Lithuania, gypsum karst is actively developing in evaporites of Late Devonian (Frasnian age. Although gypsum and mixed sulphate-carbonate karst only occupy small areas in the Baltic countries, they have important engineering and geo-ecological consequences. Due to the rapid dissolution of gypsum, the evolution of gypsum karst causes not only geological hazards such as subsidence, but it also has a highly adverse effect on groundwater quality. The karst territory of the Baltic states lies along the western side of the area, called the Great Devonian Field that form part of the Russian Plain. Within southern Latvia and northern Lithuania there is an area, exceeding 1000 sq. km, where mature gypsum karst occurs at the land surface and in the subsurface. This karst area is referred to here as the Gypsum Karst Region of the Baltic States. Here the surface karst forms include sinkholes, karst shafts, land subsidence, lakes and dolines. In Lithuania the maximum density of sinkholes is 200 per sq. km; in Latvia they reach 138 units per sq. km. Caves, enlarged dissolution voids and cavities are uncommon in both areas.

  15. Experimental investigation of Ca isotopic fractionation during abiotic gypsum precipitation (United States)

    Harouaka, Khadouja; Eisenhauer, Anton; Fantle, Matthew S.


    Experiments investigating Ca isotopic fractionation during gypsum precipitation were undertaken in order to elucidate the mechanisms and conditions that govern isotopic fractionation during mineral precipitation. Both stirred and unstirred free drift gypsum precipitation experiments were conducted at constant initial ionic strength (0.6 M) and variable initial saturation states (4.8-1.5) and Ca2+:SO42- ratios (3 and 0.33). Experimental durations varied between 0.5 and 190 h, while temperature (25.9-24.0 °C), pH (5.8-5.4) and ionic strength (0.6-0.5) were relatively constant. In all experiments, 20-80% of the initial dissolved Ca reservoir was precipitated. Isotopically light Ca preferentially partitioned into the precipitated gypsum; the effective isotopic fractionation factor (Δ44/40Cas-f = δ44/40Casolid - δ44/40Cafluid) of the experimental gypsum ranged from -2.25‰ to -0.82‰. The log weight-averaged, surface area normalized precipitation rates correlated with saturation state and varied between 4.6 and 2.0 μmol/m2/h. The crystal size and aspect ratios, determined by SEM images, BET surface area, and particle size measurements, co-varied with precipitation rate, such that fast growth produced small (10-20 μm), tabular crystals and slow growth produced larger (>1000 μm), needle shaped crystals. Mass balance derived δ44Cas and Δ44Cas-f, calculated using the initial fluid δ44Ca and the mass fraction of Ca removed during precipitation (fCa) as constraints, suggest that the precipitate was not always sampled homogeneously due to the need to preserve the sample for SEM, surface area, and particle size analyses. The fractionation factor (αs-f), derived from Rayleigh model fits to the fluid and calculated bulk solid, ranged from 0.9985 to 0.9988 in stirred experiments and 0.9987 to 0.9992 in unstirred experiments. The αs-f demonstrated no clear dependence on either precipitation rate or initial saturation state in stirred reactors, but exhibited a positive


    Directory of Open Access Journals (Sweden)

    Anto Gabrić


    Full Text Available The occurences and deposits of gypsum can be found in big karst poljes (Sinjsko, Vrličko, Petrovo, Kosovo and Kninsko as well as in tectonnically predestined river valleys of Zrmanja, Butišnica and Una. There also appear spatially localized occurences on the island of Vis and in the vicinity of Samobor. Evaporites (gypsum and anhydrite with adjoining overlying clastic rocks (red sandstones, siltites and pelites, carbonate rocks (dolomites and limestones and porous carbonate breccias (Rauhwackes were deposited during the period of Upper Permian. The recent position of the Upper Permian beds is a result of complex tectonic, particularly neotectonic, movements and diapiric displacements. Evaporites were deposited in marginal areas of the epicontinental marine basin, in a period of favourable conditions for the sabkha and playa sedimentation due to the continuous shoreline progradation. The Upper Permian age of these sediments in Dalmatio is proved by the characteristic mineral paragenesis and palinological determinations in elastics rocks, as well as by isotope analyses of sulphure in gypsum. Gypsum is a significant ore mineral resource in building, cement production, as well as in a number of tehnological processes used in chemical industry and elsewhere. According to the recent investigations gypsum is predestined to serve as an ore mineral resource of significant perspectives (the paper is published in Croatian.

  17. Nanomodified energy-efficient gypsum materials: structure and properties (United States)

    Grishina, A.; Korolev, E.


    Currently, many building materials for interior finishing are based on gypsum as a binder. Usage of gypsum allows to significantly simplify both the production of building materials and to increase the operational properties related to energy efficiency. This makes important the studies directed to the improvement of gypsum-based binders. In the present work the influence of nanoscale modifiers based on zinc hydrosilicates to the structure and properties of gypsum was examined. The dependence between compressive strength of gypsum and content of the modifier was approximated by a rational function. It was found that the reason for the increase of strength is a change in the structure of the newly forming gypsum; such a change consists, in particular, in the formation of split crystals. At the same time, chemical composition of the nanomodified gypsum remains unchanged. It is shown that the formation of split gypsum crystals is observed when using nanomodifiers that significantly shorten the setting time.

  18. Suitability of Nafada Gypsum for the Production of Jute Fibre ...

    African Journals Online (AJOL)

    High demand for Plaster of Paris (POP) in the Nigeria building industry, particularly within the north-east geopolitical zone has made local procurement of the raw gypsum inevitable. The study was conducted to evaluate the characteristics of gypsum from Nafada mining site, one of the northeast rich gypsum deposits with an ...

  19. Mechanical properties of gypsum board at elevated temperatures (United States)

    S.M. Cramer; O.M. Friday; R.H. White; G. Sriprutkiat


    Gypsum board is a common fire barrier used in house and general building construction. Recently, evaluation of the collapses of the World Trade Center Towers highlighted the potential role and failure of gypsum board in containing the fires and resisting damage. The use of gypsum board as primary fire protection of light-flame wood or steel construction is ubiquitous....

  20. Comparison of the surface roughness of gypsum models constructed using various impression materials and gypsum products

    Directory of Open Access Journals (Sweden)

    Yi-Chih Chang


    Conclusion: The surface roughness of stone models was mainly determined by the type of alginate impression material, and was less affected by the type of silicone rubber impression material or gypsum product, or the storage time before repouring.

  1. Deformation processes in polycrystalline aggregates of gypsum

    NARCIS (Netherlands)

    de Meer, S.


    On the basis of both field and laboratory studies it is well established that polycrystalline gypsum is one of the weakest and most ductile rock materials found in the Earth's crust (e.g. Heard & Rubey, 1966; Murrell & Ismail, 1976; Baumann, 1985; Jordan, 1988; 1991; 1994). The deformation and

  2. LCA of Recycling Options for Gypsum from Construction and Demolition Waste

    DEFF Research Database (Denmark)

    Butera, Stefania; Møller, Jacob; Christensen, Thomas Højlund


    restrictions; source separation, however, makes gypsum waste recycling feasible. Different alternatives for recycling exist, but their overall environmental impacts have never been quantified and compared in details. This study investigates from a life cycle perspective the environmental impacts of two......Large amounts of gypsum waste are annually produced from the construction and demolition sector. Its landfilling is becoming more and more expensive due to stricter EU regulations, while its recycling together with the rest of construction and demolition waste might be hampered due to technical...

  3. Investigation of the gypsum quality at three full-scale wet flue gas desulphurisation plants

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Kiil, Søren; Johnsson, Jan Erik


    In the present study the gypsum (CaSO4·2H2O) quality at three full-scale wet flue gas desulphurisation (FGD) plants and a pilot plant were examined and compared. Gypsum quality can be expressed in terms of moisture content (particle size and morphology dependent) and the concentration of residual...... or accumulation of fly ash and impurities from the sorbent. The crystal morphology obtained in the pilot plant was columnar with distinct crystal faces as opposed to the rounded shapes found at the full-scale plants. All the investigated full-scale plants consistently produced high quality gypsum (High purity...... limestone and other impurities. The particle size distributions (PSD) in the holding tanks of the investigated plants were similar, apart from a slightly higher fraction of small particles in the full-scale plants. These high levels of small particles could originate from nucleation, attrition...

  4. Dental dam clamp adaptation method on carved gypsum cast. (United States)

    Cazacu, N C E


    Dental Dam is the safest and most efficient isolation technique in endodontics and restorative dentistry, but it also used in esthetics, orthodontics, prosthetics, pedodontics and periodontology (for teeth immobilization). While in most cases the standard clamps are efficient, in some clinical situations clamp adaptation is mandatory in order to assure a tight contact on the tooth. The purpose of this study is to list the elements of the clamp, which should be modified in order to assure a secure constriction of the clamp on the anchor tooth, by using the carved gypsum cast method. 100 patients were examined, diagnosed and treated for various diagnoses like simple decay, gangrene, chronic apical periodontitis, and endodontic retreatments. The clamps used in this study were produced by Hu-Friedy, Hygenic, KKD, SDI, Hager & Werken. In 10 cases, the anchor tooth did not provide enough stability to the standard clamp--as provided by the producer. Therefore, we have done some adjustments to some of the elements of the clamp: the arch, the wings, the plateau, the active area, and the contact points. In 6 cases, major clamp adaptations on carved gypsum cast were imperative. The classic clamps cannot provide a grip to be enough in all the clinical cases due to the huge variety and position and implantation of the anchor teeth. Therefore, in such situations, the clamps should be adapted in order to provide stability and assure the safe isolation during the treatment. The modified clamps will be useful in similar cases, so they must be kept.

  5. Gypsum crystals observed in experimental and natural sea ice

    DEFF Research Database (Denmark)

    Geilfus, Nicolas-Xavier; Galley, Ryan; Cooper, Marc


    , the gypsum crystals were identified as being authigenic. The FREeZing CHEMistry (FREZCHEM) model results support our observations of both gypsum and ikaite precipitation at typical in situ sea ice temperatures and confirms the “Gitterman pathway” where gypsum is predicted to precipitate. The occurrence...... of authigenic gypsum in sea ice during its formation represents a new observation of precipitate formation and potential marine deposition in polar seas. Citation: Geilfus, N.-X., R. J. Galley, M. Cooper, N. Halden, A. Hare, F. Wang, D. H. Søgaard, and S. Rysgaard (2013), Gypsum crystals observed...

  6. Use of by-products rich in carbon and nitrogen as a nutrient source to produce Bacillus thuringiensis (Berliner)-based bio pesticide

    Energy Technology Data Exchange (ETDEWEB)

    Valicente, Fernando H. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail:; Mourao, Andre H.C. [Curso de Meio Ambiente, Sete Lagoas, MG (Brazil)


    The amount and sources of carbon and nitrogen used to produce Bacillus thuringiensis (Berliner)-based biopesticide may influence the quality of the fi nal product. The objective of this research was to test different levels of carbon and nitrogen: medium 1 - 1.5% maize glucose + 0.5% soy fl our, medium 2 - 3.0% maize glucose + 1.0% soy flour, medium 3 - 1.0% maize glucose + 3.0% soy fl our and medium 4 - Luria Bertani (LB) + salts (FeSO{sub 4}, ZnSO{sub 4}, MnSO{sub 4}, MgSO{sub 4}). The seed culture was produced in LB medium plus salt, under agitation (200 rpm) for 18h at 30 deg C. The strain 344 of Bt was used (B. thuringiensis var tolworthi - belonging to the EMBRAPA's Bt Bank). The pH was measured at regular intervals, and After culturing for 96h, the pH of the four tested media was basified (6.91 and 8.15), the number of spores yielded 4.39 x 10{sup 9} spores/ml in medium 3, where the amount of protein is high. The dry biomass weight accumulated in media 3 was 39.3 g/l. Mortality of 2-day-old larvae Spodoptera frugiperda (J.E. Smith) was 100% when using Bt produced in media 3 and 4. CL{sub 50} for medium 3 was 8.4 x 10{sup 6} spores/ml. All tested media were satisfactory to Bt growth, and medium 3 was the most promising to be used on a large scale Bt-based biopesticide production. (author)

  7. Fluoride accumulation by plants grown in acid soils amended with flue gas desulphurisation gypsum. (United States)

    Álvarez-Ayuso, E; Giménez, A; Ballesteros, J C


    The application of flue gas desulphurisation (FGD) gypsum as an acid soil ameliorant was studied in order to establish the possible detrimental effects on plants and animals feeding on them caused by the high fluoride content in this by-product. A greenhouse experiment was conducted under controlled conditions to determine the F accumulation by two plant species (alfalfa (Medicago sativa L.) and ryegrass (Lolium perenne L.)) grown in acid soils amended with different FGD gypsum doses (0-10%). The F concentrations in plant aerial parts were comprised in the range 22-65 mg kg(-1), and those in plant roots varied from 49 to 135 mg kg(-1). The F contents in the above-ground plant tissues showed to decrease with the FGD gypsum application rate, whereas an inverse trend was manifested by plant roots. The increase in the soil content of soluble Ca as a result of the FGD gypsum addition seemed to play an important role in limiting the translocation of F to plant aerial parts. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Constructive applications of composite gypsum reinforced with Typha Latifolia fibres

    Directory of Open Access Journals (Sweden)

    Garcia Santos, A.


    Full Text Available The present research analyses the possibility to reinforce gypsum using enea fibres (Typha Latifolia creating a compound material in wich the fibres contribute to increase mechanical resistance, producing as well a reduction of the weight and a possible regulation of the set time.

    La investigación presente analiza la posibilidad de reforzar los morteros de escayola mediante la utilización dé fibras de Typha Latifolia, creando un material compuesto en el que las fibras contribuyen al aumento de resistencia mecánica, a la vez que se produce una reducción del peso y una regulación de los tiempos de fraguado. Las propiedades de estos materiales hacen que, en determinadas aplicaciones, su utilización resulte ventajosa con respecto a materiales tradicionales.

  9. Ternary gypsum-based materials: Composition, properties and utilization (United States)

    Doleželová, M.; Svora, P.; Vimmrová, A.


    In spite of the fact that gypsum is one of the most environmentally friendly binders, utilization of gypsum products is relatively narrow. The main problem of gypsum materials is their low resistance to the wet environment and radical decrease of mechanical properties with increasing moisture. The solution of the problem could be in use of composed gypsum-based binders, usually ternary, comprising gypsum, pozzolan and alkali activator of pozzolan reaction. These materials have a better moisture resistance and often also better mechanical properties. Paper provides literature survey of the possible compositions, properties and ways of utilization of the composed gypsum-based binders with latent hydraulic and pozzolan materials together with some results of present research performed by authors.


    Directory of Open Access Journals (Sweden)

    Mikheenkov Mikhail Arkad'evich


    Full Text Available In the article, the authors consider the feasibility of development of water-hardened gypsum that is capable of hardening in the water. The gypsum in question is made of the gypsum binding material, sulphated Portland cement, and granulated blast-furnace slag. The gypsum developed hereunder has a softening coefficient over 1 while the building gypsum content exceeds 75 %.

  11. Reclamation of acid, toxic coal spoils using wet flue gas desulfurization by-product, fly ash and sewage sludge. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kost, D.A.; Vimmerstedt, J.P.; Stehouwer, R.C.


    Establishment of vegetation on acid abandoned minelands requires modification of soil physical and chemical conditions. Covering the acid minesoil with topsoil or borrow soil is a common practice but this method may be restricted by availability of borrow soil and cause damage to the borrow site. An alternative approach is to use waste materials as soil amendments. There is a long history of using sewage sludge and fly ash as amendments for acid minesoils. Flue gas desulfurization (FGD) by-products are newer materials that are also promising amendments. Most flue gas sludges are mixtures of Calcium sulfate (CaSO{sub 4}), calcium sulfite (CaSO{sub 3}), calcium carbonate (CaCO{sub 3}), calcium hydroxide [Ca(OH){sub 2}], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO{sub 4}2H{sub 2}O). The primary purpose of the project is to evaluate two wet FGD by-products for effects on vegetation establishment and surface and ground water quality on an acid minesoil. One by-product from the Conesville, OH power plant (American Electric Power Service Corporation) contains primarily calcium sulfite and fly ash. The other by-product (Mg-gypsum FGD) from an experimental scrubber at the Zimmer power plant (Cincinnati Gas and Electric Company) is primarily gypsum with 4% magnesium hydroxide. These materials were compared with borrow soil and sewage sludge as minesoil amendments. Combinations of each FGD sludge with sewage sludge were also tested. This report summarizes two years of measurements of chemical composition of runoff water, ground water at two depths in the subsoil, soil chemical properties, elemental composition and yield of herbaceous ground cover, and elemental composition, survival and height of trees planted on plots treated with the various amendments. The borrow soil is the control for comparison with the other treatments.

  12. Investigation of Parameters Affecting Gypsum Dewatering Properties in a Wet Flue Gas Desulphurization Pilot Plant

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Kiil, Søren


    Wet flue gas desulphurization (FGD) plants with forced oxidation, installed at coal and oil fired power plants for removal of SO2(g), must produce gypsum of high quality. However, quality issues such as an excessive moisture content, due to poor gypsum dewatering properties, may occur from time...... to time. In this work, the particle size distribution, morphology, and filtration rate of wet FGD gypsum formed in a pilot-scale experimental setup, operated in forced oxidation mode, have been studied. The influence of holding tank residence time (10–408 h), solids content (30–169 g/L), and the presence...... of impurities (0.002 M Al2F6; 50 g quartz/L; 0.02 M Al3+, and 0.040 M Mg2+) were investigated. In addition, slurry from a full-scale wet FGD plant, experiencing formation of flat shaped crystals and poor gypsum dewatering properties, was transferred to the pilot plant to test if the plant would now start...

  13. Dental dam clamp adaptation method on carved gypsum cast (United States)

    Cazacu, NCE


    Rationale. Dental Dam is the safest and most efficient isolation technique in endodontics and restorative dentistry, but it also used in esthetics, orthodontics, prosthetics, pedodontics and periodontology (for teeth immobilization). While in most cases the standard clamps are efficient, in some clinical situations clamp adaptation is mandatory in order to assure a tight contact on the tooth. Objective. The purpose of this study is to list the elements of the clamp, which should be modified in order to assure a secure constriction of the clamp on the anchor tooth, by using the carved gypsum cast method. Methods and Results. 100 patients were examined, diagnosed and treated for various diagnoses like simple decay, gangrene, chronic apical periodontitis, and endodontic retreatments. The clamps used in this study were produced by Hu-Friedy, Hygenic, KKD, SDI, Hager & Werken. In 10 cases, the anchor tooth did not provide enough stability to the standard clamp – as provided by the producer. Therefore, we have done some adjustments to some of the elements of the clamp: the arch, the wings, the plateau, the active area, and the contact points. In 6 cases, major clamp adaptations on carved gypsum cast were imperative. Discussion. The classic clamps cannot provide a grip to be enough in all the clinical cases due to the huge variety and position and implantation of the anchor teeth. Therefore, in such situations, the clamps should be adapted in order to provide stability and assure the safe isolation during the treatment. The modified clamps will be useful in similar cases, so they must be kept. PMID:25713609

  14. Optimal fluorite/gypsum mineralizer ratio in Portland cement clinkering

    Directory of Open Access Journals (Sweden)

    Tobón, J. I.


    Full Text Available This paper presents an analysis of the joint effect of fluorite and gypsum as mineralizers in the manufacture of Portland cement. A laboratory- scale Box-Behnken statistical design was used to quantify the effects of the explanatory variables fluorite content (0.00, 0.25, 0.50, and 0.75%, fluorite/gypsum ratio (2/15, 1/3 and 8/15, and clinkering temperature (1250, 1300, and 1350 °C on the response variable free CaO content in the clinker produced. The clinker was characterized by the ethylene method, XRD, DSC and optical microscopy. Free CaO decreases of 81% and 56% were found in the mineralized clinker, compared to the same clinker without mineralizers, at 1300 °C and 1250 °C, respectively. Petrographic analysis showed that at lower temperatures, the amount of alite in the mineralized clinker was higher than the amount of alite in the clinker without mineralizers. The best condition was found for the fluorite/gypsum ratio of 2/15.Este artículo presenta el efecto combinado de la fluorita y el yeso como mineralizadores. Se usó el diseño experimental estadístico Box-Behnken, a escala de laboratorio, para cuantificar el efecto de la fluorita en porcentajes de 0.00, 0.25, 0.50 y 0.75%; relaciones fluorita/yeso de 2/15, 1/3 y 8/15; con temperaturas de clinkerización de 1250, 1300 y 1350 °C y la cal libre como variable de respuesta. El clínker producido fue caracterizado midiendo el contenido de cal libre por el método de etileno, DRX, DSC y microscopía óptica. Se encontró un descenso de la cal libre del 81 y 56% en el clinker mineralizado en comparación con el clinker sin mineralizadores a 1300 y 1250 °C respectivamente. El análisis petrográfico mostró que la cantidad de alita en el clinker mineralizado a bajas temperaturas es más alta que en el clinker sin mineralizadores. La mejor condición se encontró para la relación fluorita/yeso de 2/15.

  15. Health survey in gypsum mines in India

    Directory of Open Access Journals (Sweden)

    Nandi Subroto


    Full Text Available Background: Mining is a hazardous occupation in which workers are exposed to adverse conditions. In India, gypsum mining is mainly carried out in the state of Rajasthan, which contributes about 99% of the total production. Objective: The present study was carried out in 12 different gypsum mines in Rajasthan state to determine the health status of the miners. Materials and Methods: One hundred and fifty workers engaged in mining activities were included in the study and their health status was compared with that of 83 office staff of the same mines. The health status of the employees was evaluated using a standardized medical questionnaire and pulmonary function testing. Statistical Analysis: The unpaired ′t′ test was used to determine whether there was any significant difference between the miners and the controls and the chi-square test to compare the prevalences of various respiratory impairments in workers with that in controls; we also examined the differences between smokers and nonsmokers. Results: Our findings show that the literacy rate is low (42% among the miners. Pulmonary restrictive impairment was significantly higher amongst smokers as compared to nonsmokers in both miners and controls. Hypertension (22.6%, diabetes (8.8%, and musculoskeletal morbidity (8% were the common diseases in miners. Conclusion: This study shows that there is high morbidity amongst miners, thus indicating the need for regular health checkups, health education, use of personal protective devices, and engineering measures for control of the workplace environment.

  16. preliminary estimate of gypsum deposit based on wenner and ...

    African Journals Online (AJOL)

    Dogara M. D. and Aloa J. O.

    The gypsum reserve deposit was estimated to be about seventeen million tons. Keywords: Estimate for Gypsum Deposit, Wenner and. Schlumberger Methods, Ikpeshi, Edo State, Nigeria. INTRODUCTION ... Exploitation of mineral resources has assumed prime importance .... nature (Boris, 2005; Olowofela, 2010). Also, the ...

  17. Occurrence and geochemistry of Nafada Gypsum, north-eastern ...

    African Journals Online (AJOL)

    Gypsum deposits occur in numerous locations within the Senonian Fika Shale at Nafada, northeastern Nigeria. Geologic investigations at Baro Winde and Wuro Dabo mines indicate the occurrence of three varieties of gypsum namely, Balatino laminated, Alabaster and Satin Spar. These are interlayered within shale and ...

  18. Mechanical, Hygric and Thermal Properties of Flue Gas Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    P. Tesárek


    Full Text Available The reference measurements of basic mechanical, thermal and hygric parameters of hardened flue gas desulfurization gypsum are carried out. Moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, volumetric heat capacity and linear thermal expansion coefficient are determined with the primary aim of comparison with data obtained for various types of modified gypsum in the future. 

  19. Raman spectroscopy of shocked gypsum from a meteorite impact crater (United States)

    Brolly, Connor; Parnell, John; Bowden, Stephen


    Impact craters and associated hydrothermal systems are regarded as sites within which life could originate on Earth, and on Mars. The Haughton impact crater, one of the most well preserved craters on Earth, is abundant in Ca-sulphates. Selenite, a transparent form of gypsum, has been colonized by viable cyanobacteria. Basement rocks, which have been shocked, are more abundant in endolithic organisms, when compared with un-shocked basement. We infer that selenitic and shocked gypsum are more suitable for microbial colonization and have enhanced habitability. This is analogous to many Martian craters, such as Gale Crater, which has sulphate deposits in a central layered mound, thought to be formed by post-impact hydrothermal springs. In preparation for the 2020 ExoMars mission, experiments were conducted to determine whether Raman spectroscopy can distinguish between gypsum with different degrees of habitability. Ca-sulphates were analysed using Raman spectroscopy and results show no significant statistical difference between gypsum that has experienced shock by meteorite impact and gypsum, which has been dissolved and re-precipitated as an evaporitic crust. Raman spectroscopy is able to distinguish between selenite and unaltered gypsum. This shows that Raman spectroscopy can identify more habitable forms of gypsum, and demonstrates the current capabilities of Raman spectroscopy for the interpretation of gypsum habitability.

  20. Effect of a bio-extract solution from water convolvulus and gypsum on yield and quality of yardlong bean seed

    Directory of Open Access Journals (Sweden)

    Santipracha, Q.


    Full Text Available An experiment to determine yardlong bean seed production using an organic farming system by application of a bio-extract solution from water convolvulus rated 1:1,000, gypsum rated 50 kg./rai, anda bio-extract solution from water convolvulus rated 1:1,000 + gypsum rated 50 kg./rai, compared with a conventional method (chemical application for control, was done at the Department of Plant Science,Faculty of Natural Resources, Prince of Songkla University, Hat Yai campus, Songkhla, during January-March, 2004. The results showed that yardlong bean with the bio-extract solution, gypsum and the bioextractsolution + gypsum produced seed yield of 40.06, 31.41 and 29.55 kg./rai respectively, which were not different among the treatments but the three treatments were different from the chemical method whichproduced seed yield of 89.78 kg./rai. Regarding the yardlong bean seed quality, all four treatments had highquality with no significantly differences among the treatments. The seed dry weight ranged from 128.54-131.90 mg/seed, standard germination 97.00-98.00%, soil emergence 99.50-100%, speed of germination index 33.16-33.33, and conductivity 27.92-28.31 μmho/cm/gm. The seedling dry weights were not significantlydifferent, and ranged from 73.21-76.00 mg/seedling, except for the gypsum treatment which gave a weight of 67.98 mg/seedling.With accelerated aging, the treatment of bio-extract solution + gypsum had thehighest germination rate of 98.00%, which was significantly different from the bio-extract solution and gypsum treatments which had germination rates of 92.50 and 90.50%, respectively, and the chemical methodwhich had a germination rate of 93.50% was not different from other treatments.

  1. Risk minimisation of FGD gypsum leachates by incorporation of aluminium sulphate. (United States)

    Alvarez-Ayuso, E; Querol, X; Ballesteros, J C; Giménez, A


    The incorporation of aluminium sulphate to (flue gas desulphurisation) FGD gypsum before its disposal was investigated as a way to minimise the risk supposed by the high fluoride content of its leachates. Using a bath method the kinetic and equilibrium processes of fluoride removal by aluminium sulphate were studied at fluoride/aluminium molar concentration (F/Al) ratios in the range 1.75 10(-2)-1.75 under the pH conditions (about 6.5) of FGD gypsum leachates. It was found that fluoride removal was a very fast process at any of the (F/Al) ratios subject of study, with equilibrium attained within the first 15 min of interaction. High decreases in solution fluoride concentrations (50-80%) were found at the equilibrium state. The use of aluminium sulphate in the stabilization of FGD gypsum proved to greatly decrease its fluoride leachable content (in the range 20-90% for aluminium sulphate doses of 0.1-5%, as determined by the European standard EN 12457-4). Such fluoride leaching minimisation assures the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC on waste disposal. Furthermore, as derived from column leaching studies, the proposed stabilization system showed to be highly effective in simulated conditions of disposal, displaying fluoride leaching reduction values about 55 and 80% for aluminium sulphate added amounts of 1 and 2%, respectively.

  2. Carbonate speleothems from western Mediterranean gypsum karst: palaeoclimate implications (United States)

    Columbu, Andrea; Drysdale, Russell; Woodhead, Jon; Chiarini, Veronica; De Waele, Jo; Hellstrom, John; Forti, Paolo; Sanna, Laura


    Gypsum caves are uncommon environments for carbonate speleothems (cave deposits). Contrary to limestone caves, the only source of non-atmospheric carbon is from biogenic CO2 produced by the overlying soils. Enhanced CO2 content in soils is in turn related with climate, where warm temperatures and high humidity favour plant activity .().....(Fairchild and Baker, 2012). Although poorly decorated, the exploration of northern Italian and Spanish gypsum karst systems reveals the existence of several generations of carbonate speleothems, which have been dated with the U-Th series method .()......(Hellstrom, 2003; Scholz and Hoffmann, 2008). Their ages coincide with current and previous two interglacials (MIS 1, 5e and 7e and Greenland interstadials (GIS) 19, 20, 21 and 24. Considering that these periods are amongst the most pronounced warm-wet pulsations over the last 250,000 ...(Martrat et al., 2007; NGRIP, 2004), and that CO2 has a fundamental role in this karst process, this study explores the climate-driven hydrogeological conditions necessary to trigger carbonate deposition in gypsum voids. The further correlation with sapropel events 5, 4, 3 and 1, considered symptomatic of enhanced rainfall across the whole Mediterranean basin .(.)(Emeis et al., 1991), highlights the importance of flow-rate in the fracture network and infiltration of meteoric water into the caves. The combination of high CO2 and a phreatic status of the fracture network is thus indispensable for the formation of carbonate speleothems in gypsum karst. This condition appears to be triggered by periods of orbital precession minimum, when the monsoonal activity peaked in the Atlantic area. Stable oxygen isotope signatures suggest that the speleothems did not grow during any interglacial-glacial or main interstadial-stadial transitions, confirming that variations from optimum climate conditions may hamper the formation of this category of speleothems. New speleological exploration and sampling campaign

  3. Corrosion of bare and galvanized steel in gypsum

    Directory of Open Access Journals (Sweden)

    Gómez, Mercedes


    Full Text Available Gypsum is a relatively low-cost building material much abounding in our country. When it is put in contact with steel, it may produce high corrosion rates due to its pH value (close to 7. This work reports the results obtained in studying the corrosion rates of bare and galvanized steel in contact with gypsum and plaster, as well as the influence curing thermal treatment applied to gypsum, enviromental relative humidity and addition of compounds with different natures and purposes may have in such process. In-situ observations, as well as the measurement of the Polarization Resistance and the weight loss have been used as measurement technics. From the results obtained it has been possible to deduce that galvanized steel has better behaviour in dry enviroments than bare steel in the same conditions and moist atmosphere induces proportionally more corrosion in galvanized steel than in bare one. Additions to gypsum do not modified these conclusions, though it may be pointed out that addition of nitrites or lime improves the behaviour of bare steel, while galvanized behaviour is not modified. The addition of lime is not recommended because phenomena of dilated along time expansion may take place.

    El yeso es un material de construcción de relativo bajo coste y que, además, es muy abundante en nuestro país. Debido a su pH cercano a la neutralidad, cuando entra en contacto con el acero, este puede corroerse a elevadas velocidades. En esta comunicación se presentan los resultados de un estudio sobre la velocidad de corrosión del acero desnudo y galvanizado en contacto con yeso y escayola y la influencia que tienen: el tratamiento térmico del curado del yeso, la humedad relativa ambiental y la adición de aditivos de diversa naturaleza y finalidad. Como técnicas de medida se han utilizado la medida de la Resistencia de Polarización y de la pérdida de peso, así como observaciones visuales. De los resultados se puede deducir que en

  4. The effect of gypsum products and separating materials on the typography of denture base materials. (United States)

    Firtell, D N; Walsh, J F; Elahi, J M


    The typography of polymethyl methacrylate processed against various gypsum products coated with various separating materials was studied under an SEM. Tinfoil and two commercial tin foil substitutes were used as separating material during processing, and the surfaces of the resulting acrylic resin forms were studied for topographical differences. Tinfoil and alpha 2 hemihydrates produced the smoothest surfaces. As a practical solution, a good quality tinfoil substitute and alpha 1 hemihydrate could be used when processing polymethyl methacrylate resin.

  5. Waste/By-Product Hydrogen (United States)


    Biogas , including anaerobic digester gas, can be reformed to produce hydrogen and used in a fuel cell to produce significant amounts of electricity...Waste/By product Hydrogen Waste H2 sources include: � Waste bio‐mass: biogas to high temp fuel cells to produce H2 – there are over two dozen sites...and heat. � When biogas is produced and used on‐site in a fuel cell, fuel utilization or overall energy efficiency can reach 90% and can reduce

  6. Effect of background electrolytes on gypsum dissolution (United States)

    Burgos-Cara, Alejandro; Putnis, Christine; Ruiz-Agudo, Encarnacion


    Knowledge of the dissolution behaviour of gypsum (CaSO4· 2H2O) in aqueous solutions is of primary importance in many natural and technological processes (Pachon-Rodriguez and Colombani, 2007), including the weathering of rocks and gypsum karst formations, deformation of gypsum-bearing rocks, the quality of drinking water, amelioration of soil acidity, scale formation in the oil and gas industry or measurement of water motion in oceanography. Specific ions in aqueous solutions can play important but very different roles on mineral dissolution. For example, the dissolution rates and the morphology of dissolution features may be considerably modified by the presence of the foreign ions in the solution, which adsorb at the surface and hinder the detachment of the ions building the crystal. Dissolution processes in the aqueous environment are closely related to the rearrangement of water molecules around solute ions and the interaction between the solvent molecules themselves. The rearrangement of water molecules with respect to solute species has been recognized as the main kinetic barrier for crystal dissolution in many systems (Davis, 2000; De Yoreo and Dove 2004; Wasylenki et al. 2005). Current research suggest that the control that electrolytes exert on water structure is limited to the local environment surrounding the ions and is not related to long-range electric fields emanating from the ions but results from effects associated with the hydration shell(s) of the ions (Collins et al. 2007) and the ions' capacity to break or structure water (i.e. chaotropic and kosmotropic ions, respectively). These effects will ultimately affect the kinetics of crystal dissolution, and could be correlated with the water affinity of the respective background ions following a trend known as the lyotropic or Hofmeister series (Kunz et al. 2004; Dove and Craven, 2005). In situ macroscopic and Atomic Force Microscopy (AFM) flow-through dissolution experiments were conducted at a

  7. Water defluoridation using Malawi’s locally sourced gypsum (United States)

    Masamba, W. R. L.; Sajidu, S. M.; Thole, B.; Mwatseteza, J. F.

    Free fluoride levels above the WHO guideline maximum value of 1.5 mg/l have been reported in several parts of Malawi. Dental fluorosis has also been observed in the same areas such that search for local defluoridation techniques has become important in the country. The present research intended to determine the potential of using Malawi gypsum in defluoridation, identify the best pre-treatment of the gypsum and optimum conditions under which effective water defluoridation with the gypsum may be obtained. Laboratory experiments were carried out to explore defluoridation of drinking water using locally sourced gypsum and gypsum calcined at high temperatures. A 400 °C calcined phase of gypsum gave the highest defluoridation capacity of 67.80% compared to raw (uncalcined) gypsum, 200, 300 and 500 °C calcined phases. Powder X-ray diffraction (PXRD) pattern of the 400 °C phase revealed existence of less crystalline CaSO 4 that was thought to be responsible for such relatively high defluoridation capacity. The dependence of the fluoride removal by the 400 °C calcined phase on other drinking water quality parameters was assessed by simple correlation analysis. Reaction kinetics and mechanisms of fluoride removal by the materials were also investigated. It was found that ion exchange was the dominant mechanism through which fluoride was removed from water by the materials.

  8. Impact of Leaching Conditions on Constituents Release from Flue Gas Desulfurization Gypsum (FGDG) and FGDG-Soil Mixture (United States)

    The interest in using Flue Gas Desulfurization Gypsum(FGDG) has increased recently. This study evaluates the leaching characteristics of trace elements in "modern" FGDG (produced after fly ash removal) and FGDG-mixed soil (SF) under different environmental conditions using rece...

  9. The production of precipitated calcium carbonate from industrial gypsum wastes

    CSIR Research Space (South Africa)

    De Beer, Morris


    Full Text Available The production of precipitated calcium carbonate from industrial gypsum wastes M. de Beer Thesis submitted for the degree Doctor Philosophiae in Chemical Engineering at the Potchefstroom Campus of the North-West University Abstract Precipitated...

  10. Uranium-series dating of gypsum speleothems: methodology and examples.

    Directory of Open Access Journals (Sweden)

    Sanna Laura


    Full Text Available The analytical problems of dating gypsum speleothems with the U-series technique are reviewed. Gypsum speleothems are, in general, very low in U content, challenging the limits of detection methods. Various approaches to dissolving gypsum and isolation of actinides from the matrix include ion-pairing dissolution with magnesium salts and using nitric acid. The most precise dating technique is Thermal Ionization Mass Spectrometry (TIMS, combined with Fe(OH3 scavenging and anionic exchange chromatography. Less satisfactory, but much quicker, is direct retention of actinides from HNO3 by means of TRU resin and MC-ICP-MS detection. We have tested these methods on gypsum speleothems from the Sorbas karst in Spain and from the Naica caves in Mexico.

  11. Gypsum crystals in the inner shelf sediments off Maharashtra, India

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Ambre, N.V.

    Gypsum crystals have been found in the inner shelf silty clay/clayey silt off the Maharashtra Coast between Vengurla and Bombay. Generally these occur as euhedral single or twinned crystals of selenite. Very often shells are found embedded within...

  12. FGD gypsum's place in American agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, C. [US Department of Agriculture (United States). Agricultural Research Service


    Surface cracks and soil clumps form when saline-sodic, high-clay soil dries out. Treatment with FGD gypsum and irrigation water flowing into these cracks leaches salts until the aggregates swell and the cracks close up. The article describes research projects to develop agricultural uses of FGD gypsum from coal-fired power plants that have been conducted by university researchers and USDA-Agricultural Research Service scientists.

  13. By Product Synergy Analysis (United States)


    AFB developed an environmental management system manual; the manual was prepared according to the ISO 14001 standard. The program is focused on...20 Design for Environment ...................................................................................20 ISO 14000 Series... ISO 14000 Framework ..................................................................................21 Figure 6. By Product Flow

  14. Effect of gypsum application on enzymatic browning activity in lettuce. (United States)

    Chutichudet, Prasit; Chutichudet, B; Kaewsit, S


    A comprehensive study to evaluate calcium, in terms of gypsum (CaSO4.2H2O) by soil dressing application, on enzymatic browning activity of Polyphenol oxidase (PPO) and internal qualities was tested on lettuce var. Grand Rapids under field conditions. A factorial in completely randomized design was arranged with four replications. The results showed that plants-treated with 50 mg kg(-1) gypsum applied at 40 DAP had the maximal fresh weight of 25.83 g plant(-1). The internal qualities of the lettuce at harvest showed that plants treated with 50 mg kg(-1) gypsum had the maximal chlorophyll content (26.80 mg m(-2)), while all gypsum concentrations applied in this study, had less content of ascorbic acid than the control plants. Plants-treated with 100 mg kg(-1) gypsum affected to the lowest level of PPO activity at week 3 after transplanting. Furthermore, gypsum application had no effect to biomass, leaf colour, the contents of phenolic and quinone in lettuce at harvesting stage.

  15. How soil type (gypsum or limestone) influences the properties and composition of thyme honey. (United States)

    González-Porto, Amelia Virginia; Martín Arroyo, Tomás; Bartolomé Esteban, Carmen


    The objective of this work was to determine the influence of the soil substrate on the characteristics and properties of a specific type of honey. As such, we analysed the features of a typical single-flower honey, thyme honey, produced in a specific Mediterranean region. Thymus is a genus of aromatic perennial plants that are native to Europe, North Africa and Asia. A total of 70 honey samples from hives situated on limestone (38 samples) or gypsum soils (32 samples) were studied. The physical and chemical properties of each samples were analyzed using standard assays. Within the same geographical area and despite a similar thyme pollen content, we observed variation in the physicochemical, antioxidant and sensorial characteristics of monofloral honeys. The quantification of certain physicochemical parameters of the honey indicated these features were influenced by the soil type. Indeed, the soil type of the hives' settlement area, limestone or gypsum, influences the conductivity, antioxidant capacity, colour and floristic composition. The present work demonstrates that soil type (gypsum or limestone) influences the characteristics of honey, potentially providing added market value to these products.

  16. Unravelling the mechanisms for plant survival on gypsum soils: an analysis of the chemical composition of gypsum plants from Turkey. (United States)

    Bolukbasi, A; Kurt, L; Palacio, S


    Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non-exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non-exclusive to gypsum (i.e. gypsovags), which may indicate their similar ecological strategy as stress-tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high- and low-gypsum content soils. Differences were explored with multivariate analyses (RDA) and mixed models (REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high-gypsum than on low-gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress-tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 1, Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kevin [Dravo Technology Center, Pittsburgh, PA (United States); Beeghly, Joel H. [Dravo Technology Center, Pittsburgh, PA (United States)


    About 30 electric utility units with a combined total of 15,000 MW utilize magnesium enhanced lime flue gas desulfurization (FGD) systems. A disadvantage of this and other inhibited or natural oxidation wet FGD systems is the capital and operating cost associated with landfill disposal of the calcium sulfite based solids. Fixation to stabilize the solids for compaction in a landfill also consumes fly ash that otherwise may be marketable. This Executive Summary describes efforts to dewater the magnesium hydroxide and gypsum slurries and then process the solids into a more user friendly and higher value form. To eliminate the cost of solids disposal in its first generation Thiosorbic® system, the Dravo Lime Company developed the ThioClear® process that utilizes a magnesium based absorber liquor to remove S02 with minimal suspended solids. Magnesium enhanced lime is added to an oxidized bleed stream of thickener overflow (TOF) to produce magnesium hydroxide [Mg(OH)2] and gypsum (CaS04 • 2H20), as by-products. This process was demonstrated at the 3 to 5 MW closed loop FGD system pilot plant at the Miami Fort Station of Cinergy, near Cincinnati, Ohio with the help of OCDO Grant Agreement CDO/D-91-6. A similar process strictly for'recovery and reuse of Mg(OH)2 began operation at the Zimmer Station of Cinergy in late 1994 that can produce 900 pounds of Mg(OH)2 per hour and 2,600 pounds of gypsum per hour. This by-product plant, called the Zimmer Slipstream Magnesium Hydroxide Recovery Project Demonstration, was conducted with the help of OCDO Grant Agreement CDO/D-921-004. Full scale ThioClear® plants began operating in 1997 at the 130 MW Applied Energy Services plant, in Monaca, PA, and in year 2000 at the 1,330 MW Allegheny Energy Pleasants Station at St. Marys, WV.

  18. Synthesis on research results of FGD gypsum briquetting

    Directory of Open Access Journals (Sweden)

    Kosturkiewicz Bogdan


    Full Text Available FGD gypsum products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water and soil. Among many approaches of preparing utilization of this waste, the process of compaction using briquetting has proved to be very effective. Using FGD gypsum products a new material of fertilizers characteristics has been acquired and this material is resistant to the conditions of transportation. This paper presents results of experimental briquetting of flue gas desulphurisation products in a roll press. The experiments were conducted in a laboratory roll presses LPW 450 and LPW 1100 equipped with two interchangeable forming rings that form material into saddle-shaped briquettes with volume 6,5 cm3 and 85 cm3. The experiments were conducted with various percentage amounts of FGD gypsum moisture. The results provided information regarding influence of moisture and roll press configuration on quality of briquettes. On the basis of obtained results, technological process and a general outline of technological line for FGD gypsum were developed. Two roll presses of own construction with different outputs were identified as appropriate for this purpose. A range of necessary works related to their adaptation for the FGD gypsum briquetting were pointed out.

  19. Influence of gypsum on efflorescence in ceramic tiles; Influence da gipsita no surgimento de eflorescencia em telhas ceramicas

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, C.M.O.L. [Servico Nacional de Aprendizagem Industrial (SENAI), Teresina, PI (Brazil); Nascimento, R.M.; Martinelli, A.E. [Universidade Federal do Rio Grande do Norte (PPgCEM/UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais


    The red ceramic industry is recognized as of major importance in Piaui State. The State capital, Teresina, is the greatest producer of this material, which is used mainly for masonry sealing blocks. One of the most frequent problems in this kind of products is the efflorescence.This paper has the main objective of studying the influence of gypsum on tiles, using the local industry production standards. The raw materials were characterized by FRX, DRX, thermal analysis and sulfates. Extruded test specimens were made with the addition of 1%, 3% and 5% of gypsum in the ceramic paste, burned at 850 deg C, 950 deg C and 1050 deg C and submitted to further technological and analysis for MEV. The reference ceramic paste did not show tendency to efflorescence formation after burning for samples with 1% gypsum added to the paste. The reference ceramic paste showed tendency to efflorescence formation after drying and consolidated efflorescence after burning for samples with 5% gypsum added to the paste. (author)

  20. Synthesis of high-purity precipitated calcium carbonate during the process of recovery of elemental sulphur from gypsum waste. (United States)

    de Beer, M; Doucet, F J; Maree, J P; Liebenberg, L


    We recently showed that the production of elemental sulphur and calcium carbonate (CaCO3) from gypsum waste by thermally reducing the waste into calcium sulphide (CaS) followed by its direct aqueous carbonation yielded low-grade carbonate products (i.e. carbonation process for the production of high-grade CaCO3 (i.e. >99 mass% as CaCO3) or precipitated calcium carbonate (PCC). The process used an acid gas (H2S) to improve the aqueous dissolution of CaS, which is otherwise poorly soluble. The carbonate product was primarily calcite (99.5%) with traces of quartz (0.5%). Calcite was the only CaCO3 polymorph obtained; no vaterite or aragonite was detected. The product was made up of micron-size particles, which were further characterised by XRD, TGA, SEM, BET and true density. Results showed that about 0.37 ton of high-grade PCC can be produced from 1.0 ton of gypsum waste, and generates about 0.19 ton of residue, a reduction of 80% from original waste gypsum mass to mass of residue that needs to be discarded off. The use of gypsum waste as primary material in replacement of mined limestone for the production of PPC could alleviate waste disposal problems, along with converting significant volumes of waste materials into marketable commodities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Acidic soil amendment with a magnesium-containing fluidized bed combustion by-product

    Energy Technology Data Exchange (ETDEWEB)

    Stehouwer, R.C.; Dick, W.A.; Sutton, P.


    Removal of SO{sub 2} from the emissions of coal-fired boilers produces by-products that often consist of CaSO{sub 4}, residual alkalinity, and coal ash. These by-products could be beneficial to acidic soils because of their alkalinity and the ability of gypsum (CaSO{sub 4}{center{underscore}dot}2H{sub 2}O) to reduce Al toxicity in acidic subsoils. A 3-yr field experiment was conducted to determine the liming efficacy of a fluidized bed combustion boiler by-product (FBC) that contained 129 g Mg kg{sup {minus}1} as CaMg(CO{sub 3}){sub 2} and MgO and its effects on surface and subsurface soil chemistry. The FBC was mixed in the surface 10 cm of two acidic soils (Wooster silt loam, an Oxyaquic Fragiudalf, and Coshocton silt loam, an Aquultic Hapludalf) at rates of 0, 0.5, 1, and 2 times each soil's lime requirement (LR). Soils were sampled in 10-cm increments to depths ranging from 20 to 110 cm, and corn (Zea mays L.) and alfalfa (Medicago sativa L.) were grown. Application of Mg-FBC increased alfalfa yields in all six site-years, whereas it had no effect on corn grain yield in five site-years and decreased grain yield in one site-year. Plant tissue concentrations of Mg, S, and Mo were increased by Mg-FBC, while most trace elements were either unaffected or decreased. Application of Mg-FBC at one or two times LR increased surface soil pH to near 7 within 1 wk. Although surface soil pH remained near 7 for 2 yr, there was minimal effect on subjacent soil pH. Application of Mg-FBC increased surface soil concentrations of Ca, Mg, and S, which promoted downward movement of Mg and SO{sub 4}. This had different effects on subsoil chemistry in the two soils: in the high-Ca-status Wooster subsoil, exchangeable Ca was decreased and exchangeable Al was increased, whereas in the high-Al-status Coshocton subsoil, exchangeable Al was decreased and exchangeable Mg was increased. The Mg-FBC was an effective liming material and, because of the presence of both Mg and SO{sub 4

  2. Effect of Time on Gypsum-Impression Material Compatibility (United States)

    Won, John Boram

    The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix ® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

  3. Gypsum scaling in pressure retarded osmosis: experiments, mechanisms and implications. (United States)

    Zhang, Minmin; Hou, Dianxun; She, Qianhong; Tang, Chuyang Y


    Pressure retarded osmosis (PRO) is an osmotically-driven membrane process that can be used to harvest salinity-gradient power. The PRO performance (both water flux and power density) can be severely limited by membrane fouling. The current study, for the first time, investigates PRO scaling in a bench-scale pressurized system using calcium sulfate dihydrate (gypsum) as a model scalant. In addition to the bulk feed solution (FS) saturation index (SI bulk), gypsum scaling was found to be strongly affected by the draw solution (DS) type and concentration, the applied hydraulic pressure, and the membrane orientation. The commonly recommended active layer facing draw solution (AL-DS) orientation was highly prone to internal scaling. In this orientation, severe internal concentration polarization (ICP) of scaling precursors induced gypsum clogging in membrane support layer even when the FS was undersaturated (e.g., SI bulk = 0.8). At higher SI bulk values, external gypsum crystal deposition occurred in addition to internal scaling. More severe scaling was observed when the DS contained scaling precursors such as Ca(2+) or SO4(2-), suggesting that the reverse diffusion of these precursors into the FS can significantly enhanced gypsum scaling. Increasing applied hydraulic pressure could enhance reverse solute diffusion and thus result in more severe gypsum scaling when the DS contained scaling precursors. A conceptual model, capturing the two important PRO scaling mechanisms (ICP of scaling precursors from FS and reverse diffusion of scaling precursors from the DS), is presented to rationalize the experimental results. Our results provide significant implications for PRO scaling control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Triple oxygen isotope systematics of structurally bonded water in gypsum (United States)

    Herwartz, Daniel; Surma, Jakub; Voigt, Claudia; Assonov, Sergey; Staubwasser, Michael


    The triple oxygen isotopic composition of gypsum mother water (gmw) is recorded in structurally bonded water in gypsum (gsbw). Respective fractionation factors have been determined experimentally for 18O/16O and 17O/16O. By taking previous experiments into account we suggest using 18αgsbw-gmw = 1.0037; 17αgsbw-gmw = 1.00195 and θgsbw-gmw = 0.5285 as fractionation factors in triple oxygen isotope space. Recent gypsum was sampled from a series of 10 ponds located in the Salar de Llamara in the Atacama Desert, Chile. Total dissolved solids (TDS) in these ponds show a gradual increase from 23 g/l to 182 g/l that is accompanied by an increase in pond water 18O/16O. Gsbw falls on a parallel curve to the ambient water from the saline ponds. The offset is mainly due to the equilibrium fractionation between gsbw and gmw. However, gsbw represents a time integrated signal biased towards times of strong evaporation, hence the estimated gmw comprises elevated 18O/16O compositions when compared to pond water samples taken on site. Gypsum precipitation is associated with algae mats in the ponds with lower salinity. No evidence for respective vital effects on the triple oxygen isotopic composition of gypsum hydration water is observed, nor are such effects expected. In principle, the array of δ18Ogsbw vs. 17Oexcess can be used to: (1) provide information on the degree of evaporation during gypsum formation; (2) estimate pristine meteoric water compositions; and (3) estimate local relative humidity which is the controlling parameter of the slope of the array for simple hydrological situations. In our case study, local mining activities may have decreased deep groundwater recharge, causing a recent change of the local hydrology.

  5. Palaeoclimatic significance of gypsum pseudomorphs in the inner shelf sediments off Machalipatnam bay

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    after gypsum. The origin of the pseudo-gypsum has been discussed and it is suggested that these are indicators of late Pleistocene climatic aridity. The bay sediments deposited during late Pleistocene were subsequently eroded by waves and currents due...

  6. Kinetics of precipitation of gypsum and implications for pressure solution creep

    NARCIS (Netherlands)

    Meer, S. de; Spiers, C.J.; Peach, C.J.


    In order to model the role of gypsum in crustal deformation and in trapping hydrocarbons, a quantitative, mechanism-based understanding of the deformation and compaction behaviour of gypsum is needed.

  7. Suitability of coarse-grade gypsum for sodic soil reclamation: a laboratory experiment

    NARCIS (Netherlands)

    Elshout, van den S.; Kamphorst, A.


    Costs of sodic soil reclamation can be reduced when coarse-grade gypsum is used, as the production and transport prices of this gypsum are much lower than that of agricultural-grade gypsum. In a feasibility study laboratory experiments were conducted to evaluate the leaching water requirements for

  8. Crystallographic preferred orientation (CPO) of gypsum measured by electron backscatter diffraction (EBSD). (United States)

    Hildyard, R C; Prior, D J; Mariani, E; Faulkner, D R


    An investigation by electron backscatter diffraction on gypsum shows that this technique can be used to study the microstructures and crystallographic preferred orientation of gypsum. Presented here are the methods, verification tests and data obtained from a naturally deformed sample of gypsum-rich rock. The electron backscatter diffraction data show the sample has a strong crystallographic preferred orientation.

  9. Gypsum adherence to forage: consideration for excessive ingestion by ruminates (United States)

    Gypsum (calcium sulfate dihydrate, CaSO4•2H2O) has long been used as a soil amendment to improve soil conditions and its use has recently been encouraged by the USDA-NRCS for soil conservation through a new National Conservation Practice Standard: Code 333. However, there is concern regarding the e...

  10. Incorporation of gypsum waste in ceramic block production: Proposal for a minimal battery of tests to evaluate technical and environmental viability of this recycling process. (United States)

    Godinho-Castro, Alcione P; Testolin, Renan C; Janke, Leandro; Corrêa, Albertina X R; Radetski, Claudemir M


    Civil engineering-related construction and demolition debris is an important source of waste disposed of in municipal solid waste landfills. After clay materials, gypsum waste is the second largest contributor to the residential construction waste stream. As demand for sustainable building practices grows, interest in recovering gypsum waste from construction and demolition debris is increasing, but there is a lack of standardized tests to evaluate the technical and environmental viability of this solid waste recycling process. By recycling gypsum waste, natural deposits of gypsum might be conserved and high amounts of the waste by-product could be reused in the civil construction industry. In this context, this paper investigates a physical property (i.e., resistance to axial compression), the chemical composition and the ecotoxicological potential of ceramic blocks constructed with different proportions of clay, cement and gypsum waste, and assesses the feasibility of using a minimal battery of tests to evaluate the viability of this recycling process. Consideration of the results for the resistance to axial compression tests together with production costs revealed that the best formulation was 35% of plastic clay, 35% of non-plastic clay, 10% of Portland cement and 20% of gypsum waste, which showed a mean resistance of 4.64MPa. Energy dispersive X-ray spectrometry showed calcium and sulfur to be the main elements, while quartz, gypsum, ettringite and nacrite were the main crystalline compounds found in this formulation. Ecotoxicity tests showed that leachate from this formulation is weakly toxic toward daphnids and bacteria (EC(20%)=69.0 and 75.0, respectively), while for algae and fish the leachate samples were not toxic at the EC(50%) level. Overall, these results show that the addition of 20% of gypsum waste to the ceramic blocks could provide a viable substitute for clay in the ceramics industry and the tests applied in this study proved to be a useful tool

  11. Gypsum-Catalyzed One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H Under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Taoues Boumoud


    Full Text Available In view of the emerging importance of the green chemistry principles in chemical and pharmaceutical industries, we disclose, herein, a new economic approach producing the biologically active dihydropyrimidinones in good yields using the solventless one-pot Biginelli condensation in the presence of gypsum as an environmental friendly and recycled catalyst.

  12. B.C. company is a world leader in gypsum waste recycling technology

    Energy Technology Data Exchange (ETDEWEB)



    A proprietary process to recycle waste gypsum, developed by New West Gypsum Recycling Inc (NWGR) of Vancouver, BC, is discussed. The process recycles gypsum wallboard waste, which is then combined with virgin gypsum to make new wallboard containing up to 25 per cent recycled content, with no loss in quality. The success of the process is underscored by the steadily rising cost of disposing of the waste gypsum properly, the lack of room in landfills, and the growing health concerns from leachates, all of which are potential problems for the gypsum industry. The critical factor in recycling is to reduce the moisture content so that the recycled gypsum will meet the requirements of wallboard manufacturers. The NWGR process meets these requirements by having developed innovative machinery, modified specifically for the processing of waste gypsum and a patented grinding technology. In the process the waste gypsum pile is hand-cleaned of metal, plastic and other debris, most of the backing paper is removed, leaving recycled granulated gypsum ready for use. The paper is further processed prior to recycling for use in a wide variety of applications. The recycling unit is portable, can be transported and set up at any site. It is capable of processing up to 25 tonnes of waste per hour. It is estimated that waste gypsum board available for recycling is in the range of four to five million tonnes annually.

  13. Behavior of gypsum-based mortars with silica fume at high temperatures (United States)

    Krejsová, Jitka; Doleželová, Magdaléna; Vimmrová, Alena


    The influence of high temperatures on the ternary and binary gypsum-based mortars is described. The gypsum-based mortar with ternary binder, composed from gypsum, hydrated lime and silica fume and mortar with binary binder, composed from gypsum and hydrated lime only were exposed to the temperatures from 50°C to 1000°C and their physical and mechanical properties were investigated. The comparison of ternary mortars and mortars without silica fume was carried out. The results were also compared with the results obtained from previous testing of gypsum-based pastes without sand. It was found, that gypsum-based mortars have better stability than gypsum-based materials without sand. Ternary materials have better volume stability than materials without pozzolan (about 5 % at 1000 °C).

  14. Gypsum and hydrohalite dynamics in sea ice brines (United States)

    Butler, Benjamin M.; Papadimitriou, Stathys; Day, Sarah J.; Kennedy, Hilary


    Mineral authigenesis from their dissolved sea salt matrix is an emergent feature of sea ice brines, fuelled by dramatic equilibrium solubility changes in the large sub-zero temperature range of this cryospheric system on the surface of high latitude oceans. The multi-electrolyte composition of seawater results in the potential for several minerals to precipitate in sea ice, each affecting the in-situ geochemical properties of the sea ice brine system, the habitat of sympagic biota. The solubility of two of these minerals, gypsum (CaSO4 ·2H2O) and hydrohalite (NaCl · 2H2O), was investigated in high ionic strength multi-electrolyte solutions at below-zero temperatures to examine their dissolution-precipitation dynamics in the sea ice brine system. The gypsum dynamics in sea ice were found to be highly dependent on the solubilities of mirabilite and hydrohalite between 0.2 and - 25.0 ° C. The hydrohalite solubility between - 14.3 and - 25.0 ° C exhibits a sharp change between undersaturated and supersaturated conditions, and, thus, distinct temperature fields of precipitation and dissolution in sea ice, with saturation occurring at - 22.9 ° C. The sharp changes in hydrohalite solubility at temperatures ⩽-22.9 °C result from the formation of an ice-hydrohalite aggregate, which alters the structural properties of brine inclusions in cold sea ice. Favourable conditions for gypsum precipitation in sea ice were determined to occur in the region of hydrohalite precipitation below - 22.9 ° C and in conditions of metastable mirabilite supersaturation above - 22.9 ° C (investigated at - 7.1 and - 8.2 ° C here) but gypsum is unlikely to persist once mirabilite forms at these warmer (>-22.9 °C) temperatures. The dynamics of hydrohalite in sea ice brines based on its experimental solubility were consistent with that derived from thermodynamic modelling (FREZCHEM code) but the gypsum dynamics derived from the code were inconsistent with that indicated by its

  15. Theoretical and Numerical Investigation of the Cavity Evolution in Gypsum Rock (United States)

    Li, Wei; Einstein, Herbert H.


    When water flows through a preexisting cylindrical tube in gypsum rock, the nonuniform dissolution alters the tube into an enlarged tapered tube. A 2-D analytical model is developed to study the transport-controlled dissolution in an enlarged tapered tube, with explicit consideration of the tapered geometry and induced radial flow. The analytical model shows that the Graetz solution can be extended to model dissolution in the tapered tube. An alternative form of the governing equations is proposed to take advantage of the invariant quantities in the Graetz solution to facilitate modeling cavity evolution in gypsum rock. A 2-D finite volume model was developed to validate the extended Graetz solution. The time evolution of the transport-controlled and the reaction-controlled dissolution models for a single tube with time-invariant flow rate are compared. This comparison shows that for time-invariant flow rate, the reaction-controlled dissolution model produces a positive feedback between the tube enlargement and dissolution, while the transport-controlled dissolution does not.

  16. The production of hydroxyapatite prototypes from solid bodies of Gypsum/Polyvinyl Alcohol composites

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Amanda Alves; Ferraz, Andrea de Vasconcelos; Dantas, Alan Christie; Olivier, Nelson Cardenas, E-mail: [Universidade Federal do Vale do Sao Francisco (UNIVASF), Juazeiro, BA (Brazil)


    Prototypes of porous hydroxyapatite (HAp) were produced from Gypsum/PVA composite, using a mass proportion of 15% polymer. The material was obtained by means of chemical conversion in (NH{sub 4}){sub 2}HPO{sub 4} 0.5 mol.L{sup -1} solution and NH{sub 4}OH 6.0 mol.L{sup -1} alkaline medium for pH control, maintained between 6.0 and 9.0. The reaction occurred at a temperature of 100°C at different test times. The obtained HAp was characterized by several techniques, such as FTIR, which identified the SO{sub 4}{sup 2-} groups characteristic for the Gypsum block, and the PO{sub 4}{sup 2-} groups that are attributed to the biomaterial HAp, besides XRD and SEM, which made it possible to confirm a successful conversion of the material. Tests for mechanical resistance to compression (σ{sub c}) were carried out for both materials as well. (author)

  17. Performance characterization of PCM impregnated gypsum board for building applications


    Shukla, N; Fallahi, A.; Kosny, J.


    Previous research studies conducted on building components containing a phase-change material (PCM) have shown a great potential for direct and indirect energy and cost savings in the building envelopes. In particular, PCM impregnated gypsum boards, one of the most popular application of PCMs in buildings, have been reported to reduce building cooling loads by 7-20%. However, in order to best design and optimize the PCM-enhanced building materials, it is critical to accurately characterize th...

  18. Lime and gypsum application on the wheat crop

    Directory of Open Access Journals (Sweden)

    Caires Eduardo Fávero


    Full Text Available Root growth and crop yield can be affected by chemical modifications of the soil profile owing to lime and gypsum applications. A field trial was carried out on a dystrophic Clayey Rhodic Hapludox at Ponta Grossa, PR, Brazil, aiming to evaluate lime (without or with incorporation into the soil and gypsum effects on root growth, mineral nutrition and grain yield of wheat (cv. OR 1. A randomized complete block design was used, with three replications, in a split-plot experiment. Treatments with dolomitic limestone (without lime and 4.5 t ha-1 of lime applied on the surface, in total rate and 1/3 of the requirement per year during 3 years, or incorporated into the soil were applied in July 1998 (main plots and the rates of gypsum (0, 3, 6 and 9 t ha-1 in October 1998 (subplots. Wheat was evaluated in the 2000 winter season. In conditions of water deficit absence, there was no limitation in root growth in depth, for exchangeable Ca of 6 mmol c dm-3. Lime incorporation of lime increased the Mg concentration in the leaves, but wheat yield was not influenced by the correction of soil acidity through liming treatments. Gypsum increased the concentrations of Ca and S in wheat leaves, with significant effects on grain yield. The critical level of S-SO4(2- in the 0-20 cm soil layer, extracted by ammonium acetate 0.5 mol L-1 in acetic acid 0.25 mol L-1, was 25.8 mg dm-3.

  19. Biological sulfate removal from gypsum contaminated construction and demolition debris. (United States)

    Kijjanapanich, Pimluck; Annachhatre, Ajit P; Esposito, Giovanni; van Hullebusch, Eric D; Lens, Piet N L


    Construction and demolition debris (CDD) contains high levels of sulfate that can cause detrimental environmental impacts when disposed without adequate treatment. In landfills, sulfate can be converted to hydrogen sulfide under anaerobic conditions. CDD can thus cause health impacts or odor problems to landfill employees and surrounding residents. Reduction of the sulfate content of CDD is an option to overcome these problems. This study aimed at developing a biological sulfate removal system to reduce the sulfate content of gypsum contaminated CDD in order to decrease the amount of solid waste, to improve the quality of CDD waste for recycling purposes and to recover sulfur from CDD. The treatment leached out the gypsum contained in CDD by water in a leaching column. The sulfate loaded leachate was then treated in a biological sulfate reducing Upflow Anaerobic Sludge Blanket (UASB) reactor to convert the sulfate to sulfide. The UASB reactor was operated at 23 ± 3 °C with a hydraulic retention time and upflow velocity of 15.5 h and 0.1 m h(-1), respectively while ethanol was added as electron donor at a final organic loading rate of 3.46 g COD L(-1) reactor d(-1). The CDD leachate had a pH of 8-9 and sulfate dissolution rates of 526.4 and 609.8 mg L(-1) d(-1) were achieved in CDD gypsum and CDD sand, respectively. Besides, it was observed that the gypsum dissolution was the rate limiting step for the biological treatment of CDD. The sulfate removal efficiency of the system stabilized at around 85%, enabling the reuse of the UASB effluent for the leaching step, proving the versatility of the bioreactor for practical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Comparison of Energy Dissipation, Stiffness, and Damage of Structural Oriented Strand Board (OSB, Conventional Gypsum, and Viscoelastic Gypsum Shearwalls Subjected to Cyclic Loads

    Directory of Open Access Journals (Sweden)

    Andrew S. Blasetti


    Full Text Available A key element in the seismic load resisting system of a wood framed structure is the shear wall which is typically sheathed on one side with plywood or oriented strand board (OSB and gypsum on the other. The shear capacity of gypsum sheathed shear walls is typically neglected in high seismic areas due to the susceptibility of conventional drywall screw connections to damage caused by earthquakes. The earthquake resistance of an innovative viscoelastic (VE gypsum shearwall is evaluated and compared to conventional structural and non-structural walls. Ten 8 ft × 8 ft wood framed wall specimens of three configurations [nailed-OSB, screw-gypsum, and VE polymer-gypsum] were subjected to a cyclic test protocol. The energy dissipation, stiffness, and damage characteristics of all shearwalls are reported herein. Testing results indicate the VE-gypsum walls can dissipate more energy than the OSB structural panels and 500% more energy that the conventional gypsum sheathed walls and contains a constant source of energy dissipation not seen in the structural and non-structural walls. The wall stiffness of the OSB wall degrades at a far greater rate that the VE gypsum wall and at continued cycling degrades below the VE wall stiffness. Unlike both of the conventional wall types, the VE wall showed no visible or audible signs of damage when subjected to shear displacements up to 1.

  1. Manufacturing of calcium phosphate scaffolds by pseudomorphic transformation of gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Batista, H. de.; Batista Cardoso, M.; Sales Vasconcelos, A.; Vinicius Lia Fook, M.; Rodriguez Barbero, M. A.; Garcia Carrodeguas, R.


    Carbonated hydroxyapatite (CHAp) and β-tricalcium phosphate (β-TCP) have been employed for decades as constituents of scaffolds for bone regeneration because they chemically resemble bone mineral. In this study, the feasibility to manufacture CHAp/β-TCP scaffolds by pseudomorphic transformation of casted blocks of gypsum was investigated. The transformation was carried out by immersing the precursor gypsum block in 1 M (NH{sub 4}){sub 2}HPO{sub 4}/1.33 M NH{sub 4}OH solution with liquid/solid ratio of 10 mL/g and autoclaving at 120 degree centigrade and 203 kPa (2 atm) for 3 h at least. Neither shape nor dimensions significantly changed during transformation. The composition of scaffolds treated for 3 h was 70 wt.% CHAp and 30 wt.% β-TCP, and their compressive and diametral compressive strengths were 6.5 ± 0.7 and 5.3 ±0.7 MPa, respectively. By increasing the time of treatment to 6 h, the composition of the scaffold enriched in β-TCP (60 wt.% CHAp and 40 wt.% β-TCP) but its compressive and diametral compressive strengths were not significantly affected (6.7 ± 0.9 and 5.4 ± 0.6 MPa, respectively). On the basis of the results obtained, it was concluded that this route is a good approach to the manufacturing of biphasic (CHAp/β-TCP) scaffolds from previously shaped pieces of gypsum. (Author)

  2. Preparation of Thermal Insulation Plaster with FGD Gypsum

    Directory of Open Access Journals (Sweden)

    Yi-Chao Zhang


    Full Text Available Thermal insulation gypsum plaster was prepared from flue gas desulphurization (FGD gypsum. K12 is more recommendable as foaming agent, when the mass fraction of K12 is around 0.1 %, the setting time and compressive strength meet the requirements of gypsum-based construction materials. In the meanwhile, the thermal conductivity is 0.18 W m–1 K–1, which can be used as a thermal insulation material. The hemihydrate mixtures obtained, allow the design of a new wall structure, which is more efficient as a thermal insulation system. The wall heat transfer coefficient test was carried out to compare thermal performance of two different thermal insulation systems. Compared with the thermal performance of a conventional system, the heat transfer coefficient of the new system was reduced by 5.6 %. Finally, energy-saving analysis of a building was carried out to compare the energy-saving effect of the conventional and new systems of building. The energy-savings of the building with the new system increased by almost 2 %, thus resulting in low energy consumption of the building.

  3. Use of laboratory geophysical and geotechnical investigation methods to characterize gypsum rich soils (United States)

    Bhamidipati, Raghava A.

    Gypsum rich soils are found in many parts of the world, particularly in arid and semi-arid regions. Most gypsum occurs in the form of evaporites, which are minerals that precipitate out of water due to a high rate of evaporation and a high mineral concentration. Gypsum rich soils make good foundation material under dry conditions but pose major engineering hazards when exposed to water. Gypsum acts as a weak cementing material and has a moderate solubility of about 2.5 g/liter. The dissolution of gypsum causes the soils to undergo unpredictable collapse settlement leading to severe structural damages. The damages incur heavy financial losses every year. The objective of this research was to use geophysical methods such as free-free resonant column testing and electrical resistivity testing to characterize gypsum rich soils based on the shear wave velocity and electrical resistivity values. The geophysical testing methods could provide quick, non-intrusive and cost-effective methodologies to screen sites known to contain gypsum deposits. Reconstituted specimens of ground gypsum and quartz sand were prepared in the laboratory with varying amounts of gypsum and tested. Additionally geotechnical tests such as direct shear strength tests and consolidation tests were conducted to estimate the shear strength parameters (drained friction angle and cohesion) and the collapse potential of the soils. The effect of gypsum content on the geophysical and geotechnical parameters of soil was of particular interest. It was found that gypsum content had an influence on the shear wave velocity but had minimal effect on electrical resistivity. The collapsibility and friction angle of the soil increased with increase in gypsum. The information derived from the geophysical and geotechnical tests was used to develop statistical design equations and correlations to estimate gypsum content and soil collapse potential.

  4. The use of gypsum mining by-product and lime on the engineering properties of compressed earth blocks

    Directory of Open Access Journals (Sweden)

    Eliana Rocío Jaramillo-Pérez


    Full Text Available Las desventajas de los bloques de tierra comprimida son sus baj as propiedades mecánicas y resistencia al daño al agua. Por lo tanto, su uso es vulnerable al deterioro y requiere cuidado y mantenimien to, dependiendo del grado de estabilización y compactación del suelo arcilloso. Residuos de minería del yeso y cal se utilizaron com o estabilizantes para mejorar las propiedades de estos material es de construcción. Resistencia a compresión y flexión, ablandamiento en agua, retracción por secado y peso unitario se determinaron . La resistencia aumento con la adición de residuo de minería. La re sistencia al ablandamiento en agua fue mayor con 25% de residuo de minería. La contracción por secado disminuyo con el aumento del contenido de residuo de minería. El peso unitario seco no esta ba en los estándares recomendados. Los resultados mostraron que los resid uos de minería del yeso pueden utilizarse como materiales alter nativos en la estabilización de bloques de tierra comprimida.

  5. Study of the use of coal fly ash as an additive to minimise fluoride leaching from FGD gypsum for its disposal. (United States)

    Alvarez-Ayuso, E; Querol, X


    The use of coal fly ash as a fluoride retention additive has been studied as a way of treating flue gas desulphurisation (FGD) gypsum for its disposal in landfills. With this end leaching studies following the standard EN-12457-4 [Characterization of waste- Leaching-Compliance test for leaching of granular waste materials and sludges - Part 4: One stage batch test at a liquid to solid ratio of 10l/kg for materials with particle size below 10mm (without or with size reduction)] have been performed on FGD gypsum samples treated with different proportions of fly ash (0.1-100%). It was found that the fluoride leachable content in FGD gypsum was reduced in the range 1-55%, depending on the fly ash proportion added to FGD gypsum. High levels of fluoride leaching reduction (close to 40%) were achieved even at relatively low fly ash additions (5%). So, low fly ash incorporations assure the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002 establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on waste disposal. Furthermore, the effectiveness of the proposed FGD gypsum stabilization method was also studied in column leaching systems, proving its good performance in simulated conditions of disposal. In such conditions a fluoride leaching reduction value slightly higher than 25% was displayed for a fly ash added amount of 5%.

  6. Crystallisation of Gypsum and Prevention of Foaming in Wet Flue Gas Desulphurisation (FGD) Plants


    Hansen, Brian Brun; Kiil, Søren; Johnsson, Jan Erik


    The aim of this project is to investigate two operational problems, which have been experienced during wet flue gas desulphurisation (FGD) operation, i.e. poor gypsum dewatering properties and foaming. The results of this work can be used for the optimization of wet FGD-plants in terms of reliability of operation and consistency of the gypsum quality obtained. This work may furthermore be of interest to other industrial systems in which foaming or gypsum crystallisation may take place. FGD is...

  7. Study of mercury in by-products from a Dutch co-combustion power station. (United States)

    Rallo, Manuela; Lopez-Anton, M Antonia; Meij, Ruud; Perry, Ron; Maroto-Valer, M Mercedes


    Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may be sent to landfills for their disposal. In this work, leaching and speciation of mercury in fly ashes and gypsum from a modern co-combustion power plant equipped with a selective catalytic reduction (SCR) unit in the Netherlands were studied. The mercury leachable contents were checked against different regulations, including Dutch, German and the Council Directive 2003/33/EC. The speciation of mercury in coal combustion products is essential not only to determine the risk when the wastes are finally disposed but also to understand the behaviour of mercury during combustion and therefore to select the appropriate mercury removal technology. A temperature-programmed decomposition technique was used in order to identify and quantify which mercury species are associated with coal combustion products. The main mercury species identified in fly ash samples was mercury sulphate, whereas in the gypsum sample the mercury present was mercury chloride. The quantitative mercury results carried out using the thermal desorption method may be considered accurate. The results obtained show that fly ash and gypsum samples from this power plant can be acceptable at landfills as a non-hazardous waste.

  8. Carbonate replacement of lacustrine gypsum deposits in two Neogene continental basins, eastern Spain (United States)

    Anadón, P.; Rosell, L.; Talbot, M. R.


    Bedded nonmarine gypsum deposits in the Miocene Teruel and Cabriel basins, eastern Spain, are partly replaced by carbonate. The Libros gypsum (Teruel Graben) is associated with fossiliferous carbonate wackestones and finely laminated, organic matter-rich mudstones which accumulated under anoxic conditions in a meromictic, permanent lake. The gypsum is locally pseudomorphed by aragonite or, less commonly, replaced by calcite. Low δ 13C values indicate that sulphate replacement resulted from bacterial sulphate reduction processes that were favoured by anacrobic conditions and abundant labile organic matter in the sediments. Petrographic evidence and oxygen isotopic composition suggest that gypsum replacement by aragonite occurred soon after deposition. A subsequent return to oxidising conditions caused some aragonite to be replaced by diagenetic gypsum. Native sulphur is associated with some of these secondary gypsum occurrences. The Los Ruices sulphate deposits (Cabriel Basin) contain beds of clastic and selenitic gypsum which are associated with limestones and red beds indicating accumulation in a shallow lake. Calcite is the principal replacement mineral. Bacterial sulphate reduction was insignificant in this basin because of a scarcity of organic matter. Stable isotope composition of diagenetic carbonate indicates that gypsum replacement occurred at shallow burial depths due to contact with dilute groundwaters of meteoric origin. Depositional environment evidently has a major influence upon the diagenetic history of primary sulphate deposits. The quantity of preserved organic matter degradable by sulphate-reducing bacteria is of particular importance and, along with groundwater composition, is the main factor controlling the mechanism of gypsum replacement by carbonate.

  9. Light in the darkening on Naica gypsum crystals

    Energy Technology Data Exchange (ETDEWEB)

    Castillo-Sandoval, I.; Fuentes-Cobas, L. E.; Esparza-Ponce, H. E.; Carreno-Márquez, J.; Montero-Cabrera, M. E., E-mail: [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih 31109, México (Mexico); Fuentes-Montero, M. E. [Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Campus Universitario#2, Circuito Universitario, C.P.31125, Chihuahua, Chih. México (Mexico); Reyes-Cortes, M. [Facultad de Ingeniería. Universidad Autónoma de Chihuahua, Campus Universitario#2, Circuito Universitario, C.P.31125, Chihuahua, Chih. México (Mexico)


    Naica mine is located in a semi-desertic region at the central-south of Chihuahua State. The Cave of Swords was discovered in 1910 and the Cave of Crystals 90 years later at Naica mines. It is expected that during the last century the human presence has changed the microclimatic conditions inside the cave, resulting in the deterioration of the crystals and the deposition of impurities on gypsum surfaces. As a contribution to the clarification of the mentioned issues, the present work refers to the use of synchrotron radiation for the identification of phases on these surfaces. All the experiments were performed at the Stanford Synchrotron Radiation Lightsource. Grazing incidence X-ray diffraction (GIXRD) and radiography-aided X-ray diffraction (RAXRD) experiments were performed at beamline 11-3. X-Ray micro-fluorescence (μ-SXRF) and micro-X-ray absorption (μ-XANES) were measured at beamline 2-3. Representative results obtained may be summarized as follows: a) Gypsum, galena, sphalerite, hematite and cuprite at the surface of the gypsum crystals were determined. b) The samples micro-structure is affected by impurities. c) The elemental distributions and correlations (0.6-0.9) of Cu, K, Fe, Mn, Pb, Zn, Ca and S were identified by μ-SXRF. The correlations among elemental contents confirmed the phase identification, with the exception of manganese and potassium due to the amorphous nature of some impurity compounds in these samples. The compounds hematite (Fe{sub 2}O{sub 3}), β-MnO{sub 2}, Mn{sub 2}O{sub 3}, MnO and/or MnCO{sub 3}, PbS, PbCO{sub 3} and/or PbSO4, ZnO{sub 4}, ZnS and/or smithsonite (ZnCO{sub 3}), CuS + Cu Oxide were identified by XANES. Plausibly, these latter compounds do not form crystalline phases.

  10. Landscape effects on pollination networks in Mediterranean gypsum islands. (United States)

    Santamaría, S; Sánchez, A M; López-Angulo, J; Ornosa, C; Mola, I; Escudero, A


    Habitat fragmentation is a major driver of global change that has operated historically on Mediterranean ecosystems. However, more needs to be understood about how fragmentation influences ecological interactions, particularly pollination. Gypsum outcrops are historically fragmented Mediterranean habitats and settings for the evolution of many endangered soil-specialist plants with narrow ranges. In this study, we aimed to determine how fragmentation (area and connectivity) affects: (i) pollinator community composition and (ii) structural properties of pollination networks; and whether there are differences in the effects of fragmentation on: (iii) the number of interactions and visits among pollinator functional groups; and (iv) the number of interactions and specialisation degree between soil-specialist and soil-generalist plants. We characterised the degree of fragmentation and the pollination network structures in 12 gypsum habitat fragments embedded in a cropland matrix during two consecutive years. We found significant relationships between fragmentation and network structure. The effects of fragmentation differed among pollinator functional groups, but not between soil-specialist and soil-generalist plants, in terms of number of interactions. However, the relatively higher pollinator specialisation of soil-specialist plants suggested greater dependence on pollinators. Inter-annual variations in the network structures demonstrated the importance of temporal replication. The observed patterns related to the landscape structure and pollination at both the network and species levels provide insights into the key ecological processes in gypsum islands. These findings may help to identify the potential drivers of species persistence, especially for endangered soil-specialist plants with narrow ranges in a changing scenario with exacerbated habitat fragmentation. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Dehydration of gypsum rock by solar energy: preliminary study


    López-Delgado, Aurora; López-Andrés, Sol; Padilla, Isabel; Alvarez, M.; Galindo, R.; Váquez, A. J.


    The dehydration process of gypsum rock was studied under concentrated solar energy by using a Fresnel lens with power density of 260 Wcm-2. Temperatures higher than 700¿C were attained for 1 min of solar exposure. The effect of grain size of sample and radiation exposure time on the formation of bassanite and anhydrite was studied by XRD. The complete transformation of dihydrate into hemihydrate and/or anhydrate phases is complete for the finer size sample. Plaster composed of 92.7% of anhydr...

  12. Synthesis of partial stabilized cement-gypsum as new dental retrograde filling material

    Energy Technology Data Exchange (ETDEWEB)

    Sadhasivam, S. [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Division of Medical Engineering Research, National Health Research Institute, Zhunan, Miaoli County, Taiwan (China); Chen, Jung-Chih [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan,Taiwan (China); Savitha, S. [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Hsu, Ming-Xiang; Hsu, Chung-King [Institute of Materials Science and Engineering, National Taipei University of Technology, Taipei, Taiwan (China); Lin, Chun-Pin [School of Dentistry and Graduate Institute of Clinical Dentistry, College of Medicine, National Taiwan University and National Taiwan University Hospital, Taipei, Taiwan (China); Lin, Feng-Huei, E-mail: [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Division of Medical Engineering Research, National Health Research Institute, Zhunan, Miaoli County, Taiwan (China)


    The study describes the sol-gel synthesis of a new dental retrograde filling material partial stabilized cement (PSC)-gypsum by adding different weight percentage of gypsum (25% PSC + 75% gypsum, 50% PSC + 50% gypsum and 75% PSC + 25% gypsum) to the PSC. The crystalline phase and hydration products of PSC-gypsum were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The handling properties such as setting time, viscosity, tensile strength, porosity and pH, were also studied. The XRD and microstructure analysis demonstrated the formation of hydroxyapatite and removal of calcium dihydrate during its immersion in simulated body fluid (SBF) on day 10 for 75% PSC + 25% gypsum. The developed PSC-gypsum not only improved the setting time but also greatly reduced the viscosity, which is very essential for endodontic surgery. The cytotoxic and cell proliferation studies indicated that the synthesized material is highly biocompatible. The increased alkaline pH of the PSC-gypsum also had a remarkable antibacterial activity. - Highlights: Black-Right-Pointing-Pointer A new dental retrograde filling material PSC-gypsum was developed. Black-Right-Pointing-Pointer PSC-gypsum cement has shown excellent initial and final setting time as 15-35 min. Black-Right-Pointing-Pointer It not only improved the setting time but also retain the viscosity, 2 Pa{center_dot}s. Black-Right-Pointing-Pointer High alkaline pH of the cement had a remarkable antibacterial activity. Black-Right-Pointing-Pointer Cytotoxicity studies revealed that the synthesized material is highly biocompatible.

  13. Direct nanoscale observations of the coupled dissolution of calcite and dolomite and the precipitation of gypsum. (United States)

    Offeddu, Francesco Giancarlo; Cama, Jordi; Soler, Josep Maria; Putnis, Christine V


    In-situ atomic force microscopy (AFM) experiments were performed to study the overall process of dissolution of common carbonate minerals (calcite and dolomite) and precipitation of gypsum in Na2SO4 and CaSO4 solutions with pH values ranging from 2 to 6 at room temperature (23 ± 1 °C). The dissolution of the carbonate minerals took place at the (104) cleavage surfaces in sulfate-rich solutions undersaturated with respect to gypsum, by the formation of characteristic rhombohedral-shaped etch pits. Rounding of the etch pit corners was observed as solutions approached close-to-equilibrium conditions with respect to calcite. The calculated dissolution rates of calcite at pH 4.8 and 5.6 agreed with the values reported in the literature. When using solutions previously equilibrated with respect to gypsum, gypsum precipitation coupled with calcite dissolution showed short gypsum nucleation induction times. The gypsum precipitate quickly coated the calcite surface, forming arrow-like forms parallel to the crystallographic orientations of the calcite etch pits. Gypsum precipitation coupled with dolomite dissolution was slower than that of calcite, indicating the dissolution rate to be the rate-controlling step. The resulting gypsum coating partially covered the surface during the experimental duration of a few hours.

  14. Incorporation of arsenic into gypsum: Relevant to arsenic removal and immobilization process in hydrometallurgical industry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Danni; Yuan, Zidan [Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Shaofeng, E-mail: [Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Jia, Yongfeng, E-mail: [Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Demopoulos, George P. [Department of Mining and Materials Engineering, McGill University, Montreal, QC H3A 2B2 (Canada)


    Highlights: • Quantitatively studied the incorporation of arsenic into the structure of gypsum. • Arsenic content in the solid increased with pH and initial arsenic concentration. • Calcium arsenate phase precipitated in addition to gypsum at higher pH values. • The structure of gypsum and its morphology was altered by the incorporated arsenate. • The incorporated arsenate formed sainfeldite-like local structure in gypsum. - Abstract: Gypsum precipitates as a major secondary mineral during the iron-arsenate coprecipitation process for the removal of arsenic from hydrometallurgical effluents. However, its role in the fixation of arsenic is still unknown. This work investigated the incorporation of arsenic into gypsum quantitatively during the crystallization process at various pHs and the initial arsenic concentrations. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray absorption near edge spectroscopy (XANES) and scanning electron microscopy (SEM) were employed to characterize the coprecipitated solids. The results showed that arsenate was measurably removed from solution during gypsum crystallization and the removal increased with increasing pH. At lower pH where the system was undersaturated with respect to calcium arsenate, arsenate ions were incorporated into gypsum structure, whereas at higher pH, calcium arsenate was formed and constituted the major arsenate bearing species in the precipitated solids. The findings may have important implications for arsenic speciation and stability of the hydrometallurgical solid wastes.

  15. Pre-contamination of new gypsum wallboard with potentially harmful fungal species

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Dosen, Ina; Lewinska, Anna Malgorzata


    Gypsum wallboard is a popular building material, but is also very frequently overgrown by Stachybotrys chartarum after severe and/or undetected water damage. The purpose of this study was to determine whether Stachybotrys and other fungi frequently isolated from wet gypsum wallboard are already...

  16. Removal of Reactive Red 1 dye from aqueous solution using gypsum

    African Journals Online (AJOL)

    In order to establish the capacity of gypsum in the removal of dyes from aqueous solutions, the adsorption behaviour of Reactive Red 1 (RR1) from aqueous solution onto gypsum was investigated under several different operating parameters namely, contact time, adsorbent dosage, pH, particle size, and adsorbate dosage, ...

  17. Direct nanoscale observations of the coupled dissolution of calcite and dolomite and the precipitation of gypsum

    Directory of Open Access Journals (Sweden)

    Francesco G. Offeddu


    Full Text Available In-situ atomic force microscopy (AFM experiments were performed to study the overall process of dissolution of common carbonate minerals (calcite and dolomite and precipitation of gypsum in Na2SO4 and CaSO4 solutions with pH values ranging from 2 to 6 at room temperature (23 ± 1 °C. The dissolution of the carbonate minerals took place at the (104 cleavage surfaces in sulfate-rich solutions undersaturated with respect to gypsum, by the formation of characteristic rhombohedral-shaped etch pits. Rounding of the etch pit corners was observed as solutions approached close-to-equilibrium conditions with respect to calcite. The calculated dissolution rates of calcite at pH 4.8 and 5.6 agreed with the values reported in the literature. When using solutions previously equilibrated with respect to gypsum, gypsum precipitation coupled with calcite dissolution showed short gypsum nucleation induction times. The gypsum precipitate quickly coated the calcite surface, forming arrow-like forms parallel to the crystallographic orientations of the calcite etch pits. Gypsum precipitation coupled with dolomite dissolution was slower than that of calcite, indicating the dissolution rate to be the rate-controlling step. The resulting gypsum coating partially covered the surface during the experimental duration of a few hours.

  18. Authigenic gypsum in a deep sea core from Southeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.

    Authigenic gypsum has been encountered in a deep sea core RC9-157 from the southeastern Arabian Sea at a depth of 4111 m which is a zone of lysocline. The formation of gypsum in the deep sea region is attributed to the prevailing sulphate rich...

  19. An important tool with no instruction manual: A review of gypsum use in agriculture (United States)

    Land application of gypsum has been studied and utilized in agriculture and environmental remediation for many years. Most of the published literature has focused on gypsum application impacts on soil properties rather than crop yields. This literature review was conducted to (i) gather results from...

  20. The Growth of Gypsum in the Presence of Hexavalent Chromium: A Multiscale Study

    Directory of Open Access Journals (Sweden)

    Juan Morales


    Full Text Available The sorption of dissolved inorganic pollutants into the structure of minerals is an important process that controls the mobility and fate of these pollutants in the Earth’s crust. It also modifies the surface structure and composition of the host mineral, affecting its crystallization kinetics. Here, we investigate the effect of hexavalent chromium, Cr(VI, on the nucleation and growth of gypsum by conducting two types of experiments: (i in situ atomic force microscopy (AFM observations of the growth of gypsum {010} surfaces in the presence of Cr(VI and (ii gypsum precipitation experiments by mixing aqueous solutions containing variable amounts of Cr(VI. Gypsum precipitation is progressively delayed when occurring from solutions bearing increasing Cr(VI concentrations. Chemical analyses of gypsum precipitates show that gypsum incorporates small Cr(VI amounts that correlate with the content of this ion in the aqueous solution. Gypsum cell parameters variation reflects this incorporation. At the molecular scale, Cr(VI induces a slowdown of step advance rates on gypsum {010} surfaces accompanied by the roughening of nanostep edges and the so-called “template effect”. This effect involves the reproduction of the original nanotopography after the completion of individual advancing monolayers and appears as a general nanoscale phenomenon occurring during growth of solid solutions from aqueous solutions even in the case of compositionally-restricted solid solutions.

  1. Effect of disinfection on irreversible hydrocolloid and alternative impression materials and the resultant gypsum casts. (United States)

    Suprono, Montry S; Kattadiyil, Mathew T; Goodacre, Charles J; Winer, Myron S


    Many new products have been introduced and marketed as alternatives to traditional irreversible hydrocolloid materials. These alternative materials have the same structural formula as addition reaction silicone, also known as vinyl polysiloxane (VPS), impression materials. Currently, there is limited in vitro and in vivo research on these products, including on the effects of chemical disinfectants on the materials. The purpose of this study was to compare the effects of a spray disinfecting technique on a traditional irreversible hydrocolloid and 3 new alternative impression materials in vitro. The tests were performed in accordance with the American National Standards Institute/American Dental Association (ANSI/ADA) Specification Nos. 18 and 19. Under standardized conditions, 100 impressions were made of a ruled test block with an irreversible hydrocolloid and 3 alternative impression materials. Nondisinfected irreversible hydrocolloid was used as the control. The impressions were examined for surface detail reproduction before and after disinfection with a chloramine-T product. Type III and Type V dental stone casts were evaluated for linear dimensional change and gypsum compatibility. Comparisons of linear dimensional change were analyzed with 2-way ANOVA of mean ranks with the Scheffé post hoc comparisons (α=.05). Data for surface detail reproduction were analyzed with the Wilcoxon Signed-Rank procedure and gypsum compatibility with the Kruskal-Wallis Rank procedure (α=.05). The alternative impression materials demonstrated significantly better outcomes with all 3 parameters tested. Disinfection with chloroamine-T did not have any effect on the 3 alternative impression materials. The irreversible hydrocolloid groups produced the most variability in the measurements of linear dimensional change. All of the tested materials were within the ADA's acceptable limit of 1.0% for linear dimensional change, except for the disinfected irreversible hydrocolloid

  2. Carbonation of gypsum from wet flue gas desulfurization process: experiments and modeling. (United States)

    Tan, Wenyi; Zhang, Zixin; Li, Hongyi; Li, Youxu; Shen, Zewen


    In this paper, waste gypsum from wet flue gas desulfurization (WFGD) mixed with NH3·H2O was applied for CO2 absorption in the solid-liquid-gas phase system. The effects of operation temperature, CO2 flow rates, and ammonia-to-gypsum ratio on carbonation process were discussed. Meanwhile, a model for CO2 absorption in the suspension of WFGD gypsum and ammonia was established. The results indicate that higher temperature favors the reaction, and WFGD gypsum conversion can be achieved above 90% even at lower ammonia-to-gypsum ratio, while CO2 conversion reaches 90% and ammonia utilization is up to 83.69%. The model fits well with the experimental results at various CO2 flow rates and predicts the concentration distribution of the main species, including CO2 absorbed, NH2COO(-), and HCO3(-).

  3. Gypsophile chemistry unveiled: Fourier transform infrared (FTIR spectroscopy provides new insight into plant adaptations to gypsum soils.

    Directory of Open Access Journals (Sweden)

    Sara Palacio

    Full Text Available Gypsum soils are among the most restrictive and widespread substrates for plant life. Plants living on gypsum are classified as gypsophiles (exclusive to gypsum and gypsovags (non-exclusive to gypsum. The former have been separated into wide and narrow gypsophiles, each with a putative different ecological strategy. Mechanisms displayed by gypsum plants to compete and survive on gypsum are still not fully understood. The aim of this study was to compare the main chemical groups in the leaves of plants with different specificity to gypsum soils and to explore the ability of Fourier transform infrared (FTIR spectra analyzed with neural network (NN modelling to discriminate groups of gypsum plants. Leaf samples of 14 species with different specificity to gypsum soils were analysed with FTIR spectroscopy coupled to neural network (NN modelling. Spectral data were further related to the N, C, S, P, K, Na, Ca, Mg and ash concentrations of samples. The FTIR spectra of the three groups analyzed showed distinct features that enabled their discrimination through NN models. Wide gypsophiles stood out for the strong presence of inorganic compounds in their leaves, particularly gypsum and, in some species, also calcium oxalate crystals. The spectra of gypsovags had less inorganic chemical species, while those of narrow gypsum endemisms had low inorganics but shared with wide gypsophiles the presence of oxalate. Gypsum and calcium oxalate crystals seem to be widespread amongst gypsum specialist plants, possibly as a way to tolerate excess Ca and sulphate. However, other mechanisms such as the accumulation of sulphates in organic molecules are also compatible with plant specialization to gypsum. While gypsovags seem to be stress tolerant plants that tightly regulate the uptake of S and Ca, the ability of narrow gypsum endemisms to accumulate excess Ca as oxalate may indicate their incipient specialization to gypsum.

  4. Heat storage in gypsum. Final report to the Energy Agency; Vaermelagring i Gips. Slutrapport foer Energimyndigheten

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Punya (Process Improvements, Plankgatan 26, Norrkoeping (Sweden)); Kindh, Torgny (Environnet AB, Norrkoeping (Sweden)); Lawrence, David; Wahlstroem, Krister (Dept. of Physics, Chemistry and Biology, Linkoeping Univ., Linkoeping (Sweden))


    The Swedish Energy Agency's project 'energy storage in gypsum', began in April 2007 and finished a year later. The objective was to demonstrate the potential of using gypsum to store and retrieve low-grade heat at a pilot scale (i.e. using 200 kg of gypsum). Gypsum undergoes a reversible reaction with water in which it stores or releases energy. Preliminary work indicated that when using commercially available gypsum powder, a packed bed would not allow sufficient mass or heat transfer. Preliminary work also revealed that simple fluidization was not possible with the very fine particles: stirred fluidization was the solution used. A pilot-scale unit was constructed (essentially a closed tank about 1 m in diameter and 1 m high). To store energy, hot, dry air is contacted with the gypsum to bring the temperature of the powder to about 110 deg C. Once the powder is 'dried' it is returned to room temperature and isolated from the surroundings - in this state energy is stored indefinitely. To recover the heat, water was atomized, mixed with warm air (to vaporize the water) and reacted with the gypsum. Typically we were able to recover about 6 kWh of energy, which is only about 20% of what is possible. This is partly the result of too little insulation on the reactor and a hesitation to over-hydrate the gypsum (which would result in solid plaster). We anticipate that this will at least double with increased operating experience. Overall gypsum behaves at a pilot scale as was expected; in terms of energy storage for space heating, it shows great promise. Our experiences to date have shown that using gypsum with a larger particle size (to allow simple fluidization) is an important improvement.

  5. PPF-reinforced, ESP-lightened gypsum plaster

    Directory of Open Access Journals (Sweden)

    García Santos, A.


    Full Text Available A new construction material has been obtained by adding aggregate to gypsum plaster which, without reducing the bending strength of plain gypsum plaster without aggregates, lowers its density, and consequently the weight of the construction elements made from the agglomerated material, by half.The aggregates used were expanded polystyrene beads and short polypropylene fibre.The new material addresses one of the issues of cardinal interest in construction materials and construction element research, namely the need to lighten materials so as to ease the burden on buildings’ bearing structures while facilitating assembly of construction units, by a single worker wherever possible.With a water / binder ratio of 0.7 and 2% (by weight of plaster of expanded polystyrene and 2% of polypropylene fibre aggregates, the decline in density achieved was 50,88% over plain gypsum plaster and 32.88% over plasterboard.Se ha obtenido un nuevo material de construcción aditivando el yeso o la escayola, mediante la incorporación de agregados, de modo que sin reducir la resistencia a flexotracción de una escayola sin ningún tipo de adición, reduce su densidad a la mitad, y por tanto, el peso de los elementos constructivos que puedan realizarse basándose en él.El material está compuesto por una adición de gránulos de poliestireno expandido y fibras cortadas de polipropileno.El nuevo material incide sobre aquellos aspectos de más interés en el campo de la investigación en construcción, en donde se intenta reducir el peso de los materiales, de modo que se grave lo menos posible la estructura resistente de las edificaciones, a la par que se facilitan los procedimientos de montaje de las unidades constructivas, al poder ser manejadas por un solo operario.La escayola, con relación de agua/conglomerante de 0,7, y con adiciones del 2% en peso (sobre la cantidad de escayola, tanto de poliestireno expandido como de fibras de polipropileno, permite reducir la

  6. Influence of gypsum amendment on methane emission from paddy rice soil affected by saline irrigation water

    Directory of Open Access Journals (Sweden)

    Ei Ei eTheint


    Full Text Available To investigate the influence of gypsum application on methane (CH4 emission from paddy rice soil affected by saline irrigation water, two pot experiments with the rice cultivation were conducted. In pot experiment (I, salinity levels 30 mMNaCl (S30 and 90 mMNaCl (S90, that showed maximum and minimum CH4 production in an incubation experiment, respectively, were selected and studied without and with application of 1 Mg gypsum ha-1(G1. In pot experiment (II, CH4 emission was investigated under different rates of gypsum application: 1 (G1, 2.5 (G2.5 and 5 (G5 Mg gypsum ha-1 under a non-saline and saline condition of 25 mMNaCl (S25. In experiment (I, the smallest CH4 emission was observed in S90. Methane emission in S30 was not significantly different with the non-saline control. The addition of gypsum showed significant lower CH4 emission in saline and non-saline treatments compared with non-saline control. In experiment (II, the CH4 emissions in the saline treatments were not significantly different to the non-saline treatments except S25-G5. However, our work has shown that gypsum can lower CH4 emissions under saline and non-saline conditions. Thus, gypsum can be used as a CH4 mitigation option in non-saline as well as in saline conditions.

  7. Use of gypsum residues as a corrective for saline-sodic soil

    Directory of Open Access Journals (Sweden)

    Paulo Medeiros dos Santos


    Full Text Available One of the hugest problems faced by the civil construction sector is the final destination of residues, especially gypsum, which presents recycling restrictions. However, these residues present a high amount of calcium in their composition, and can be alternatively used for replacing mined gypsum as a saline-sodic soil corrective. This study aimed at evaluating the efficiency of gypsum residues from the civil construction, when compared to mined gypsum, for correcting a saline-sodic soil. A randomized blocks design was used, in a factorial arrangement consisting of two kinds of corrective (gypsum residue and mined gypsum and five leaching depths (0.5, 1.0, 1.5, 2.0 and 2.5 times the soil pores volume, with three replications. Electric conductivity, soluble cations and sodium adsorption ratio were evaluated in the soil saturation extract. The use of gypsum residue proved to be effective in leaching salts and soluble sodium in saline-sodic soil, and can be recommended as a calcium source for recovering from sodicity.

  8. Initiation and growth of gypsum piercement structures in the Zechstein Basin (United States)

    Williams-Stroud, S. C.; Paul, J.


    The importance of tectonic processes in initiating halite diapirs has become much better understood in recent years. Less well understood is the development of diapiric structures involving rocks composed predominantly of gypsum. Below about 1000 m, gypsum dehydrates to anhydrite, which often obscures primary sedimentary textures. If the strain associated with diapiric rise in the rock induces the transition to anhydrite, obliteration of primary features in the gypsum can be expected. In our study, we infer that the diapiric movement in the Werra Anhydrite member of cycle 1 of the Zechstein Formation of Europe occurred before the initial transition of gypsum to anhydrite based on the presence of pseudomorphs of bedded primary gypsum crystals, the overburden lithologies and depositional environment, and the mechanical properties of gypsum, anhydrite and carbonate rocks. Faulting and differential loading of a shallow overburden were the key components in initiating the gypsum diapirism. The transition to anhydrite occurred after burial and after cessation of diapirism. In comparison, the diapirism of calcium sulfate of the Leine Anhydrite into the Leine Halite members of cycle 3 of the Zechstein Formation probably occurred much later after burial and appears to have been triggered by halite diapirism, which in turn triggered the dehydration reaction, causing the calcium sulfate to become the incompetent phase relative to the halite. Published by Elsevier Science Ltd.

  9. The effects of K2SO4 solution on the compressive strength of dental gypsum type III (United States)

    Adeilina, T.; Triaminingsih, S.; Indrani, D. J.


    Dental gypsum type III is used as a material for manufacturing working models of dentures. The aim of this study was to identify the effects of the addition of a K2SO4 solution on the compressive strength of gypsum type III. A compressive strength test was performed using a universal testing machine with a crosshead speed of 1 mm/min. The data were analyzed using a one-way ANOVA. The results showed that the compressive strength of gypsum type III with a 1.5% K2SO4 solution added was higher than for gypsum type III alone but lower than the compressive strength of gypsum type IV.

  10. Stabilization of FGD gypsum for its disposal in landfills using amorphous aluminium oxide as a fluoride retention additive. (United States)

    Alvarez-Ayuso, E; Querol, X


    The applicability of amorphous aluminium oxide as a fluoride retention additive to flue gas desulphurisation (FGD) gypsum was studied as a way of stabilizing this by-product for its disposal in landfills. Using a batch method the sorption behaviour of amorphous aluminium oxide was evaluated at the pH (about 6.5) and background electrolyte conditions (high chloride and sulphate concentrations) found in FGD gypsum leachates. It was found that fluoride sorption on amorphous aluminium oxide was a very fast process with equilibrium attained within the first half an hour of interaction. The sorption process was well described by the Langmuir model, offering a maximum fluoride sorption capacity of 61.7 mg g(-1). Fluoride sorption was unaffected by chloride co-existing ions, while slightly decreased (about 20%) by competing sulphate ions. The use of amorphous aluminium oxide in the stabilization of FGD gypsum proved to greatly decreased its fluoride leachable content (in the range 5-75% for amorphous aluminium oxide doses of 0.1-2%, as determined by the European standard EN 12457-4 [EN-12457-4 Characterization of waste-leaching-compliance test for leaching of granular waste materials and sludges-Part 4: one stage batch test at a liquid to solid ratio of 10 l/kg for materials with particle size below 10mm (without or with size reduction)]), assuring the characterization of this by-product as a waste acceptable at landfills of non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002. Establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on landfill of wastes. Furthermore, as derived from column leaching studies, the proposed stabilization system proved to be highly effective in simulated conditions of disposal, displaying a fluoride leaching reduction value about 81% for an amorphous aluminium oxide added amount of 2%.

  11. Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils (United States)

    Chen, Qun; Wang, Shujuan; Li, Yan; Zhang, Ning; Zhao, Bo; Zhuo, Yuqun; Chen, Changhe


    Abstract Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline–alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation. PMID:26064038

  12. Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils. (United States)

    Chen, Qun; Wang, Shujuan; Li, Yan; Zhang, Ning; Zhao, Bo; Zhuo, Yuqun; Chen, Changhe


    Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline-alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation.

  13. Influence of shelf life on the setting time of type IV gypsum (United States)

    Hapsari, M. L.; Irawan, B.; Damiyanti, M.


    Although expired materials can exhibit a deterioration in their properties, expired type IV gypsum can still be found on the market. In order to evaluate the influence of the shelf life on its setting time, two groups of type IV gypsum (GC Fuji rock EP) with different expiration dates were used in this research. The setting time tests were done in a mold using a Vicat Needle apparatus. The results of the statistical analysis showed a significant difference (p<0.05) between the two different expiration date groups. Therefore, the shelf life did influence the setting time of the type IV gypsum.

  14. Hydrogeological flow in gypsum karst areas: some examples from northern Italy and main circulation models


    Bartolomeo Vigna; Ilenia M. D'Angeli; Adriano Fiorucci; Jo De Waele


    A Messinian succession containing gypsum beds crops out in northern Italy, mainly in Piedmont and along the northern flank of the Apennine mountains in Emilia-Romagna. These gypsum bodies have been extensively quarried at the surface, in outcrops, and through underground quarries. In Emilia-Romagna these gypsum outcrops can be rather extensive, several km long and up to 1 km wide, while in Piedmont they are mostly covered by silty-marly deposits of Upper Messinian and Pliocene age and show on...

  15. Boron availability to plants from coal combustion by-products

    Energy Technology Data Exchange (ETDEWEB)

    Kukier, U.; Sumner, M.E. [University of Georgia, Athens, GA (United States). Dept. of Crop and Soil Sciences


    Agronomic use of coal combustion by-products is often associated with boron (B) excess in amended soils and subsequently in plants. A greenhouse study with corn ({ital Zea mays L.}) as test plant was conducted to determine safe application rates of five fly ashes and one flue gas desulfurization gypsum (FDG). All by-products increased soil and corn tissue B concentration, in some cases above toxicity levels which are 5 mg hot water soluble B (hwsB)kg{sup -1} soil and 100 mg B kg{sup -1} in corn tissue. Acceptable application rates varied from 4 to 100 Mg ha{sup -1} for different by-products. Leaching and weathering of a high B fly ash under ponding conditions decreased its B content and that of corn grown in fly ash amended soil, while leaching of the same fly ash under laboratory conditions increased fly ash B availability to corn in comparison to the fresh fly ash. Hot water soluble B in fly ash or FDG amended soil correlated very well with corn tissue B. Hot water soluble B in fly ash amended soil could be predicted based on soil pH and B solubility in ash at different pH values but not so in the case of FDG. Another greenhouse study was conducted to compare the influence of FDG and Ca(OH{sub 2}) on B concentration in spinach ({ital Spinacia oleracea L.}) leaves grown in soil amended with the high B fly ash. The Ca(OH){sub 2} significantly decreased tissue B content, while FDG did not affect B uptake from fly ash amended soil. 41 refs., 6 figs., 5 tabs.

  16. A rapid analysis of {sup 226}Ra in raw materials and by-products using gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chung Sup; Chung, Kun Ho; Kim, Chang Jong; Ji, Young Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    A gamma-ray peak of {sup 226}Ra (186.2 keV) overlaps with one of {sup 235}U (185.7 keV) in a gamma-ray spectrometry system. Though reference peaks of {sup 235}U can be used to correct the peak interference of {sup 235}U in the analysis of {sup 226}Ra, this requires a complicated calculation process and a high limit of quantitation. On the other hand, evaluating {sup 226}Ra using the correction constant in the overlapped peak can make a rapid measurement of {sup 226}Ra without the complicated calculation process as well as overcome the disadvantage in the indirect measurement of {sup 214}Bi, which means the confinement of {sup 222}Rn gas in a sample container and a time period to recover the secular equilibrium. About 93 samples with 6 species for raw-materials and by-products were prepared to evaluate the activity of {sup 226}Ra using the correction constant. The results were compared with the activity of {sup 214}Bi, which means the indirect measurement of {sup 226}Ra, to validate the method of the direct measurement of {sup 226}Ra using the correction constant. The difference between the direct and indirect measurement of {sup 226}Ra was generally below about ± 20%. However, in the case of the phospho gypsum, a large error of about 50% was found in the comparison results, which indicates the disequilibrium between {sup 238}U and {sup 226}Ra in the materials. Application results of the contribution ratio of {sup 226}Ra were below about ± 10% . The direct measurement of {sup 226}Ra using the correction constant can be an effective method for its rapid measurement of raw materials and by-products because the activity of {sup 226}Ra can be produced with a simple calculation without the consideration of the integrity of a sample container and the time period to recover the secular equilibrium.

  17. Final Critical Habitat for the Gypsum wild-buckwheat (Eriogonum gypsophilum) (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for gypsum wild-buckwheat (Eriogonum gypsophilum) occur based on the description...

  18. How soil type (gypsum or limestone) influences the properties and composition of thyme honey

    National Research Council Canada - National Science Library

    González-Porto, Amelia Virginia; Martín Arroyo, Tomás; Bartolomé Esteban, Carmen


    ... and Asia.A total of 70 honey samples from hives situated on limestone (38 samples) or gypsum soils (32 samples) were studied. The physical and chemical properties of each samples were analyzed using standard...

  19. Gypsum-induced decay in granite monuments in Northwestern Spain

    Directory of Open Access Journals (Sweden)

    Silva Hermo, B.


    Full Text Available One of the most common forms of decay in granite monuments is the detachment of the superficial layer of the stone (plaques, plaquettes and scales. Previous studies of granite monuments in the northwest Iberian Peninsula revealed a direct relation between this type of weathering and the presence of calcium sulphate, and a mechanism whereby the salt causes this type of decay was suggested. In the present study, various hypotheses as regards the origin of the gypsum found in granite monuments are proposed. The study involved analysis of the contents of ions soluble in water, the results of X-ray diffraction analyses and the ratios of CaO/SO3 in samples of stone, mortar and deposits collected from different monuments. It was concluded that in most cases the gypsum originated from old paintworks or/and from the joint mortars, although inputs from other sources cannot be discounted, as discussed

    Una de las formas de deterioro más frecuente en los monumentos graníticos es la separación de la capa superficial de la piedra (placas, plaquetas y escamas. En trabajos anteriores centrados en monumentos del noroeste de la Península Ibérica, se constató la relación directa entre esta forma de alteración y la presencia de sulfato de calcio y se propuso el mecanismo a través del cual esta sal provoca este tipo de deterioro. En este trabajo se plantean varias hipótesis acerca del origen del yeso encontrado en monumentos graníticos. Para ello se comparan los contenidos de iones solubilizados en agua, los resultados de difracción de rayos X y las relaciones OCa/SO3 de muestras de piedra, morteros y depósitos recogidas en diferentes monumentos. Se llega a la conclusión de que en la mayor parte de los casos el yeso procede de antiguas pinturas o de revestimientos superficiales y de los morteros de juntas entre sillares, pero no se puede descartar la contribución de otros aportes, los cuales se discuten también en este artículo.

  20. End-of-life of gypsum plasterboard: European case studies analysis


    Jiménez Rivero, Ana; Garcia Navarro, Justo; Guzmán Báez, Ana de; Rodríguez Quijano, M.


    Construction and Demolition (C&D) waste recycling is increasingly gaining stakeholders' attention as an strategy for contributing to sustainable construction. Although a multitude of materials are part of C&D waste, the recycling of certain fractions (i.e. metal or concrete) have a longer-established background, compared with others such as gypsum waste which is still commonly sent to landfill. Efforts are being made in order to promote gypsum recycling practices all over Europe, and the proc...

  1. Design of Cold-Formed Steel Screw Connections with Gypsum Sheathing at Ambient and Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Wei Chen


    Full Text Available Load-bearing cold-formed steel (CFS walls sheathed with double layers of gypsum plasterboard on both sides have demonstrated good fire resistance and attracted increasing interest for use in mid-rise CFS structures. As the main connection method, screw connections between CFS and gypsum sheathing play an important role in both the structural design and fire resistance of this wall system. However, studies on the mechanical behavior of screw connections with double-layer gypsum sheathing are still limited. In this study, 200 monotonic tests of screw connections with single- or double-layer gypsum sheathing at both ambient and elevated temperatures were conducted. The failure of screw connections with double-layer gypsum sheathing in shear was different from that of single-layer gypsum sheathing connections at ambient temperature, and it could be described as the breaking of the loaded sheathing edge combined with significant screw tilting and the loaded sheathing edge flexing fracture. However, the screw tilting and flexing fracture of the loaded sheathing edge gradually disappear at elevated temperatures. In addition, the influence of the loaded edge distance, double-layer sheathing and elevated temperatures is discussed in detail with clear conclusions. A unified design formula for the shear strength of screw connections with gypsum sheathing is proposed for ambient and elevated temperatures with adequate accuracy. A simplified load–displacement model with the post-peak branch is developed to evaluate the load–displacement response of screw connections with gypsum sheathing at ambient and elevated temperatures.

  2. Broiler Litter × Industrial By-Products Reduce Nutrients and Microbial Losses in Surface Runoff When Applied to Forages. (United States)

    Adeli, Ardeshir; Read, John J; Brooks, John P; Miles, Dana; Feng, Gary; Jenkins, Johnie N


    The inability to incorporate broiler litter (BL) into permanent hayfields and pastures leads to nutrient accumulation near the soil surface and increases the potential transport of nutrients in runoff. This study was conducted on Marietta silt loam soil to determine the effect of flue gas desulfurization (FGD) gypsum and lignite on P, N, C, and microbial concentrations in runoff. Treatments were (i) control (unfertilized) and (ii) BL at 13.4 Mg ha alone or (iii) treated with either FGD gypsum or lignite applied at 20% (w/w) (2.68 Mg ha). Rainfall simulators were used to produce a 5.6 cm h storm event sufficient in duration to cause 15 min of continuous runoff. Repeated rains were applied at 3-d intervals to determine how long FGD gypsum and lignite are effective in reducing loss of litter-derived N, P, and C from soil. Application of BL increased N, P, and C concentrations in runoff as compared to the control. Addition of FGD gypsum reduced ( 20%. Thus, BL treated with FGD and lignite can be considered as cost-effective management practices in the mitigation of P, N, and C and possibly microbial concentration in runoff. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Gypsum amendment to soil can reduce selenium uptake by alfalfa grown in the presence of coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, M.A.; Rubin, G.; Woodbury, P.B.; Weinstein, L.H. (Cornell University, Ithaca, NY (USA). Boyce Thompson Institute of Plant Research)


    Experiments in the field and greenhouse were conducted in the presence of coal fly ash to determine whether gypsum can reduce Se concentration in alfalfa (Medicago sativa L.). In the field experiment, conducted at a coal fly ash landfill, 11.2 t ha[sup -1] gypsum was applied to soil as a top dressing to test the effect of gypsum in reducing selenium (Se) concentration in aboveground plant tissue. There were four treatment combinations of gypsum over a two year period, 1990, and 1991: (0, 0), (0, 11.2) (11.2, 0) and (11.2, 11.2). In 1991, the Se concentration was lower in alfalfa grown with gypsum, regardless of whether the gypsum was applied in both years or in only one year, indicating that the effect of gypsum application in the first year persisted into the second year. Since there was no increase in aboveground biomass with added gypsum, differences in Se concentration reflect a competitive interaction between S and Se. In the greenhouse experiment, 12 soil treatments were tested: three levels of fly ash (0, 10 and 20%) in combination with each of four levels of gypsum (0, 2.5, 5 and 7.5%). The Se concentration in alfalfa grown in 10% fly ash declined linearly with increasing gypsum dose, resulting in a reduction in Se concentration of 0.04 [+-] 0.02 [mu]g g[sup -1] for each 1% gypsum added for the first harvest and 0.06 [+-] 0.03 [mu]g g[sup -1] for each 1% gypsum added in the second harvest. Based on these results, gypsum may prove useful as a management tool to reduce the uptake of Se by plants growing on coal fly ash landfills.

  4. Comparative evaluation of few physical properties of epoxy resin, resin-modified gypsum and conventional type IV gypsum die materials: an in vitro study. (United States)

    Gujjarlapudi, Manmohan Choudary; Reddy, S Varalakshmi; Madineni, Praveen Kumar; Ealla, Kranti Kiran Reddy; Nunna, Venkata Narayana; Manne, Sanjay Dutt


    To compare and evaluate few physical properties of epoxy resin, resin-modified gypsum and conventional type-IV gypsum die material. In the present study, dimensional accuracy, surface detail reproduction and transverse strength of three die materials like epoxy resin (Diemet-E), resin-modified gypsum (Synarock) and conventional type-IV gypsum (Ultrarock) are analyzed. For dimensional accuracy, master die (Bailey's die) is used and calibrations were made with digital microscope. For surface detail reproduction and transverse strength, rectangular stainless steel master die (Duke's die) was used and calibrations were made with Toolmaker's microscope and Instron universal testing machine respectively. One-way analysis of variance (ANOVA) was performed on the means and standard deviation for groups of each test. The results of the study showed statistically significant difference among these materials in dimensional accuracy, surface detail reproduction and transverse strength. Epoxy resin exhibited superiority in dimensional accuracy, surface detail reproduction and transverse strength and is nearest to the standards of accurate die material.

  5. Petrography of gypsum-bearing facies of the Codó Formation (Late Aptian, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Jackson D.S. Paz


    Full Text Available An original and detailed study focusing the petrography of evaporites from the Late Aptian deposits exposed in the eastern and southern São Luís-Grajaú Basin is presented herein, with the attempt of distinguishing between primary and secondary evaporites, and reconstructing their post-depositional evolution. Seven evaporites phases were recognized: 1. chevron gypsum; 2. nodular to lensoidal gypsum or anhydrite; 3. fibrous to acicular gypsum; 4. mosaic gypsum; 5. brecciated gypsum or gypsarenite; 6. pseudo-nodular anhydrite or gypsum; and 7. rosettes of gypsum. The three first phases of gypsum display petrographic characteristics that conform to a primary nature. The fibrous to acicular and mosaic gypsum were formed by replacement of primary gypsum, but their origin took place during the eodiagenesis, still under influence of the depositional setting. These gypsum morphologies are closely related to the laminated evaporites, serving to demonstrate that their formation was related to replacements that did not affect the primary sedimentary structures. The pseudo-nodular anhydrite or gypsum seems to have originated by mobilization of sulfate-rich fluids during burial, probably related to halokinesis. The rosettes of gypsum, which intercept all the other gypsum varieties, represent the latest phase of evaporite formation in the study area, resulting from either intrastratal waters or surface waters during weathering.Neste trabalho, é apresentado um estudo original e detalhado enfocando os aspectos petrográficos dos evaporitos de depósitos aptianos superiores expostos no sul e leste da Bacia de São Luís-Grajaú. O objetivo é o estabelecimento de critérios que permitam distinguir entre evaporitos primários e secundários, além da reconstrução de sua evolução pós-deposicional. Sete fases de evaporitos foram reconhecidas: 1. gipsita em chevron; 2. gipsita ou anidrita nodular a lenticular; 3. gipsita fibrosa a acicular; 4. gipsita em

  6. Soil composition and nutritional status of apple as affected by long-term application of gypsum

    Directory of Open Access Journals (Sweden)

    Gilberto Nava


    Full Text Available Gypsum does not affect the soil negative charges and maintains sulfate in the soil solution, making it one of the cheapest products to increase Ca activity in soil solution, especially in the deeper soil layers. Higher Ca levels in the soil solution can increase the uptake of this nutrient by apple trees, reducing the risk of physiological disorders caused by Ca deficiency. This study assessed the effect of long-term gypsum application on some soil properties and on the chemical composition of leaves and fruits of an apple cultivar susceptible to fruit disorders associated with low Ca. The experiment was conducted in São Joaquim, in the South of Brazil, from 2001 to 2009. Gypsum rates of 0, 1.0, 2.0 and 3.0 t ha-1 were annually broadcast over the soil surface, without incorporation, in an apple orchard with cultivar ´Catarina´, planted in 1997. Gypsum application over eight consecutive years had no effect on soil exchangeable K and Al to a depth of 80 cm, but increased exchangeable Ca in the sampled layers (0-10, 10-20, 40-60 and 60-80 cm, while exchangeable Mg decreased only in the surface layer (0-20 cm. Gypsum did not affect the concentration of any nutrient in the fruits, including Ca. The same was verified in the leaves, except for Mg which decreased with increased gypsum rate. Despite increasing the availability of Ca in the soil profile to a depth of 80 cm, gypsum was not effective to increase the Ca content in leaves and fruits of an apple cultivar susceptible to Ca deficiency grown in an appropriately limed soil.

  7. Desodification from calcareous saline sodic soil through phytoremediation with Phragmites australis (Cav.) Trin. ex Steud. and gypsum. (United States)

    Abro, Saeed Akhter; Otho, Aijaz Ali; Bughio, Farooque A; Sahito, Oan Mohammad; Jamali, Abdul Rauf; Mahar, Amanullah


    The reclamation of saline sodic soils requires sodium removal and the phytoremediation is one of the proven low-cost, low-risk technologies for reclaiming such soils. However, the role of P. australis in reclaiming saline sodic soil has not been evaluated extensively. The comparative reclaiming role of P. australis and gypsum was evaluated in a column experiment on a sandy clay saline sodic soil with ECe 74.7 dS m(-1), SAR 63.2, Na(+) 361 g kg(-1) and pH 8.46. The gypsum at 100% soil requirement, planting common reed (P. australis) alone, P. australis + gypsum at 50% soil gypsum requirements and leaching (control without plant and gypsum) were four treatments applied. After 11 weeks of incubation, the results showed that all treatments including control significantly reduced pH, EC, exchangeable Na(+) and SAR from the initial values but the control being with least results. The gypsum and P. australis + gypsum were highly effective in salinity (ECe) reduction while, sodicity (SAR) and Na(+) reductions were significantly higher in P. australis + gypsum treatment. The reclamation efficiency in terms of Na(+) (83.4%) and SAR (86.8%) reduction was highest in P. australis + gypsum. It is concluded that phytoremediation is an effective tool to reclaim saline sodic soil.

  8. Survey report of the projects: Characterization and management of waste water from desulfurization of flue gas by the wet absorption process with following oxidation. Biological removal of nitrogen from waste water from desulfurization of flue gas by the gypsum producing wet absorption process. Resumerapport for projekterne: Karakterisering og behandling af spildevand fra roeggasafsvovling ved vaadabsorptionsprocessen med efterfoelgende oxidation. Biologisk kvaelstoffjernelse fra spildevand fra roeggasafsvovling ved den gipsproducerende vaadabsorptionsproces

    Energy Technology Data Exchange (ETDEWEB)

    Holm Kristensen, G.; Jepsen, S.-E.; Mose Pedersen, B. (Vandkvalitetsinstituttet (DK)); Sund, C. (I. Krueger A/S (DK))


    Aspects of the treatment of waste water from the wet desulphurization process dealt with are: data evaluation of the waste water before and after treatment, estimation of possible effluent standards, the origin and fate of heavy metals in the desulphurization process, the description and evaluation of potential processes for reduction of heavy metals, laboratory experiments with the chemical precipitation of waste water from West German power plants, laboratory experiments with biological denitrification at high temperature and with high salt and nitrate concentration, the evaluation of the applicability of external carbon sources (methanol and acetate), and the technical/economical evaluation of process alternatives prepared in the light of the investigations mentioned above. It is claimed that sulphide precipitation is a highly effective method to remove heavy metals from waste water. It is recommended to add ferric chloride to remove possible excess of sulphide after the precipitation, thereby preventing formation of hydrogen sulphide. By hydroxide/sulphide precipitation a dissolved concentration of mercury on < 0.5 {mu}g/l and a concentration of cadmium on approximately 6 {mu}g/l was achieved. It was possible with acetate as carbon source to obtain biological denitrification even at a concentration of 30,000 mg chloride/l and a temperatue of 40 deg. C. At higher temperature the denitrification rate decreased and stopped at 50 deg. C. The cost of construction for a treatment plant for removal of hevy metals by chemical precipitation and biological removal of nitrate including a plant for production of gypsum is estimated to be in the order of 30 million and with annually operating costs of approximately 3.5 million (1989). (AB).

  9. The influence of surface and incorporated lime and gypsiferous by-products on surface and subsurface soil acidity. II. Root growth and agronomic implications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.L.; Hedley, M.J.; Bolan, N.S.; Horne, D.J. [New Zealand Forest Research Institute, Rotorua (New Zealand)


    Lucerne (Medicago sativa. L) root elongation in acid soils amended by gypsiferous coal combustion by-products was investigated in a glasshouse study. Lime, fluidised bed boiler ash (FBA), and flue gas desulfurisation gypsum (FGDG) were mixed into the surface 50 mm of either an Allophanic (the Patua sand loam) or an Ultic (the Kaawa clay loam) soil column, at rates containing calcium equivalent to 5000 kg/ha of CaCO{sub 3}. Lucerne was grown on each column after it was leached with 400 mm of water. Whereas the lime treatment had no effect on root elongation in the acidic subsurface of the Patua soil, the FBA and FGDG treatments significantly improved lucerne root penetration into the subsurface soil. This was due to the `self liming effect` induced by sulfate adsorption. In contrast, topsoil incorporated amendments did not influence root penetration into the acidic subsurface of the Kaawa soil, which is dominated by permanently charged clay minerals. The `self-liming erect` caused by gypsum application is not a sustainable practice. Lime should be applied to neutralise the topsoil acidity, when gypsum is used as subsurface soil acidity ameliorant. FBA, which contains both lime and gypsum, can meet these requirements.

  10. The use of soil gypsum concentration as an indicator of arable land degradation (United States)

    Robledo, Irene; Marqués Pérez, Maria Jose; Hernandez, Zulimar; Carral, Pilar; Crittenden, Stephen; Sastre, Blanca; Bienes, Ramón


    Gypsiferous soils are frequent in arid and semi-arid areas. These soils can be used for farming but shallow soils and steep slopes are detrimental to establishing their profitability. Tillage of sloping land increases risk of soil erosion processes that lead to diminished thickness of the richer topsoil layer. Topsoil loss exposes subsoil layers with higher gypsum concentration. This increased gypsum concentration can influence the potential biomass production and agricultural suitability of gypsiferous soils. In the literature, soils having more than 15% gypsum tend to have weak soil structure and inhibited root growth. Consequently, there is a need to diagnose these eroded soils and to develop a soil protection strategy for arable land if continued soil loss is to be abated and productivity is to be restored or maintained. Indicators to establish the level of degradation are needed, particularly ones that are easy to measure. We hypothesize that pale soil colours indicate proximity to soil conditions linked to high concentrations of gypsum that are detrimental to plant growth. Spain leads the list of European countries having gypsiferous soils, with an area of approximately 35 000 sq km covered. Gypsiferous soils analysed in this study are located at the centre of Spain, where average temperature is 16°C and soils receive around 400 mm of rainfall per year. Sampling was conducted in various areas of a sloping agricultural land with olive trees. Topsoil disturbed samples were randomly collected, in addition, six 70 cm deep soil core were collected. Two soil cores at the top, two in the middle, and two at the bottom slope areas were taken. Colour and gypsum concentration were analysed in the soil samples and also for sub-samples each 5 cm of the core samples. Gypsum was analysed by chemical and thermogravimetric methods. Other parameters like aggregate stability, electrical conductivity, water retention, and bulk density were also analysed. Gypsum concentration

  11. Gypsum-permineralized microfossils and their relevance to the search for life on Mars. (United States)

    Schopf, J William; Farmer, Jack D; Foster, Ian S; Kudryavtsev, Anatoliy B; Gallardo, Victor A; Espinoza, Carola


    Orbital and in situ analyses establish that aerially extensive deposits of evaporitic sulfates, including gypsum, are present on the surface of Mars. Although comparable gypsiferous sediments on Earth have been largely ignored by paleontologists, we here report the finding of diverse fossil microscopic organisms permineralized in bottom-nucleated gypsums of seven deposits: two from the Permian (∼260 Ma) of New Mexico, USA; one from the Miocene (∼6 Ma) of Italy; and four from Recent lacustrine and saltern deposits of Australia, Mexico, and Peru. In addition to presenting the first report of the widespread occurrence of microscopic fossils in bottom-nucleated primary gypsum, we show the striking morphological similarity of the majority of the benthic filamentous fossils of these units to the microorganisms of a modern sulfuretum biocoenose. Based on such similarity, in morphology as well as habitat, these findings suggest that anaerobic sulfur-metabolizing microbial assemblages have changed relatively little over hundreds of millions of years. Their discovery as fossilized components of the seven gypsiferous units reported suggests that primary bottom-nucleated gypsum represents a promising target in the search for evidence of past life on Mars. Key Words: Confocal laser scanning microscopy-Gypsum fossils-Mars sample return missions-Raman spectroscopy-Sample Analysis at Mars (SAM) instrument-Sulfuretum.

  12. Potential of a gypsum-free composting process of wheat straw for mushroom production (United States)

    Mouthier, Thibaut M. B.; Kilic, Baris; Vervoort, Pieter; Gruppen, Harry


    Wheat straw based composting generates a selective substrate for mushroom production. The first phase of this process requires 5 days, and a reduction in time is wished. Here, we aim at understanding the effect of gypsum on the duration of the first phase and the mechanism behind it. Hereto, the regular process with gypsum addition and the same process without gypsum were studied during a 5-day period. The compost quality was evaluated based on compost lignin composition analysed by py-GC/MS and its degradability by a commercial (hemi-)cellulolytic enzyme cocktail. The composting phase lead to the decrease of the pyrolysis products 4-vinylphenol and 4-vinylguaiacol that can be associated with p-coumarates and ferulates linking xylan and lignin. In the regular compost, the enzymatic conversion reached 32 and 39% for cellulose, and 23 and 32% for xylan after 3 and 5 days, respectively. In absence of gypsum similar values were reached after 2 and 4 days, respectively. Thus, our data show that in absence of gypsum the desired compost quality was reached 20% earlier compared to the control process. PMID:28982119

  13. Reactive-transport modelling of gypsum dissolution in a coastal karst aquifer in Puglia, southern Italy (United States)

    Campana, Claudia; Fidelibus, Maria Dolores


    The gypsum coastal aquifer of Lesina Marina (Puglia, southern Italy) has been affected by sinkhole formation in recent decades. Previous studies based on geomorphologic and hydrogeological data ascribed the onset of collapse phenomena to the erosion of material that fills palaeo-cavities (suffosion sinkholes). The change in the hydrodynamic conditions of groundwater induced by the excavation of a canal within the evaporite formation nearly 100 years ago was identified as the major factor in triggering the erosion, while the contribution of gypsum dissolution was considered negligible. A combined reactive-transport/density-dependent flow model was applied to the gypsum aquifer to evaluate whether gypsum dissolution rate is a dominant or insignificant factor in recent sinkhole formation under current hydrodynamic conditions. The conceptual model was first defined with a set of assumptions based on field and laboratory data along a two-dimensional transect of the aquifer, and then a density-dependent, tide-influenced flow model was set up and solved using the numerical code SEAWAT. Finally, the resulting transient flow field was used by the reactive multicomponent transport model PHT3D to estimate the gypsum dissolution rate. The validation tests show that the model accurately represents the real system, and the multi-disciplinary approach provides consistent information about the causes and evolution time of dissolution processes. The modelled porosity development rate is too low to represent a significant contribution to the recent sinkhole formation in the Lesina Marina area, although it justifies cavity formation and cavity position over geological time.

  14. The effects of disinfectants on dimensional accuracy and surface quality of impression materials and gypsum casts. (United States)

    Amin, Wala M; Al-Ali, Muna H; Al Tarawneh, Sandra K; Taha, Sahar Th; Saleh, Mohamed W; Ereifij, Nadia


    The study aimed to evaluating the effect of disinfecting impression materials on the dimensional accuracy and surface quality of the resulting casts. Impressions of a steel die constructed according to ANSI/ADA specification No.18 were made with each of alginate, addition cured silicone, condensation cured silicone and zinc oxide eugenol paste, and disinfected consequently by each of 0.2% chlorhexidine gluconate, 1% sodium hypochlorite, 2% gluteraldehyde for 5 minutes, and 0.5% sodium hypochlorite for 10 minutes. Dimensions of the disinfected impressions and their resultant casts were measured using a computerized digital caliper, and the dimensional changes were calculated. Reproduction of detail and surface quality of the resultant casts were assessed by grading casts surfaces according to a specific scoring system. The 0.5% sodium hypochlorite was found to produce the least dimensional changes in all the impression materials. Corsodyl produced the maximum changes in both alginate and zinc-oxide eugenol while addition-cured silicon was most affected by Gluteraldehyde and condensation-cured silicon was most affected by Hexana. The dimensional changes, however, were minimal and clinically insignificant. Addition-cured silicon showed the best surface quality and dimensional stability followed by condensation-cured silicon. Alginate and zinc-oxide eugenol had poorer surface quality and were affected to a higher extent by the disinfection procedures. The results were comparable with the standard specifications for dimensional stability. Recommendations were made for the use of 10 minutes immersion in 0.5% sodium hypochlorite as the most appropriate disinfection protocol to the investigated impression materials. Disinfectants; Gypsum casts; Impressions; Alginate; Addition-cured silicone; Sodium hypochlorite.

  15. Natural and human-induced sinkholes in gypsum terrain and associated environmental problems in NE Spain (United States)

    Benito, G.; Del Campo, P. Pérez; Gutiérrez-Elorza, M.; Sancho, C.


    The central Ebro Basin comprises thick evaporite materials whose high solubility produces typically karstic landforms. The sinkhole morphology developed in the overlying alluvium has been studied using gravimetry and ground-penetrating radar (GPR) on stream terraces, as well as analyzing the evolution of sinkhole morphologies observed in aerial photographs taken in 1928, 1957, and 1985. The sinkhole morphologies give some idea of possible subsurface processes as well as an indication of the final mechanisms involve in sinkhole development. On stream terraces and cover pediments the most commonly encountered dolines are bowl-shaped in their morphology with both diffuse and scarped edges. In contrast, dolines developed in the gypsiferous silt infilled valleys have a funnel and well-shaped morphology. The diffuse-edged bowl-shaped dolines are developed through the progressive subsidence of the alluvial cover, due to washing down of alluvial particles through small voids and cracks into deeper subsurface caves, resulting in a decrease alluvial density. Future compaction of the alluvial cover will produce surface subsidences. This type of dolines are associated with negative gravity anomalies. In contrast, the scarped-edge dolines are formed by the sudden collapse of a cavity roof. The cavities and cracks formed in the gypsum karst may migrate to the surface through the alluvial deposits by piping, and they may subsequently collapse. In this instance, the cavities can be detected by both gravity and GPR anomalies where the voids are not deeper than 4 5 m from the surface. These processes forming sinkholes can be enhanced by man-induced changes in the groundwater hydrologic regime by both inflows, due to irrigation, ditch losses, or pipe leakages, and by outflows from pumping activities.

  16. Effects of flue gas desulfurization and mined gypsums on soil properties and on hay and corn growth in eastern ohio. (United States)

    Kost, David; Chen, Liming; Guo, Xialou; Tian, Yongqiang; Ladwig, Ken; Dick, Warren A


    Gypsum (CaSO·2HO) is a quality source of Ca and S and has various beneficial uses that can improve agricultural production. This study was conducted to compare rates of flue gas desulfurization (FGD) gypsum and commercially available agricultural (i.e., mined) gypsum as soil amendments on soils typical of eastern Ohio or western Pennsylvania. Two field experiments were conducted, one involving a mixed grass hay field and the other corn ( L.). Gypsum was applied once at rates of 0.2, 2.0, and 20 Mg ha and a seventh treatment was a zero rate control. Corn grain yields response to gypsum was mixed with significant differences between low and high gypsum rates in 2010 but not between gypsum and no gypsum treatments. In the hay study, the low and intermediate gypsum rates generally did not result in any significant changes compared with the control treatment. At the high rate of 20 Mg ha, the following results were observed for the hay study: (i) both gypsums generally increased Ca, S, and soluble salts (electrical conductivity) in the topsoil and subsoil, when compared with the control; (ii) the FGD gypsum decreased Mg in soil when compared with all other treatments, and mined gypsum decreased Mg when compared with the control; and (iii) there were few effects on soil concentrations of trace elements, including Hg. Also at the high application rate, hay yield for the first cutting (May) in 2009 and 2010 was significantly less for mined and FGD gypsum compared with the control, but increased yields in subsequent cutting resulted in no significant treatment differences in total annual hay yield for 2008, 2009, or 2010 or cumulative yield for 2008 to 2010. Overall, for the hay study, the absence of significant soil chemical effects for the intermediate gypsum rate and the decrease in soil Mg concentrations for the high gypsum rate indicate that an application rate of approximately 2.0 Mg ha would be optimal for this soil. Copyright © by the American Society of Agronomy

  17. A DOC coagulant, gypsum treatment can simultaneously reduce As, Cd and Pb uptake by medicinal plants grown in contaminated soil. (United States)

    Kim, Hyuck Soo; Seo, Byoung-Hwan; Kuppusamy, Saranya; Lee, Yong Bok; Lee, Jae-Hwang; Yang, Jae-E; Owens, Gary; Kim, Kwon-Rae


    The efficiency of gypsum, as a dissolved organic carbon (DOC) coagulator, for the simultaneous immobilization of two heavy metals (Cd and Pb) and one metalloid (As) in agricultural soils near an abandoned mining site was examined. The agricultural soil was defined as long-term contaminated as As (1540mgkg-1), Cd (55mgkg-1) and Pb (1283mgkg-1) concentrations exceeded the Korean guideline values for As (25mgkg-1), Cd (4mgkg-1), and Pb (200mgkg-1). Gypsum was incorporated into the contaminated soil at 3% (w/w). In comparison two commonly using immobilizing agents (lime and compost), together with a mixture (lime+gypsum) were also included in the pot trial for the cultivation of two medical plants (A. gigas and A. macrocephala) and to evaluate the effectiveness of gypsum on As, Cd and Pb immobilization. The results showed that even though pH change-induced immobilizing agents such as lime were more effective than gypsum at immobilizing Cd and Pb, addition of gypsum also effectively reduced heavy metal phytoavailability as indicated by decreases in the concentration of Cd and Pb in medicinal plants. Furthermore, gypsum and gypsum+ lime were also most effective in reducing As concentrations in both plants studied. This was mainly attributed to significant decreases in soil DOC (48-64%) when gypsum and gypsum+lime were applied to the soil. Consequently, it was concluded that enhanced DOC coagulation with gypsum, could be considered as a promising technique for the immobilization of both metals (Cd and Pb) and metalloids (As) in agricultural soils. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Analysis of cubic and orthorhombic C3A hydration in presence of gypsum and lime

    KAUST Repository

    Kirchheim, A. P.


    Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime. The results demonstrate that important differences occur in the hydration of each C3A polymorph and gypsum when no lime is added; orthorhombic C3A reacts faster with gypsum than the cubic phase, forming longer ettringite needles; however, the presence of lime slows down the formation of ettringite in the orthorhombic sample. Additional rheometric tests showed the possible effects on the setting time in these cementitious mixes.

  19. Use of flue gas desulfurization gypsum for leaching Cd and Pb in reclaimed tidal flat soil. (United States)

    Yang, Ping; Li, Xian; Tong, Ze-Jun; Li, Qu-Sheng; He, Bao-Yan; Wang, Li-Li; Guo, Shi-Hong; Xu, Zhi-Min


    A soil column leaching experiment was conducted to eliminate heavy metals from reclaimed tidal flat soil. Flue gas desulfurization (FGD) gypsum was used for leaching. The highest removal rates of Cd and Pb in the upper soil layers (0-30 cm) were 52.7 and 30.5 %, respectively. Most of the exchangeable and carbonate-bound Cd and Pb were removed. The optimum FGD gypsum application rate was 7.05 kg·m(-2), and the optimum leaching water amount for the application was 217.74 L·m(-2). The application of FGD gypsum (two times) and the extension of the leaching interval time to 20 days increased the heavy metal removal rate in the upper soil layers. The heavy metals desorbed from the upper soil layers were re-adsorbed and fixed in the 30-70 cm soil layers.

  20. Dimensional accuracy and surface property of titanium casting using gypsum-bonded alumina investment. (United States)

    Yan, Min; Takahashi, Hidekazu; Nishimura, Fumio


    The aim of the present study was to evaluate the dimensional accuracy and surface property of titanium casting obtained using a gypsum-bonded alumina investment. The experimental gypsum-bonded alumina investment with 20 mass% gypsum content mixed with 2 mass% potassium sulfate was used for five cp titanium castings and three Cu-Zn alloy castings. The accuracy, surface roughness (Ra), and reaction layer thickness of these castings were investigated. The accuracy of the castings obtained from the experimental investment ranged from -0.04 to 0.23%, while surface roughness (Ra) ranged from 7.6 to 10.3microm. A reaction layer of about 150 microm thickness under the titanium casting surface was observed. These results suggested that the titanium casting obtained using the experimental investment was acceptable. Although the reaction layer was thin, surface roughness should be improved.

  1. Effect of shelf life on compressive strength of type iv gypsum (United States)

    Kusumastuti, K. S.; Irawan, B.; Damiyanti, M.


    Type IV gypsum, as a dental material for an indirect restoration’s working model, should have strength and abrasive-resistant properties. These properties depend on the product’s shelf life and its proper storage, which sometimes are easily missed by sellers. The aim of this research was to observe the effect of shelf life on the compressive strength of type IV gypsum with different production dates. Twenty cylindrical specimens were separated into two groups with different production dates and tested with a universal testing with the crosshead speed of 1 mm per minute and a load of 2,500 kgf. The data were analyzed with independent t-tests. There was a significant difference (p<0.05) in the compressive strength between the two groups with an increase in compressive strength seen in the gypsum that was stored longer.

  2. The effect of magnesium on partial sulphate removal from mine water as gypsum. (United States)

    Tolonen, Emma-Tuulia; Rämö, Jaakko; Lassi, Ulla


    The aim of this research was to investigate the effect of magnesium on the removal efficiency of sulphate as gypsum from mine water. The precipitation conditions were simulated with MINEQL + software and the simulation results were compared with the results from laboratory jar test experiments. Both the simulation and the laboratory results showed that magnesium in the mine water was maintaining sulphate in a soluble form as magnesium sulphate (MgSO4) at pH 9.6. Thus magnesium was preventing the removal of sulphate as gypsum (CaSO4·2H2O). However, change in the lime precipitation pH from 9.6 to 12.5 resulted in magnesium hydroxide (Mg(OH)2) precipitation and improved sulphate removal. Additionally, magnesium hydroxide could act as seed crystals for gypsum precipitation or co-precipitate sulphate further enhancing the removal of sulphate from mine water. Copyright © 2015 Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    CHUMAK Anastasia Gennadievna


    Full Text Available The aim of this work is to carry out a number of studies in the area of nanomodi­fication of gypsum binder matrix and to investigate the influence of multilayer carbon nanotubes on the structure, physical and mechanical properties of obtained compos­ites. The study of the gypsum binders structure formation mechanisms with the use of nanoadditives makes it possible to control the production processes of gypsum materi­als and articles with the given set of properties. The main tasks of the binder nanomodification are: even distribution of carbon nanostructures over the whole volume of material and provision of stability for the nanodimensional modifier during production process of the construction composite.

  4. By-products of palm oil extraction and refining

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    Tan Yew-Ai


    Full Text Available This paper outlines the utilisation of by-products resulting from the extraction and refining of palm oil. It summarises research by the Malaysian Palm Oil Board (MPOB directed at producing zero waste from the palm oil industry. MPOB regards by-products of the palm oil industry not as waste but resources. It will be evident that by-products from the palm oil industry can be and have been used extensively and that the research carried out is relevant to both the milling and refining sectors.

  5. Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility. (United States)

    Lehoux, Alizée P; Lockwood, Cindy L; Mayes, William M; Stewart, Douglas I; Mortimer, Robert J G; Gruiz, Katalin; Burke, Ian T


    Red mud is highly alkaline (pH 13), saline and can contain elevated concentrations of several potentially toxic elements (e.g. Al, As, Mo and V). Release of up to 1 million m(3) of bauxite residue (red mud) suspension from the Ajka repository, western Hungary, caused large-scale contamination of downstream rivers and floodplains. There is now concern about the potential leaching of toxic metal(loid)s from the red mud as some have enhanced solubility at high pH. This study investigated the impact of red mud addition to three different Hungarian soils with respect to trace element solubility and soil geochemistry. The effectiveness of gypsum amendment for the rehabilitation of red mud-contaminated soils was also examined. Red mud addition to soils caused a pH increase, proportional to red mud addition, of up to 4 pH units (e.g. pH 7 → 11). Increasing red mud addition also led to significant increases in salinity, dissolved organic carbon and aqueous trace element concentrations. However, the response was highly soil specific and one of the soils tested buffered pH to around pH 8.5 even with the highest red mud loading tested (33 % w/w); experiments using this soil also had much lower aqueous Al, As and V concentrations. Gypsum addition to soil/red mud mixtures, even at relatively low concentrations (1 % w/w), was sufficient to buffer experimental pH to 7.5-8.5. This effect was attributed to the reaction of Ca(2+) supplied by the gypsum with OH(-) and carbonate from the red mud to precipitate calcite. The lowered pH enhanced trace element sorption and largely inhibited the release of Al, As and V. Mo concentrations, however, were largely unaffected by gypsum induced pH buffering due to the greater solubility of Mo (as molybdate) at circumneutral pH. Gypsum addition also leads to significantly higher porewater salinities, and column experiments demonstrated that this increase in total dissolved solids persisted even after 25 pore volume replacements. Gypsum

  6. Experimental Shock Transformation of Gypsum to Anhydrite: A New Low Pressure Regime Shock Indicator (United States)

    Bell, Mary S.; Zolensky, Michael E.


    The shock behavior of gypsum is important in understanding the Cretaceous/Paleogene event and other terrestrial impacts that contain evaporite sediments in their targets (e.g., Mars Exploration Rover Spirit detected sulfate at Gusev crater, [1]). Most interest focuses on issues of devolatilization to quantify the production of SO2 to better understand its role in generating a temporary atmosphere and its effects on climate and biota [2,3]. Kondo and Ahrens [4] measured induced radiation emitted from single crystal gypsum shocked to 30 and 40 GPa. They observed greybody emission spectra corresponding to temperatures in the range of 3,000 to 4,000 K that are a factor of 2 to 10 times greater than calculated pressure-density energy equation of state temperatures (Hugoniot) and are high enough to melt gypsum. Chen et al. [5] reported results of shock experiments on anhydrite, gypsum, and mixtures of these phases with silica. Their observations indicated little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another report of shock experiments on calcite, anhydrite, and gypsum, Badjukov et al. [6] observed only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa but have not experimentally shocked gypsum in a step-wise manner to constrain possible incipient transformation effects. Schmitt and Hornemann [7] shock loaded anhydrite and quartz to a peak pressure of 60 GPa and report the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggested that recrystallization of anhydrite grains is the result of a solid-state transformation. They concluded that significant decomposition of anhydrite requires shock pressures higher than 60 GPa. Gupta et al. [8

  7. Gypsum and organic matter distribution in a mixed construction and demolition waste sorting process and their possible removal from outputs. (United States)

    Montero, A; Tojo, Y; Matsuo, T; Matsuto, T; Yamada, M; Asakura, H; Ono, Y


    With insufficient source separation, construction and demolition (C&D) waste becomes a mixed material that is difficult to recycle. Treatment of mixed C&D waste generates residue that contains gypsum and organic matter and poses a risk of H(2)S formation in landfills. Therefore, removing gypsum and organic matter from the residue is vital. This study investigated the distribution of gypsum and organic matter in a sorting process. Heavy liquid separation was used to determine the density ranges in which gypsum and organic matter were most concentrated. The fine residue that was separated before shredding accounted for 27.9% of the waste mass and contained the greatest quantity of gypsum; therefore, most of the gypsum (52.4%) was distributed in this fraction. When this fine fraction was subjected to heavy liquid separation, 93% of the gypsum was concentrated in the density range of 1.59-2.28, which contained 24% of the total waste mass. Therefore, removing this density range after segregating fine particles should reduce the amount of gypsum sent to landfills. Organic matter tends to float as density increases; nevertheless, separation at 1.0 density could be more efficient. (c) 2009 Elsevier B.V. All rights reserved.

  8. The effects of a K2SO4 solution on the surface hardness of gypsum type III (United States)

    Permana, B. N.; Triaminingsih, S.; Indrani, D. J.


    Gypsum type III is commonly used for working models and as a tool for restorations or dentures manufacturing in the laboratory. K2SO4 solution is recommended to be added to gypsum type III because it can accelerate the setting time. The aim of this study was to identify the effects of a K2SO4 solution on the surface hardness of gypsum type III. The surface hardness was tested using a Vickers Hardness Tester with a load of 500 gf. The results were analyzed using a one-way ANOVA. The surface hardness of gypsum type III manipulated using a 1.5% K2SO4 solution was higher than the surface hardness of gypsum type III manipulated without K2SO4 but lower than the surface hardness of gypsum type IV. Therefore, the use of a 1.5% K2SO4 solution can increase the hardness of gypsum type III but not enough to make it equivalent to the surface hardness of gypsum type IV.


    Energy Technology Data Exchange (ETDEWEB)

    Michael W. Grutzeck; Maria DiCola; Paul Brenner


    Flue gas desulphurization (FGD) materials are produced in abundant quantities by coal burning utilities. Due to environmental restrains, flue gases must be ''cleaned'' prior to release to the atmosphere. They are two general methods to ''scrub'' flue gas: wet and dry. The choice of scrubbing material is often defined by the type of coal being burned, i.e. its composition. Scrubbing is traditionally carried out using a slurry of calcium containing material (slaked lime or calcium carbonate) that is made to contact exiting flue gas as either a spay injected into the gas or in a bubble tower. The calcium combined with the SO{sub 2} in the gas to form insoluble precipitates. Some plants have been using dry injection of these same materials or their own Class C fly ash to scrub. In either case the end product contains primarily hannebachite (CaSO{sub 3} {center_dot} 1/2H{sub 2}O) with smaller amounts of gypsum (CaSO{sub 4} {center_dot} 2H{sub 2}O). These materials have little commercial use. Experiments were carried out that were meant to explore the feasibility of using blends of hannebachite and fly ash mixed with concentrated sodium hydroxide to make masonry products. The results suggest that some of these mixtures could be used in place of conventional Portland cement based products such as retaining wall bricks and pavers.

  10. Gypsum-carbonate speleothems from Cueva de las Espadas (Naica mine, Mexico: mineralogy and palaeohydrogeological implications

    Directory of Open Access Journals (Sweden)

    Martínez-Frías Jesús


    Full Text Available Some of the most outstanding hypogenic gypsum speleothems worldwide have been recently discovered in the Naica mines. The Cueva de las Espadas (Swords Cave, which lies at 120 m depth, hosts a rare type of speleothem called “espada” (“sword”. This study contributes to the understanding of the mineralogical composition of these singular speleothems, by means of their examination using micro-Raman spectroscopy, FT-IR spectroscopy and EDX microprobe. Our data revealed a complex mineralogy comprising a high-purity selenite core covered by several layers of calcite, aragonite and gypsum. Solid inclusions of polymetallic oxides (Mn-Pb-Zn and graphite were also detected. The position of the water table during the genesis of the “espada” speleothems (over the past 60 kyr was deduced from their mineralogy. Water level fluctuations at around -120 m depth led to environmental changes within the Cueva de las Espadas. The selenite core and gypsum layers were precipitated under biphasic (water-rock conditions when the cave was submerged under hydrothermal water. The aragonite precipitation required triphasic (air-water-rock conditions and occurred when the water table intercepted the cave, allowing the CO2 exchange necessary for carbonate precipitation. Solid inclusions were trapped in an aerobic environment when the gypsum-aragonite boundary condition occurred. A thin calcite layer was precipitated under vadose conditions after the water table definitively moved out of the cave.

  11. Morphology and stability of aggregates of an Oxisol according to tillage system and gypsum application

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    Fábio Régis de Souza


    Full Text Available Morphological characterization and aggregate stability is an important factor in evaluating management systems. The aim of this paper is to evaluate the stability and morphology of the aggregates of a dystrophic Oxisol managed with no-tillage and conventional tillage with and without the residual action of gypsum. The experimental design was randomized blocks arranged in split-split plot, where the treatments were two soil management systems (plots with 0 and 2000 kg ha-1 of gypsum (subplots and five depths (0-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20 and 0.20-0.30 m as the subsubplots, with four replications. The aggregate morphology was determined through images and later evaluated by the Quantporo software. Stability was determined by the wet method. The results showed that the no-tillage system, with or without gypsum residual effect, provided the aggregates with the largest geometric diameters. The combination of no-tillage system and the gypsum residual effect provided rougher aggregates.

  12. Composting and gypsum amendment of broiler litter to reduce nutrient leaching loss (United States)

    Relative to fresh broiler litter, little is known about the dynamics of composted litter derived-nutrient in the ecosystem. In this study, the potential leaching losses of nutrients from compost relative to fresh broiler litter along with flue gas desulfurization (FGD gypsum), as a nutrient immobil...

  13. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile (United States)

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  14. Responses to Environmental Stress in Plants Adapted to Mediterranean Gypsum Habitats

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    Josep V. LLINARES


    Full Text Available Gypsum areas are stressful environments inhabited by gypsophytes, plants that are exclusive for such habitats, and by plants that grow on gypsum but also on other soil types, the so-called gypsovags. To investigate possible differences between gypsovags and gypsophytes with respect to basic stress response mechanisms, two common osmolytes, glycine betaine and total soluble sugars, as well as monovalent (Na+ and K+ and bivalent (Ca2+ and Mg2+ cations, were quantified, under field conditions, in two Iberian endemic gypsophytes (Gypsophila struthium subsp. hispanica and Ononis tridentata and two common Mediterranean gypsovags (Rosmarinus officinalis and Helianthemum syriacum. Their spatial variation according to a topographic gradient and their temporal variation over a period of three successive seasons were correlated with climatic data and soil characteristics. This analysis confirmed that water stress is the main environmental stress factor in gypsum habitats, whereas the percentage of gypsum in the soil does not seem to play any relevant role in the activation of stress responses in plants. Glycine betaine may contribute to stress tolerance in the gypsophytes, but not in the gypsovags, according to the close correlation found between the level of this osmolyte and the gypsophily of the investigated taxa. Cation contents in the plants did not correlate with those present in the soil, but the gypsophytes have higher levels of Ca2+ and Mg2+ than the gypsovags, under all environmental conditions, which may represent an adaptation mechanism to their specific habitat.

  15. Gypsum plasterboards enhanced with phase change materials: A fire safety assessment using experimental and computational techniques

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    Kolaitis Dionysios I.


    Full Text Available Phase Change Materials (PCM can be used for thermal energy storage, aiming to enhance building energy efficiency. Recently, gypsum plasterboards with incorporated paraffin-based PCM blends have become commercially available. In the high temperature environment developed during a fire, the paraffins, which exhibit relatively low boiling points, may evaporate and, escaping through the gypsum plasterboard's porous structure, emerge to the fire region, where they may ignite, thus adversely affecting the fire resistance characteristics of the building. Aiming to assess the fire safety behaviour of such building materials, an extensive experimental and computational analysis is performed. The fire behaviour and the main thermo-physical physical properties of PCM-enhanced gypsum plasterboards are investigated, using a variety of standard tests and devices (Scanning Electron Microscopy, Thermo Gravimetric Analysis, Cone Calorimeter. The obtained results are used to develop a dedicated numerical model, which is implemented in a CFD code. CFD simulations are validated using measurements obtained in a cone calorimeter. In addition, the CFD code is used to simulate an ISO 9705 room exposed to fire conditions, demonstrating that PCM addition may indeed adversely affect the fire safety of a gypsum plasterboard clad building.

  16. The effects of gypsum on the transfer of phosphorus and other nutrients through clay soil monoliths

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    Risto Uusitalo


    Full Text Available We applied gypsum (CaSO4×2 H2O amendments to 100 m2 plots within two clay-textured fields, one under shallow cultivation to 10 cm depth and the other ploughed to 20 cm depth. Unamended plots and plots subjected to a CaCO3 (finely ground limestone application served as controls. Separate soil monoliths (30 cm in diameter, 40 cm in depth were collected for laboratory rainfall simulations from all plots 7, 19 and 31 months after the initial application of the amendments. Water passed through the monoliths during these simulations was analysed for turbidity, dissolved and particulate phosphorus (DRP and PP, nitrogen species, dissolved organic carbon (DOC, as well as dissolved Ca2+, Mg2+, K+ and S, pH, and electrical conductivity (EC. Over the three-year monitoring period, gypsum amended soils exhibited substantial decreases in turbidity (45%, PP (70%, DRP (50% and DOC (35% relative to control samples. The effects gradually decreased with time, and after 31 months gypsum effects on P species were detectible, but no longer statistically significant. We consider gypsum amendments as a potential tool for slowing P loss from agricultural areas with high P loss potential.

  17. Elaboration and characterization of dental plasters obtained from a Moroccan gypsum (United States)

    El Kanouni, M. A.; Aazzab, B.; Tricha, L.; Samdi, A.; Moussa, R.; Hamel, J.; Gomina, M.


    Three experimental batches of plaster elaborated from a Moroccan gypsum were characterized by conductimetry, dimensional variations measurements during setting and mechanical tests. Comparison with commercial dental plasters are undertaken to check whether these experimental materials possess good characteristics for dentistry applications.

  18. Seepage Analysis of Upper Gotvand Dam Concerning Gypsum Karstification (2D and 3D Approaches)

    DEFF Research Database (Denmark)

    Sadrekarimi, Jamshid; Kiyani, Majid; Fakhri, Behnam


    Upper Gotvand Dam is constructed on the Karun River at the south west of Iran. In this paper, 2D and 3D models of the dam together with the foundation and abutments were established, and several seepage analyses were carried out. Then, the gypsum veins that are scattered throughout the foundation...... ground were included in the models, and the seepage pattern, considering the dissolution law of gypsum, was analyzed. It was disclosed that the discharge fluxes obtained from 2D and 3D analyses are not similar, and the discharge flux in 3D model is about four times that of the 2D model. Also, the 3D....... In the current case, the rate of increase of discharge flux due to dissolution of gypsum veins was obtained to be a third-order function of the aperture width. In spite of the fact that the grout curtain is designed to be about 170 m deep, however, complete dissolve of gypsum will severely increase the discharge...

  19. Potential of a gypsum-free composting process of wheat straw for mushroom production

    NARCIS (Netherlands)

    Mouthier, Thibaut M.B.; Kilic, Baris; Vervoort, Pieter; Gruppen, Harry; Kabel, Mirjam A.


    Wheat straw based composting generates a selective substrate for mushroom production. The first phase of this process requires 5 days, and a reduction in time is wished. Here, we aim at understanding the effect of gypsum on the duration of the first phase and the mechanism behind it. Hereto, the

  20. Hydrogeological flow in gypsum karst areas: some examples from northern Italy and main circulation models

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    Bartolomeo Vigna


    Full Text Available A Messinian succession containing gypsum beds crops out in northern Italy, mainly in Piedmont and along the northern flank of the Apennine mountains in Emilia-Romagna. These gypsum bodies have been extensively quarried at the surface, in outcrops, and through underground quarries. In Emilia-Romagna these gypsum outcrops can be rather extensive, several km long and up to 1 km wide, while in Piedmont they are mostly covered by silty-marly deposits of Upper Messinian and Pliocene age and show only sparse and small outcrops. The underground quarrying of these evaporite bodies in Piedmont has allowed studying in detail their hydrogeology, and the ways in which water flows through these karst rocks. In contrast, in Emilia-Romagna the hydrogeology of these aquifers has been studied with traditional spring water monitoring and speleological methods. On the basis of the results it has been possible to define three conceptual models regarding the water circulation in these evaporites, similar to the models existing for carbonate aquifers. The models represent aquifers with decreasing vulnerability to pollution, from the more vulnerable system with dominant conduit drainage, characterizing most of the known gypsum aquifers, to those with interconnected conduit drainage and with dispersive circulation.

  1. Potential use of FGD gypsum for overcoming environmental problems in the Southeast (United States)

    Agricultural productivity is constrained by unfavorable soil, climate and management factors in the southeastern USA. Flue gas desulfurization gypsum (FGDG) has the potential for alleviating some of these problems but its effectiveness in southeastern environments needs to be established by addition...

  2. Gypsum as a best management practice for reducing P loss from agricultural fields (United States)

    Phosphorus loss from agricultural fields fertilized with poultry litter (PL) may contribute to eutrophication of nearby rivers, lakes, and streams. It has been suggested that gypsum can be used as a soil amendment to reduce P loss from these fields. Also, a new USDA-NRCS National Conservation Practi...

  3. Investigation on the Permeability Evolution of Gypsum Interlayer Under High Temperature and Triaxial Pressure (United States)

    Tao, Meng; Yechao, You; Jie, Chen; Yaoqing, Hu


    The permeability of the surrounding rock is a critical parameter for the designing and assessment of radioactive waste disposal repositories in the rock salt. Generally, in the locations that are chosen for radioactive waste storage, the bedded rock salt is a sedimentary rock that contains NaCl and Na2SO4. Most likely, there are also layers of gypsum ( {CaSO}_{ 4} \\cdot 2 {H}_{ 2} {O)} present in the salt deposit. Radioactive wastes emit a large amount of heat and hydrogen during the process of disposal, which may result in thermal damage of the surrounding rocks and cause a great change in their permeability and tightness. Therefore, it is necessary to investigate the permeability evolution of the gypsum interlayer under high temperature and high pressure in order to evaluate the tightness and security of the nuclear waste repositories in bedded rock salt. In this study, a self-designed rock triaxial testing system by which high temperature and pressure can be applied is used; the μCT225kVFCB micro-CT system is also employed to investigate the permeability and microstructure of gypsum specimens under a constant hydrostatic pressure of 25 MPa, an increasing temperature (ranging from 20 to 650 °C), and a variable inlet gas pressure (1, 2, 4, 6 MPa). The experimental results show: (a) the maximum permeability measured during the whole experiment is less than 10-17 m2, which indicates that the gypsum interlayer has low permeability under high temperature and pressure that meet the requirements for radioactive waste repository. (b) Under the same temperature, the permeability of the gypsum specimen decreases at the beginning and then increases as the pore pressure elevates. When the inlet gas pressure is between 0 and 2 MPa, the Klinkenberg effect is very pronounced. Then, as the pore pressure increases, the movement behavior of gas molecules gradually changes from free motion to forced directional motion. So the role of free movement of gas molecules gradually

  4. Composting and gypsum amendment of broiler litter to reduce nutrient leaching loss. (United States)

    Adeli, Ardeshir; Sheng, J; Jenkins, J N; Feng, G


    The effect of composted litter relative to fresh litter on leaching losses of nutrients has not been well documented. Fresh and composted broiler litter was surface-applied to bermudagrass (hay) [ (L.) Pers.] established in undisturbed soil columns based on N need of the grass in the presence or absence of flue gas desulfurization (FGD) gypsum to evaluate an approach to reduce broiler litter nutrient leaching potential. Columns were periodically leached and biomass was harvested during the 60-d experiment. Total N applied to bermudagrass from broiler litter was 320 kg ha. Gypsum was mixed with fresh and composted litter at the rate based on 20% of litter weight. For composted broiler litter, NO-N, P, K, Cu, and Zn contents in the leachate obtained from the first leaching event were 58, 50, 40, 32, and 38% less than fresh broiler litter, respectively. Significant decreases in NO-N (13%), P (53%), Cu (17%), and Zn (28%) in leachate were obtained when gypsum was mixed with fresh broiler litter. Fresh broiler litter and composted broiler litter applications increased bermudagrass growth compared with the control and gypsum significantly increased yields when mixed with broiler litter. Composted broiler litter application significantly increased N and organic C in the soil compared with fresh litter. Results demonstrate that coapplication of composted broiler litter with FGD gypsum provide the most effective management option for minimizing leaching losses of nutrients while sustaining crop productivity. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.


    Directory of Open Access Journals (Sweden)



    Full Text Available Summary. Problem statement. In the next 10 years, more than 90% of materials will be replaced with new materials – nanocomposites [1]. The nanocomponents application will allow manufacture of high-strength materials with reduced production cost and will ensure demand for products [2]. Researches aimed to determination of carbon nanotube type nanomodifier concentration impact on the physical and mechanical properties of gypsum binders are important today and must result in creation of competitive strong nano-materials. Purpose. Research of carbon nanotube (CNT type nanomodifier concentration impact on the physical and mechanical properties of gypsum binders. Conclusion. Sample microstructure analysis revealed that the non-modified gypsum sample structure is dominated by prismatic and lamellar crystals randomly distributed throughout the matrix volume. In this case, loose structure with increased porosity is formed, which results in sample mechanical strength reduction. In the CNT-modified gypsum matrix, well-ordered and homogeneous structure is formed with larger needle-shaped crystals, which results in the phase-contacting area increase, porosity reduction and thus the physical and mechanical characteristics improvement. It is experimentally proved that at the identical nano-modifier content in the gypsum matrix (0.035 %, maximum compression strength gain is achieved with the use of CNT and makes 28- 30%. At the use of initial carbon nanotubes, increase in strength at the same nano-modifier content makes 13-15%. The Ca2+ ions interaction with the graphene-like carbon surface was investigated by the DFT method. Capability is demonstrated of the covalent calcium bonding with the hexagonal carbon surface cell as a result of overlap of Ca2+ valence 3p orbitals and carbon 2р orbitals.

  6. Characterization of mudejar mortars from St. Gil Abbot church (Zaragoza, Spain: Investigation of the manufacturing technology of ancient gypsum mortars

    Directory of Open Access Journals (Sweden)

    Igea, J.


    Full Text Available This work has been focused on the investigation of the technological procedure of Mudejar mortars applied to the characterization of a group of unaltered samples from an example church of Mudejar architecture of Aragon. The research was carried out using multi-analytical techniques including petrographic study, chemistry and mineralogical analysis. All mortars present a homogeneous composition. The binder is made up of a mixture of gypsum and a very low proportion of lime, while the main components of the aggregate are gypsum and carbonate rock fragments, both in a different thermal state of decomposition. The results have proved that both, binder and aggregates display the same composition in these mortars. These aggregates are the by-product of a grinding process of the previously burnt raw materials which have had a positive influence on the properties of the mortars in improving their quality.

    Este trabajo se ha centrado en la investigación de la tecnología de fabricación de morteros mudéjares mediante la caracterización de un conjunto de muestras inalteradas procedentes de una iglesia representativa de la arquitectura Mudéjar aragonesa. La investigación se llevó a cabo mediante el uso combinado de técnicas analíticas incluyendo el estudio petrográfico y el análisis químico y mineralógico. Todos los morteros presentan una composición constante formada por una mezcla de yeso y cal, en muy baja proporción, como ligante, mientras que el árido está formado por fragmentos de rocas yesíferas y carbonatadas en distinto estado de descomposición térmica. Los resultados confirman que en la fabricación de los morteros, ligante y áridos presentan la misma composición, siendo éstos últimos el subproducto de la misma materia prima calcinada, incorporados para elaborar el mortero, tras un proceso de molienda. Esta característica ha influido positivamente en las propiedades de los morteros, mejorando su calidad.

  7. Soil fertility, nutrition and yield of maize and barley with gypsum application on soil surface in no-till

    Directory of Open Access Journals (Sweden)

    Leandro Michalovicz


    Full Text Available Annual crop yield and nutrition have shown differentiated responses to modifications in soil chemical properties brought about by gypsum application. The aim of this study was to evaluate the effect of gypsum application rates on the chemical properties of a Latossolo Bruno (Clayey Oxisol, as well as on the nutrition and yield of a maize-barley succession under no-till. The experiment was set up in November 2009 in Guarapuava, Parana, Brazil, applying gypsum rates of 0.0, 1.5, 3.0, 4.5, and 6.0 Mg ha-1 to the soil surface upon sowing maize, with crop succession of barley. Gypsum application decreased the levels of Al3+ and Mg2+ in the 0.0-0.1 m layer and increased soil pH in the layers from 0.2-0.6 m depth. Gypsum application has increased the levels of Ca2+ in all soil layers up to 0.6 m, and the levels of S-SO4(2- up to 0.8 m. In both crops, the leaf concentrations of Ca and S were increased while Mg concentrations have decreased as a function of gypsum rates. There was also an effect of gypsum rates on grain yield, with a quadratic response of maize and a linear increase for barley. Yield increases were up to 11 and 12 % in relation to control for the maximum technical efficiency (MTE rates of 3.8 and 6.0 Mg ha-1 of gypsum, respectively. Gypsum application improved soil fertility in the profile, especially in the subsurface, as well as plant nutrition, increasing the yields of maize and barley.

  8. Examination of the possibilities of the application of waste materials (gypsum, fly ash and bottom ash in construction

    Directory of Open Access Journals (Sweden)

    Trifunović Prvoslav


    Full Text Available The possibilities of the application of waste gypsum (citrogypsum, nitrogyosum and sulphogypsum, fly ash and bottom ash in construction: for production of gypsum binders (a-calcium sulphate hemihydrate, b-calcium sulphata hemihydrate and b-anhydrite, for obtaining construction products (bricks and blocks and as component materials for road layers were presented in this work. Also, the possibilities of the application of sulphogypsum (or FGD gypsum for solidification and stabilization of fly ash were presented. The obtained results could have great importance in both ecological and economic views (elimination of important pollutants of water, air and soil, replacement of natural by waste materials, reduction of waste disposal cost.

  9. Effect of amino acids on the precipitation kinetics and Ca isotopic composition of gypsum (United States)

    Harouaka, Khadouja; Kubicki, James D.; Fantle, Matthew S.


    Stirred gypsum (CaSO4 · 2H2O) precipitation experiments (initial Ωgypsum = 2.4 ± 0.14, duration ≈ 1.0-1.5 h) were conducted in the presence of the amino acids glycine (190 μM), L-alanine (190 μM), D- and L-arginine (45 μM), and L-tyrosine (200 μM) to investigate the effect of simple organic compounds on both the precipitation kinetics and Ca isotopic composition of gypsum. Relative to abiotic controls, glycine, tyrosine, and alanine inhibited precipitation rates by ∼22%, 27%, and 29%, respectively, while L- and D-arginine accelerated crystal growth by ∼8% and 48%, respectively. With the exception of tyrosine, amino acid induced inhibition resulted in fractionation factors (αs-f) associated with precipitation that were no more than 0.3‰ lower than amino acid-free controls. In contrast, the tyrosine and D- and L-arginine experiments had αs-f values associated with precipitation that were similar to the controls. Our experimental results indicate that Ca isotopic fractionation associated with gypsum precipitation is impacted by growth inhibition in the presence of amino acids. Specifically, we propose that the surface-specific binding of amino acids to gypsum can change the equilibrium fractionation factor of the bulk mineral. We investigate the hypothesis that amino acids can influence the growth of gypsum at specific crystal faces via adsorption and that different faces have distinct fractionation factors (αface-fluid). Accordingly, preferential sorption of amino acids at particular faces changes the relative, face-specific mass fluxes of Ca during growth, which influences the bulk isotopic composition of the mineral. Density functional theory (DFT) calculations suggest that the energetic favorability of glycine sorption onto gypsum crystal faces occurs in the order: (1 1 0) > (0 1 0) > (1 2 0) > (0 1 1), while glycine sorption onto the (-1 1 1) face was found to be energetically unfavorable. Face-specific fractionation factors constrained by

  10. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 3, Product development of gypsum, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kevin [Dravo Technology Center, Pittsburgh, PA (United States); Beeghly, Joel H. [Dravo Technology Center, Pittsburgh, PA (United States)


    In the way of background information about 30 electric utility units with a combined total of 15,000 MW utilize magnesium enhanced lime flue gas desulfurization (FGD) systems. The first generation process begun in 1973, called the Thiosorbic® Process, was a technical breakthrough that offered significantly improved operating and performance characteristics compared with competing FGD technologies. The process is described as Flow Diagram "A" in Figure 1. A disadvantage of this and other inhibited or natural oxidation wet FGD systems is the capital and operating cost associated with landfill disposal of the calcium sulfite based solids. Fixation to stabilize the sludge solids for compunction in a landfill also consumes fly ash that otherwise may be marketable.

  11. EXAFS speciation and phytoavailability of Pb in a contaminated soil amended with compost and gypsum. (United States)

    Hashimoto, Yohey; Yamaguchi, Noriko; Takaoka, Masaki; Shiota, Kenji


    Due to unregulated uses of lead pellets for hunting purposes in Japan, soils and sediments in some river basins and wetlands have become highly contaminated with Pb. Deterioration of natural vegetation has occurred sporadically in these areas, and therefore revegetation is needed for ecological restoration. The objectives of the present study were to assess the effects of surface applications of compost and gypsum amendments on Pb availability to a watercress plant (Nasturtium officinale W.T. Aiton) and molecular-scale speciation of Pb in soil solid phases. The compost and gypsum amendments significantly decreased dissolved Pb and Sb in pore water. The concentration of Pb in aboveground plant tissues was 190mg kg(-1) in the control soil and was reduced to <20mg kg(-1) in the compost and gypsum-amended soils. The concentration of Sb in plants grown in the control soil was 13mg kg(-1), whereas that in the soils receiving compost and gypsum decreased below detectable levels. Redox potential was higher in vegetated soils (ave. 349mV) than in the unvegetated soils (ave. 99mV) due to oxygen introduced by plant roots. Extended X-ray absorption fine structure (EXAFS) spectroscopy illustrated that Pb occurred as Pb sorbed on birnessite and/or ferrihydrite (Pb-Mn/Fe, ~60%) and Pb sorbed on organic matter (Pb-org, ~15%), and galena (PbS, ~10%) in the vegetated and unvegetated control soils. The compost amendment increased the proportion of Pb-org by 2-fold than in the control soils. The amended soils with plant growth decreased the proportion of Pb-Mn/Fe phases by half of that without plant growth. Galena and anglesite (PbSO(4)) were not detected in compost-amended soils and even in gypsum-amended soils since a significant soil reduction to anoxic levels did not occur in the entire soil. The present study indicated that, under flooded conditions, surface applications of compost and gypsum amendments reduced plant Pb uptake from the Pb contaminated soil. Crown Copyright

  12. Authigenic Gypsum in Gas-Hydrate Associated Sediments from the East Coast of India (Bay of Bengal)

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.

    Authigenic gypsum crystals, along with pyrite and carbonate mineralization, predominantly calcites were noticed in distinct intervals in a 32 m long piston core, collected in the gas hydrate-bearing sediments in the northern portion of the Krishna...

  13. Inflammatory potential of low doses of airborne fungi from fungal infested damp and dry gypsum boards

    DEFF Research Database (Denmark)

    Knudsen, Sofie Marie; Gunnarsen, Lars Bo; Madsen, Anne Mette


    This study has investigated the total inflammatory potential (TIP) of low concentration fungal samples from moisture-damaged and fungal infested gypsum boards. The fungal aerosols were generated from damp and dried surfaces, and sampled using filter sampling and liquid impingement. The TIP...... association was found between concentration of fungi and the TIP of the samples. This is likely due to the J-shaped dose response curve. The aerosol samples from the dried gypsum boards had a significantly higher TIP compared to aerosols from the damp surfaces. However, the J-shaped dose-response curve...... weakens the conclusion on the influence of surfaces dampness, sampling time, fungal species or sampling methods. It could, however, be concluded that samples from both damp and dry surfaces induce inflammation in the HL60 cells, despite the low concentration of fungi. Thus, a dried fungal infestation...

  14. Perimbangan Gypsum Bonded Investment terhadap Penysutan Logam Paduan Emas pada Saat Pengecoran


    Ronnie Rusli


    Gypsum bonded investment is usually used for dental gold alloys casting procedure. Casting alloys shrink during solidified from melting temperature to room temperature. In order to obtain an accurate restoration, the shrinkage of the alloy should be compensated by the expansion of the investment at the time of casting procedure. Ideally, the shrinkage of the alloy is equal to the expansion of the investment. However, no investment material fulfills this ideal condition properly. In this paper...

  15. Application of reject of gypsum from Trindade/PE in ceramic masses formulations; Aplicacao de residuos de gipsita em formulacoes de massas ceramicas

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thalles Confessor de; Souza, Marcondes Mendes de; Almeida, Ana Beatriz Dantas de; Farias, Debora Santos Umbelino de; Nobrega, Luiz Felipe Pereira de Medeiros, E-mail: [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio Grande do Norte (IFRN), Mossoro, RN (Brazil); Mendes, Luciana Bezerra [Fundacao de Apoio a Pesquisa do Rio Grande do Norte (FAPERN), Natal RN (Brazil)


    The mining industry is a major producer of waste is to be harmful to the environment besides not being made possible for use in producing means, since the product of economic interest has been extracted. In order to reduce this problem, this work shows the characterization of the waste generated by gypsum mining in Trindade/PE in the ceramic coating. The residue was collected, ground and sieved to #200, then was chemically characterized by XRF analysis process, to evaluate its potential to be incorporated into the formulation of ceramic material, the material studied can be used in porcelain tile formulation as a flux element for that were obtained in the laboratory ceramic bodies adding the residue then were performed physical testing of linear shrinkage, water absorption and flexural breaking strain technically order to evaluate the addition of this residue ceramic coating. (author)

  16. Mercury transportation in soil via using gypsum from flue gas desulfurization unit in coal-fired power plant. (United States)

    Wang, Kelin; Orndorff, William; Cao, Yan; Pan, Weiping


    The mercury flux in soils was investigated, which were amended by gypsums from flue gas desulphurization (FGD) units of coal-fired power plants. Studies have been carried out in confined greenhouses using FGD gypsum treated soils. Major research focus is uptakes of mercury by plants, and emission of mercury into the atmosphere under varying application rates of FGD gypsum, simulating rainfall irrigations, soils, and plants types. Higher FGD gypsum application rates generally led to higher mercury concentrations in the soils, the increased mercury emissions into the atmosphere, and the increased mercury contents in plants (especially in roots and leaves). Soil properties and plant species can play important roles in mercury transports. Some plants, such as tall fescue, were able to prevent mercury from atmospheric emission and infiltration in the soil. Mercury concentration in the stem of plants was found to be increased and then leveled off upon increasing FGD gypsum application. However, mercury in roots and leaves was generally increased upon increasing FGD gypsum application rates. Some mercury was likely absorbed by leaves of plants from emitted mercury in the atmosphere.

  17. Implications of moisture content determination in the environmental characterisation of FGD gypsum for its disposal in landfills. (United States)

    Alvarez-Ayuso, E; Querol, X; Tomás, A


    The leachable contents of elements of environmental concern considered in the Council Decision 2003/33/EC on waste disposal were determined in flue gas desulphurisation (FGD) gypsum. To this end, leaching tests were performed following the standard EN-12457-4 which specifies the determination of the dry mass of the material at 105 degrees C and the use of a liquid to solid (L/S) ratio of 10l kg(-1) dry matter. Additionally, leaching tests were also carried out taking into account the dry mass of the material at 60 degrees C and using different L/S ratios (2, 5, 8, 10, 15 and 20l kg(-1) dry matter). It was found that the dry mass determination at 105 degrees C turns out to be inappropriate for FGD gypsum since at this temperature gypsum transforms into bassanite, and so, in addition to moisture content, crystalline water is removed. As a consequence the moisture content is overvalued (about 16%), what makes consider a lower L/S ratio than that specified by the standard EN-12457-4. As a result the leachable contents in FGD gypsum are, in general, overestimated, what could lead to more strict environmental requirements for FGD gypsum when considering its disposal in landfills, specially concerning those elements (e.g., F) risking the characterisation of FGD gypsum as a waste acceptable at landfills for non-hazardous wastes.

  18. Mechanical properties of simulated Mars materials: gypsum-rich sandstones and lapilli tuff (United States)

    Morrow, Carolyn; Lockner, David; Okubo, Chris


    Observations by the Mars Exploration Rover (MER) Opportunity, and other recent studies on diagenesis in the extensive equatorial layered deposits on Mars, suggest that the likely lithologies of these deposits are gypsum-rich sandstones and tuffaceous sediments (for example, Murchie and others, 2009; Squyres and others, 2012; Zimbelman and Scheidt, 2012). Of particular interest is how the diagenesis history of these sediments (degree of cementation and composition) influences the strength and brittle behavior of the material. For instance, fractures are more common in lower porosity materials under strain, whereas deformation bands, characterized by distributed strain throughout a broader discontinuity in a material, are common in higher porosity sedimentary materials. Such discontinuities can either enhance or restrict fluid flow; hence, failure mode plays an important role in determining the mechanics of fluid migration through sediments (Antonellini and Aydin, 1994; 1995; Taylor and Pollard, 2000; Ogilvie and Glover, 2001). As part of a larger study to characterize processes of fault-controlled fluid flow in volcaniclastic and gypsum-rich sediments on Mars, we have completed a series of laboratory experiments to focus on how gypsum clast content and degree of authigenic cementation affects the strength behavior of simulated Mars rocks. Both axial deformation and hydrostatic pressure tests were done at room temperature under dry conditions.

  19. Histological Comparison in Rats between Carbonate Apatite Fabricated from Gypsum and Sintered Hydroxyapatite on Bone Remodeling

    Directory of Open Access Journals (Sweden)

    Yasunori Ayukawa


    Full Text Available Carbonate apatite (CO3Ap, the form of apatite found in bone, has recently attracted attention. The purpose of the present study was to histologically evaluate the tissue/cellular response toward the low-crystalline CO3Ap fabricated using a dissolution-precipitation reaction with set gypsum as a precursor. When set gypsum was immersed in a 100°C 1 mol/L Na3PO4 aqueous solution for 24 h, the set gypsum transformed into CO3Ap. Both CO3Ap and sintered hydroxyapatite (s-HAp, which was used as a control, were implanted into surgically created tibial bone defects of rats for histological evaluation. Two and 4 weeks after the implantation, histological sections were created and observed using light microscopy. The CO3Ap granules revealed both direct apposition of the bone matrix by osteoblasts and osteoclastic resorption. In contrast, the s-HAp granules maintained their contour even after 4 weeks following implantation which implied that there was a lack of replacement into the bone. The s-HAp granules were sometimes encapsulated with fibrous tissue, and macrophage polykaryon was occasionally observed directly apposed to the implanted granules. From the viewpoint of bone remodeling, the CO3Ap granules mimicked the bone matrix, suggesting that CO3Ap may be an appropriate bone substitute.

  20. Modelling of Fluidised Geomaterials: The Case of the Aberfan and the Gypsum Tailings Impoundment Flowslides

    Directory of Open Access Journals (Sweden)

    Paola Dutto


    Full Text Available The choice of a pure cohesive or a pure frictional viscoplastic model to represent the rheological behaviour of a flowslide is of paramount importance in order to obtain accurate results for real cases. The principal goal of the present work is to clarify the influence of the type of viscous model—pure cohesive versus pure frictional—with the numerical reproduction of two different real flowslides that occurred in 1966: the Aberfan flowslide and the Gypsum tailings impoundment flowslide. In the present work, a depth-integrated model based on the v - p w Biot–Zienkiewicz formulation, enhanced with a diffusion-like equation to account for the pore pressure evolution within the soil mass, is applied to both 1966 cases. For the Aberfan flowslide, a frictional viscous model based on Perzyna viscoplasticity is considered, while a pure cohesive viscous model (Bingham model is considered for the case of the Gypsum flowslide. The numerical approach followed is the SPH method, which has been enriched by adding a 1D finite difference grid to each SPH node in order to improve the description of the pore water evolution in the propagating mixture. The results obtained by the performed simulations are in agreement with the documentation obtained through the UK National Archive (Aberfan flowslide and the International Commission of large Dams (Gypsum flowslide.

  1. Developing biodiversity indicators on a stakeholders' opinions basis: the gypsum industry Key Performance Indicators framework. (United States)

    Pitz, Carline; Mahy, Grégory; Vermeulen, Cédric; Marlet, Christine; Séleck, Maxime


    This study aims to establish a common Key Performance Indicators (KPIs) framework for reporting about the gypsum industry biodiversity at the European level. In order to integrate different opinions and to reach a consensus framework, an original participatory process approach has been developed among different stakeholder groups: Eurogypsum, European and regional authorities, university scientists, consulting offices, European and regional associations for the conservation of nature, and the extractive industry. The strategy is developed around four main steps: (1) building of a maximum set of indicators to be submitted to stakeholders based on the literature (Focus Group method); (2) evaluating the consensus about indicators through a policy Delphi survey aiming at the prioritization of indicator classes using the Analytic Hierarchy Process method (AHP) and of individual indicators; (3) testing acceptability and feasibility through analysis of Environmental Impact Assessments (EIAs) and visits to three European quarries; (4) Eurogypsum final decision and communication. The resulting framework contains a set of 11 indicators considered the most suitable for all the stakeholders. Our KPIs respond to European legislation and strategies for biodiversity. The framework aims at improving sustainability in quarries and at helping to manage biodiversity as well as to allow the creation of coherent reporting systems. The final goal is to allow for the definition of the actual biodiversity status of gypsum quarries and allow for enhancing it. The framework is adaptable to the local context of each gypsum quarry.

  2. Do Ca2+-adsorbing ceramics reduce the release of calcium ions from gypsum-based biomaterials? (United States)

    Belcarz, Anna; Zalewska, Justyna; Pałka, Krzysztof; Hajnos, Mieczysław; Ginalska, Grazyna


    Bone implantable materials based on calcium sulfate dihydrate dissolve quickly in tissue liquids and release calcium ions at very high levels. This phenomenon induces temporary toxicity for osteoblasts, may cause local inflammation and delay the healing process. Reduction in the calcium ion release rate by gypsum could be therefore beneficial for the healing of gypsum-filled bone defects. The aim of this study concerned the potential use of calcium phosphate ceramics of various porosities for the reduction of high Ca(2+) ion release from gypsum-based materials. Highly porous ceramics failed to reduce the level of Ca(2+) ions released to the medium in a continuous flow system. However, it succeeded to shorten the period of high calcium level. It was not the phase composition but the high porosity of ceramics that was found crucial for both the shortening of the Ca(2+) release-related toxicity period and intensification of apatite deposition on the composite. Nonporous ceramics was completely ineffective for this purpose and did not show any ability to absorb calcium ions at a significant level. Moreover, according to our observations, complex studies imitating in vivo systems, rather than standard tests, are essential for the proper evaluation of implantable biomaterials. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Major element, trace element, nutrient, and radionuclide mobility in a mining by-product-amended soil. (United States)

    Douglas, G; Adeney, J; Johnston, K; Wendling, L; Coleman, S


    This study investigates the use of a mineral processing by-product, neutralized used acid (NUA), primarily composed of gypsum and Fe-oxyhydroxide, as a soil amendment. A 1489-d turf farm field trial assessed nutrient, trace element, and radionuclide mobility of a soil amended with ∼5% by mass to a depth of 15 cm of NUA. Average PO-P fluxes collected as subsoil leachates were 0.7 and 26.6 kg ha yr for NUA-amended and control sites, respectively, equating to a 97% reduction in PO-P loss after 434 kg P ha was applied. Total nitrogen fluxes in NUA-amended soil leachates were similarly reduced by 82%. Incorporation of NUA conferred major changes in leachate geochemistry with a diverse suite of trace elements depleted within NUA-amended leachates. Gypsum dissolution from NUA resulted in an increase from under- to oversaturation of the soil leachates for a range of Fe- and Ca-minerals including calcite and ferrihydrite, many of which have a well-documented ability to assimilate PO-P and trace elements. Isotopic analysis indicated little Pb addition from NUA. Both Sr and Nd isotope results revealed that NUA and added fertilizer became an important source of Ca to leachate and turf biomass. The NUA-amended soils retained a range of U-Th series radionuclides, with little evidence of transfer to soil leachate or turf biomass. Calculated radioactivity dose rates indicate only a small increment due to NUA amendment. With increased nutrient, trace element, and solute retention, and increased productivity, a range of potential agronomic benefits may be conferred by NUA amendment of soils, in addition to the potential to limit offsite nutrient loss and eutrophication. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. The gypsophyte Gypsophila struthium as nurse plant for vegetation recovery in degraded gypsum substrates (United States)

    María Foronda, Ana; Pueyo, Yolanda; Castillejo, José Miguel; Alados, Conceción L.


    Degraded areas such as quarries or dumps are devoid of vegetation where the spontaneous vegetation recovery is a very slow process that requires restoration actions, especially under harsh environmental conditions such as arid conditions and special substrates. Specifically, gypsum substrates have physical and chemical limitations such as surface crusts, poor water availability or high concentrations of SO4 and Ca. Some plants, the so called gypsophytes, are adapted to tolerate such limitations and thus, might be able to establish in gypsum bare soils. Thus, well adapted gypsophytes might play an important role in vegetation recovery by acting as ecosystem engineers, improving the environmental conditions under their canopy and facilitating the establishment of other species. Facilitation is being recently considered as a key process in restoration practices because it might enhance restoration effectiveness by favoring the plant establishment and therefore, plant succession. The aim of this study was to test the effectiveness of a gypsophyte (Gypsophila struthium) in facilitating the establishment and development of other species and thus in vegetation recovery of degraded gypsum substrates. To address this objective, a sowing and planting experiment was set in November 2014 in a gypsum dump located in Andorra municipality (Teruel, NE Spain). Forty well-established adults of G. struthium previously planted in that dump were employed as nurse plants in the experiment. Two species were used as test species in the experiment: Helianthemum squamatum (gypsophyte) and Stipa lagascae (non-gypsophyte). Seeds and seedlings of those test species were sowed and planted in two different microsites: under the canopy and in the surrounding bare soil of each G. struthium individual (n=80 per test species). Germination, survival and growth of test species were surveyed twice a year during two years. Soil compaction and soil temperature were seasonally measured at both microsites

  5. Laboratory Salinization of Brazilian Alluvial Soils and the Spectral Effects of Gypsum

    Directory of Open Access Journals (Sweden)

    Luis Clenio J. Moreira


    Full Text Available Irrigation-induced salinization is an important land degradation process that affects crop yield in the Brazilian semi-arid region, and gypsum has been used as a corrective measure for saline soils. Fluvent soil samples (180 were treated with increasing levels of salinization of NaCl, MgCl2 and CaCl2. The salinity was gauged using electrical conductivity (EC. Gypsum was added to one split of these samples before they were treated by the saline solutions. Laboratory reflectance spectra were measured at nadir under a controlled environment using a FieldSpec spectrometer, a 250-W halogen lamp and a Spectralon panel. Variations in spectral reflectance and brightness were evaluated using principal component analysis, as well as the continuum-removed absorption depths of major features at 1450, 1950, 1750 and 2200 nm for both the gypsum-treated (TG and non-treated (NTG air-dried soil samples as a function of EC. Pearson’s correlation coefficients of reflectance and the band depth with EC were also obtained to establish the relationships with salinity. Results showed that NTG samples presented a decrease in reflectance and brightness with increasing CaCl2 and MgCl2 salinization. The reverse was observed for NaCl. Gypsum increased the spectral reflectance of the soil. The best negative correlations between reflectance and EC were observed in the 1500–2400 nm range for CaCl2 and MgCl2, probably because these wavelengths are most affected by water absorption, as Ca and Mg are much more hygroscopic than Na. These decreased after chemical treatment with gypsum. The most prominent features were observed at 1450, 1950 and 1750 nm in salinized-soil spectra. The 2200-nm clay mineral absorption band depth was inversely correlated with salt concentration. From these features, only the 1750 and 2200 nm ones are within atmospheric absorption windows and can be more easily measured using hyperspectral sensors.

  6. Reforestation and landscape reconstruction in gypsum mine area from the semiarid region of NE Brazil (United States)

    Bittar, S. M. B.; Straaten, P. V.; de Araujo Vieura Santos, M. de Fatima; Agra Bezerra da Silva, Y. J.; da Silva, M.; Saraiva de Melo Pinheiro, T.; Gusmao Didier de Moraes, F.; de Aguiar Accioly, A. M.; Alves de Santana, S. R.; dos Santos, H. A.; de Carvalho, D. M.; de Lima Ferreira, G.; de Carvalho Santos, C.


    In the Araripe region, Northeast Brazil, exist the world's second largest reserve of gypsum, estimated at over than one billion tons, which accounts for 95% of the Brazilian production and constitutes an important segment of the regional economy. The gypsum deposit occurs in the Lower Cretaceous Santana Formation of the Araripe basin, which is constituted by siltstones, marls, limestones, shales and gypsum layers. The ore extraction is from an open pit, on simple benches with a height of about 15 meters. Activities in mining operations involve stripping, drilling, loading explosives, blast, fragmentation and block loading / transport. Currently, gypsum mining and processing results in major changes in the landscape (pits and wastes heaps sedimentary rocks and soil mixture), deforestation of the "caatinga" ecosystem for use as firewood in small calcinations, dust pollution and changes in hydrology. To promote environmental remediation of this area, a multidisciplinary research has being done with the aim to support reforestation at the wastes heaps. The study involved the following activities: collection and physical, chemical and mineralogical characterization of mine waste materials; a floristic survey around the mines (botanical identification and measuring physical parameters in 16 plots, in order to identify which species are best suited to the conditions of the substrate at the mine site); an experiment (randomized block design) developed in a greenhouse, where seedlings of various native tree species were grown in a "constructed soil" made up of gypsum waste combined with chicken, goat and cattle manure, aimed to select tree species and soil treatment to be used in a waste heap; and an assessment of water quality for irrigation of the reforestation areas. The waste materials consist of large clayey aggregates, which may present physical/chemical properties unfavorable for plant development. The mineralogy of the sand fraction (> 85% quartz, gypsum and

  7. Anaerobic digestion of slaughterhouse by-products

    Energy Technology Data Exchange (ETDEWEB)

    Hejnfelt, Anette; Angelidaki, Irini [Department of Environmental Engineering, Technical University of Denmark, DTU, Building 113, DK-2800 Kgs. Lyngby (Denmark)


    Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 C and for some experiments also at 37 C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone flour, fat, blood, hair, meat, ribs, raw waste were: 225, 497, 487, 561, 582, 575, 359, 619 dm{sup 3} kg{sup -1} respectively, corresponding to 50-100% of the calculated theoretical methane potential. Dilution of the by-products had a positive effect on the specific methane yield with the highest dilutions giving the best results. High concentrations of long-chain fatty acids and ammonia in the by-products were found to inhibit the biogas process at concentrations higher than 5 g lipids dm{sup -3} and 7 g N dm{sup -3} respectively. Pretreatment (pasteurization: 70 C, sterilization: 133 C), and alkali hydrolysis (NaOH) had no effect on achieved methane yields. Mesophilic digestion was more stable than thermophilic digestion, and higher methane yield was noticed at high waste concentrations. The lower yield at thermophilic temperature and high waste concentration was due to ammonia inhibition. Co-digestion of 5% pork by-products mixed with pig manure at 37 C showed 40% higher methane production compared to digestion of manure alone. (author)

  8. Contaminant mobility and carbon sequestration downstream of the Ajka (Hungary) red mud spill: The effects of gypsum dosing. (United States)

    Renforth, P; Mayes, W M; Jarvis, A P; Burke, I T; Manning, D A C; Gruiz, K


    A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite processing residue that occurred in Ajka, western Hungary in October, 2010. These centred on acid and gypsum dosing to reduce pH and minimise mobility of oxyanion contaminants mobile at high pH. This study assessed the effectiveness of gypsum dosing on contaminant mobility and carbon sequestration through assessment of red mud and gypsum-affected fluvial sediments via elemental analysis and stable isotope analysis. There was a modest uptake of contaminants (notably As, Cr, and Mn) on secondary carbonate-dominated deposits in reaches subjected to gypsum dosing. C and O stable isotope ratios of carbonate precipitates formed as a result of gypsum dosing were used to quantify the importance of the neutralisation process in sequestering atmospheric carbon dioxide. This process was particularly pronounced at sites most affected by gypsum addition, where up to 36% of carbonate-C appears to be derived from atmospheric in-gassing of CO(2). The site is discussed as a large scale analogue for potential remedial approaches and carbon sequestration technologies that could be applied to red mud slurries and other hyperalkaline wastes. The results of this work have substantial implications for the aluminium production industry in which 3-4% of the direct CO(2) emissions may be offset by carbonate precipitation. Furthermore, carbonation by gypsum addition may be important for contaminant remediation, also providing a physical stabilisation strategy for the numerous historic stockpiles of red mud. Copyright © 2012 Elsevier B.V. All rights reserved.


    Directory of Open Access Journals (Sweden)

    Lilianna Bartoszek


    Full Text Available The paper presents a research covering the stability of phosphorus retention in the bottom sediments, resulting from application of gypsum in anoxic conditions and in slightly acidic environment (pH~5 of solutions. The present work also contains an analysis of possible effects of gypsum application for water from the reservoir, on the basis of selected parameters of overlying water. Undisturbed deposit cores extracted from two research stations on the Solina Reservoir have been a subject to a 10-weeks long exposure in determinate conditions, after application of gypsum. The conducted research indicated that retention capacities of deposits, which become increased after the use of gypsum, will decrease over time (e.g. after winter period. Application of gypsum led to a quite significant increase in concentrations of calcium in solutions. Intense release of iron from the sediments into the solutions and decrease in SO42- content, during the said 10-week exposure in anoxic conditions, indicates the use of iron (III and sulphates as electron acceptors in process of oxidization of an organic substance.

  10. Analysis of the Relationship between Density and Mechanical Strength of Lightened Gypsums: Proposal for a Coefficient of Lightening

    Directory of Open Access Journals (Sweden)

    Jaime Santa Cruz Astorqui


    Full Text Available This article develops a relationship between the reduction of density in lightened gypsum and the addition of expanded and/or extruded polystyrene waste from the construction sector and their mechanical behavior. The equations determined in this study allow us to know the flexural and compressive strengths of a lightened gypsum/plaster compound once its density is known. The results show that there is an exponential relationship between the density of the compound and its strength. The methodology followed included a compilation of the results obtained in previous research works on lightweight gypsums, analyzing the relationship between density and mechanical strength and comparing them with the equations developed in this research. The results obtained by previous researchers have a good adjustment with the proposed models, and only perlite compounds present greater deviations in the compressive strength analysis. Also, a dimensionless lightening coefficient is defined which can help to determine the best application for a lightweight gypsum compound, comparing it with an ideal lightweight gypsum.

  11. GyPSuM: A Detailed Tomographic Model of Mantle Density and Seismic Wave Speeds

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, N A; Forte, A M; Boschi, L; Grand, S P


    GyPSuM is a tomographic model fo mantle seismic shear wave (S) speeds, compressional wave (P) speeds and detailed density anomalies that drive mantle flow. the model is developed through simultaneous inversion of seismic body wave travel times (P and S) and geodynamic observations while considering realistic mineral physics parameters linking the relative behavior of mantle properties (wave speeds and density). Geodynamic observations include the (up to degree 16) global free-air gravity field, divergence of the tectonic plates, dynamic topography of the free surface, and the flow-induced excess ellipticity of the core-mantle boundary. GyPSuM is built with the philosophy that heterogeneity that most closely resembles thermal variations is the simplest possible solution. Models of the density field from Earth's free oscillations have provided great insight into the density configuration of the mantle; but are limited to very long-wavelength solutions. Alternatively, simply scaling higher resolution seismic images to density anomalies generates density fields that do not satisfy geodynamic observations. The current study provides detailed density structures in the mantle while directly satisfying geodynamic observations through a joint seismic-geodynamic inversion process. Notable density field observations include high-density piles at the base of the superplume structures, supporting the fundamental results of past normal mode studies. However, these features are more localized and lower amplitude than past studies would suggest. When we consider all seismic anomalies in GyPSuM, we find that P and S-wave speeds are strongly correlated throughout the mantle. However, correlations between the high-velocity S zones in the deep mantle ({approx} 2000 km depth) and corresponding P-wave anomalies are very low suggesting a systematic divergence from simplified thermal effects in ancient subducted slab anomalies. Nevertheless, they argue that temperature variations are

  12. Perimbangan Gypsum Bonded Investment terhadap Penysutan Logam Paduan Emas pada Saat Pengecoran

    Directory of Open Access Journals (Sweden)

    Ronnie Rusli


    Full Text Available Gypsum bonded investment is usually used for dental gold alloys casting procedure. Casting alloys shrink during solidified from melting temperature to room temperature. In order to obtain an accurate restoration, the shrinkage of the alloy should be compensated by the expansion of the investment at the time of casting procedure. Ideally, the shrinkage of the alloy is equal to the expansion of the investment. However, no investment material fulfills this ideal condition properly. In this paper, how the investment material compensated the shrinkage of the casting alloys will be described briefly.

  13. Testing antimicrobial cleaner efficacy on gypsum wallboard contaminated with Stachybotrys chartarum. (United States)

    Menetrez, Marc Y; Foarde, Karin K; Webber, Tricia D; Dean, Timothy R; Betancourt, Doris A


    Reducing occupant exposure to indoor mold is the goal of this research, through the efficacy testing of antimicrobial cleaners. Often mold contaminated building materials are not properly removed, but instead surface cleaners are applied in an attempt to alleviate the problem. The efficacy of antimicrobial cleaners to remove, eliminate or control mold growth on surfaces can easily be tested on non-porous surfaces. However, the testing of antimicrobial cleaner efficacy on porous surfaces, such as those found in the indoor environment such as gypsum board can be more complicated and prone to incorrect conclusions regarding residual organisms. The mold Stachybotrys chartarum has been found to be associated with idiopathic pulmonary hemorrhage in infants and has been studied for toxin production and its occurrence in water damaged buildings. Growth of S. chartarum on building materials such as gypsum wallboard has been frequently documented. Research to control S. chartarum growth using 13 separate antimicrobial cleaners on contaminated gypsum wallboard has been performed in laboratory testing. Popular brands of cleaning products were tested by following directions printed on the product packaging. A variety of gypsum wallboard surfaces were used to test these cleaning products at high relative humidity. The results indicate differences in antimicrobial efficacy for the six month period of testing. Results for the six types of GWB surfaces varied extensively. However, three cleaning products exhibited significantly better results than others. Lysol All-Purpose Cleaner-Orange Breeze (full strength) demonstrated results which ranked among the best in five of the six surfaces tested. Both Borax and Orange Glo Multipurpose Degreaser demonstrated results which ranked among the best in four of the six surfaces tested. The best antimicrobial cleaner to choose is often dependent on the type of surface to be cleaned of S. chartarum contamination. For Plain GWB, no paint, the

  14. Physical and mechanical characterization of gypsum boards containing phase change materials for latent heat storage

    Directory of Open Access Journals (Sweden)

    Oliver-Ramírez, A.


    Full Text Available This article describes the design and manufacture of a gypsum board which, despite its 45 % wt content of phase change materials, meets the minimum physical and mechanical requirements laid down in the legislation on gypsum plasters (Spanish and European standard UNE EN 13279 and Spanish specifications for gypsum acceptance, RY 85. Under this design, a one-metre square, 1.5-cm thick board contains 4.75 kg of PCM, much more than in any prior drylining (the maximum attained to date is 3 kg per m2. The mechanical and physical characteristics of this new composite were previously improved with two joint-action additives: polypropylene fibres and melamine formaldehyde as a dispersing agent. In the 20-30 ºC temperature range, a gypsum board 1.5 cm thick containing this percentage of PCMs can store five times more thermal energy than conventional plasterboard of the same thickness, and the same amount of energy as half-foot hollow brick masonry.

    En esta investigación se ha diseñado y fabricado un panel de escayola que incorpora un 45% en peso de material de cambio de fase, manteniendo las propiedades físicas y mecánicas exigidas en la normativa de aplicación para yesos de construcción (UNE EN 13279 y referencias a la RY 85. Así, un panel de 1,0 m2 y 1,5 cm de espesor, contiene 4,75 kg de PCM, cantidad muy superior a la conseguida hasta la fecha (3 kg/m2. Para ello se ha mejorado previamente sus prestaciones mecánicas y físicas mediante adiciones binarias: fibras de polipropileno y dispersión de melanina formaldehído. Este porcentaje es capaz de almacenar en 1,5 cm de espesor cinco veces la energía térmica de un panel de cartón yeso con el mismo espesor y la misma cantidad que una fábrica de 1/2 pie de ladrillo hueco, en el rango de temperaturas próximas a la de confort (20-30 ºC.

  15. Constraints from sulfur isotopes on the origin of gypsum at concrete/claystone interfaces (United States)

    Lerouge, Catherine; Claret, Francis; Tournassat, Christophe; Grangeon, Sylvain; Gaboreau, Stéphane; Boyer, Bernard; Borschnek, Daniel; Linard, Yannick

    Two in situ concrete/claystone interfaces were sampled at the laboratory level in the Andra Meuse/Haute Marne (France) Underground Research Laboratory (URL) in order to study five years of interactions between Callovian-Oxfordian (COx) claystone and two cementitious materials (concrete bottom slab and shotcrete on the walls of the main gallery), with a specific focus on sulfur. Combined mineralogical, chemical and sulfur isotopic investigations were carried out to define the degree of the perturbation of the sulfur system in the claystone and in both the cementitious materials. At both interfaces, results show that the main perturbation on the claystone side is the formation of scarce μm-sized gypsum, the sulfur content of which is essentially derived from pyrite oxidation. The distribution of gypsum is highly correlated with the fissure network of the damaged zone due to excavation of the gallery. Its presence is also often associated with a loss of cohesion of the concrete/claystone interface. Due to the small amounts of gypsum and its μm-size, measurements were performed by ion microprobe. Adaptations were needed on account of the reactivity of gypsum and sulfates in general under the beam. The use of ion microprobe analysis provided evidence of high local isotopic heterogeneity that could be attributed to kinetic fractionation effects. Some analyses suggest a minor contribution of dissolved sulfates in pore water of claystone and possibly of concrete. The perturbation on the concrete side is marked by a significant increase in the bulk sulfur content within three millimeters of the interface with the claystone, showing a sulfur gradient from claystone to concrete. The main objective of this work was to define the extent of the chemical and mineralogical perturbations, taking into account in situ URL conditions, i.e. hydrodynamic conditions (shotcrete sprayed on the gallery walls and subjected to ventilation of the galleries), damaged zone of claystone induced

  16. Kinetics of gypsum crystal growth from high ionic strength solutions: A case study of Dead Sea - seawater mixtures (United States)

    Reznik, Itay J.; Gavrieli, Ittai; Antler, Gilad; Ganor, Jiwchar


    Gypsum precipitation kinetics were examined from a wide range of chemical compositions (11Bosbach and Rammensee, 1994). Under further-away-from-equilibrium conditions, the reaction is dominated by an apparent 10th order reaction. A conceptual model for gypsum growth kinetics is presented. The model is based on the 2nd order kinetic coefficients determined in the present study and data from the literature and is valid under a wide range of ionic strengths and Ca/SO42- ratios. According to this model, the integration of SO42- to kinks on the surface of the growing crystals is the rate-limiting step in the precipitation reaction. At ionic strengths above 8.5 m the precipitation rate of gypsum is enhanced, possibly due to the formation of CaSO4° ion pairs and/or a decrease in hydration frequencies.

  17. Land application uses for dry FGD by-products

    Energy Technology Data Exchange (ETDEWEB)

    Bigham, J.; Dick, W.; Forster, L.; Hitzhusen, F.; McCoy, E.; Stehouwer, R.; Traina, S.; Wolfe, W. (Ohio State Univ., Columbus, OH (United States)); Haefner, R. (Geological Survey, Columbus, OH (United States). Water Resources Div.)


    The 1990 amendments to the Clean Air Act have spurred the development of flue gas desulfurization (FGD) processes, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. Presently FGD by-product materials are treated as solid wastes and must be landfilled. However, landfill sites are becoming more scarce and tipping fees are constantly increasing. It is, therefore, highly desirable to find beneficial reuses for these materials provided the environmental impacts are minimal and socially acceptable. Phase 1 results of a 4 and 1/2 year study to demonstrate large volume beneficial uses of FGD by-products are reported. The purpose of the Phase 1 portion of the project was to characterize the chemical, physical, mineralogical and engineering properties of the FGD by-product materials obtained from various FGD technologies being developed in the state of Ohio. Phase 1 also involved the collection of baseline economic data related to the beneficial reuse of these FGD materials. A total of 58 samples were collected and analyzed. In summary Phase 1 results revealed that FGD by-product materials are essentially coal fly ash materials diluted with unreacted sorbent and reaction products. High volume beneficial reuses will depend on the economics of their substituting for existing materials for various types of applications (e.g. as an agricultural liming material, soil borrow for highway embankment construction, and reclamation of active and abandoned surface coal mines). Environmental constraints to the beneficial reuse of dry FGD byproduct materials, based on laboratory and leachate studies, seem to be less than for coal fly ash.

  18. Biogeochemical oxidation of calcium sulfite hemihydrate to gypsum in flue gas desulfurization byproduct using sulfur-oxidizing bacteria. (United States)

    Graves, Duane; Smith, Jacques J; Chen, Linxi; Kreinberg, Allison; Wallace, Brianna; White, Robby


    Flue gas desulfurization (FGD) is a well-established air treatment technology for coal and oil combustion gases that commonly uses lime or pulverized limestone aqueous slurries to precipitate sulfur dioxide (SO2) as crystalline calcium salts. Under forced oxidation (excess oxygen) conditions, FGD byproduct contains almost entirely (>92%) gypsum (CaSO4·2H2O), a useful and marketable commodity. In contrast, FGD byproduct formed in oxygen deficient oxidation systems contains a high percentage of hannebachite (CaSO3·0.5H2O) to yield a material with no commercial value, poor dewatering characteristics, and that is typically disposed in landfills. Hannebachite in FGD byproduct can be chemically converted to gypsum; however, the conditions that support rapid formation of gypsum require large quantities of acids or oxidizers. This work describes a novel, patent pending application of microbial physiology where a natural consortium of sulfur-oxidizing bacteria (SOB) was used to convert hannebachite-enriched FGD byproduct into a commercially valuable, gypsum-enriched product (US Patent Assignment 503373611). To optimize the conversion of hannebachite into gypsum, physiological studies on the SOB were performed to define their growth characteristics. The SOB were found to be aerobic, mesophilic, neutrophilic, and dependent on a ready supply of ammonia. They were capable of converting hannebachite to gypsum at a rate of approximately five percent per day when the culture was applied to a 20 percent FGD byproduct slurry and SOB growth medium. 16S rDNA sequencing revealed that the SOB consortium contained a variety of different bacterial genera including both SOB and sulfate-reducing bacteria. Halothiobacillus, Thiovirga and Thiomonas were the dominant sulfur-oxidizing genera. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Research on Crack Formation in Gypsum Partitions with Doorway by Means of FEM and Fracture Mechanics (United States)

    Kania, Tomasz; Stawiski, Bohdan


    Cracking damage in non-loadbearing internal partition walls is a serious problem that frequently occurs in new buildings within the short term after putting them into service or even before completion of construction. Damage in partition walls is sometimes so great that they cannot be accepted by their occupiers. This problem was illustrated by the example of damage in a gypsum partition wall with doorway attributed to deflection of the slabs beneath and above it. In searching for the deflection which causes damage in masonry walls, fracture mechanics applied to the Finite Element Method (FEM) have been used. For a description of gypsum behaviour, the smeared cracking material model has been selected, where stresses are transferred across the narrowly opened crack until its width reaches the ultimate value. Cracks in the Finite Element models overlapped the real damage observed in the buildings. In order to avoid cracks under the deflection of large floor slabs, the model of a wall with reinforcement in the doorstep zone and a 40 mm thick elastic junction between the partition and ceiling has been analysed.

  20. A Method for Optimizing Lightweight-Gypsum Design Based on Sequential Measurements of Physical Parameters

    Directory of Open Access Journals (Sweden)

    Vimmrová Alena


    Full Text Available A method for lightweight-gypsum material design using waste stone dust as the foaming agent is described. The main objective is to reach several physical properties which are inversely related in a certain way. Therefore, a linear optimization method is applied to handle this task systematically. The optimization process is based on sequential measurement of physical properties. The results are subsequently point-awarded according to a complex point criterion and new composition is proposed. After 17 trials the final mixture is obtained, having the bulk density equal to (586 ± 19 kg/m3 and compressive strength (1.10 ± 0.07 MPa. According to a detailed comparative analysis with reference gypsum, the newly developed material can be used as excellent thermally insulating interior plaster with the thermal conductivity of (0.082 ± 0.005 W/(m·K. In addition, its practical application can bring substantial economic and environmental benefits as the material contains 25 % of waste stone dust.

  1. Biological denitrification of waste water from wet lime-gypsum flue gas desulphurization plants

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, G.H.; Jepsen, S.E. (Water Quality Institute, Hoersholm (Denmark))


    Waste water from flue gas desulphurization by the wet lime-gypsum process is characterized by high contents of nitrate (150-300 mg/l N) and chloride (10-30 g/l cl) and high temperature (40-50{degree}C). Continuous and batch experiments with biological denitrification were performed with suspended cultures in lab-scale reactors fed with synthetic waste water with chloride concentrations up to 30 g/l Cl. Process temperatures in the range of 30-50{degree}C were investigated. Acetate was added as carbon source. The results of the experiments show that biological denitrification was feasible at the extreme environmental conditions prevailing in wet lime-gypsum flue gas desulphurization waste water. Stable continuous denitrification was performed at chloride concentrations up to 30 g/1 and at temperatures up to 45{degree}C. A temperature optimum of 40{degree}C was found for nitrate removal. At 50{degree}C the denitrification had ceased in the reactors. In batch experiments an increased tendency to intermediate nitrite accumulation at increased temperatures and increased chloride levels was observed. This indicates that efforts should be made to equal out load variations in high chloride and high temperature biological denitrification in order to avoid periodical nitrite accumulation. 14 refs., 8 figs., 3 tabs.

  2. In situ nanoscale observations of gypsum dissolution by digital holographic microscopy. (United States)

    Feng, Pan; Brand, Alexander S; Chen, Lei; Bullard, Jeffrey W


    Recent topography measurements of gypsum dissolution have not reported the absolute dissolution rates, but instead focus on the rates of formation and growth of etch pits. In this study, the in situ absolute retreat rates of gypsum (010) cleavage surfaces at etch pits, at cleavage steps, and at apparently defect-free portions of the surface are measured in flowing water by reflection digital holographic microscopy. Observations made on randomly sampled fields of view on seven different cleavage surfaces reveal a range of local dissolution rates, the local rate being determined by the topographical features at which material is removed. Four characteristic types of topographical activity are observed: 1) smooth regions, free of etch pits or other noticeable defects, where dissolution rates are relatively low; 2) shallow, wide etch pits bounded by faceted walls which grow gradually at rates somewhat greater than in smooth regions; 3) narrow, deep etch pits which form and grow throughout the observation period at rates that exceed those at the shallow etch pits; and 4) relatively few, submicrometer cleavage steps which move in a wave-like manner and yield local dissolution fluxes that are about five times greater than at etch pits. Molar dissolution rates at all topographical features except submicrometer steps can be aggregated into a continuous, mildly bimodal distribution with a mean of 3.0 µmolm(-2) s(-1) and a standard deviation of 0.7 µmolm(-2) s(-1).

  3. Influence of Curing Humidity on the Compressive Strength of Gypsum-Cemented Similar Materials

    Directory of Open Access Journals (Sweden)

    Weiming Guan


    Full Text Available The analogous simulation experiment is widely used in geotechnical and mining engineering. However, systematic errors derived from unified standard curing procedure have been underestimated to some extent. In this study, 140 gypsum-cemented similar material specimens were chosen to study their curing procedure with different relative humidity, which is 10%–15%, 40%, 60%, and 80%, respectively. SEM microstructures and XRD spectra were adopted to detect the correlation between microstructures and macroscopic mechanical strength during curing. Our results indicated that the needle-like phases of similar materials began to develop in the early stage of the hydration process through intersecting with each other and eventually transformed into mat-like phases. Increase of humidity may inhibit the development of needle-like phases; thus the compressive strength changes more smoothly, and the time required for the material strength to reach the peak value will be prolonged. The peak strength decreases along with the increase of humidity while the humidity is higher than 40%; however, the reverse tendency was observed if the humidity was lower than 40%. Finally, we noticed that the material strength usually reaches the peak value when the water content continuously reduces and tends towards stability. Based on the above observation, a curing method determination model and experimental strength predication method for gypsum-cemented similar materials were proposed.

  4. Populations of some molds in water-damaged homes may differ if the home was constructed with gypsum drywall compared to plaster (United States)

    Starting in the 1940s, gypsum drywall began replacing plaster and lathe in the U.S. home construction industry. Our goal was to evaluate whether some mold populations differ in water- damaged homes primarily constructed with gypsum drywall compared to plaster. The dust samples fr...

  5. Assessment of the Environmental Impacts of Coalbed Methane Development in the Powder River Basin - Use of Coalbead Methane Produced Water for Cropland Irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Morris


    Water quality is a major concern with regard to development of coalbed methane (CBM) in the Powder River Basin, Wyoming. Large quantities of water are being produced and discharged as a by-product in the process of releasing natural gas from coal. Current practices of discharging large volumes of water into drainage channels or using it to irrigate cropland areas has the potential to elevate salinity and sodicity in soils. Elevated salinity affects the ability of plants to uptake water to facilitate biochemical processes such as photosynthesis and plant growth. Elevated sodicity in irrigation water adversely affects soil structure necessary for water infiltration, nutrient supply, and aeration. Salinity and sodicity concentrations are important in that a sodic soil can maintain its structure if the salinity level is maintained above the threshold electrolyte concentration. In this study, cropland soil and CBM water were treated with gypsum and sulfur. Changes in soil chemistry among different treatments were monitored using a split plot experiment. The CBM water used for irrigation had an EC of 1380 {micro}S cm{sup -1} and SAR of 24.3 mmol{sup 1/2} L{sup -1/2}. Baseline and post treatment soil samples were collected to a depth of 60 cm within each study plot, analyzed, and characterized for chemical parameters. Comparisons between Spring 2004 and Fall 2004 soil chemistry data after one irrigation season (using the equivalent of 1 month of irrigation water or {approx}12 inches) indicated that irrigating with Piney Creek water or a 50:50 blend of Piney Creek water and CBM water did not cause SAR values to increase. A combination of using a gypsum amendment to the soil along with a gypsum injection and sulfur burner treatment to the irrigation water resulted in the lowest SAR value in the first soil horizon among treatments irrigated solely with CBM produced water. The SAR value resulting from this combination treatment was 53% lower than using CBM water with no

  6. Biogas from by-products; Biogas aus Nebenprodukten

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Andreas [Eisenmann Anlagenbau GmbH und Co. KG, Boeblingen (Germany)


    The Italian sugar producer Co.Pro.B. (Minerbio, Italy) looked for an industrially experienced plant engineer for the biogas process in order to utilize energetically the by-products from the processing of sugar beets. Co.Pro.B. found the German environmental technology specialist Eisenmann Anlagenbau GmbH and Co. KG (Boeblingen, Federal Republic of Germany). After a planning and building period of only six months, even three biogas plants with plug-flow fermentation were brought on line in the provinces Bologna and Padua in autumn 2012.

  7. Economical Recovery of By-products in the Mining Industry

    Energy Technology Data Exchange (ETDEWEB)

    Berry, J.B.


    The U.S. Department of Energy (DOE) Office of Industrial Technologies, Mining Industry of the Future Program, works with the mining industry to further the industry's advances toward environmental and economic goals. Two of these goals are (1) responsible emission and by-product management and (2) low-cost and efficient production (DOE 1998). DOE formed an alliance with the National Mining Association (NMA) to strengthen the basis for research projects conducted to benefit the mining industry. NMA and industry representatives actively participate in this alliance by evaluating project proposals and by recommending research project selection to DOE. Similarly, the National Research Council (NRC) has recently and independently recommended research and technology development opportunities in the mining industry (NRC 2001). The Oak Ridge National Laboratory (ORNL) and Colorado School of Mines engineers conducted one such project for DOE regarding by -product recovery from mining process residue. The results of this project include this report on mining industry process residue and waste with opportunity for by-product recovery. The U.S. mineral processing industry produces over 30,000,000 metric tons per year of process residue and waste that may contain hazardous species as well as valuable by-products. This study evaluates the copper, lead, and zinc commodity sectors which generate between 23,300,000 and 24,000,000 metric tons per year. The distribution of residual elements in process residues and wastes varies over wide ranges* because of variations in the original ore content as it is extracted from the earth's crust. In the earth's crust, the elements of interest to mining fall into two general geochemical classifications, lithophiles and chalcophiles** (Cox 1997). Groups of elements are almost always present together in a given geochemical classification, but the relative amounts of each element are unique to a particular ore body. This paper

  8. By-product information can stabilize the reliability of communication. (United States)

    Schaefer, H Martin; Ruxton, G D


    Although communication underpins many biological processes, its function and basic definition remain contentious. In particular, researchers have debated whether information should be an integral part of a definition of communication and how it remains reliable. So far the handicap principle, assuming signal costs to stabilize reliable communication, has been the predominant paradigm in the study of animal communication. The role of by-product information produced by mechanisms other than the communicative interaction has been neglected in the debate on signal reliability. We argue that by-product information is common and that it provides the starting point for ritualization as the process of the evolution of communication. Second, by-product information remains unchanged during ritualization and enforces reliable communication by restricting the options for manipulation and cheating. Third, this perspective changes the focus of research on communication from studying signal costs to studying the costs of cheating. It can thus explain the reliability of signalling in many communication systems that do not rely on handicaps. We emphasize that communication can often be informative but that the evolution of communication does not cause the evolution of information because by-product information often predates and stimulates the evolution of communication. Communication is thus a consequence but not a cause of reliability. Communication is the interplay of inadvertent, informative traits and evolved traits that increase the stimulation and perception of perceivers. Viewing communication as a complex of inadvertent and derived traits facilitates understanding of the selective pressures shaping communication and those shaping information and its reliability. This viewpoint further contributes to resolving the current controversy on the role of information in communication. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary


    Energy Technology Data Exchange (ETDEWEB)

    J.A. Withum; J.E. Locke; S.C. Tseng


    There is concern that mercury (Hg) in coal combustion by-products might be emitted into the environment during processing to other products or after the disposal/landfill of these by-products. This perception may limit the opportunities to use coal combustion by-products in recycle/reuse applications and may result in additional, costly disposal regulations. In this program, CONSOL conducted a comprehensive sampling and analytical program to include ash, flue gas desulfurization (FGD) sludge, and coal combustion by-products. This work is necessary to help identify potential problems and solutions important to energy production from fossil fuels. The program objective was to evaluate the potential for mercury emissions by leaching or volatilization, to determine if mercury enters the water surrounding an active FGD disposal site and an active fly ash slurry impoundment site, and to provide data that will allow a scientific assessment of the issue. Toxicity Characteristic Leaching Procedure (TCLP) test results showed that mercury did not leach from coal, bottom ash, fly ash, spray dryer/fabric filter ash or forced oxidation gypsum (FOG) in amounts leading to concentrations greater than the detection limit of the TCLP method (1.0 ng/mL). Mercury was detected at very low concentrations in acidic leachates from all of the fixated and more than half of the unfixated FGD sludge samples, and one of the synthetic aggregate samples. Mercury was not detected in leachates from any sample when deionized water (DI water) was the leaching solution. Mercury did not leach from electrostatic precipitator (ESP) fly ash samples collected during activated carbon injection for mercury control in amounts greater than the detection limit of the TCLP method (1.0 ng/mL). Volatilization tests could not detect mercury loss from fly ash, spray dryer/fabric filter ash, unfixated FGD sludge, or forced oxidation gypsum; the mercury concentration of these samples all increased, possibly due to

  10. Synthesis of high-purity precipitated calcium carbonate during the process of recovery of elemental sulphur from gypsum waste

    CSIR Research Space (South Africa)

    De Beer, Morris


    Full Text Available We recently showed that the production of elemental sulphur and calcium carbonate (CaCO3) from gypsum waste by thermally reducing the waste into calcium sulphide (CaS) followed by its direct aqueous carbonation yielded low-grade carbonate products...

  11. Conversion of calcium sulphide to calcium carbonate during the process of recovery of elemental sulphur from gypsum waste

    CSIR Research Space (South Africa)

    De Beer, Morris


    Full Text Available The production of elemental sulphur and calcium carbonate (CaCO(sub3)) from gypsum waste can be achieved by thermally reducing the waste into calcium sulphide (CaS), which is then subjected to a direct aqueous carbonation step for the generation...

  12. Characterization of gypsum crystals exposed to a high CO{sub 2} concentration fog using x-ray

    Energy Technology Data Exchange (ETDEWEB)

    Carreño-Márquez, I. J. A.; Castillo-Sandoval, I.; Esparza-Ponce, H. E.; Fuentes-Cobas, L.; Montero-Cabrera, M. E., E-mail: [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih. 31136 (Mexico)


    In Chihuahua State, a little town called Naica has the largest gypsum single crystals in the world. The growth of these structures has been described as a long and stable process developed over thousands of years. Due to the change in the environmental conditions, these crystals could suffer alterations on their surface. In this project we study the cause of possible deterioration of the giant crystals and intend to suggest measures for their preservation. For this sake, our first experiment consists on several gypsum crystals that have been subjected in a climate chamber to a fog at high CO{sub 2} concentration and 51 °C for a period of time of six months, extracting two crystals every 15 days. Then the crystals have been characterized through Grazing Incidence X-Ray Diffraction using a diffractometer PanAlytical X’PertPro with two different detectors; Xe-filled proportional detector and a Pixel 3D detector. The results were compared to determine which technique is the most suitable to study the degradation of gypsum single crystals. In the two cases, we have identified only the gypsum phase, but with different crystal plane orientations.

  13. Gypsum (CaSO42H2O) scaling on polybenzimidazole and cellulose acetate hollow fiber membranes under forward osmosis

    KAUST Repository

    Chen, Si Cong


    We have examined the gypsum (CaSO42H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42 14.85 after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. 2013 by the authors; licensee MDPI, Basel, Switzerland.

  14. Use of Gypsum as a Preventive Measure for Strength Deterioration during Curing in Class F Fly Ash Geopolymer System (United States)

    Jun, Yubin; Oh, Jae Eun


    This study discusses strength deterioration during the curing process of fly ash geopolymer and the use of CaSO4·2H2O (gypsum) as a deterioration remedy when the ash was synthesized using a 10M NaOH and Na-silicate solution. The strength decline was mainly due to the widespread formation of nanometer-sized cracks that were related to excessive Na and Si concentrations at an early age. Use of 2 wt% CaSO4·2H2O resulted in the best measured strength by temporarily reducing Na and Si concentrations; Na was absorbed by SO42−, up to 11% in the matrix within one day, and formed Na2SO4 (thenardite), which gradually dissolved over time, slowly releasing Na ions. However, more than 4% gypsum suppressed overall strength development because too many Na ions were locked into Na2SO4 and could not participate in geopolymerization. The addition of gypsum impeded glass dissolution and even halted the process when more than 4% gypsum was used.


    Energy Technology Data Exchange (ETDEWEB)

    Rodney Andrews; Aurora Rubel; Jack Groppo; Ari Geertsema; M. Mercedes Maroto-Valer; Zhe Lu; Harold Schobert


    The results of laboratory investigations and supporting technical assessments conducted under DOE Subcontract No. DE-FG26-03NT41795 are reported for the period September 1, 2003 to August 31, 2004. This contract is with the University of Kentucky Research Foundation, which supports work with the University of Kentucky Center for Applied Energy Research and The Pennsylvania State University Energy Institute. The worked described was part of a project entitled ''Advanced Gasification By-Product Utilization''. This work involves the development of technologies for the separation and characterization of coal gasification slags from operating gasification units, activation of these materials to increase mercury and nitrogen oxide capture efficiency, assessment of these materials as sorbents for mercury and nitrogen oxides, and characterization of these materials for use as polymer fillers.

  16. Assessing the efficacy over time of the addition of industrial by-products to remediate contaminated soils at a pilot-plant scale. (United States)

    González-Núñez, Raquel; Rigol, Anna; Vidal, Miquel


    The effect of the addition of industrial by-products (gypsum and calcite) on the leaching of As and metals (Cu, Zn, Ni, Pb and Cd) in a soil contaminated by pyritic minerals was monitored over a period of 6 months at a two-pit pilot plant. The contaminated soil was placed in one pit (non-remediated soil), whereas a mixture of the contaminated soil (80% w/w) with gypsum (10% w/w) and calcite (10% w/w) was placed in the other pit (remediated soil). Soil samples and leachates of the two pits were collected at different times. Moreover, the leaching pattern of major and trace elements in the soil samples was assessed at laboratory level through the application of the pH stat leaching test. Addition of the by-products led to an increase in initial soil pH from around 2.0 to 7.5, and it also provoked that the concentration of trace elements in soil extracts obtained from the pH stat leaching test decreased to values lower than quantification limits of inductively coupled plasma optical emission spectrometry and lower than the hazardous waste threshold for soil management. The trace element concentration in the pilot-plant leachates decreased over time in the non-remediated soil, probably due to the formation of more insoluble secondary minerals containing sulphur, but especially decreased in pit of the remediated soil, in agreement with laboratory data. The pH in the remediated soil remained constant over the 6-month period, and the X-ray diffraction analyses confirmed that the phases did not vary over time, thus indicating the efficacy of the addition of the by-products. This finding suggests that soil remediation may be a feasible option for the re-use of non-hazardous industrial by-products.

  17. Age and speleogenesis of epigenic gypsum caves in the northern Apennines (Italy) (United States)

    Columbu, Andrea; Chiarini, Veronica; De Waele, Jo; Drysdale, Russell; Forti, Paolo; Hellstrom, John; Woodhead, Jon


    Triassic and Messinian gypsum beds host the majority of the caves in the eastern flank of the northern Apennines. To date, more than six hundreds voids have been mapped, including the longest known epigenic gypsum cave system in the world (Spipola-Acquafredda, ~11 km of tunnels) (De Waele et al., 2013). Superimposed caves are typically sub-horizontal (Klimchouk, 2000) and connected through vertical shafts, reflecting the palaeo base-level variations. When preserved, river terraces at the surface lie at the same palaeo altitude of the base level and horizontal cave passages. Notwithstanding the well-known geology of the area known (Vai and Martini, 2001), the age of these caves has been greatly underestimated in the past. Considering the rapid dissolution of the gypsum and uplifting of the area, the start of speleogenesis activity was considered to have occurred during the last glacial age. The age of karst voids can be only indirectly estimated by the dating of the infilling sediments. U-Th dating on carbonate speleothems provides high-precision and accurate ages (Hellstrom, 2003; Scholz and Hoffmann, 2008). We thus applied this methodology to 20 speleothems coming from 14 different caves belonging to the Monte Tondo, Spipola Acquafredda, Castelnuovo, Stella-Rio Basino and Brisighella systems. The results show that: i) caves were forming since at least ~300 ka; ii) the peak of speleogenesis was reached during relatively cold climate stages, when rivers formed terraces at the surface and aggradation caused paragenesis in the stable cave levels (Columbu et al., 2015). Besides the significant contribution to the understanding of the Apennines evaporite karst evolution, this study (and its further advancement) may also refine knowledge of the local vs regional uplifting rates and base-level variations since the late Pleistocene (Wegmann and Pazzaglia, 2009). References Columbu, A., De Waele, J., Forti, P., Montagna, P., Picotti, V., Pons-Branchu, E., Hellstrom, J

  18. Calibration of a hysteretic model for glass fiber reinforced gypsum wall panels (United States)

    Janardhana, Maganti; Robin Davis, P.; Ravichandran, S. S.; Prasad, A. M.; Menon, D.


    Glass fiber reinforced gypsum (GFRG) wall panels are prefabricated panels with hollow cores, originally developed in Australia and subsequently adopted by India and China for use in buildings. This paper discusses identification and calibration of a suitable hysteretic model for GFRG wall panels filled with reinforced concrete. As considerable pinching was observed in the experimental results, a suitable hysteretic model with pinched hysteretic rule is used to conduct a series of quasi-static as inelastic hysteretic response analyses of GFRG panels with two different widths. The calibration of the pinching model parameters was carried out to approximately match the simulated and experimental responses up to 80% of the peak load in the post peak region. Interestingly, the same values of various parameters (energy dissipation and pinching related parameters) were obtained for all five test specimens.

  19. Coagulation-condensation structure formation in aqueous suspensions of mixtures of sulfur and gypsum

    Directory of Open Access Journals (Sweden)

    K. Toshtay


    Full Text Available The characteristics of structure formation in hydrosuspensions of powdered sulfur and its mixtures with gypsum was investigated. The effect of cationic (CTAB and anionic (SDBS surfactants on the surface tension of water; ζ-potential of the sulfur particles and wettability of sulfur was learned. Both surfactants at low concentrations; lead to an increase in plastic strength (Pm of the suspension; and at high concentrations (above CMC – they lead to Pm reduce. In addition; it was found that the surfactants substantially change ζ-potential of the sulfur particles – cationic surfactants  lead to charge exchange and anionic surfactants increase the negative charge of the particles. These changes are the result to restructuring in the adsorption layers of surfactants - the formation of a saturated mono-layer while up to Pm maximum; bilayer - after CMC (while the Pm is reducing.

  20. Effect Of Coir Fibres On The Compaction And Unconfined Compressive Strength Of Bentonite-Lime-Gypsum Mixture

    Directory of Open Access Journals (Sweden)

    Tilak B. Vidya


    Full Text Available This paper presents the effect of coir fibres on the compaction and unconfined compressive strength of a bentonite-lime-gypsum mixture. The coir fiber content varied from 0.5 to 2 %. The results indicated that the dry unit weight and the optimum moisture content of a bentonite – lime mix increased with the addition of gypsum. The unconfined compressive strength of the bentonite increased with the increase in the lime content up to 8 %. Beyond 8 %, the unconfined compressive strength decreased. The dry unit weight of the reference mix decreased, and the optimum moisture content increased with the addition of coir fibre. The unconfined compressive strength of the bentonite + 8 % lime mix increased up to 4 % with the gypsum. Beyond 4 %, the unconfined compressive strength decreased. The unconfined compressive strength of the reference mix increased with the addition of coir fibre up to a fibre content of 1.5 %. The unconfined compressive strength of the reference mix-coir fibre composite was less in comparison to the reference mix. The unconfined compressive strength of the bentonite increased with the addition of lime and gypsum and with the increase in the curing period. The improvement in the post-peak region was better for the reference mix with reinforced coir fibres as compared to the unreinforced reference mix. The improved post-peak behaviour of the bentonite-lime-gypsum-coir fibre mixture could boost the construction of temporary roads on such problematic soils. Further, its use will also provide an environmental motivation for providing a means of consuming large quantities of coir fibres.

  1. Triple oxygen and hydrogen isotopes of gypsum hydration water for quantitative paleo-humidity reconstruction (United States)

    Gázquez, Fernando; Morellón, Mario; Bauska, Thomas; Herwartz, Daniel; Surma, Jakub; Moreno, Ana; Staubwasser, Michael; Valero-Garcés, Blas; Delgado-Huertas, Antonio; Hodell, David A.


    Atmospheric relative humidity is an important parameter affecting vegetation yet paleo-humidity proxies are scarce and difficult to calibrate. Here we use triple oxygen (δ17O and δ18O) and hydrogen (δD) isotopes of structurally-bound gypsum hydration water (GHW) extracted from lacustrine gypsum to quantify past changes in atmospheric relative humidity. An evaporation isotope-mass-balance model is used together with Monte Carlo simulations to determine the range of climatological conditions that simultaneously satisfy the stable isotope results of GHW, and with statistically robust estimates of uncertainty. We apply this method to reconstruct the isotopic composition of paleo-waters of Lake Estanya (NE Spain) and changes in normalized atmospheric relative humidity (RHn) over the last glacial termination and Holocene (from ∼15 to 0.6 cal. kyrs BP). The isotopic record indicates the driest conditions occurred during the Younger Dryas (YD; ∼12-13 cal. kyrs BP). We estimate a RHn of ∼40-45% during the YD, which is ∼30-35% lower than today. Because of the southward displacement of the Polar Front to ∼42°N, it was both windier and drier during the YD than the Bølling-Allerød period and Holocene. Mean atmospheric moisture gradually increased from the Preboreal to Early Holocene (∼11 to 8 cal. kyrs BP, 50-60%), reaching 70-75% RHn from ∼7.5 cal. kyrs BP until present-day. We demonstrate that combining hydrogen and triple oxygen isotopes in GHW provides a powerful tool for quantitative estimates of past changes in relative humidity.

  2. [Determination of multi-element contents in gypsum by ICP-AES]. (United States)

    Guo, Zhong-bao; Bai, Yong-zhi; Cui, Jin-hua; Mei, Yi-fei; Ma, Zhen-zhu


    The content of multi-element in gypsum was determined by ICP-AES. The sample was pretreated by acid-soluble method or alkali-fusion method. Acid-soluble method is suitable for the determination of CaO, SOs, Al2O3, Fe2O3, MgO, K2O, Na2O, TiO2, P2O5, MnO, SrO and BaO. Alkali-fusion method is suitable for the determination of CaO, SO3, SiO2, Al2O3, Fe2O3, MgO, TiO2, P2O5, MnO, SrO, BaO and B2O3. Different series standard solutions were prepared considering the properties and content of elements and solution matrix. The limit of detection and quantification were confirmed for each element under their best analysis spectral lines. The recoveries of the two pretreatment methods were from 93% to 110%, besides that for TiO2 was 81%-87% as pretreated by acid-soluble method. All RSDs (n=6) of tests were from 0.70%-3.42%. The accuracies of CaO and SO3 with ICP-AES method were less than the chemical analysis method. The determination of CaO and SO3 with ICP-AES method is only suitable for the case of low accuracy requirement. The results showed that the method can be used for the determination of multi-element contents in gypsum, with simple operation, fast analysis and reliable results. Total elements can be analysed with both acid-soluble method and alkali-fusion method.

  3. The arbuscular mycorrhizal fungus Glomus geosporum in European saline, sodic and gypsum soils. (United States)

    Landwehr, Melanie; Hildebrandt, Ulrich; Wilde, Petra; Nawrath, Kerstin; Tóth, Tibor; Biró, Borbála; Bothe, Hermann


    Plants of saline and sodic soils of the Hungarian steppe and of gypsum rock in the German Harz mountains, thus soils of high ionic strength and electric conductivity, were examined for their colonization by arbuscular mycorrhizal fungi (AMF). Roots of several plants of the saline and sodic soils such as Artemisia maritima, Aster tripolium or Plantago maritima are strongly colonized and show typical AMF structures (arbuscules, vesicles) whereas others like the members of the Chenopodiaceae, Salicornia europaea, Suaeda maritima or Camphorosma annua, are not. The vegetation of the gypsum rock is totally different, but several plants are also strongly colonized there. The number of spores in samples from the saline and sodic soils examined is rather variable, but high on average, although with an apparent low species diversity. Spore numbers in the soil adjacent to the roots of plants often, but not always, correlate with the degree of AMF colonization of the plants. As in German salt marshes [Hildebrandt et al. (2001)], the dominant AMF in the Hungarian saline and sodic soils is Glomus geosporum. All these isolates provided nearly identical restriction fragment length polymorphism (RFLP) patterns of the internal transcribed spacer (ITS) region of spore DNA amplified by polymerase chain reaction (PCR). Cloning and sequencing of several PCR products of the ITS regions indicated that ecotypes of the G. geosporum/ Glomus caledonium clade might exist at the different habitats. A phylogenetic dendrogram constructed from the ITS or 5.8S rDNA sequences was nearly identical to the one published for 18S rDNA data (Schwarzott et al. 2001). It is tempting to speculate that specific ecotypes may be particularly adapted to the peculiar saline or sodic conditions in such soils. They could have an enormous potential in conferring salt resistance to plants.

  4. Molecular and lipid biomarker analysis of a gypsum-hosted endoevaporitic microbial community. (United States)

    Jahnke, L L; Turk-Kubo, K A; N Parenteau, M; Green, S J; Kubo, M D Y; Vogel, M; Summons, R E; Des Marais, D J


    Modern evaporitic microbial ecosystems are important analogs for understanding the record of earliest life on Earth. Although mineral-depositing shallow-marine environments were prevalent during the Precambrian, few such environments are now available today for study. We investigated the molecular and lipid biomarker composition of an endoevaporitic gypsarenite microbial mat community in Guerrero Negro, Mexico. The 16S ribosomal RNA gene-based phylogenetic analyses of this mat corroborate prior observations indicating that characteristic layered microbial communities colonize gypsum deposits world-wide despite considerable textural and morphological variability. Membrane fatty acid analysis of the surface tan/orange and lower green mat crust layers indicated cell densities of 1.6 × 10(9) and 4.2 × 10(9)  cells cm(-3) , respectively. Several biomarker fatty acids, ∆7,10-hexadecadienoic, iso-heptadecenoic, 10-methylhexadecanoic, and a ∆12-methyloctadecenoic, correlated well with distributions of Euhalothece, Stenotrophomonas, Desulfohalobium, and Rhodobacterales, respectively, revealed by the phylogenetic analyses. Chlorophyll (Chl) a and cyanobacterial phylotypes were present at all depths in the mat. Bacteriochlorophyl (Bchl) a and Bchl c were first detected in the oxic-anoxic transition zone and increased with depth. A series of monomethylalkanes (MMA), 8-methylhexadecane, 8-methylheptadecane, and 9-methyloctadecane were present in the surface crust but increased in abundance in the lower anoxic layers. The MMA structures are similar to those identified previously in cultures of the marine Chloroflexus-like organism 'Candidatus Chlorothrix halophila' gen. nov., sp. nov., and may represent the Bchl c community. Novel 3-methylhopanoids were identified in cultures of marine purple non-sulfur bacteria and serve as a probable biomarker for this group in the lower anoxic purple and olive-black layers. Together microbial culture and environmental analyses

  5. Pseudomorphs of Neotethyan Evaporites in Anatolia's HP/LT belts - Aptian basin-wide pelagic gypsum deposits (United States)

    Scheffler, Franziska; Oberhänsli, Roland; Pourteau, Amaury; Immenhauser, Adrian; Candan, Osman


    Rosetta Marble was defined in SW Anatolia as 3D-radiating textures of dm-to-m-long calcite rods in the HP/LT metamorphosed Mid-Cretaceous pelagic carbonate sequence of the Ören Unit. Rosetta Marble in the type locality are interbedded with meta-chert beds, and may constitute entire carbonate beds. Rare aragonite relicts and Sr-rich, fibrous calcite pseudomorphs after aragonite witness the HP metamorphic imprint of this sequence during the closure of a Neotethyan oceanic domain during latest Cretaceous-Palaeocene times. We investigated the Rosetta Marble of the Ören Unit, as well as other known and newly found localities in the Tavşanlı and Afyon zones, and the Alanya Massif and Malatya area, to decipher the metamorphic, diagenetic and sedimentologic significance of these uncommon textures. Based on field, petrographic and geochemical investigations, we document a wide variety of Rosetta-type textures. A striking resemblance with well-known gypsum morphologies (e.g. shallow-tail, palm-tree textures) leads us to argue that Rosetta Marble was initially composed of giant gypsum crystals (selenite). The absence of anhydrite relicts of pseudomorphs indicate that gypsum transformed into calcite soon after the deposition by the mean of a sulphate reduction reaction. The gypsum-to-calcite transformation requires that organic matter intervened as a reactant phase. Mid Cretaceous oceanic domains in the Tethyan realm are characterised by overall anoxic conditions that allowed the preservation of organic material. Rosetta Marble exposures are widely distributed over 600 km along the Neotethyan suture zone. During deepening of the Neotethyan ocean in Mid Cretaceous times, basin-wide and cyclic sedimentation of gypsum and radiolarite occurred. The origin of high-salinity waters needed for gypsum precipitation was located at shelf levels. Density and gravity effects forced the brines to cascade downwards into the deep ocean. Favorable climatic conditions trigger the formation

  6. Mango (Mangifera indica L.) by-products and their valuable components: a review. (United States)

    Jahurul, M H A; Zaidul, I S M; Ghafoor, Kashif; Al-Juhaimi, Fahad Y; Nyam, Kar-Lin; Norulaini, N A N; Sahena, F; Mohd Omar, A K


    The large amount of waste produced by the food industries causes serious environmental problems and also results in economic losses if not utilized effectively. Different research reports have revealed that food industry by-products can be good sources of potentially valuable bioactive compounds. As such, the mango juice industry uses only the edible portions of the mangoes, and a considerable amount of peels and seeds are discarded as industrial waste. These mango by-products come from the tropical or subtropical fruit processing industries. Mango by-products, especially seeds and peels, are considered to be cheap sources of valuable food and nutraceutical ingredients. The main uses of natural food ingredients derived from mango by-products are presented and discussed, and the mainstream sectors of application for these by-products, such as in the food, pharmaceutical, nutraceutical and cosmetic industries, are highlighted. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Technical Note: Historic gypsum-kilns (Morata de Tajuña, Madrid

    Directory of Open Access Journals (Sweden)

    Llamas Borrajo, J. F.


    Full Text Available In the locality of Morata de Tajuña and surroundings there was an important settlement of gypsum pits and limekilns, together with other historical industries, now disappear. These activities were developed mainly during the 1960´s and 70´s, but its production decreased because of changes in the productive processes (substitution of discontinuous processes by continuous ones, higher kilns, etc. (1. Nevertheless, some of these furnaces still remain, as well as ancient workers who have provided important information. Within the research project funded by the Madrid´s Government, entitled: Industrial archaeology: Conservation of the mining and metallurgical heritage of Madrid (IV, ancient gypsum pits have been identified and inventoried. The ancient gypsiferous extraction history was recovered and the productive processes fluxes were reconstructed. The state of the heritage is evaluated and the conservation of some of the elements is recommended. Likewise, the intangible heritage was also investigated, being able to show a legend related with these kilns.En Morata de Tajuña y pueblos limítrofes hay una importante tradición yesera y calera, así como de otras industrias de materiales de la construcción ya desaparecidas, sobre todo en los años 60-70 del pasado siglo, debido a cambios en los sistemas productivos (paso de sistemas discontinuos a continuos, hornos mayores, etc. (1. Por eso aún se conservan algunos hornos y también viven antiguos productores, a los que hemos podido preguntar sobre los procesos productivos. En el marco de un proyecto de investigación de la Consejería de Educación de la Comunidad de Madrid titulado “Arqueología Industrial: conservación del patrimonio minero-metalúrgico madrileño (IV” se están identificando e inventariando viejas yeserías, recuperando la historia yesera local, reconstruyendo los flujos productivos y entrevistando a antiguos operarios. De esta manera, se pretende evaluar

  8. Characterization mixtures of thick gypsum with addition of treated waste from laminated plasterboards

    Directory of Open Access Journals (Sweden)

    Rodríguez-Orejón, A.


    Full Text Available nvironmental protection involves the reuse of construction and demolition waste. In order to improve recycling, waste from laminated plasterboards is used in the cement and laminated gypsum boards manufacture.This article analyzes the use of ground and burnt laminated plasterboard (BLG waste mixed with thick gypsum (TG. Physical-mechanical characterization of superficial hardness and mechanical strength has been performed on different batches of plaster powder materials with different BLG waste particle sizes to determine its suitability. Coarse particle sizes were preferred in order to reduce the waste treatment. From all the mixtures studied, the one with the best results was TG + 5% BLG1.25 which forms a material of higher superficial hardness and strength. The results obtained in the study have proved suitable products for building use (both as renders and as prefabricated elements enabling for a reduction in the consumption of natural resources.La protección del medio ambiente implica la reutilización de los residuos de construcción y demolición. Los residuos de placas de yeso laminado se utilizan en la fabricación de cemento y de placas de yeso laminado. En este artículo se ha estudiado la utilización deresiduos de placa de yeso laminado cocido (YLC mezclado con yeso grueso (YG, realizándose la caracterización físico-mecánica de dureza superficial y resistencias mecánicas, para determinar su idoneidad formando materiales de yeso en polvo con distintas granulometrías de residuos de (YLC, teniendo preferencia por granulometrías gruesas, que reducen el tratamiento del residuo. De las mezclas estudiadas la que mejores resultados ha ofrecido es YG + 5%YLC1,25 formando un material de mayor dureza superficial y resistencia. De los resultados obtenidos en el estudio se puede afirmar que se han conseguido productos aptos para su utilización en edificación posibilitando una reducción del consumo de recursos naturales.

  9. Quantifying mold biomass on gypsum board: Comparison of ergosterol and beta-N-acetylhexosaminidase as mold biomass parameters

    DEFF Research Database (Denmark)

    Reeslev, M.; Miller, M.; Nielsen, Kristian Fog


    Two mold species, Stachybotrys chartarum and Aspergillus versicolor, were inoculated onto agar overlaid with cellophane, allowing determination of a direct measurement of biomass density by weighing. Biomass density, ergosterol content, and beta-N-acetylhexosaminidase ( activity were...... monitored from inoculation to stationary phase. Regression analysis showed a good linear correlation to biomass density for both ergosterol content and beta-N-acetylhexosaminidase activity. The same two mold species were inoculated onto wallpapered gypsum board, from which a direct biomass measurement...... density from ergosterol content and beta-N-acetylhexosaminidase activity were determined. The CFs were used to estimate the biomass density of the molds grown on gypsum board. The biomass densities estimated from ergosterol content and beta-N-acetylhexosaminidase activity data gave similar results...

  10. Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    Dezhi Shao


    Full Text Available This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain.

  11. Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast-An in vitro Study. (United States)

    Madhavan, Ranjith; George, Navia; Thummala, Niharika R; Ravi, S V; Nagpal, Ajay


    For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. A total of 30 impressions of stainless steel die were made, out of which 15 impressions were made with conventional alginate and 15 were made with self-disinfecting alginate and poured using Type III dental stone. Thirty stone specimens were subjected for hardness testing. Data were analyzed using independent samples t-test to compare the mean surface hardness. Difference in surface hardness was statistically insignificant (p > 0.05). Surface hardness of gypsum casts poured using impressions made from self-disinfecting alginate and conventional alginates were comparable. Self-disinfecting alginates may be employed in clinical practice as safe and effective materials to overcome the infection control issues without compromising on the properties of the material.

  12. Blended Cements Produced With Synthetic Zeolite Made from Industrial By-Product

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    Vitoldas Vaitkevičius


    Full Text Available Zeolites are appropriate supplementary cementitious materials in cement and concrete industry. In the present work synthetic zeolites was used like supplementary material in hardened cement paste and some properties as well as its influence on Portland cement hydration was determinate. X-ray powder diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy, FTIR spectroscopy were used as investigation methods. The compressive strength of hardened cement paste was measured at day 3, 28 and 60. The instrumental analysis showed that zeolite A(Na dominates and unreacted Al(OH3 remains in investigated synthetics zeolites, made from thermal and mechanical treated AlF3 production waste. The Chapelle test showed that both zeolites have good pozzolanic properties. The samples compressive strength remained close to the control samples compressive strength, reducing the amount of Portland cement, i.e., changing it by zeolite. After 60 days, the compressive strength was the best in the samples where 5% of Portland cement was replaced by the 2-zeolite. The compressive strength of the samples increased by 9 % compared with control samples. This research provides a real opportunity to save cement thus disposing the waste.DOI:

  13. Advanced Gasification By-Product Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Rodney Andrews; Aurora Rubel; Jack Groppo; Brock Marrs; Ari Geertsema; Frank Huggins; M. Mercedes Maroto-Valer; Brandie M. Markley; Zhe Lu; Harold Schobert


    With the passing of legislation designed to permanently cap and reduce mercury emissions from coal-fired utilities, it is more important than ever to develop and improve upon methods of controlling mercury emissions. One promising technique is carbon sorbent injection into the flue gas of the coal-fired power plant. Currently, this technology is very expensive as costly commercially activated carbons are used as sorbents. There is also a significant lack of understanding of the interaction between mercury vapor and the carbon sorbent, which adds to the difficulty of predicting the amount of sorbent needed for specific plant configurations. Due to its inherent porosity and adsorption properties as well as on-site availability, carbons derived from gasifiers are potential mercury sorbent candidates. Furthermore, because of the increasing restricted use of landfilling, the coal industry is very interested in finding uses for these materials as an alternative to the current disposal practice. The results of laboratory investigations and supporting technical assessments conducted under DOE Subcontract No. DE-FG26-03NT41795 are reported. This contract was with the University of Kentucky Research Foundation, which supports work with the University of Kentucky Center for Applied Energy Research and The Pennsylvania State University Energy Institute. The worked described was part of a project entitled ''Advanced Gasification By-Product Utilization''. This work involved the development of technologies for the separation and characterization of coal gasification slags from operating gasification units, activation of these materials to increase mercury and nitrogen oxide capture efficiency, assessment of these materials as sorbents for mercury and nitrogen oxides, assessment of the potential for leaching of Hg captured by the carbons, analysis of the slags for cement applications, and characterization of these materials for use as polymer fillers. The

  14. Hydrochemical features of groundwater in a coastal gypsum karst (Marina di Lesina, Gargano, Southern Italy) in relation to tides (United States)

    Fidelibus, Maria Dolores; Campana, Claudia


    As part of a complex monitoring aimed at collecting suitable data for conceptual and numerical modelling of the coastal gypsum karst of Marina di Lesina (Gargano, Southern Italy), 64 groundwater samples were collected during three surveys at different depths from 9 monitoring wells aligned along two transects. The transects, perpendicular to the Acquarotta canal, are less of 1 Km long. The canal is directly connected to the sea and to the Lesina Lagoon and behaves as an oscillating border following sea tides. The sampling campaigns were carried out concurrently to phases of increasing, decreasing, and low tide and provide different frameworks of the chemical composition of ground waters. TDS (Total Dissolved Solids) of ground water samples ranges from 0.2 g/l to 35 g/l and increases generally along the flow lines towards the canal, and downward. The concentrations of the major ions deviate from theoretical ones defined by non-reactive mixing lines, which have as saline end-member either standard seawater or local seawater sampled offshore.Owing to the multi-component character of the hydrochemical system, the cation concentrations are controlled by competition among concurrent water-rock interaction processes that overlap to non-reactive freshwater-saltwater (FW-SW) mixing, being even triggered and/or enhanced by the same mixing, with feedback loops: gypsum and calcite dissolution, ion exchange (with direction depending on hydrodynamic conditions mainly driven by tides, and justified due to the presence of clay in the gypsum bedrock), and dedolomitization. The geochemical study also highlights the involvement of saline ground waters belonging to regional circuits that develop in the huge Mesozoic carbonate basement. The study highlights that in the saturated thickness of the gypsum coastal aquifer closer to the coast, the hydrochemical system is extremely reactive and strongly influenced by the different groundwater hydraulic conditions induced by the tide phases.

  15. Geotechnical properties of peat soil stabilised with shredded waste tyre chips in combination with gypsum, lime or cement

    Directory of Open Access Journals (Sweden)

    M. Saberian


    Full Text Available Peat has a high content of water and organic substances. These weak components can cause low bearing capacity and high consolidation settlement under load, which means that peat deposits must usually be stabilised if they are to bear constructions such as buildings or roads. In this study we investigated the performance of waste tyre chips (10 % by weight and sand (400 kg m-3 supplemented with a pozzolanic binder (gypsum, lime or cement at a range of dosages (5 %, 10 % or 15 % by weight as a stabiliser for peat soil. Peat samples were taken from a fen peatland at Chaghakhor Wetland in Chahar Mahal and Bakhtiari Province, Iran. In total, 162 test specimens were prepared and subjected to laboratory strength testing (unconfined compression test and direct shear test. Additionally, the pH of each admixture was recorded immediately after mixing, elemental compositions were determined by X-Ray Fluorescence (XRF, and structures were examined using Scanning Electron Microscopy (SEM. It was observed that: (1 the total percentage of pozzolanic compounds in the peat soil was well below the minimum of 70 % set by the standard ASTM C 618 (ASTM 2000, so an additive such as cement, lime or gypsum would certainly be required; (2 specimens stabilised with gypsum or lime showed improvements in unconfined compressive strength (UCS, but those stabilised with ordinary Portland cement exhibited the greatest improvement in UCS (up to 12,200 % as well as improvements in the direct shear parameters c and φ; (3 according to the XRF tests, additives such as cement, lime and gypsum introduced considerable amounts of Si, Al, Ca and O, which are important for pozzolanic reactions in peat soils; and (4 on the basis of the results of UCS and direct shear tests, the optimum percentage of the additives tested would be 5 %.

  16. Potential use of peanut by-products in food processing: a review. (United States)

    Zhao, Xiaoyan; Chen, Jun; Du, Fangling


    Peanut is one of the most important oil and protein producing crops in the world. Yet the amounts of peanut processing by-products containing proteins, fiber and polyphenolics are staggering. With the environmental awareness and scarcity of space for landfilling, wastes/by-product utilization has become an attractive alternative to disposal. Several peanut by-products are produced from crush peanut processes and harvested peanut, including peanut meal, peanut skin, peanut hull and peanut vine. Some of peanut by-products/waste materials could possibility be used in food processing industry, The by-products of peanut contain many functional compounds, such as protein, fiber and polyphenolics, which can be incorporated into processed foods to serve as functional ingredients. This paper briefly describes various peanut by-products produced, as well as current best recovering and recycling use options for these peanut byproducts. Materials, productions, properties, potential applications in food manufacture of emerging materials, as well as environmental impact are also briefly discussed.

  17. Characteristics of fine processed construction and demolition waste in Japan and method to obtain fines having low gypsum component and wood contents. (United States)

    Asakura, Hiroshi; Watanabe, Yoichi; Ono, Yusaku; Yamada, Masato; Inoue, Yuzo; Alfaro, Alonso Montero


    A method to obtain processed residue from mixed construction and demolition waste (mixed C&D-W) - free from environmental pollutants - for deposition in landfill is discussed. In particular, additional sieving, the presence of gypsum board in mixed C&D-W at the first stage of manual presorting, and the color of processed residue were studied for the basic characterization of the different fractions. Considerable precautions should be taken to prevent leaching of hazardous substances, such as T-Hg, Pb, Cr(6+), As, and fluoride and its compounds, when processed residue, particularly in crushed fraction at an intermediate treatment facility, is used as construction material. A relatively high content of gypsum was noted in processed residue generated at demolition work compared to that generated at construction work in processed residue from mixed C&D-W in which the presence of gypsum board was observed at the first stage of manual presorting, and in white processed residue. Additional sieving for removal was ineffective because gypsum and wood have wide particle size distributions. To obtain processed residue having low gypsum and wood contents, white processed residue should be removed to eliminate gypsum (content, 59% of initial sample), and brown or brown and yellow processed residue should be removed to eliminate wood (content, 32% of initial sample) without mixing with processed residue containing other colors at stockyards. The removed residue should be deposited in a controlled-type landfill site.

  18. Contribution study to the thermal insulation of the builders in the desert regions of exploiting gypsum fiber reinforced palm (United States)

    Hafsi, Fouad; Kriker, Abdelouahed; Abani, Said


    Algerian Desert areas were characterized by very hot climate in summer and very cold in winter. The most widely used building material in these areas are concrete, mortar cement, which has a bad thermal insulation, causing a significant increase in cooling and heating costs; in order to avoid this problem it become a must to replace these materials with a good thermal isolation material and lower production cost. This work is part of the evaluation of local materials by improving their performance in the field of thermal insulation, which is considered a first step in the development of new local materials to be used in the construction field, the material used in this study is the gypsum reinforced with date palm fiber. In fact, Algeria has extraordinary resources in natural fibers (from Palm, Abaca, Hemp…) but without any large valorization in building materials. The aim of this work is then to characterization of those date palm fibers in new building materials approved for use in the construction of buildings in the desert areas. The date palm fibers were added to samples of the gypsum material in the form of cutting layers at different volume fraction, so as to determine the extent of their impact in the improvement of the thermal performance. The results were very satisfactory, reaching improvement rate of 16% for samples gypsum reinforced with single cut fiber form, and 32% of the samples reinforced with fiber in the form of layers.

  19. Potential of Soil Amendments (Biochar and Gypsum in increasing Water Use Efficiency of Abelmoschus esculentus L. Moench

    Directory of Open Access Journals (Sweden)

    Aniqa eBatool


    Full Text Available Water being an essential component for plant growth and development, its scarcity poses serious threat to crops around the world. Climate changes and global warming are increasing the temperature of earth hence becoming an ultimate cause of water scarcity. It is need of the day to use potential soil amendments that could increase the plants’ resistance under such situations. Biochar and gypsum were used in the present study to improve the water use efficiency and growth of Abelmoschus esculentus L. Moench (Lady’s Finger. A six weeks experiment was conducted under greenhouse conditions. Stress treatments were applied after thirty days of sowing. Plant height, leaf area, photosynthesis, transpiration rate, stomatal conductance and water use efficiency were determined weekly under stressed (60% field capacity and non-stressed (100% field capacity conditions. Stomatal conductance and transpiration rate decreased and reached near to zero in stressed plants. Stressed plants also showed resistance to water stress upto five weeks and gradually perished at sixth week. On the other hand, water use efficiency improved in stressed plants containing biochar and gypsum as compared to untreated plants. Biochar alone is a better strategy to promote plant growth and WUE specifically of Abelmoschus esculentus, compared to its application in combination with gypsum.

  20. Simulation and prediction of ion transport in the reclamation of sodic soils with gypsum based on the support vector machine. (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling


    The effect of gypsum on the physical and chemical characteristics of sodic soils is nonlinear and controlled by multiple factors. The support vector machine (SVM) is able to solve practical problems such as small samples, nonlinearity, high dimensions, and local minima points. This paper reports the use of the SVM regression method to predict changes in the chemical properties of sodic soils under different gypsum application rates in a soil column experiment and to evaluate the effect of gypsum reclamation on sodic soils. The research results show that (1) the SVM soil solute transport model using the Matlab toolbox represents the change in Ca(2+) and Na(+) in the soil solution and leachate well, with a high prediction accuracy. (2) Using the SVM model to predict the spatial and temporal variations in the soil solute content is feasible and does not require a specific mathematical model. The SVM model can take full advantage of the distribution characteristics of the training sample. (3) The workload of the soil solute transport prediction model based on the SVM is greatly reduced by not having to determine the hydrodynamic dispersion coefficient and retardation coefficient, and the model is thus highly practical.

  1. Remediation of saline-sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China. (United States)

    Mao, Yumei; Li, Xiaping; Dick, Warren A; Chen, Liming


    Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization (FGD)-gypsum applied at rates of 0, 15, 30, 45 and 60Mg/ha to remediate tidal flat soils of the Yangtze River estuary. Exchangeable sodium percentage (ESP), exchangeable sodium (ExNa), pH, soluble salt concentration, and composition of soluble salts were measured in 10cm increments from the surface to 30cm depth after 6 and 18months. The results indicated that the effect of FGD-gypsum is greatest in the 0-10cm mixing soil layer and 60Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil pH to neutral (7.0). The improvement effect was reached after 6months, and remained after 18months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na(+), HCO3(-)+CO3(2-) and Cl(-) to neutral salt ions mainly containing Ca(2+) and SO4(2-). Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising. Copyright © 2016. Published by Elsevier B.V.

  2. Simulation and Prediction of Ion Transport in the Reclamation of Sodic Soils with Gypsum Based on the Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Jinman Wang


    Full Text Available The effect of gypsum on the physical and chemical characteristics of sodic soils is nonlinear and controlled by multiple factors. The support vector machine (SVM is able to solve practical problems such as small samples, nonlinearity, high dimensions, and local minima points. This paper reports the use of the SVM regression method to predict changes in the chemical properties of sodic soils under different gypsum application rates in a soil column experiment and to evaluate the effect of gypsum reclamation on sodic soils. The research results show that (1 the SVM soil solute transport model using the Matlab toolbox represents the change in Ca2+ and Na+ in the soil solution and leachate well, with a high prediction accuracy. (2 Using the SVM model to predict the spatial and temporal variations in the soil solute content is feasible and does not require a specific mathematical model. The SVM model can take full advantage of the distribution characteristics of the training sample. (3 The workload of the soil solute transport prediction model based on the SVM is greatly reduced by not having to determine the hydrodynamic dispersion coefficient and retardation coefficient, and the model is thus highly practical.

  3. Investigation on Mercury Reemission from Limestone-Gypsum Wet Flue Gas Desulfurization Slurry (United States)

    Liu, Songtao; Liu, Yongchao


    Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+ to Hg0 and lead to a damping of the cobenefit mercury removal efficiency by WFGD systems. The experiment on Hg0 reemission from limestone-gypsum WFGD slurry was carried out by changing the operating conditions such as the pH, temperature, Cl− concentrations, and oxygen concentrations. The partitioning behavior of mercury in the solid and liquid byproducts was also discussed. The experimental results indicated that the Hg0 reemission rate from WFGD slurry increased as the operational temperatures and pH values increased. The Hg0 reemission rates decreased as the O2 concentration of flue gas and Cl− concentration of WFGD slurry increased. The concentrations of O2 in flue gas have an evident effect on the mercury retention in the solid byproducts. The temperature and Cl− concentration have a slight effect on the mercury partitioning in the byproducts. No evident relation was found between mercury retention in the solid byproducts and the pH. The present findings could be valuable for industrial application of characterizing and optimizing mercury control in wet FGD systems. PMID:24737981

  4. Gypsum veins in Triassic Moenkopi mudrocks of southern Utah: Analogs to calcium sulfate veins on Mars (United States)

    Young, B. W.; Chan, M. A.


    Well-exposed gypsum veins in the Triassic Moenkopi formation in southern Utah, USA, are similar to veins at Endeavour and Gale Craters on Mars. Both Moenkopi and Mars veins are hydrated calcium sulfate, have fibrous textures, and crosscut other diagenetic features. Moenkopi veins are stratigraphically localized with strontium and sulfur isotope ratios similar to primary Moenkopi sulfate beds and are thus interpreted to be sourced from within the unit. Endeavour veins seem to be distributed by lithology and may have a local source. Gale veins cut across multiple lithologies and appear to be sourced from another stratigraphic interval. Evaluation of vein network geometries indicates that horizontal Moenkopi veins are longer and thicker than vertical veins. Moenkopi veins are also generally oriented with the modern stress field, so are interpreted to have formed in the latest stages of exhumation. Endeavour veins appear to be generally vertical and oriented parallel to the margins of Cape York and are interpreted to have formed in response to topographic collapse of the crater rim. Gale horizontal veins appear to be slightly more continuous than vertical veins and may have formed during exhumation. Abrupt changes in orientation, complex crosscutting relationships, and fibrous (antitaxial) texture in Moenkopi and Mars veins suggest emplacement via hydraulic fracture at low temperatures. Moenkopi and Mars veins are interpreted as late-stage diagenetic features that have experienced little alteration since emplacement. Moenkopi veins are useful terrestrial analogs for Mars veins because vein geometry, texture, and chemistry record information about crustal deformation and vein emplacement.

  5. A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils. (United States)

    Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.


    The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

  6. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects (United States)

    Zhang, Jing; Wang, Huiming; Shi, Jue; Wang, Ying; Lai, Kaichen; Yang, Xianyan; Chen, Xiaoyi; Yang, Guoli


    The present study was performed to determine whether simvastatin improves bone regeneration when combined with calcium silicate/gypsum and gelatin (CS-GEL). The surface morphology was determined using field-emission scanning electron microscopy (FSEM). Degradation in vitro was evaluated by monitoring the weight change of the composites soaked in phosphate buffered saline (PBS). Drug release was evaluated using high-performance liquid chromatography (HPLC). Cytotoxicity testing was performed to assess the biocompatibility of composites. Four 5 mm-diameter bone defects were created in rabbit calvaria. Three sites were filled with CS-GEL, 0.5 mg simvastatin-loaded CS-GEL (SIM-0.5) and 1.0 mg simvastatin-loaded CS-GEL (SIM-1.0), respectively, and the fourth was left empty as the control group. Micro-computed tomography (micro-CT) and histological analysis were carried out at 4 and 12 weeks postoperatively. The composites all exhibited three-dimensional structures and showed the residue with nearly 80% after 4 weeks of immersion. Drug release was explosive on the first day and then the release rate remained stable. The composites did not induce any cytotoxicity. The results in vivo demonstrated that the new bone formation and the expressions of BMP-2, OC and type I collagen were improved in the simvastatin-loaded CS-GEL group. It was concluded that the simvastatin-loaded CS-GEL may improve bone regeneration.

  7. Disinfection by-product formation during seawater desalination: A review. (United States)

    Kim, Daekyun; Amy, Gary L; Karanfil, Tanju


    Due to increased freshwater demand across the globe, seawater desalination has become the technology of choice in augmenting water supplies in many parts of the world. The use of chemical disinfection is necessary in desalination plants for pre-treatment to control both biofouling as well as the post-disinfection of desalinated water. Although chlorine is the most commonly used disinfectant in desalination plants, its reaction with organic matter produces various disinfection by-products (DBPs) (e.g., trihalomethanes [THMs], haloacetic acids [HAAs], and haloacetonitriles [HANs]), and some DBPs are regulated in many countries due to their potential risks to public health. To reduce the formation of chlorinated DBPs, alternative oxidants (disinfectants) such as chloramines, chlorine dioxide, and ozone can be considered, but they also produce other types of DBPs. In addition, due to high levels of bromide and iodide concentrations in seawater, highly cytotoxic and genotoxic DBP species (i.e., brominated and iodinated DBPs) may form in distribution systems, especially when desalinated water is blended with other source waters having higher levels of organic matter. This article reviews the knowledge accumulated in the last few decades on DBP formation during seawater desalination, and summarizes in detail, the occurrence of DBPs in various thermal and membrane plants involving different desalination processes. The review also identifies the current challenges and future research needs for controlling DBP formation in seawater desalination plants and to reduce the potential toxicity of desalinated water. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Indoor Pollution Emissions from Building Materials; Case of Study: Gypsum Boards Indoor Pollution Emissions from Building Materials; Case of Study: Gypsum Boards

    Directory of Open Access Journals (Sweden)

    Silverio Hernández Moreno


    Full Text Available Este reporte presenta una evaluación de las emisiones de materiales de construcción, al interior de los edificios que pueden causar daño a la salud de los usuarios durante la ocupación, pues emiten sustancias tóxicas al interior de los edificios. Este reporte presenta un caso de studio que evalúa a los tableros de yeso, frecuentemente usados en la construcción de muros divisorios y falsos plafones. La parte experimental se basa en un espacio tridimensional el cual simula un cuarto de cualquier tipo de edificación; por ejemplo: un salón de clases u oficina. Las condiciones ambientales al interior, tales como: ventilación, temperatura y humedad, afectan directamente las emisiones de sustancias químicas por los materiales de construcción. La metodología se basa en la comparación de materiales convencionales y materiales alternativos con distinta composición y similares características, en donde usamos métodos de prueba, condiciones ambientales, instrumentos y herramientas similares. Este es un estudio muy importante para entender los problemas relacionadoscon la contaminación ambiental, específicamente del aire y sus efectos en el interior de los edificios, y que se relaciona directamente con la salud pública e indirectamente con los sistemas constructivos y la selección de materiales en los edificios. Las pruebas concluyen que los materiales alternativos (de contenido reciclado son mejores que los tradicionales, porque reducen la contaminación del aire al interior de los edificios. This report presents an evaluation of emissions from indoor building materials that may cause health damage to the people who occupy the building, since these materials emit toxic chemicals into the air and indoor surfaces. This report presents a case study which evaluates Gypsum Boards, frequently used in the construction of dividing walls and ceilings. The experimental part of this report is based on a three-dimensional space that simulates a

  9. Analyzing the rules of fracture and damage, and the characteristics of the acoustic emission signal of a gypsum specimen under uniaxial loading (United States)

    Chen, Dong; Wang, En-yuan; Li, Nan


    In order to study the mechanism of rock bursts in a mined-out area of a gypsum mine, in this paper acoustic emission testing of the uniaxial compression of gypsum and sandstone samples is carried out. The case of rupture of the specimen is observed, and the load axial deformation curve and acoustic emission parameters are obtained for the whole process of specimen rupture. The similarities and differences between the gypsum and sandstone samples are determined in terms of their mechanical properties, their damage evolution laws and frequency band energy distributions, and the instantaneous energy characteristics of their acoustic emission. The results show that the main fracture morphology of gypsum is ‘eight’-type, and the macroscopic fracture morphology of sandstone is mainly of partial ‘Y’-type and inverted Y-type. The intensity and uniformity of the gypsum and sandstone of the medium are different; because the gypsum is more uniform, it does not show as much variation as sandstone, instead suddenly increasing and decreasing. The maximum value of the damage variable D of gypsum reached 1, but the maximum value of D of the sandstone only reached 0.9. The frequency band of the maximum energy of gypsum and sandstone gradually decreased across the the four stages of rupture, while the maximum energy percentage increased gradually. From the stage where damage gradually increases to the stage of integral fracture of the specimen, the instantaneous energy showed a certain degree of increase. With an increase in the strength of the sample, the maximum energy percentage of the two materials corresponding to each phase gradually increases, and from the stage where damage gradually increases to the stage of integral fracture of the specimen, the value of instantaneous energy obviously increases. The results indicate that gypsum mines will also experience rock bursts, as coal mines do, but the intensity will be different. Therefore, using the three indicators, the



    Imam, Syed H.; Bor-Sen Chiou; Delilah Woods; Justin Shey; Glenn, Gregory M.; William J. Orts; Rajnesh Narayan; Robert J. Avena-Bustillos; McHugh, Tara H.; Alberto Pantoja; Bechtel, Peter J.


    Baked starch/pulp foams were prepared from formulations containing zero to 25 weight percent of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads, and pollock frames (bones and associated remains produced in the filleting operation). Fish by-products thermoformed well along with starch and pulp fiber, and the foam product (panels) exhibited useful mechanical properties. Foams with all three fish by-products, ranging between 10 and 15 wt%, showed the highe...

  11. Residual effects of monoammonium phosphate, gypsum and elemental sulfur on cadmium phytoavailability and translocation from soil to wheat in an effluent irrigated field. (United States)

    Qayyum, Muhammad Farooq; Rehman, Muhammad Zia Ur; Ali, Shafaqat; Rizwan, Muhammad; Naeem, Asif; Maqsood, Muhammad Aamer; Khalid, Hinnan; Rinklebe, Jörg; Ok, Yong Sik


    Cadmium (Cd) accumulation in agricultural soils is one of the major threats to food security. The application of inorganic amendments such as mono-ammonium phosphate (MAP), gypsum and elemental sulfur (S) could alleviate the negative effects of Cd in crops. However, their long-term residual effects on decreasing Cd uptake in latter crops remain unclear. A field that had previously been applied with treatments including control and 0.2, 0.4 and 0.8% by weight of each MAP, gypsum and S, and grown with wheat and rice and thereafter wheat in the rotation was selected for this study. Wheat (Triticum aestivum L.) was grown in the same field as the third crop without further application of amendments to evaluate the residual effects of the amendments on Cd uptake by wheat. Plants were harvested at maturity and grain, and straw yield along with Cd concentration in soil, straw, and grains was determined. The addition of MAP and gypsum significantly increased wheat growth and yield and decreased Cd accumulation in straw and grains compared to control while the reverse was found in S application. Both MAP and gypsum decreased AB-DTPA extractable Cd in soil while S increased the bioavailable Cd in soil. Both MAP and gypsum increased the Cd immobilization in the soil and S decreased Cd immobilization in a dose-additive manner. We conclude that MAP and gypsum had a significant residual effect on decreasing Cd uptake in wheat. The cost-benefit ratio revealed that gypsum is an effective amendment for decreasing Cd concentration in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions. (United States)

    Córdoba, Patricia; Castro, Iria; Maroto-Valer, Mercedes; Querol, Xavier


    Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation (FGD)-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the pH and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the pH value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO2SO4, H2Se, and HAsO2 are the aqueous complexes with the highest activities under acidic conditions. The speciation of Zn, Li, and Ni is not affected in spite of pH changes; these elements occur as free cations and associated to SO4(2) in the FGD-gypsum leachates. The mobility of Cu and Mo decreases by decreasing the pH of the FGD-gypsum leachates, which might be associated to the precipitation of CuSe2 and MoSe2, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples. Copyright © 2015. Published by Elsevier B.V.

  13. Uptake and speciation of uranium in synthetic gypsum (CaSO4•2H2O): Applications to radioactive mine tailings. (United States)

    Lin, Jinru; Sun, Wei; Desmarais, Jacques; Chen, Ning; Feng, Renfei; Zhang, Patrick; Li, Dien; Lieu, Arthur; Tse, John S; Pan, Yuanming


    Phosphogypsum formed from the production of phosphoric acid represents by far the biggest accumulation of gypsum-rich wastes in the world and commonly contains elevated radionuclides, including uranium, as well as other heavy metals and metalloids. Therefore, billions-of-tons of phosphogypsum stockpiled worldwide not only possess serious environmental problems but also represent a potential uranium resource. Gypsum is also a major solid constituent in many other types of radioactive mine tailings, which stems from the common usage of sulfuric acid in extraction processes. Therefore, management and remediation of radioactive mine tailings as well as future beneficiation of uranium from phosphogysum all require detailed knowledge about the nature and behavior of uranium in gypsum. However, little is known about the uptake mechanism or speciation of uranium in gypsum. In this study, synthesis experiments suggest an apparent pH control on the uptake of uranium in gypsum at ambient conditions: increase in U from 16 μg/g at pH = 6.5 to 339 μg/g at pH = 9.5. Uranium L3-edge synchrotron X-ray absorption spectroscopic analyses of synthetic gypsum show that uranyl (UO2)2+ at the Ca site is the dominant species. The EXAFS fitting results also indicate that uranyl in synthetic gypsum occurs most likely as carbonate complexes and yields an average U-O distance ∼0.25 Å shorter than the average Ca-O distance, signifying a marked local structural distortion. Applications to phosphogypsum from the New Wales phosphoric acid plant (Florida, USA) and uranium mine tailings from the Key Lake mill (Saskatchewan, Canada) show that gypsum is an important carrier of uranium over a wide range of pH and controls the fate of this radionuclide in mine tailings. Also, development of new technologies for recovering U from phosphogypsum in the future must consider lattice-bound uranyl in gypsum. Copyright © 2017 Elsevier Ltd. All rights reserved.


    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang; X. Huang; M.G. McKimpson; R.E. Tieder; A.M. Hein; J.M. Gillis; D.C. Popko; K.L. Paxton; Z. Li; X. Liu; X. Song; R.I. Kramer


    Low NO{sub x} combustion practices are critical for reducing NO{sub x} emissions from power plants. These low NO{sub x} combustion practices, however, generate high residual carbon contents in the fly ash produced. These high carbon contents threaten utilization of this combustion by-product. This research has successfully developed a separation technology to render fly ash into useful, quality-controlled materials. This technology offers great flexibility and has been shown to be applicable to all of the fly ashes tested (more than 10). The separated materials can be utilized in traditional fly ash applications, such as cement and concrete, as well as in nontraditional applications such as plastic fillers, metal matrix composites, refractories, and carbon adsorbents. Technologies to use beneficiated fly ash in these applications are being successfully developed. In the future, we will continue to refine the separation and utilization technologies to expand the utilization of fly ash. The disposal of more than 31 million tons of fly ash per year is an important environmental issue. With continued development, it will be possible to increase economic, energy and environmental benefits by re-directing more of this fly ash into useful materials.

  15. Synthesis of zeolite phases from combustion by-products

    Energy Technology Data Exchange (ETDEWEB)

    Pimraksa, K.; Chindaprasirt, P.; Setthaya, N. [Chiang Mai University, Chiang Mai (Thailand). Dept. of Industrial Chemistry


    Synthesis of zeolites from combustion by-products, including fly ash, bottom ash and rice husk ash, was studied. A molar ratio of SiO{sub 2}/Al2O{sub 3} of 1.5 was used for the syntheses. Refluxing and hydrothermal methods were also used for synthesis for comparison. The reaction temperatures of refluxing and hydrothermal methods were 100{sup o}C and 130{sup o}C, respectively. Sodalite, phillipsite-K, and zeolite P1 with analcime were obtained when fly ash, bottom ash and rice husk ash were used as starting materials, respectively. With rice husk ash as a starting material, zeolite P1 was produced. This result had advantages over previous studies as there was no prior activation required for the synthesis. The concentrations and types of alkaline used in the synthesis also determined the zeolite type. The different zeolites obtained from three systems were measured for specific surface area and pore size by using BET and Hg-porosimetry, respectively. Ammonium exchange capacities of the synthesised powders containing zeolites, sodalite, zeolite P1 and phillipsite-K were 38.5, 65.0 and 154.7 meq 100 g{sup 1}, respectively.

  16. Local agro-industrial by-products with potential use in Ghanaian aquaculture: a review

    DEFF Research Database (Denmark)

    Obirikorang, Kwasi Adu; Amisah, Stephen; Fialor, Simon Cudjoe


    The inability of Ghana’s capture-based fisheries to meet national demand has placed aquaculture in an advantageous position to satisfy this supply deficit. The majority of fish farmers in Ghana, however, resort to local feed mixtures, occasionally in combination with commercial aquafeeds...... regions of the world where these crops and their resulting by-products are produced in commercial quantities...

  17. Digestion kinetics of carbohydrate fractions of citrus by-products. (United States)

    Lashkari, Saman; Taghizadeh, Akbar


    The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the in vitro gas production technique. Fermentation kinetics of the neutral detergent soluble carbohydrates (NDSC) fraction and hemicelluloses were calculated using a curve subtraction. The fermentation rate of whole was the highest for the LE (p citrus by-products lag time was longer for hemicellulose than other carbohydrate fractions. There was no significant difference among potential gas production (A) volumes of whole test feeds (p citrus by-products have high potential for degradability. It could also be concluded that carbohydrate fractions of citrus by-products have remarkable difference in digestion kinetics and digestive behavior.

  18. Bacterial communities and the nitrogen cycle in the gypsum soils of Cuatro Ciénegas Basin, coahuila: a Mars analogue. (United States)

    López-Lozano, Nguyen E; Eguiarte, Luis E; Bonilla-Rosso, Germán; García-Oliva, Felipe; Martínez-Piedragil, Celeste; Rooks, Christine; Souza, Valeria


    The OMEGA/Mars Express hyperspectral imager identified gypsum at several sites on Mars in 2005. These minerals constitute a direct record of past aqueous activity and are important with regard to the search of extraterrestrial life. Gale Crater was chosen as Mars Science Laboratory Curiosity's landing site because it is rich in gypsum, as are some desert soils of the Cuatro Ciénegas Basin (CCB) (Chihuahuan Desert, Mexico). The gypsum of the CCB, which is overlain by minimal carbonate deposits, was the product of magmatic activity that occurred under the Tethys Sea. To examine this Mars analogue, we retrieved gypsum-rich soil samples from two contrasting sites with different humidity in the CCB. To characterize the site, we obtained nutrient data and analyzed the genes related to the N cycle (nifH, nirS, and nirK) and the bacterial community composition by using 16S rRNA clone libraries. As expected, the soil content for almost all measured forms of carbon, nitrogen, and phosphorus were higher at the more humid site than at the drier site. What was unexpected is the presence of a rich and divergent community at both sites, with higher taxonomic diversity at the humid site and almost no taxonomic overlap. Our results suggest that the gypsum-rich soils of the CCB host a unique microbial ecosystem that includes novel microbial assemblies.

  19. Digestion kinetics of carbohydrate fractions of citrus by-products


    Lashkari, Saman; Taghizadeh, Akbar


    The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the in vitro gas production technique. Fermentation kinetics of the neutral detergent soluble carbohydrate...

  20. Growth of cowpea plants inoculated with Rhizobium in a saline-sodic soil after application of gypsum

    Directory of Open Access Journals (Sweden)

    Angela Jessyka Pereira Brito Fontenele

    Full Text Available Two experiments were carried out with the aim of evaluating the growth of cowpea cultivated in saline-sodic soils corrected with gypsum: one experiment in the laboratory, to identify the best level of gypsum for the correction of the saline-sodic soils of the state of Pernambuco, Brazil; and the other in a greenhouse, after correction of the soils. As the test plant, the cowpea cultivar pele de moça, inoculated with Rhizobium strain BR3267 was used. The experiments were arranged in a randomised block design in a 2 x 5 factorial arrangement, two soils and five levels of the gypsum requirement (GR, equivalent to 50, 100, 150, 200 and 250% of the GR of the soil, as determined by the Schoonover M-1 method, with five replications. The following were evaluated: electrical conductivity of the soil saturation extract (EC, soil exchangeable sodium and percentage of soil exchangeable sodium (ESP, number of nodules (NN, nodule dry weight (NDW, shoot dry weight (SDW, shoot height (PH and nitrogen concentration (N in the shoots. Application of 100% of the GR, followed by the enough water for leaching, was effective for the correction of soil sodicity. The application of increasing levels of soil GR resulted in an increase in the number of nodules, dry weight of the nodules and shoots, and the height and levels of N absorbed by the plants in soil S2. In soil S1, the use of levels of 200 and 250% of soil the GR caused a decrease in all the variables under study.

  1. Reciclado de placas de yeso laminado aligeradas con residuos de poliuretano = Recycling of gypsum plasterboard lightened with polyurethane waste

    Directory of Open Access Journals (Sweden)

    Lourdes Alameda


    Full Text Available Este trabajo presenta los resultados de un proceso experimental de reutilización de residuos obtenidos de desechos de placas de yeso laminado elaboradas con residuos poliméricos de origen industrial (espuma de poliuretano y reforzadas con fibras de polipropileno, para la fabricación de nuevas placas de yeso laminado. Para ello, se expone la metodología de reciclado de placas prefabricadas buscando de esta forma aumentar el ciclo de vida del yeso y de los residuos de poliuretano empleados. Para ello se detalla el proceso de fabricación las nuevas placas así como su caracterización mediante ensayos físicos y mecánicos a través de ensayos normalizados para placas de yeso laminado (densidad aparente, resistencia a flexión, absorción total en agua y dureza superficial. Los resultados obtenidos indican que es posible reciclar este tipo de prefabricados de una manera sencilla. De la misma forma se ha demostrado que las nuevas placas fabricadas con el residuo recuperado, presentan un buen comportamiento mecánico, a la par que se reduce su capacidad de absorción de agua y se aumenta su dureza su superficial. Abstract This paper presents the results of an experimental process of reusing waste obtained from waste gypsum plasterboard made from polymeric industrial waste (polyurethane foam and polypropylene fibers whit the aim to manufacturer new gypsum plasterboards. Therefore, a methodology to recycle is presented to increase the life cycle of waste gypsum. The manufacturing process of the plates is detailed as well as their physical and mechanical characterization by means of standardized for gypsum plasterboard (bulk density, flexion strength, total water absorption and surface hardness. The results indicate that it is possible to recycle this type of prefabricated in a simple way. Likewise it has been demonstrated that new plates made with the residue reusing, have good mechanical strength, at the same time reduce the capacity of water

  2. Soil Chemical and Physical Properties on an Inceptisol after Liming (Surface and Incorporated Associated with Gypsum Application

    Directory of Open Access Journals (Sweden)

    Delcio Rudinei Bortolanza


    Full Text Available ABSTRACT Inceptsoils have high aluminum contents, and amendments are required to ensure a satisfactory crop development. Liming is efficient in neutralizing Al3+, but when applied to the topsoil its action is restricted to the surface layers, and sometimes lime incorporation into the soil is recommendable. However, tillage may negatively alter physical soil properties. Thus, gypsum could be an alternative to increase Ca2+ levels and reduce Al saturation in deeper layers, without requiring tillage. An experiment was initiated in 2010, to assess chemical and physical soil properties. Soil samples were collected in February 2013. A random block design with sub-subplots and two replications was used. Lime was applied to the surface of the main plot (0, 8 and 16 Mg ha-1 and incorporated into the soil by plowing and light harrowing. Gypsum was applied to the subplot (0 and 6 Mg ha-1, and the sub-subplots corresponded to the sampled layers (thickness of 0.05 m, to a depth of 0.25 m. The following parameters were evaluated: pH in water, base saturation, Al saturation, Ca2+, Mg2+, soil organic matter, water retention, and least limiting water range (LLWR. Lime incorporated into the soil reduced Al3+ and increased pH and Ca2+ levels, especially in the deeper soil layers, although pH levels did not exceed 5.1 and base saturation was lower than 60 %, still inadequate for crops. The gypsum rate of 6 Mg ha-1 did not decrease Al saturation, but reduced Mg2+ levels in top soil layers. Soil water retention and LLWR were not affected by plowing and harrowing within a period of three years. Gypsum rates below 6 Mg ha-1 were not effective in reducing Al saturation and increasing Ca2+ levels. Incorporated lime is more effective in correcting the acidity of the soil profile and, after three years, soil water retention and LLWR were similar under both liming methods.

  3. Use of the “red gypsum” industrial waste as substitute of natural gypsum for commercial cements manufacturing

    Directory of Open Access Journals (Sweden)

    Gázquez, M. J.


    Full Text Available The main objective of this research has been the valorisation of a waste from the TiO2 production process (sulphate method, called red gypsum, in the production of cements. This waste is mainly formed by di-hydrate calcium sulphate and iron hydroxides. To cover this objective it has been necessary to perform the physico-chemical characterisation of the red gypsum as well as the main components in the production of cements and of the new cements generated. Moreover, for the red gypsum, has been analyzed its radioactive content because it is generated in a NORM (Naturally Occurring Radioactive Materials industry. Finally, the most important properties of the obtained cements with different proportions of red gypsum in their composition have been studied by comparing them with the standard ones obtained in a Portland cement. Lastly, we have demonstrated that the new cements fulfil all the quality tests imposed by the European legislation.

    El objetivo de esta investigación ha sido analizar la valorización de un residuo generado en el proceso de producción de dióxido de titanio (vía sulfato, denominado yeso rojo, en la producción de cementos. Dicho residuo está compuesto fundamentalmente por sulfato de calcio di-hidratado e hidróxidos de hierro. Para ello, ha sido necesaria la caracterización físico-química del yeso rojo, así como la de los otros componentes fundamentales en la fabricación de cementos y de los cementos generados con el mencionado residuo. Además, en el caso del yeso rojo, se ha analizado su contenido radiactivo al generarse éste en una industria NORM (Natural Occurring Radioactive Materials. Posteriormente, se han estudiado las propiedades más importantes de los cementos producidos con diferentes porcentajes de yeso rojo añadido, comparando estas mezclas con las propiedades de un cemento Portland comercial, comprobándose que se cumplen todas las normas Europeas de calidad exigibles.

  4. Thermal Characteristics of Eutectic Mixture of Capric-Lauric Acids as Phase Change Material (PCM) in Gypsum Board


    Riza, Medyan


    Thermal characteristics of some eutectic mixtures of fatty acids as phase change materials (PCM) for passive solar building heating and cooling application have been studied previously. This study looked at the effect of using capric – lauric acids eutectic mixture with a composition of 65: 35 w/w % as PCM in gypsum board. Capric – lauric acids eutectic mixture has melting point of 17.48oC and latent heat of 133.08 kJ kg-1. The melting point is considered suitable to maintain a comfortabl...

  5. Relative Shock Effects in Mixed Powders of Calcite, Gypsum, and Quartz: A Calibration Scheme from Shock Experiments (United States)

    Bell, Mary S.


    The shock behavior of calcite and gypsum is important in understanding the Cretaceous/Tertiary event and other terrestrial impacts that contain evaporite sediments in their targets. Most interest focuses on issues of devolatilization to quantify the production of CO2 or SO2 to better understand their role in generating a temporary atmosphere and its effects on climate and biota [e.g., papers in 1,2,3,4]. Devolatilization of carbonate is also important because the dispersion and fragmentation of ejecta is strongly controlled by the expansion of large volumes of gas during the impact process as well [5,6]. Shock recovery experiments for calcite yield seemingly conflicting results: early experimental devolatilization studies [7,8,9] suggested that calcite was substantially outgassed at 30 GPa (> 50%). However, the recent petrographic work of [10,11,12] presented evidence that essentially intact calcite is recovered from 60 GPa experiments. [13] reported results of shock experiments on anhydrite, gypsum, and mixtures of those phases with silica. Their observations indicate little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another (preliminary) report of shock experiments on calcite, anhydrite, and gypsum, [14] observe calcite recrystallization when shock loaded at 61 GPa, only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa. [15] shock loaded anhydrite and quartz to a peak pressure of 60 GPa. All of the quartz grains were trans-formed to glass and the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggest that recrystallization of anhydrite grains is the result of a solid state transformation. [16] reanalyzed the calcite and anhydrite shock


    Energy Technology Data Exchange (ETDEWEB)

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu


    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  7. Land application uses for dry flue gas desulfurization by-products: Phase 3

    Energy Technology Data Exchange (ETDEWEB)

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.


    New flue gas desulfurization (FGD) scrubbing technologies create a dry, solid by-product material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Generally, dry FGD by-products are treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing. Provided the environmental impacts are socially and scientifically acceptable, beneficial uses via recycling can provide economic benefits to both the producer and the end user of the FGD. A study titled ''Land Application Uses for Dry Flue Gas Desulfurization By-Products'' was initiated in December, 1990 to develop and demonstrate large volume, beneficial uses of FGD by-products. Phase 1 and Phase 2 reports have been published by the Electric Power Research Institute (EPRI), Palo Alto, CA. Phase 3 objectives were to demonstrate, using field studies, the beneficial uses of FGD by-products (1) as an amendment material on agricultural lands and on abandoned surface coal mine land, (2) as an engineering material for soil stabilization and raid repair, and (3) to assess the environmental and economic impacts of such beneficial uses. Application of dry FGD by-product to three soils in place of agricultural limestone increased alfalfa (Medicago sativa L.) and corn (Zea may L.) yields. No detrimental effects on soil and plant quality were observed.

  8. Removal of phosphorus, fluoride and metals from a gypsum mining leachate using steel slag filters. (United States)

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves


    The objective of this work was to evaluate the capacity of steel slag filters to treat a gypsum mining leachate containing 11-107 mg P/L ortho-phosphates, 9-37 mg/L fluoride, 0.24-0.83 mg/L manganese, 0.20-3.3 zinc and 1.7-8.2 mg/L aluminum. Column tests fed with reconstituted leachates were conducted for 145-222 days and sampled twice a week. Two types of electric arc furnace (EAF) slags and three filter sequences were tested. The voids hydraulic retention time (HRT(v)) of columns ranged between 4.3 and 19.2 h. Precipitates of contaminants present in columns were sampled and analyzed with X-ray diffraction at the end of tests. The best removal efficiencies over a period of 179 days were obtained with sequential filters that were composed of Fort Smith EAF slag operated at a total HRT(v) of 34 h which removed 99.9% of phosphorus, 85.3% of fluoride, 98.0% of manganese and 99.3% of zinc. Mean concentration at this system's effluent was 0.04 mg P/L ortho-phosphates, 4 mg/L fluoride, 0.02 mg/L manganese, 0.02 zinc and 0.5 mg/L aluminum. Thus, slag filters are promising passive and economical systems for the remediation of mining effluents. Phosphorus was removed by the formation of apatite (hydroxyapatite, Ca(5)(PO(4))(3)OH or fluoroapatite, Ca(5)(PO(4))(3)F) as confirmed by visual and X-ray diffraction analyses. The growth rate of apatite was favored by a high phosphorus concentration. Calcite crystals were present in columns and appeared to be competing for calcium and volume needed for apatite formation. The calcite crystal growth rate was higher than that of apatite crystals. Fluoride was removed by precipitation of fluoroapatite and its removal was favored by a high ratio of phosphorus to fluoride in the wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Life Cycle Greenhouse Gas Emissions of By-product Hydrogen from Chlor-Alkali Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Yeon [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division; Elgowainy, Amgad A. [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division; Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States). Systems Assessment Group, Energy Systems Division


    Current hydrogen production capacity in the U.S. is about 15.8 million tonne (or metric ton) per year (Brown 2016). Some of the hydrogen (2 million tonne) is combusted for its heating energy value, which makes total annual net production 13.8 million tonne (Table 1). If captive by-product hydrogen (3.3 million tonne) from catalytic reforming at oil refineries is excluded (Brown 2016; EIA 2008), approximately 11 million tonne is available from the conventional captive and merchant hydrogen market (DOE 2013). Captive hydrogen (owned by the refiner) is produced and consumed on site (e.g., process input at refineries), whereas merchant hydrogen is produced and sold as a commodity to external consumers. Whether it is merchant or captive, most hydrogen produced in the U.S. is on-purpose (not by-product)— around 10 million tonne/year.


    Directory of Open Access Journals (Sweden)

    Hanna Siwek


    Full Text Available The effect of ash from biomass, lime and gypsum fertilization on quality of grain, flour and dough of spring wheat variety Żura was analysed. The experience was realized in 2016 in the village Noskowo (54º38'N, 16º82'S, located in the district of Sławno in the West Pomeranian Voivodeship.The study compared three factors: wood ash and straw ash (I. factor, 2 types of ash additive: lime or gypsum (factor II, 4 doses of ash mixture with lime or gypsum: 2, 4, 6 t Ha-1 (factor III. After application of straw ash, higher value of MTZ of spring wheat grain was obtained. The doses of biomass ash and the lime (the trade name PROFITKALK or gypsum (SulfoPROFIT did not affect the value of this parameter. Differentiated ash fertilization in combination with increasing doses of calcium or gypsum fertilizer did not modify the seed parameters of spring wheat: density of the grain in the test weight, falling number, protein and starch content, gluten content and Zeleny test. By applying ash from biomass obtained from wood or straw the dough stability time was varied, and the dough softening after 10 and 12 minutes. Dough stability and softening of dough after 10 and 12 minutes of dough obtained from wheat Żura were not significantly determined by the dose of ash from biomass and the applied calcium fertilizer with or gypsum fertilizer. Exception was the parameter of softening the dough of flour after 12 minutes. The application of fertilization in the studies enabled the grain of spring wheat of Żura with right quality parameters.

  11. Flue-gas desulfurization gypsum effects on urea-degrading bacteria and ammonia volatilization from broiler litter. (United States)

    Burt, Christopher D; Cabrera, Miguel L; Rothrock, Michael J; Kissel, D E


    A major concern of the broiler industry is the volatilization of ammonia (NH3) from the mixture of bedding material and broiler excretion that covers the floor of broiler houses. Gypsum has been proposed as a litter amendment to reduce NH3 volatilization, but reports of NH3 abatement vary among studies and the mechanism responsible for decreasing NH3 volatilization is not well understood. The goal of this study was to evaluate the effect of adding 20 or 40% flue-gas desulfurization gypsum (FGDG) to broiler litter on pH, electrical conductivity (EC), water potential, urea-degrading bacteria abundance, NH3 and carbon dioxide (CO2) evolution, and nitrogen (N) mineralization in several 21-d experiments. The addition of FGDG to broiler litter increased EC by 24 to 33% (P broiler litter decreased NH3 volatilization by 18 to 28% (P broiler litter with 20% FGDG can decrease NH3 volatilization and increase the fertlizer value of broiler litter. © 2017 Poultry Science Association Inc.

  12. The comparison of safety level in kilns in two gypsum production factories by Failure modes and effects Analysis (FMEA

    Directory of Open Access Journals (Sweden)

    I. Alimohammadi


    Full Text Available Background and aims Failure Modes and Effects Analysis (FMEA is a qualitative method for determination of components' fails and study of its effects on machineries. In present study, kilns safety level of two gypsum factories examine.MethodsProduction process of gypsum and especially kilns structure studied. FMEAmethod conducted by four steps including determination of analysis insight, information gathering, making of list of kilns' components and filling up the FMEA tables. On the other hand, the effects of fails on production, how to fail, failure rates, severity of fails, and controls of fails considered.  Furthermore, the cost of fails and priority of control methods studied.ResultsCrack and deformation of shoe plats had highest failure rate in two factories kilns. Some fails such as separation of bricks in kiln of second factory is less than the other one. Meanwhile, some fails including wrapping of kilns trunk, ring corrosion, and fracture of truster's shaft is only present in first kiln.ConclusionPresent study shows that technical features and design of kilns is most important factors in decreasing of failure rates and its cost.

  13. Successful lichen translocation on disturbed gypsum areas: A test with adhesives to promote the recovery of biological soil crusts (United States)

    Ballesteros, M.; Ayerbe, J.; Casares, M.; Cañadas, E. M.; Lorite, J.


    The loss of biological soil crusts represents a challenge for the restoration of disturbed environments, specifically in particular substrates hosting unique lichen communities. However, the recovery of lichen species affected by mining is rarely addressed in restoration projects. Here, we evaluate the translocation of Diploschistes diacapsis, a representative species of gypsum lichen communities affected by quarrying. We tested how a selection of adhesives could improve thallus attachment to the substrate and affect lichen vitality (as CO2 exchange and fluorescence) in rainfall-simulation and field experiments. Treatments included: white glue, water, hydroseeding stabiliser, gum arabic, synthetic resin, and a control with no adhesive. Attachment differed only in the field, where white glue and water performed best. Adhesives altered CO2 exchange and fluorescence yield. Notably, wet spoils allowed thalli to bind to the substrate after drying, revealing as the most suitable option for translocation. The satisfactory results applying water on gypsum spoils are encouraging to test this methodology with other lichen species. Implementing these measures in restoration projects would be relatively easy and cost-effective. It would help not only to recover lichen species in the disturbed areas but also to take advantage of an extremely valuable biological material that otherwise would be lost.

  14. Study of heat and mass transfer of water evaporation in a gypsum board subjected to natural convection (United States)

    Zannouni, K.; El Abrach, H.; Dhahri, H.; Mhimid, A.


    The present paper reports a numerical study to investigate the drying of rectangular gypsum sample based on a diffusive model. Both vertical and low sides of the porous media are treated as adiabatic and impermeable surfaces plate. The upper face of the plate represents the permeable interface. The energy equation model is based on the local thermal equilibrium assumption between the fluid and the solid phases. The lattice Boltzmann method (LBM) is used for solving the governing differential equations system. The obtained numerical results concerning the moisture content and the temperature within a gypsum sample were discussed. A comprehensive analysis of the influence of the mass transfer coefficient, the convective heat transfer coefficient, the external temperature, the relative humidity and the diffusion coefficient on macroscopic fields are also investigated. They all presented results in this paper and obtained in the stable regime correspond to time superior than 4000 s. Therefore the numerical error is inferior to 2%. The experimental data and the descriptive information of the approach indicate an excellent agreement between the results of our developed numerical code based on the LBM and the published ones.

  15. Investigation on the relationship between the fine particle emission and crystallization characteristics of gypsum during wet flue gas desulfurization process. (United States)

    Pan, Danping; Wu, Hao; Yang, Linjun


    The relationship between the fine particles emitted after desulfurization and gypsum crystals in the desulfurization slurry was investigated, and the crystallization characteristics varying with the operation parameters and compositions of the desulfurization slurry were discussed. The results showed that the fine particles generated during the desulfurization process were closely related to the crystal characteristics in the desulfurization slurry by comparison of their morphology and elements. With the higher proportion of fine crystals in the desulfurization slurry, the number concentration of fine particles after desulfurization was increased and their particle sizes were smaller, indicating that the optimization of gypsum crystallization was beneficial for the reduction of the fine particle emission. The lower pH value and an optimal temperature of the desulfurization slurry were beneficial to restrain the generation of fine crystals in the desulfurization slurry. In addition, the higher concentrations of the Fe(3+) ions and the F(-) ions in the desulfurization slurry both promoted the generation of fine crystals with corresponding change of the morphology and the effect of the Fe(3+) ions was more obvious. With the application of the desulfurization synergist additive, it was beneficial for the inhibition of fine crystals while the thinner crystals were generated. Copyright © 2016. Published by Elsevier B.V.

  16. Evidence for micro-biological induction of {101} montmartre twinning of gypsum (CaSO 4 ⋯ 2H 2O) (United States)

    Cody, A. M.; Cody, R. D.


    Natural gypsum crystals twinned on d{101} have been found almost exclusively in deposits from saline lakes and secondary mine alterations. The presence of α-amylase, an enzyme excreted into soils and water by bacteria, fungi, algae, and plant roots, was found to induce d{101} twinning of gypsum crystals formed by diffusion in laboratory growth experiments. From this evidence, extensive deposits of d{101} twinned crystals such as those of the Paris Basin are proposed to form in the α-amylase concentrations that results from certain microbial blooms.

  17. Filler de grafito reciclado de EDM en pastas de yeso = EDM recycled graphite filler in gypsum pastes

    Directory of Open Access Journals (Sweden)

    Nelson Flores


    Full Text Available El grafito puede obtenerse de forma natural o sintética, pero este último se ha utilizado en carreteras debido a su dureza, así como en placas de cerámica fina. Se demuestran las posibilidades de la adición del polvo de grafito isostático procedente del fresado de moldes fabricados por Electroerosión de Penetración (EDM en compuestos a base de yeso. Para ello se prepararon mezclas de yeso industrial con adiciones en porcentajes diferentes de grafito EDM para evaluar las propiedades físicas y mecánicas, caracterizando previamente ambos materiales. El yeso fue sustituido por grafito en cinco fracciones diferentes, 5, 10, 15, 20 y 25%, en peso, en la preparación de las mezclas. En la designación Y-0.7G-0 y Y-0.6G-0 de las series de probetas prismáticas de 40x40x160mm, la letra Y se refiere al yeso y G significa grafito (G-0 probetas patrón sin grafito, con relaciones agua/yeso (a/y 0,7 y 0,6. Después del análisis de los resultados obtenidos, se realizó unas nuevas series con la adición de plastificante y también con mayor cantidad de grafito, 25 a 50% en peso y otras relaciones a/y basadas en su trabajabilidad, para verificar la incidencia en la resistencia a flexión y compresión. Abstract Graphite can be obtained naturally or synthetically, but the latter has been used on roads because of its hardness, as well as in thin ceramic plates. The possibilities of the addition of the isostatic graphite powder from the milling of molds made by EDM in gypsum-based compounds are demonstrated. For this purpose mixtures of industrial gypsum with additions in different percentages of EDM graphite were prepared to evaluate the physical and mechanical properties, previously characterizing both materials. The gypsum was replaced by graphite in five different fractions, 5, 10, 15, 20 and 25% by weight, in the preparation of the mixtures. In the designation Y-0.7G-0 and Y-0.6G-0 of the series of prismatic specimens of 40x40x160mm, the letter Y

  18. By-products of Opuntia ficus-indica as a source of antioxidant dietary fiber. (United States)

    Bensadón, Sara; Hervert-Hernández, Deisy; Sáyago-Ayerdi, Sonia G; Goñi, Isabel


    Dietary fiber and bioactive compounds are widely used as functional ingredients in processed foods. The market in this field is competitive and the development of new types of quality ingredients for the food industry is on the rise. Opuntia ficus-indica (cactus pear) produces edible tender stems (cladodes) and fruits with a high nutritional value in terms of minerals, protein, dietary fiber and phytochemicals; however, around 20% of fresh weight of cladodes and 45% of fresh weight of fruits are by-products. The objective of this study was therefore to determine the nutritional value of by-products obtained from cladodes and fruits from two varieties of Opuntia ficus-indica, examining their dietary fiber and natural antioxidant compound contents in order to obtain quality ingredients for functional foods and increase the added value of these by-products.

  19. Wastes and by-products - alternatives for agricultural use

    Energy Technology Data Exchange (ETDEWEB)

    Boles, J.L.; Craft, D.J.; Parker, B.R.


    Top address a growing national problem with generation of wastes and by-products, TVA has been involved for several years with developing and commercializing environmentally responsible practices for eliminating, minimizing, or utilizing various wastes/by-products. In many cases, reducing waste generation is impractical, but the wastes/by-products can be converted into other environmentally sound products. In some instances, conversion of safe, value-added agricultural products in the best or only practical alternative. TVA is currently involved with a diversity of projects converting wastes/by-products into safe, economical, and agriculturally beneficial products. Environmental improvement projects have involved poultry litter, cellulosic wastes, used battery acid, ammonium sulfate fines, lead smelting effluents, deep-welled sulfuric acid/ammonium bisulfate solutions, wood ash, waste magnesium ammonium sulfate slurry from recording tape production, and ammunition plant waste sodium nitrate/ammonium nitrate streams.

  20. Land application uses for dry FGD by-products. Phase 2 report

    Energy Technology Data Exchange (ETDEWEB)

    Stehouwer, R.; Dick, W.; Bigham, J. [Ohio State Univ., Columbus, OH (United States)] [and others


    A study was initiated in December 1990 to demonstrate large volume beneficial uses of flue gas desulfurization (FGD) by-products. A Phase 1 report provided results of an extensive characterization of chemical, physical, mineralogical and engineering properties of 58 dry FGD by-product samples. The Phase 1 report concluded that high volume beneficial reuses will depend on the economics related to their ability to substitute for existing materials for various types of applications (e.g. as an agricultural liming material, soil borrow for highway embankment construction, and reclamation of active and abandoned surface coal mine lands). Phase 2 objectives were (1) to conduct laboratory and greenhouse studies of FGD and soil (spoil) mixtures for agronomic and engineering applications, (2) to initiate field studies related to high volume agronomic and engineering uses, and (3) to develop the basic methodological framework for estimation of the financial and economic costs and benefits to society of several FGD reuse options and to make some preliminary runs of economic models. High volume beneficial reuses of dry FGD by-products have been successfully demonstrated. Adverse environmental impacts have been negligible. Although few sources of dry FGD by-products currently exist in Ohio and the United States there is potential for smaller coal-fired facilities to adopt S0{sub 2} scrubbing technologies that produce dry FGD material. Also much of what we have learned from studies on dry FGD by-products is applicable to the more prevalent wet FGD by-products. The adaptation of the technologies demonstrated in this project seem to be not only limited by economic constraints, but even more so, by the need to create awareness of the market potential of using these FGD by-products.

  1. Effect of snack food by-product inclusion on production of laying hens. (United States)

    Van Wyhe, R C; Fraley, S E; Szybisty, C A; Karcher, D M; Karcher, E L


    The increased interest in becoming green for consumers and companies is driving groups to develop innovative ways to become more efficient and reduce their waste. Foods past their expiration dates are large sources of waste and are causing food-manufacturing companies to develop waste disposal strategies. Integrating by-products from these companies into animal diets, specifically that of laying hens, could be significantly more cost effective for both the human food manufacturers and the agricultural producers. The study's objective is to evaluate laying hen diets containing snack food by-product, consisting mostly of expired potato chips, and the effect on hen performance. In total, 192 White Leghorn laying hens (45 wk old) were selected from the Michigan State University Poultry Farm. Hens were housed in conventional cages (3 birds/cage) and received 1 of 4 diets for 5 wk: 1) industry control corn-soybean meal, 2) control with 3% by-product, 3) control with 6% by-product, and 4) control with 9% by-product. Diets were formulated to be isocaloric, isonitrogenous, and balanced for sodium. Feed intake was measured for 3 consecutive days each week, and no overall differences between treatments were observed. However, during the first week, feed intake was significantly higher in birds fed the 6% and 9% diets compared with those fed control (P production, egg weight, and specific gravity were measured weekly. Hen BW was measured on d 1, 14, 28, and 35. Egg production, egg weight, specific gravity, and BW were not significantly affected by the addition of snack food by-products to the diet. In conclusion, the addition of expired snack food by-product into poultry diets does not significantly affect laying hen egg production and has the potential to be used as an alternative feed stuff in the future.

  2. Land application uses for dry FGD by-products, Phase 1 report

    Energy Technology Data Exchange (ETDEWEB)

    Bigham, J.; Dick, W.; Forster, L.; Hitzhusen, F.; McCoy, E.; Stehouwer, R.; Traina, S.; Wolfe, W.


    The 1990 amendments to the Clean Air Act have spurred the development of flue gas desulfurization (FGD) processes, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. FGD by-product materials are treated as solid wastes and must be landfilled. It is highly desirable to find beneficial reuses for these materials provided the environmental impacts are minimal and socially acceptable. Phase 1 results of a 4 and 1/2 year study to demonstrate large volume beneficial uses of FGD by-products are reported. The purpose of the Phase 1 portion of the project was to characterize the chemical, physical, mineralogical and engineering properties of the FGD by-product materials obtained from various FGD technologies being developed in the state of Ohio. Phase 1 also involved the collection of baseline economic data related to the beneficial reuse of these FGD materials. A total of 58 samples were collected and analyzed. The results indicated the chemical composition of the FGD by-product materials were dominated by Ca, S, Al, and Si. Many of the elements regulated by the US Environmental Protection Agency reside primarily in the fly ash. Phase 1 results revealed that FGD by-product materials are essentially coal fly ash materials diluted with unreacted sorbent and reaction products. High volume beneficial reuses will depend on the economics of their substituting for existing materials for various types of applications (e.g. as an agricultural liming material, soil borrow for highway embankment construction, and reclamation of active and abandoned surface coal mines). Environmental constraints to the beneficial reuse of dry FGD by-product materials, based on laboratory and leachate studies, seem to be less than for coal fly ash.

  3. Utilization of low rank coal and agricultural by-products

    Energy Technology Data Exchange (ETDEWEB)

    Ekinci, E.; Yardim, M.F.; Petrova, B.; Budinova, T.; Petrov, N. [Istanbul Technical University, Maslak-Istanbul (Turkey). Department of Chemical Engineering


    The present investigation deals with alternative utilization processes to convert low rank coal and agricultural by products into solid, liquid and gaseous products for a more efficient exploitation of these materials. Low rank coals and different agricultural by-products were subjected to different thermochemical treatments. The composition and physico-chemical properties of liquid products obtained from agricultural by-products were investigated. The identified compounds are predominantly oxygen derivatives of phenol, dihydroxybenzenes, guaiacol, syringol, vanilin, veratrol, furan and acids. Liquids from low rank coals contain higher quality of aromatic compounds predominantly mono- and bicyclic. The amount of oxygen containing structures is high as well. By thermo-chemical treatment of liquid products from agricultural by-products, low rank coals and their mixtures with H{sub 2}SO{sub 4} carbon adsorbents with very low ash and sulfur content are obtained. Using different activation reagents large scale carbon adsorbents are prepared from agricultural by-products and coals. The results of the investigations open-up possibilities for utilization of low rank coals and agricultural by-products. 18 refs., 5 figs., 7 tabs.

  4. Potential of chicken by-products as sources of useful biological resources

    Energy Technology Data Exchange (ETDEWEB)

    Lasekan, Adeseye [Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Abu Bakar, Fatimah, E-mail: [Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Hashim, Dzulkifly [Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)


    By-products from different animal sources are currently being utilised for beneficial purposes. Chicken processing plants all over the world generate large amount of solid by-products in form of heads, legs, bones, viscera and feather. These wastes are often processed into livestock feed, fertilizers and pet foods or totally discarded. Inappropriate disposal of these wastes causes environmental pollution, diseases and loss of useful biological resources like protein, enzymes and lipids. Utilisation methods that make use of these biological components for producing value added products rather than the direct use of the actual waste material might be another viable option for dealing with these wastes. This line of thought has consequently led to researches on these wastes as sources of protein hydrolysates, enzymes and polyunsaturated fatty acids. Due to the multi-applications of protein hydrolysates in various branches of science and industry, and the large body of literature reporting the conversion of animal wastes to hydrolysates, a large section of this review was devoted to this subject. Thus, this review reports the known functional and bioactive properties of hydrolysates derived from chicken by-products as well their utilisation as source of peptone in microbiological media. Methods of producing these hydrolysates including their microbiological safety are discussed. Based on the few references available in the literature, the potential of some chicken by-product as sources of proteases and polyunsaturated fatty acids are pointed out along with some other future applications.

  5. Olive oil enriched in lycopene from tomato by-product through a co-milling process. (United States)

    Bendini, Alessandra; Di Lecce, Giuseppe; Valli, Enrico; Barbieri, Sara; Tesini, Federica; Toschi, Tullia Gallina


    The aim of this investigation was to produce an olive oil (OO) naturally enriched with antioxidants, recovering carotenoids, in particular lycopene, using an industrial by-product of tomato seeds and skin. For this purpose, a technological process in a low-scale industrial plant to co-mill olives and tomato by-product in de-frosted or freeze-dried forms was applied and studied with respect to control samples. Preliminary results obtained from two different experiments were carried out by 40 kg of cultivar Correggiolo olives and 60 kg of olive blends from different cultivars. In both the experiments, the co-milling showed significant enrichment in carotenoids, especially in lycopene (mean values of 5.4 and 7.2 mg/kg oil from defrosted and freeze-dried by-products, respectively). The experimental results demonstrated the possibility to obtain a new functional food naturally enriched in antioxidant compounds, which might be marketed as "OO dressing enriched in lycopene" or "condiment produced using olives and tomato by-product".

  6. Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine (United States)

    Muirhead, Dean; Carrier, Christopher


    In this study, three different mineral acids were substituted for sulfuric acid (H2SO4) in the urine stabilizer solution to eliminate the excess of sulfate ions in pretreated urine and assess the impact on maximum water recovery to avoid precipitation of minerals during distillation. The study evaluated replacing 98% sulfuric acid with 85% phosphoric acid (H3PO4), 37% hydrochloric acid (HCl), or 70% nitric acid (HNO3). The effect of lowering the oxidizer concentration in the pretreatment formulation also was studied. This paper summarizes the test results, defines candidate formulations for further study, and specifies the injection masses required to stabilize urine and minimize the risk of mineral precipitation during distillation. In the first test with a brine ersatz acidified with different acids, the solubility of calcium in gypsum saturated solutions was measured. The solubility of gypsum was doubled in the brines acidified with the alternative acids compared to sulfuric acid. In a second series of tests, the alternative acid pretreatment concentrations were effective at preventing precipitation of gypsum and other minerals up to 85% water recovery from 95th-percentile pretreated, augmented urine. Based on test results, phosphoric acid is recommended as the safest alternative to sulfuric acid. It also is recommended that the injected mass concentration of chromium trioxide solution be reduced by 75% to minimize liquid resupply mass by about 50%, reduce toxicity of brines, and reduce the concentration of organic acids in distillate. The new stabilizer solution formulations and required doses to stabilize urine and prevent precipitation of minerals up to 85% water recovery are given. The formulations in this study were tested on a limited number of artificially augmented urine batches collected from employees at the Johnson Space Center (JSC). This study successfully demonstrated that the desired physical and chemical stability of pretreated urine and brines

  7. Effects of surface application of calcium-magnesium silicate and gypsum on soil fertility and sugarcane yield

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol


    Full Text Available Lime application recommendations for amendment of soil acidity in sugarcane were developed with a burnt cane harvesting system in mind. Sugarcane is now harvested in most areas without burning, and lime application for amendment of soil acidity in this system in which the sugarcane crop residue remains on the ground has been carried out without a scientific basis. The aim of this study was to evaluate the changes in soil acidity and stalk and sugar yield with different rates of surface application of calcium, magnesium silicate, and gypsum in ratoon cane. The experiment was performed after the 3rd harvest of the variety SP 81-3250 in a commercial green sugarcane plantation of the São Luiz Sugar Mill (47º 25' 33" W; 21º 59' 46" S, located in Pirassununga, São Paulo, in southeast Brazil. A factorial arrangement of four Ca-Mg silicate rates (0, 850, 1700, and 3400 kg ha-1 and two gypsum rates (0 and 1700 kg ha-1 was used in the experiment. After 12 months, the experiment was harvested and technological measurements of stalk and sugar yield were made. After harvest, soil samples were taken at the depths of 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40, and 0.40-0.60 m in all plots, and the following determinations were made: soil pH in CaCl2, organic matter, P, S, K, Ca, Mg, H+Al, Al, Si, and base saturation. The results show that the application of gypsum reduced the exchangeable Al3+ content and Al saturation below 0.05 m, and increased the Ca2+ concentration in the whole profile, the Mg2+ content below 0.10 m, K+ below 0.4 m, and base saturation below 0.20 m. This contributed to the effect of surface application of silicate on amendment of soil acidity reaching deeper layers. From the results of this study, it may be concluded that the silicate rate recommended may be too low, since the greater rates used in this experiment showed greater reduction in soil acidity, higher levels of nutrients at greater depths and an increase in stalk and sugar

  8. Compósitos à base de gesso com resíduos de EVA e vermiculita Gypsum-based composites with EVA waste and vermiculite

    Directory of Open Access Journals (Sweden)

    Marilia P. de Oliveira


    Full Text Available O gesso é um dos materiais de construção mais antigos de que se tem conhecimento. Algumas de suas propriedades lhes conferem vantagens, tais como resistência ao fogo e isolamentos térmico e acústico. Objetivou-se, com este trabalho, avaliar as propriedades físico-mecânicas de compósitos à base de gesso com a incorporação de resíduos da indústria de calçados, o etileno acetato de vinila (EVA e a vermiculita. O desenvolvimento desses compósitos tem como propósito a produção de elementos de revestimento para proteção térmica de alvenarias. Para determinar a influência dos teores de resíduo de EVA e vermiculita e da relação água/gesso nas propriedades massa específica aparente e nas resistências a flexão e a compressão, foram incorporados cinco diferentes percentuais desses materiais, combinados com três relações água/gesso. Os resultados foram analisados por meio da estatística multivariável e indicaram que a massa específica aparente de ambos os compósitos e a resistência à flexão do compósito com vermiculita, mostraram maior dependência da relação água/gesso; por sua vez, o percentual de agregado apresentou maior influência na resistência à flexão do compósito com EVA e na resistência a compressão de ambos os compósitos.Gypsum is one of the oldest known building materials. Some of its properties confer advantages such as fire resistance, thermal and acoustic insulation. This work aims to study the physical and mechanical properties of gypsum-based composite with the incorporation of residues from the footwear industry ethylene vinyl acetate (EVA and vermiculite. The aim to develop these composites is to produce components for thermal protection of masonry. To determine the influence of different residue levels of EVA and vermiculite, and the water/plaster ratio on the bulk density, flexural and compressive strength, five different percentages of these materials were incorporated combined with

  9. Mixture of natural fiber with gypsum to improve the fire resistance rating of a fire door: The effect of kapok fiber (United States)

    Azieyanti, N. A.; Hakim, Alif; Hasini, Hasril


    A composite mixture of gypsum and natural fibers has been considered in this study to enhance the fire resistance rating of a fire door. Previously the materials used to make a fire door are gypsum and fiber wool where it acts as a protective coating. Normally this fire door must be compact and able to close on its own. Natural fibers have the ability to replace glass fiber cotton because of its features that are available in fiber glass wool. When using fiberglass, it can cause health problem once it is swallowed and inhaled, and may remain in the lungs indefinitely. It also can contribute to lungs cancer. Kapok fiber has been used in this experiment as natural fibers. The objective of the experiment is to analyze the fire resistant rating of the composite mixture of gypsum with kapok fiber. The scopes of the experiment consist of a preparation of composite mixture samples of gypsum with kapok fiber with different composition and thickness, and the fabrication of a fire resistant testing furnace. A testing of samples which were conducted in accordance with the standard MS 1073: PART 2:1996.

  10. Gypsum amendment to rice paddy soil stimulated bacteria involved in sulfur cycling but largely preserved the phylogenetic composition of the total bacterial community. (United States)

    Wörner, Susanne; Zecchin, Sarah; Dan, Jianguo; Todorova, Nadezhda Hristova; Loy, Alexander; Conrad, Ralf; Pester, Michael


    Rice paddies are indispensable for human food supply but emit large amounts of the greenhouse gas methane. Sulfur cycling occurs at high rates in these water-submerged soils and controls methane production, an effect that is increased by sulfate-containing fertilizers or soil amendments. We grew rice plants until their late vegetative phase with and without gypsum (CaSO4 ·2H2 O) amendment and identified responsive bacteria by 16S rRNA gene amplicon sequencing. Gypsum amendment decreased methane emissions by up to 99% but had no major impact on the general phylogenetic composition of the bacterial community. It rather selectively stimulated or repressed a small number of 129 and 27 species-level operational taxonomic units (OTUs) (out of 1883-2287 observed) in the rhizosphere and bulk soil, respectively. Gypsum-stimulated OTUs were affiliated with several potential sulfate-reducing (Syntrophobacter, Desulfovibrio, unclassified Desulfobulbaceae, unclassified Desulfobacteraceae) and sulfur-oxidizing taxa (Thiobacillus, unclassified Rhodocyclaceae), while gypsum-repressed OTUs were dominated by aerobic methanotrophs (Methylococcaceae). Abundance correlation networks suggested that two abundant (>1%) OTUs (Desulfobulbaceae, Rhodocyclaceae) were central to the reductive and oxidative parts of the sulfur cycle. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Gypsum (CaSO4·2H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis (United States)

    Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung


    We have examined the gypsum (CaSO4·2H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42° ± 14.85° after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 °C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062

  12. Land subsidence and caprock dolines caused by subsurface gypsum dissolution and the effect of subsidence on the fluvial system in the Upper Tigris Basin (between Bismil Batman, Turkey) (United States)

    Doğan, Uğur


    Karstification-based land subsidence was found in the Upper Tigris Basin with dimensions not seen anywhere else in Turkey. The area of land subsidence, where there are secondary and tertiary subsidence developments, reaches 140 km 2. Subsidence depth ranges between 40 and 70 m. The subsidence was formed as a result of subsurface gypsum dissolution in Lower Miocene formation. Although there are limestones together with gypsum and Eocene limestone below them in the area, a subsidence with such a large area is indicative of karstification in the gypsum. The stratigraphical cross-sections taken from the wells and the water analyses also verify this fact. The Lower Miocene gypsum, which shows confined aquifer features, was completely dissolved by the aggressive waters injected from the top and discharged through by Zellek Fault. This resulted in the development of subsidence and formation of caprock dolines on loosely textured Upper Miocene-Pliocene cover formations. The Tigris River runs through the subsidence area between Batman and Bismil. There are four terrace levels as T1 (40 m), T2 (30 m), T3 (10 m) and T4 (4-5 m) in the Tigris River valley. It was also found that there were some movements of the levels of the terraces in the valley by subsidence. The subsidence developed gradually throughout the Quaternary; however no terrace was formed purely because of subsidence.

  13. A Scanning Transmission X-ray Microscopy Study of Cubic and Orthorhombic C3A and Their Hydration Products in the Presence of Gypsum

    Directory of Open Access Journals (Sweden)

    Vanessa Rheinheimer


    Full Text Available This paper shows the microstructural differences and phase characterization of pure phases and hydrated products of the cubic and orthorhombic (Na-doped polymorphs of tricalcium aluminate (C3A, which are commonly found in traditional Portland cements. Pure, anhydrous samples were characterized using scanning transmission X-ray microscopy (STXM, X-ray photoelectron spectroscopy (XPS and X-ray diffraction (XRD and demonstrated differences in the chemical and mineralogical composition as well as the morphology on a micro/nano-scale. C3A/gypsum blends with mass ratios of 0.2 and 1.9 were hydrated using a water/C3A ratio of 1.2, and the products obtained after three days were assessed using STXM. The hydration process and subsequent formation of calcium sulfate in the C3A/gypsum systems were identified through the changes in the LIII edge fine structure for Calcium. The results also show greater Ca LII binding energies between hydrated samples with different gypsum contents. Conversely, the hydrated samples from the cubic and orthorhombic C3A at the same amount of gypsum exhibited strong morphological differences but similar chemical environments.

  14. Estimation of radioactivity level and associated radiological hazards of limestone and gypsum used as raw building materials in Rawalpindi/Islamabad region of Pakistan. (United States)

    Gul, Rahmat; Ali, Safdar; Hussain, Manzur


    This study was undertaken to asses the radioactivity level of limestone and gypsum and its associated radiological hazard due to the presence of naturally occurring radioactive materials. Representative samples of limestone and gypsum were collected from cement factories located in the Rawalpindi/Islamabad region of Pakistan and were analysed by using an N-type high-purity germanium detector of 80 % relative efficiency. The average activity concentration of (40)K, (226)Ra and (232)Th were 60.22±3.47, 29.25±5.23 and 4.07±3.31 Bq kg(-1), respectively, in limestone and 70.86±4.1, 5.01±2.10 and 4.49±3.1 Bq kg(-1), respectively, in gypsum. The radiological hazard parameters radium equivalent activities, absorbed dose rate in air, external hazard index, internal hazard index, annual effective dose equivalent, gamma index and alpha index were computed. The results of the average activity concentrations of (40)K, (226)Ra and (232)Th and radiological hazard parameters were within the range of the reported average worldwide/United Nations Scientific Committee on the Effect of Atomic Radiation values. It is concluded that limestone and gypsum used in the Rawalpindi/Islamabad region does not pose any excessive radiological health hazard as a building raw materials and in industrial uses.

  15. Castanea sativa by-products: a review on added value and sustainable application. (United States)

    Braga, Nair; Rodrigues, Francisca; Oliveira, M Beatriz P P


    Castanea sativa Mill. is a species of the family Fagaceae abundant in south Europe and Asia. The fruits (chestnut) are an added value resource in producing countries. Chestnut economic value is increasing not only for nutritional qualities but also for the beneficial health effects related with its consumption. During chestnut processing, a large amount of waste material is generated namely inner shell, outer shell and leaves. Studies on chestnut by-products revealed a good profile of bioactive compounds with antioxidant, anticarcinogenic and cardioprotective properties. These agro-industrial wastes, after valorisation, can be used by other industries, such as pharmaceutical, food or cosmetics, generating more profits, reducing pollution costs and improving social, economic and environmental sustainability. The purpose of this review is to provide knowledge about the type of chestnut by-products produced, the studies concerning its chemical composition and biological activity, and also to discuss other possible applications of these materials.

  16. Grape marc, wine lees and deposit of the must: How to manage oenological by-products?


    Lempereur Valérie; Penavayre Sophie


    Winemaking produces solid (grape marc) and liquid (wine lees and deposit of the must) wastes named “oenological by-products”, which, according to European regulations, must be eliminated following the environmental regulatory requirement [1]. In France, these European regulations forced wine growers, until the 2013/2014 campaign, to deliver all by-products to wine distilleries. This French obligation is known as the “prestation vinique” [2, 3]. Following the Common Market Organisation wine re...

  17. Effect of Organic Matter and Gypsum Powder Some Traits of Maize in a Saline-Sodic Soil

    Directory of Open Access Journals (Sweden)

    M Khotabaee


    Full Text Available Saline-sodic soils have improper physical, chemical and biological condition and the crop productivity is low in these conditions. Application of conditioners often can be a proper solution for reclamation and improving the productivity of saline-sodic soils. In order to study the effect of some conditioners on soil chemical characteristics and yield of maize (SC260 cultivar in a saline-sodic soil, an experiment was carried out as a completely randomized design with 3 replications in a research greenhouse of Ferdowsi university of Mashhad. The studied treatments included control and 10 ton/ha of compost (MC, vermi-compost (VC, poultry manure (PM, and gypsum powder (G. The results showed that poultry manure and vemi-compost treatments increased significantly (p

  18. Gypsum scarps and asymmetric fluvial valleys in evaporitic terrains. The role of river migration, landslides, karstification and lithology (Ebro River, NE Spain) (United States)

    Guerrero, J.; Gutiérrez, F.


    Most of the Spanish fluvial systems excavated in Tertiary evaporitic gypsum formations show asymmetric valleys characterized by a stepped sequence of fluvial terraces on one valley flank and kilometric-long and > 100-m high prominent river scarp on the opposite side of the valley. Scarp undermining by the continuous preferential lateral migration of the river channel toward the valley margin leads to vertical to overhanging unstable slopes affected by a large number of slope failures that become the main geological hazard for villages located at the toe of the scarps. Detailed mapping of the gypsum scarps along the Ebro and Huerva Rivers gypsum scarps demonstrates that landslides and lateral spreading processes are predominant when claystones crop out at the base of the scarp, while rockfalls and topples become the dominant movement in those reaches where the rock mass is mainly constituted by evaporites. The dissolution of gypsum nodules, seasonal swelling and shrinking, and dispersion processes contribute to a decrease in the mechanical strength of claystones. The existence of dissolution-enlarged joints, sinkholes, and severely damaged buildings at the toe of the scarp from karstic subsidence demonstrates that the interstratal karstification of evaporites becomes a triggering factor in the instability of the rock mass. The genesis of asymmetric valleys and river gypsum scarps in the study area seem to be caused by the random migration of the river channel in the absence of lateral tilting related to tectonics or dissolution-induced subsidence. Once the scarp is developed, its preservation depends on the physicochemical properties of the substratum, the ratio between bedrock erosion and river incision rates, and climatic conditions that favour runoff erosion versus dissolution.

  19. Evaluation and comparison of high-level microwave oven disinfection with chemical disinfection of dental gypsum casts. (United States)

    Meghashri, K; Kumar, Prasanna; Prasad, D Krishna; Hegde, Rakshit


    The aim of this study was to evaluate and compare microwave disinfection with chemical disinfection of dental gypsum casts. A total of 120 casts were prepared from a silicone mold using Type III dental stone. Of the 120 casts, 60 casts were contaminated with 1 ml suspension of Staphylococcus aureus and 60 casts were contaminated with 1 ml suspension of Pseudomonas aeruginosa. Then, the casts were disinfected with microwave irradiation and chemical disinfection using the microwave oven and 0.5% sodium hypochlorite. Bacteriologic procedures were performed; the cfu/ml for each cast was calculated as a weighted mean. The results were analyzed using Kruskal-Wallis test and Mann-Whitney test. The untreated casts showed Brain heart infusion broth counts of 106 log cfu/ml compared to irradiated and chemically disinfected casts, in which 105 log reduction of cfu/ml was seen. These results satisfied the requirements of current infection control guidelines for the dental laboratory. The results obtained for chemical disinfection were in equivalence with microwave disinfection. Within the limitation of this in vitro study, it was found that microwave disinfection of casts for 5 min at 900 W gives high-level disinfection that complies with the current infection control guidelines for the dental laboratory and microwave disinfection method is an effective and validated method as chemical disinfection. How to cite the article: Meghashri K, Kumar P, Prasad DK, Hegde R. Evaluation and comparison of high-level microwave oven disinfection with chemical disinfection of dental gypsum casts. J Int Oral Health 2014;6(3):56-60 .

  20. The study of Influencing Maintenance Factors on Failures of Two gypsum Kilns by Failure Modes and Effects Analysis (FMEA

    Directory of Open Access Journals (Sweden)

    Iraj Alimohammadi


    Full Text Available Developing technology and using equipment in Iranian industries caused that maintenance system would be more important to use. Using proper management techniques not only increase the performance of production system but also reduce the failures and costs. The aim of this study was to determine the quality of maintenance system and the effects of its components on failures of kilns in two gypsum production companies using Failure Modes and Effects Analysis (FMEA. Furthermore the costs of failures were studied. After the study of gypsum production steps in the factories, FMEA was conducted by the determination of analysis insight, information gathering, making list of kilns’ component and filling up the FMEA’s tables. The effects of failures on production, how to fail, failure rate, failure severity, and control measures were studied. The evaluation of maintenance system was studied by a check list including questions related to system components. The costs of failures were determined by refer in accounting notebooks and interview with the head of accounting department. It was found the total qualities of maintenance system in NO.1 was more than NO.2 but because of lower quality of NO.1’s kiln design, number of failures and their costs were more. In addition it was determined that repair costs in NO.2’s kiln were about one third of NO.1’s. The low severity failures caused the most costs in comparison to the moderate and low ones. The technical characteristics of kilns were appeared to be the most important factors in reducing of failures and costs.

  1. Biological waste by-production costs in forest management and possibilities for their reduction

    Directory of Open Access Journals (Sweden)

    Jiří Kadlec


    Full Text Available Biological wastes in forestry were observed from view of their by-production in silvicultural and logging operations. There were identified points where biological waste was produced in this paper, waste costs ratio for silvicultural and logging operations and were made suggestions for reduction of these costs. Biological waste costs give 34.4% of total costs of silvicultural operations and 30% of total costs of logging operations. Natural regeneration and minor forest produce operations are opportunities for reduction of these costs.

  2. Optimization of the liquid biofertilizer production in batch fermentation with by-product from MSG (United States)

    Namfon, Panjanapongchai; Ratchanok, Sahaworarak; Chalida, Daengbussade


    The long term use of chemical fertilizers destroyed the friability of soil which obviously decreased quantity and quality of crops and especially affect microorganisms living in soils. The bio-fertilizer with microbial consortium is an environmental friendly alternative to solve this bottleneck due to harboring soil microorganisms such as Bacillus sp., Micrococcus sp., Pseudomonas sp., Staphylococcus sp. and Deinococcus sp. produced with natural by-product or waste from industries that is alternative and sustainable such as nutrient-rich (by-product) from Mono Sodium Glutamate (MSG) for producing liquid biofertilizer by batch fermentation. In this work, the concentration of reducing sugar from substrate as main carbon source was evaluated in shake flask with mixed cultures. The optimal conditions were studied comparing with two levels of reducing sugar concentration (10, 20 g/L) and inoculums concentration (10, 20 %v/v) with using (2×2) full factorial design. The results indicated that the by-product from monosodium glutamate is feasible for fermentation and inoculums concentration is mainly influenced the batch fermentation process. Moreover, the combined 20 g/L and 10%v/v were considerably concluded as an optimal condition, of which the concentration of vegetative cells and spores attained at 8.29×109 CFU/mL and 1.97×105 CFU/mL, respectively. Their spores cell yields from reducing sugar (Yx/s) were obtained at 1.22×106 and 3.34×105 CFU/g were markedly different. In conclusion, the liquid Biofertilizer was produced satisfactorily at 20 g/L reducing sugar and 10% v/v inoculums in shake flask culture. Moreover, these results suggested that the by-product from monosodium glutamate is feasible for low-cost substrate in economical scale and environmental-friendly.

  3. Monitoring natural organic matter and disinfection by-products at ...

    African Journals Online (AJOL)

    Natural organic matter (NOM) is a complex organic material present in natural surface water. NOM can cause problems during water treatment . most notably the formation of toxic disinfection by-products. This study was undertaken in order to assess the effectiveness of some of the water treatment techniques employed by ...

  4. Maximizing Utilization of Energy from Crop By-products

    Directory of Open Access Journals (Sweden)

    Budi Haryanto


    Full Text Available The availability of crop by-products is huge during harvesting times as related to the vast agricultural land area; however, their utilization is still limited due to lack of knowledge and handling problem. Seasonal effect is obvious especially during wet season when high rainfall hinders proper management of crop by-products. Crop by-products are energy rich feedstuffs in the form of chemical substance such as cellulose and hemicellulose. The utilization of cellulose and hemicellulose as sources of energy can be maximized by the application of technologies to increase the digestibility. Cellulose is polymer of glucose while hemicellulose is polymer of xylose which both can be converted to volatile fatty acids by rumen microbial enzyme activities and subsequently used by the host animal as source of energy. In addition, cellulose and hemicellulose can also be used as substrates for bioethanol production leaving behind residual matter with higher concentration of protein which is also appropriate for ruminant feeds. The fat content of crop by-products such as those in rice bran and corn germ can be extracted for oil production that can be used for human consumption with concomitant production of high nutritive value of residues for ruminant feeds. The oil extraction technologies are available; however the high cost of ethanol and oil production should obtain high attention to make the technologies more applicable at farmers’ level.

  5. Effect of sterilisation on dietary fibre and physicochemical properties of onion by-products. (United States)

    Benítez, Vanesa; Mollá, Esperanza; Martín-Cabrejas, María A; Aguilera, Yolanda; López-Andréu, Francisco J; Esteban, Rosa M


    Food industries are forced to develop productions without secondary residues. Therefore, there is a considerable emphasis on the recovery, recycling and upgrading of wastes. The possibility has been suggested for the conversion of onion waste into food ingredients, but with a stabilisation treatment being necessary. The objective of this work was to study the effect of sterilisation on fibre fractions, fibre composition and physicochemical properties of onion by-products to evaluate the use of sterilised onion by-products as a source of fibre. Sterilisation produced insoluble dietary fibre decreases and soluble dietary fibre increases, improving the soluble:insoluble ratio. Uronic acids of insoluble dietary fibre were partly solubilised and losses of cellulose and Klason lignin were observed. Physicochemical properties slightly changed with sterilisation. Sterilised by-products showed less oil holding capacity, cation exchange capacity and swelling capacity than control ones, although their physicochemical properties were generally higher than those of cellulose. Therefore, sterilisation would be considered a good method to stabilise onion by-products to use as a potential dietary fibre ingredient. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. New by-products rich in bioactive substances from the olive oil mill processing. (United States)

    Romero, Concepción; Medina, Eduardo; Mateo, Maria Antonia; Brenes, Manuel


    Olive oil extraction generates a large amount of residue consisting mainly of the pomace and leaves when using a two-phase centrifugation system. The aim of this study was to assess the content of phenolic and triterpene compounds in the by-products produced in Spanish olive oil mills. Olive pomace had concentrations of phenolic and triterpene substances lower than 2 and 3 g kg -1 , respectively. The leaves contained a high concentration of these substances, although those collected from ground-picked olives had lost most of their phenolic compounds. Moreover, the sediment from the bottom of the olive oil storage tanks did not have a significant amount of these substances. By contrast, a new by-product called olive pomace skin has been revealed as a very rich source of triterpenic acids, the content of which can reach up to 120 g kg -1 in this waste product, maslinic acid comprising around 70% of total triterpenics. Among the by-products generated during extraction of olive oil, olive pomace skin has been discovered to be a very rich source of triterpenic acids, which can reach up to 120 g kg -1 of the waste. These results will contribute to the valorization of olive oil by-products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Evolution characteristic of gypsum-salt rocks of the upper member of Oligocene Lower Ganchaigou Fm in the Shizigou area, western Qaidam Basin

    Directory of Open Access Journals (Sweden)

    Dinghong Yi


    Full Text Available Over years of oil and gas exploration in the Qaidam Basin, reservoirs have been discovered in many layers. In the Shizigou area, western Qaidam Basin, the upper member of Oligocene Lower Ganchaigou Fm is an important target for oil and gas exploration, and gypsum-salt rocks are the high-quality caprocks for the preservation of oil and gas reservoirs in this area. For predicting oil and gas exploration direction and target in the western Qaidam Basin and providing guidance for its oil and gas exploration deployment, its depositional characteristics and environment of gypsum-salt rocks in this area were investigated based on the core observation, thin section identification, and analysis of grain size, sensitivity parameter ratios (Sr/Cu, Fe/Mn, (Fe + Al/(Ca + Mg, V/(V + Ni and Pr/Ph, pyrite content and inclusions. The following characteristics are identified. First, gypsum-salt rocks are mainly distributed in the depocenter of the lake basin and their thickness decreases towards the margin of the basin. They are laterally transformed into carbonate rocks or terrigenous clastic rocks. They are areally distributed in the shape of irregular ellipse. Second, gypsum-salt rocks are vertically developed mainly in the middle and upper parts of the upper member of Lower Ganchaigou Fm and they are interbedded with carbonate rocks or terrigenous clastic rocks. Their single layer thickness changes greatly, and there are many layers with good continuity. Third, Sand Group III to Group I in the upper member of Lower Ganchaigou Fm (inter-salt are of reductive water environment of semi-deep to deep lake facies due to their sedimentation in an arid and hot climate. It is concluded that gypsum-salt rocks of the upper member of Lower Ganchaigou Fm are distributed widely with great accumulative thickness in this area; and that they are originated from deep lake water by virtue of evaporation, concentration and crystallization in an arid and hot climate instead

  8. Technical viability of self-compacting concretes with by-products from crushed coarse aggregate production

    Directory of Open Access Journals (Sweden)

    Edgar Bacarji

    Full Text Available Abstract The main objective of this work is to present the technical viability of Self Compacting Concretes (SCC containing by-products from crushed coarse aggregate production. For this purpose, a vast characterization of these by-products was made; six mixtures of SCC were produced using two different aggregates: granite and mica schist. The binder/dry aggregate (b/agg ratio by mass was 1:3. The following properties were analyzed: compressive strength, direct tensile strength, flexural tensile strength and splitting tensile strength. Granite presented the best mechanical performance. The replacement of natural sand by granite sand generated concretes with the same level of compressive strength and caused an increase in tensile strength values. The incorporation of silica fume into concrete with granite produced an increase of 17% in compressive strength. So, the use of these by-product materials can provide a technically feasible solution that is also consistent with the aims of sustainable development and preservation of the environment.

  9. Hydrate Phase Assemblages in Blends of Ye'elimite and Gypsum with Alite and Belite

    DEFF Research Database (Denmark)

    Pedersen, Malene Thostrup; Skibsted, Jørgen

    Calcium sulpho-aluminate (CSA) cements all contain ye’elimite, either as the main phase or in intermediate amounts, while they differ in their content of accessory phases. Belite is the main phase in most CSA cements, however, alite - CSA cements have been produced. The hydrate phases formed during...

  10. Hydrate Phase Assemblages in Blends of Ye’elimite and Gypsum with Alite and Belite

    DEFF Research Database (Denmark)

    Pedersen, Malene Thostrup; Skibsted, Jørgen


    Calcium sulpho-aluminate (CSA) cements all contain ye’elimite, either as the main phase or in intermediate amounts, while they differ in their content of accessory phases. Belite is the main phase in most CSA cements, however, alite - CSA cements have been produced. The hydrate phases formed during...

  11. The next chapter in experimental petrology: Metamorphic dehydration of polycrystalline gypsum captured in 3D microtomographic time series datasets (United States)

    Bedford, John; Fusseis, Florian; Leclere, Henry; Wheeler, John; Faulkner, Dan


    Nucleation and growth of new minerals in response to disequilibrium is the most fundamental metamorphic process. However, our current kinetic models of metamorphic reactions are largely based on inference from fossil mineral assemblages, rather than from direct observation. The experimental investigation of metamorphism has also been limited, typically to concealed vessels that restrict the possibility of direct microstructural monitoring. Here we present one of the first time series datasets that captures a metamorphic reaction, dehydration of polycrystalline gypsum to form hemihydrate, in a series of three dimensional x-ray microtomographic datasets. We achieved this by installing an x-ray transparent hydrothermal cell (Fusseis et al., 2014, J. Synchrotron Rad. 21, 251-253) in the microtomography beamline 2BM at the Advanced Photon Source (USA). In the cell, we heated a millimetre-sized sample of Volterra Alabaster to 388 K while applying an effective pressure of 5 MPa. Using hard x-rays that penetrate the pressure vessel, we imaged the specimen 40 times while it reacted for approximately 10 hours. Each microtomographic dataset was acquired in 300 seconds without interrupting the reaction. Our absorption microtomographic data have a voxel size of 1.3 μm, which suffices to analyse the reaction progress in 4D. Gypsum can clearly be distinguished from hemihydrate and pores, which form due to the large negative solid volume change. On the resolved scale, the first hemihydrate needles appear after about 2 hours. Our data allow tracking of individual needles throughout the entire experiment. We quantified their growth rates by measuring their circumference. While individual grains grow at different rates, they all start slowly during the initial nucleation stage, then accelerate and grow steadily between about 200 and 400 minutes before reaction rate decelerates again. Hemihydrate needles are surrounded by porous haloes, which grow with the needles, link up and

  12. Utilization of oleo-chemical industry by-products for biosurfactant production (United States)


    Biosurfactants are the surface active compounds produced by micro-organisms. The eco-friendly and biodegradable nature of biosurfactants makes their usage more advantageous over chemical surfactants. Biosurfactants encompass the properties of dropping surface tension, stabilizing emulsions, promoting foaming and are usually non- toxic and biodegradable. Biosurfactants offer advantages over their synthetic counterparts in many applications ranging from environmental, food, and biomedical, cosmetic and pharmaceutical industries. The important environmental applications of biosurfactants include bioremediation and dispersion of oil spills, enhanced oil recovery and transfer of crude oil. The emphasis of present review shall be with reference to the commercial production, current developments and future perspectives of a variety of approaches of biosurfactant production from the micro-organisms isolated from various oil- contaminated sites and from the by-products of oleo-chemical industry wastes/ by-products viz. used edible oil, industrial residues, acid oil, deodorizer distillate, soap-stock etc. PMID:24262384

  13. Effective utilization of by-product oxygen from electrolysis hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takeyoshi; Kubota, Mitsuhiro; Kobayashi, Noriyuki; Suzuoki, Yasuo [Nagoya University (Japan)


    To avoid fossil-fuel consumption and greenhouse-gas emissions, hydrogen should be produced by renewable energy resources. Water electrolysis using proton exchange membrane (PEM) is considered a promising hydrogen-production method, although the cost of the hydrogen from PEM would be very high compared with that from other mature technologies, such as steam methane reforming (SMR). In this study, we focus on the effective utilization of by-product oxygen from electrolysis hydrogen production and discuss the potential demand for it, as well as evaluating its contribution to improving process efficiency. Taking as an example the utilization of by-product oxygen for medical use, we compare the relative costs of hydrogen production by means of PEM electrolysis and SMR. (author)

  14. Chlorine dioxide and by-products in water distribution systems


    Ferreira, Francisco Cardoso


    Chlorine dioxide is used as both a pre-oxidant and/or a post-disinfectant in several water treatment plants in the United States. Chlorine dioxide is associated with its byproducts chlorite and chlorate. Chlorine dioxide, chlorine, chlori te and chlorate were sampled in four distribution systems where chlorine dioxide is used for disinfection purposes: Charleston, WV, Columbus, GA, New Castle, PA, and Skagit, WA. The fate of chlorine dioxide and its by-products in dist...

  15. Water disinfection agents and disinfection by-products (United States)

    Ilavský, J.; Barloková, D.; Kapusta, O.; Kunštek, M.


    The aim of this work is to describe factors of water quality change in the distribution network and legislative requirements in Slovakia for disinfectants and disinfection byproducts (DBPs). In the experimental part, the time dependence of the application of the chlorine dioxide and sodium hypochlorite on the formation of some by-products of disinfection for drinking water from WTP Hriňová is studied. We monitored trihalomethanes, free chlorine, chlorine dioxide and chlorites.

  16. Recovery of soil physical properties by green manure, liming, gypsum and pasture and spontaneous native species¹

    Directory of Open Access Journals (Sweden)

    Carolina dos Santos Batista Bonini


    Full Text Available Inadequate usage can degrade natural resources, particularly soils. More attention has been paid to practices aiming at the recovery of degraded soils in the last years, e.g, the use of organic fertilizers, liming and introduction of species adapted to adverse conditions. The purpose of this study was therefore to investigate the recovery of physical properties of a Red Latosol (Oxisol degraded by the construction of a hydroelectric power station. In the study area, a soil layer about 8m thick had been withdrawn by heavy machines leading not only to soil compaction, but resulting in high-degree degradation. The experiment was arranged in a completely randomized design with nine treatments and four replications. The treatments consisted of: 1- soil mobilization by tilling (to ensure the effect of mechanical mobilization in all treatments without planting, but growth of spontaneous vegetation; 2- Black velvet bean (Stizolobium aterrimum Piper & Tracy; 3- Pigeonpea (Cajanus cajan (L. DC; 4- Liming + black velvet bean; 5-Liming + pigeonpea until 1994, when replaced by jack bean (Canavalia ensiformis; 6- Liming + gypsum + black velvet bean; 7- Liming + gypsum + pigeonpea until 1994, when replaced by jack bean; and two controls as reference: 8- Native Cerrado vegetation and 9- bare soil (no tilling and no planting, left under natural conditions and in this situation, without spontaneous vegetation. In treatments 1 through 7, the soil was tilled. Treatments were installed in 1992 and left unmanaged for seven years, until brachiaria (Brachiaria decumbens was planted in all plots in 1999. Seventeen years after implantation, the properties soil macroporosity, microporosity, total porosity, bulk density and aggregate stability were assessed in the previously described treatments in the soil layers 0.00-0.10; 0.10-0.20 and 0.20-0.40 m, and soil Penetration Resistance and soil moisture in 0.00-0.15 and 0.15-0.30 m. The plants were evaluated for: brachiaria

  17. A new use of hydroxyapatite-based consolidant: cleaning and consolidation of stones in one step by reaction with gypsum crust (United States)

    Molina Piernas, Eduardo; Rueda Quero, Lucia; Cultrone, Giuseppe; Ruiz Agudo, Encarnación


    The reaction between diammonium hydrogen phosphate (DAP) and calcite in the stone to form hydroxyapatite (HAP) had provided a new product to consolidate limestone or Ca-rich stones, for example sandstones with carbonatic cement. However, what does it happen with the stones without Ca-bearing compounds? Obviously, HAP cannot form. In the other hand, recent research about consolidation with DAP show a good interaction between carbonatic stones and HAP, improving their mechanical properties. For these reasons, we propose a new method for the consolidation of building stone capable of cleaning the gypsum crust and consolidating stones at the same time, based in the Ferroni-Dini method [1] and using DAP. Based on this method, we aim at obtaining a consolidating component reacting DAP (instead of ammonium carbonate) and the gypsum contained in the crust of weathered stones in polluted environments. As an advantage, we do not need to use barium hydroxide (the second step required in the Ferroni-Dini method), thereby reducing the time necessary to carry out the consolidation. Here, we report different tests to evaluate this new procedure. In a first set of experiments, a DAP solution was poured on a gypsum (dihydrate calcium sulphate) saturated solution and by monitoring the free calcium content of the solution using an ion-selective electrode we have evaluated the fluctuations in the content in calcium of the solution and the speed of the reaction. Once the reaction finished, we analyzed the solids formed to verify the formation of hydroxyapatite by FTIR and microRAMAN. The second test consisted in the alteration of limestone blocks with sulfuric acid to obtain a crust of gypsum and, after that, the samples were consolidated by means of cellulose compress soaked in DAP 3M during different reaction times (30 minutes, 1 hour and 4 hours, at controlled temperature -20 °C- and relative humidity -40% HR-). The samples were then analyzed by XRD, FTIR, microRAMAN and SEM-EDX to

  18. Scorpion in Combination with Gypsum: Novel Antidiabetic Activities in Streptozotocin-Induced Diabetic Mice by Up-Regulating Pancreatic PPARγ and PDX-1 Expressions

    Directory of Open Access Journals (Sweden)

    Weidong Xie


    Full Text Available The management of diabetes without any side effects remains a challenge in medicine. In this study, antidiabetic activity and the mechanism of action of scorpion combined with gypsum (SG were investigated. Streptozotocin-induced diabetic mice were orally administrated with scorpion (200 mg kg−1 per day in combination with gypsum (200 mg kg−1 per day for 5 weeks. SG treatment resulted in decreased body weight, blood glucose and lipid levels, and increased serum and pancreatic insulin levels in diabetic mice. Furthermore, SG significantly increased the number and volume of beta cells in the Islets of Langerhans and promoted peroxisome proliferator-activated receptor gamma and pancreatic duodenal homeobox 1 expressions in pancreatic tissues. However, scorpion or gypsum alone had no significant effect in this animal model. Metformin showed a slight or moderate effect in this diabetic model, but this effect was weak compared with that of SG. Taken together, SG showed a new antidiabetic effect in streptozotocin-induced diabetic mice. This effect may possibly be involved in enhancing beta-cell regeneration and promoting insulin secretion by targeting PPARγ and PDX-1. Moreover, this new effect of SG offers a promising step toward the treatment of diabetic patients with beta-cell failure as a complementary and alternative medicine.

  19. Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions. (United States)

    Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N Suman; Tadi, Durga Prasad


    This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In moist condition, aquasil performed significantly better than impregum. Regarding gypsum compatibility according to ADA specification, in dry condition both the materials performed almost equally, and in moist condition aquasil performed better than impregum. When tested by macroscopic evaluation, impregum performed better than aquasil in both the conditions.

  20. Application of coal fly ash to circumneutral mine waters for the removal of sulphates as gypsum and ettringite

    Energy Technology Data Exchange (ETDEWEB)

    Madzivire, G.; Petrik, L.F.; Gitari, W.M.; Ojumu, T.V.; Balfour, G. [University of Western Cape, Cape Town (South Africa)


    South African power stations generate large amounts of highly alkaline fly ash (FA). This waste product has a serious impact on the environment. Acid mine drainage (AMD) is another environmental problem associated with mining. AMD has high heavy metal content in addition to high sulphate concentrations. Several studies have shown that 80-90% of sulphates can be removed when FA is co-disposed with AMD rich in Fe and Al. In South Africa, sources of contaminated mine waters, unlike AMD have circumneutral pH and much lower concentrations of Fe and Al, but rich in Ca and Mg. Treatment of such waters with FA resulted in no significant removal of sulphates when treated to pH less than 10. Subsequent treatment of circumneutral mine water to pH greater than 11 resulted in more than 60% sulphate removal. Treatment of circumneutral mine water to pH greater than 11 with FA followed by seeding with gypsum crystals and the addition of amorphous Al(OH){sub 3} resulted in removal of sulphate to levels below the Department of Water Affairs and Forestry (DWAF) water quality effluent limit (500 ppm).

  1. Detection of pigments of halophilic endoliths from gypsum: Raman portable instrument and European Space Agency's prototype analysis. (United States)

    Culka, Adam; Osterrothová, Kateřina; Hutchinson, Ian; Ingley, Richard; McHugh, Melissa; Oren, Aharon; Edwards, Howell G M; Jehlička, Jan


    A prototype instrument, under development at the University of Leicester, for the future European Space Agency (ESA) ExoMars mission, was used for the analysis of microbial pigments within a stratified gypsum crust from a hypersaline saltern evaporation pond at Eilat (Israel). Additionally, the same samples were analysed using a miniaturized Raman spectrometer, featuring the same 532 nm excitation. The differences in the position of the specific bands, attributed to carotenoid pigments from different coloured layers, were minor when analysed by the ESA prototype instrument; therefore, making it difficult to distinguish among the different pigments. The portable Delta Nu Advantage instrument allowed for the discrimination of microbial carotenoids from the orange/green and purple layers. The purpose of this study was to complement previous laboratory results with new data and experience with portable or handheld Raman systems, even with a dedicated prototype Raman system for the exploration of Mars. The latter is equipped with an excitation wavelength falling within the carotenoid polyene resonance region. The ESA prototype Raman instrument detected the carotenoid pigments (biomarkers) with ease, although further detailed distinctions among them were not achieved. © 2014 The Author(s) Published by the Royal Society. All rights reserved.



    Wojciech Czekała


    More than 30% of the world's food production is wasted. Organic waste and residues are produced in a variety of sectors, including agriculture, food industry and forestry. Residues and waste are generated throughout the entire food production and use cycle: surplus food production, processing and distribution, and consumption. Some food that has not been consumed should be managed. Bioconversion using insects provides the opportunity to produce feed and energy using by-products of the agro-fo...

  3. Grape marc, wine lees and deposit of the must: How to manage oenological by-products?

    Directory of Open Access Journals (Sweden)

    Lempereur Valérie


    Full Text Available Winemaking produces solid (grape marc and liquid (wine lees and deposit of the must wastes named “oenological by-products”, which, according to European regulations, must be eliminated following the environmental regulatory requirement [1]. In France, these European regulations forced wine growers, until the 2013/2014 campaign, to deliver all by-products to wine distilleries. This French obligation is known as the “prestation vinique” [2, 3]. Following the Common Market Organisation wine reform, a consultation was initiated by FranceAgriMer on the potential value of oenological by-products. The French Institute of Vine and Wine (IFV coordinated a national experimentation from 2010 to 2013 about recovery of by-products, with the support of members of the Technical Group: Association des Viticulteurs d'Alsace (AVA, Comité Interprofessionnel du Vin de Champagne (CIVC, Institut Technique des Corps Gras (ITERG, et Union Nationale des Groupements de Distillateurs d'Alcool (UNGDA. Distillation of grape marc and wine lees spreading and composting, and anaerobic digestion of grape marc were studied in order to answer the following questions: What technical feasibility? What environmental impact? What cost for winegrowers? What conformity with the regulations, including environmental regulatory obligations? [4].

  4. [Degradation Kinetics and Formation of Disinfection By-products During Linuron Chlorination in Drinking Water]. (United States)

    Ling, Xiao; Hu, Chen-yan; Cheng, Ming; Gu, Jian


    Chlorination degradation of linuron was studied using the common disinfectant sodium hypochlorite, the effects of chlorine dosage, pH value, bromine ion concentrationand temperature were systematically investigated, and the formation characteristics of disinfection by-products (DBPs) during the chlorination reaction was analyzed. The results showed that the chlorination degradation kinetics of linuron by sodium hypochlorite could be well described by the second-order kinetic model. Moreover, pH values had a great impact on the degradation reaction, and the rate constant reached the maximum level at pH 7, and the base elementary reaction rate constants of HOCl and OCl- with linuron were 4.84 x 10(2) L · (mol · h)(-1) and 3.80 x 10(2) L · (mol · h)(-1), respectively. The reaction rate decreased with the addition of bromide ion and increased with increasing temperature. Furthermore, many kinds of disinfection by- products were produced during the chlorination degradation of linuron, including CF, DCAN, TCNM and halogen acetone. Under conditions of different solution pH and different bromide ion concentrations, there would be significant difference in the types and concentrations of disinfection by-products.

  5. Utilization of Biodiesel By-Products for Biogas Production (United States)

    Kolesárová, Nina; Hutňan, Miroslav; Bodík, Igor; Špalková, Viera


    This contribution reviews the possibility of using the by-products from biodiesel production as substrates for anaerobic digestion and production of biogas. The process of biodiesel production is predominantly carried out by catalyzed transesterification. Besides desired methylesters, this reaction provides also few other products, including crude glycerol, oil-pressed cakes, and washing water. Crude glycerol or g-phase is heavier separate liquid phase, composed mainly by glycerol. A couple of studies have demonstrated the possibility of biogas production, using g-phase as a single substrate, and it has also shown a great potential as a cosubstrate by anaerobic treatment of different types of organic waste or energy crops. Oil cakes or oil meals are solid residues obtained after oil extraction from the seeds. Another possible by-product is the washing water from raw biodiesel purification, which is an oily and soapy liquid. All of these materials have been suggested as feasible substrates for anaerobic degradation, although some issues and inhibitory factors have to be considered. PMID:21403868

  6. Arsenic Removal from Water Using Industrial By-Products

    Directory of Open Access Journals (Sweden)

    Branislava M. Lekić


    Full Text Available In this study, removal of arsenic ions using two industrial by-products as adsorbents is represented. Removal of As(III and As(V from water was carried out with industrial by-products: residual from the groundwater treatment process, iron-manganese oxide coated sand (IMOCS, and blast furnace slag from steel production (BFS, both inexpensive and locally available. In addition, the BFS was modified in order to minimise its deteriorating impact on the initial water quality. Kinetic and equilibrium studies were carried out using batch and fixed-bed column adsorption techniques under the conditions that are likely to occur in real water treatment systems. To evaluate the application for real groundwater treatment, the capacities of the selected materials were further compared to those exhibited by commercial sorbents, which were examined under the same experimental conditions. IMOCS was found to be a good and inexpensive sorbent for arsenic, while BFS and modified slag showed the highest affinity towards arsenic. All examined waste materials exhibited better sorption performances for As(V. The maximum sorption capacity in the batch reactor was obtained for blast furnace slag, 4040 μgAs(V/g.

  7. Utilization of Chicken By-Products to Form Collagen Films

    Directory of Open Access Journals (Sweden)

    Kumudini A. Munasinghe


    Full Text Available Chicken collagen casings could be an alternate source of collagen casings that are manufactured for sausages. The overall objective of this project was to extract chicken collagen from by-products of the broiler processing industries and to explore the possibility of making films. Chicken skin was washed, ground, and pretreated to remove the noncollagenous compounds. Collagen was extracted using acetic acid and pepsin. Solubilized collagen was salted-out and centrifuged at 20,000 ×g at 4°C for one hour. The precipitates were dissolved in 0.5 M acetic acid and dialyzed against 0.1 M acetic acid and distilled water before freeze-drying. Molecular weight, collagen solubility at different pH values, and NaCl concentrations were determined. TA-XT2 texture analyzer was used to characterize mechanical properties of collagen films. The highest collagen solubility was obtained at pH 2 and 2% NaCl. Hand-homogenized, nonfiltered, and conditioned samples had the highest hardness (3,262 g and the least brittleness (30.5 mm. These results demonstrate that chicken collagen extracted from chicken by-products has the ability to form films and could be considered for making casings or be used in various other industries.

  8. Wheat bread biofortification with rootlets, a malting by-product. (United States)

    Waters, Deborah M; Kingston, Wilma; Jacob, Fritz; Titze, Jean; Arendt, Elke K; Zannini, Emanuele


    Barley rootlets, a malting by-product, are currently discarded or used as fodder. In this study, milled rootlets and Lactobacillus plantarum FST 1.7-fermented rootlets were incorporated into wheat bread. The objective was to formulate a high-nutrition alternative to wholemeal breads with improved technological attributes. Chemical analyses showed that rootlets contribute nutrients and bioactive compounds, including proteins, amino acids, fatty acids, carbohydrates, dietary fibre, polyphenols and minerals. Rootlets are particularly rich in essential amino acids, especially lysine, the typically limiting essential amino acid of cereals. Additionally, rootlets offer potential dietary fibre health benefits such as protection against cardiovascular disease, cancers and digestive disorders. Breads prepared with a (fermented) rootlet inclusion level of up to 10% compared favourably with wholemeal breads from nutritive, technological and textural perspectives. Furthermore, they were well accepted by sensory panellists. Using rootlets as a food ingredient would have the added benefit of increasing this malting by-product's market value. © 2013 Society of Chemical Industry.

  9. Valorisation of fish by-products against waste management treatments--Comparison of environmental impacts. (United States)

    Lopes, Carla; Antelo, Luis T; Franco-Uría, Amaya; Alonso, Antonio A; Pérez-Martín, Ricardo


    Reuse and valorisation of fish by-products is a key process for marine resources conservation. Usually, fishmeal and oil processing factories collect the by-products generated by fishing port and industry processing activities, producing an economical benefit to both parts. In the same way, different added-value products can be recovered by the valorisation industries whereas fishing companies save the costs associated with the management of those wastes. However, it is important to estimate the advantages of valorisation processes not only in terms of economic income, but also considering the environmental impacts. This would help to know if the valorisation of a residue provokes higher impact than other waste management options, which means that its advantages are probably not enough for guarantying a sustainable waste reuse. To that purpose, there are several methodologies to evaluate the environmental impacts of processes, including those of waste management, providing different indicators which give information on relevant environmental aspects. In the current study, a comparative environmental assessment between a valorisation process (fishmeal and oil production) and different waste management scenarios (composting, incineration and landfilling) was developed. This comparison is a necessary step for the development and industrial implementation of these processes as the best alternative treatment for fish by-products. The obtained results showed that both valorisation process and waste management treatments presented similar impacts. However, a significant benefit can be achieved through valorisation of fish by-products. Additionally, the implications of the possible presence of pollutants were discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. An attractive way of egg white protein by-product use for producing of novel anti-hypertensive peptides. (United States)

    Pokora, M; Zambrowicz, A; Dąbrowska, A; Eckert, E; Setner, B; Szołtysik, M; Szewczuk, Z; Zabłocka, A; Polanowski, A; Trziszka, T; Chrzanowska, J


    The aim of this study was to (i) examine how enzymatic hydrolysis with a non-commercially available proteinase of fig-leaf gourd fruit (Cucurbita ficifolia) increased the use value of egg white protein preparations, generated as byproducts in the industrial process of lysozyme and cystatin isolation from egg white, and (ii) evaluate the inhibition of angiotensin I-converting enzyme (ACE) by the obtained hydrolysates. Purification procedures including membrane filtration, gel filtration chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) led to the production of several peptide fractions. Two novel ovalbumin-derived tetrapeptides: SWVE (f 148-151) and DILN (f 86-89) with ACE inhibitory activity were obtained. Study of their inhibitory kinetics revealed a non-competitive binding mode, with an IC50 value against ACE of 33.88 and 73.44 μg for SWVE and DILN, respectively. Synthetic peptides which were designed on the basis of peptide SWVE were examined. A tripeptide sequence of SWV revealed the strongest ACE-inhibitory activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Conversion of the biodiesel by-product glycerol by the non-conventional yeast Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying

    of further studiesfor conversion of glycerol to ethanol. In chapter 3, ph ysiology studies in lab scale fermentation of the ethanol production process with P. tannophilus were investigated on glycerol. The effect of aeration, pH and nitrogen source was studied for improving the ethanol production and yield...... for glycerol fermentation. Two candidates Pachia pastoris and Pachysolen tannophilus were shown to be capable of producing ethanol with glycerol as the sole carbon source. After growth comparison on glycerol and tests for extracellular metabolites in agitated flasks, P. tannophilus was selected as the object...... production process. Since the volume of the glycerol by-product has exceeded the current market need, biodiesel producers are looking for new methods for sustainable glycerol management and improving the competitiveness of the biodiesel industries. The EU Commission funded GLYFINERY project is one initiative...

  12. A Management State of POPs (Persistent Organic Pollutants) and the Measuring Direction - Centered By-Products

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Gyu; Lee, Hee Seon [Korea Environment Institute, Seoul (Korea)


    The chemical materials, DDT and Dioxin, threaten the human health and take the high toxicity on ecosystem and a living thing. Because the chemical materials remain in environment for a long time due to a slow natural decomposition, they are biologically concentrated through the food cycle in ecosystem and have a characteristic to move a long distance. Owing to such toxicity and the characteristics of chemical materials, the world organization named them as Persistent Organic Pollutants (POPs) and has been actively progressing the international movement to strictly restrict them since the middle of 1990s. POPs regulation agreement, which is on progress centered in UNEP, is facing to the conclusion of the agreement of 2001 year. An agricultural chemical of organic chlorine among 12 POPs indicated by UNEP has been already prohibited in the domestic use and manufacturing or not registered, so the basic research, including search and monitoring if POPs remain or not, is required afterward. Because Dioxin, Puran, Hexachlorobenzene (HCB) among POPs, which are produced as by-products from all kinds of industrial processes, are not raw materials dislike other POPs, their use and manufacturing cannot be only prohibited by the related law but also they have few substitutes. Therefore, they should be applied by the different regulation from the existing toxic chemicals in order to manage the toxicity of the materials. However, the regulation on by-products among POPs is just in the beginning stage, and even the producing source has not been yet confirmed. This study suggests the necessity of the management on Dioxin, Puran, HCB, by-products among POPs, and presents the measuring direction with grasping the domestic and foreign trend of the regulation on the materials. 70 refs., 2 figs., 56 tabs.

  13. Nanodetection of the disinfection by-products on GC-MS techniques (United States)

    Ristoiu, Dumitru; Haydee, Melinda; Ristoiu, Tania


    Exposures to disinfection by-products (DBPs) in residential drinking water occur through multiple routes and vary across the population because of differences in the amount and ways people use water. Municipal water in the Romania is disinfected, with chlorine being the most common disinfectant agent. Disinfection of water, in additional to having the benefit of destroying microbes that can transmit diseases, has the drawback of producing a series of compounds known as disinfection by-products (DBPs). Chlorination produces many compounds containing chlorine and/or bromine, some of which have been shown to be carcinogenic, mutagenic, and/or teratogenic in animal studies. The most abundant class of DBPs that result from chlorination of drinking water are trihalomethanes (THMs) - chloroform (CHCl3), dichlorobromomethane (CHCl2Br), dibromochloromethane (CHBr2Cl) and bromoform (CHBr3). The most predominant THM species was CHCl3 and it highest concentration was 85•106 ng/m3. The others THMs compounds concentration were lower, between 65•104 ng/m3 and 12•106 ng/m3. THMs compounds were analyzed on gas chromatography coupled with mass spectrometer detector (GC-MS) and head space technique (HS) was used for all analysis.

  14. Bacterial Cellulose Production from Industrial Waste and by-Product Streams (United States)

    Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis


    The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients. PMID:26140376

  15. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Directory of Open Access Journals (Sweden)

    Erminda Tsouko


    Full Text Available The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L and commercial sucrose (4.9 g/L were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

  16. Pathway engineering of Enterobacter aerogenes to improve acetoin production by reducing by-products formation. (United States)

    Jang, Ji-Woong; Jung, Hwi-Min; Im, Dae-Kyun; Jung, Moo-Young; Oh, Min-Kyu


    Enterobacter aerogenes was metabolically engineered for acetoin production. To remove the pathway enzymes that catalyzed the formation of by-products, the three genes encoding a lactate dehydrogenase (ldhA) and two 2,3-butanediol dehydrogenases (budC, and dhaD), respectively, were deleted from the genome. The acetoin production was higher under highly aerobic conditions. However, an extracellular glucose oxidative pathway in E. aerogenes was activated under the aerobic conditions, resulting in the accumulation of 2-ketogluconate. To decrease the accumulation of this by-product, the gene encoding a glucose dehydrogenase (gcd) was also deleted. The resulting strain did not produce 2-ketogluconate but produced significant amounts of acetoin, with concentration reaching 71.7g/L with 2.87g/L/h productivity in fed-batch fermentation. This result demonstrated the importance of blocking the glucose oxidative pathway under highly aerobic conditions for acetoin production using E. aerogenes. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Origin of disinfection by-products in cheese. (United States)

    Cardador, Maria Jose; Gallego, Mercedes; Prados, Francisco; Fernández-Salguero, José


    The disinfection of water, equipment and surfaces in a cheese factory is one of the factors that can originate disinfection by-products (DBPs) in cheese. This research has focused on studying cheese factories in order to evaluate the individual contribution of each step of the cheese-making process that can contribute to the presence of DBPs in cheese. Ten factories were selected according to their salting processes (brine or dry salting). Each factory was monitored by the collection of six representative samples (factory water supply, brine solution, milk, whey, curd and cheese) in which the concentrations of up to eight chemicals were detected. The study shows that contact with brine solutions containing significant levels of DBPs is the main source of these chemicals in cheese. A minor factor is the pasteurised milk used in their manufacture.

  18. Chlorine dioxine DBPs (disinfection by-products in drinking water

    Directory of Open Access Journals (Sweden)

    C. Lasagna


    Full Text Available Since the 1970s it has been well known that, though water for human consumption is generally disinfected before being distributed along the network, the use of chemicals results in the formation of many different Disinfection By-Products (DBPs. In the case of chlorine dioxide, the most important and represented DBPs are chlorite and chlorate: after an introduction concerning the current Italian regulation on this subject, in the experimental part the results of a 7-year minitoring campaign, concerning water of different origin collected from taps in various Italian regions, are shown. The analytical technique used for the determination of chlorite and chlorate was Ion Chromatography. The result obtained are finally discussed.

  19. Effect of Celebrity Endorsement in Advertising Activities by Product Type

    Directory of Open Access Journals (Sweden)

    Karasiewicz Grzegorz


    Full Text Available This article seeks to answer two related questions: are celebrity endorsements more likely to be result in a higher evaluation of the product being advertised than use of an anonymous individual (e.g. a typical consumer; and, if present, do these positive effects vary by product category? To answer these two questions research was conducted on a 237 student sample employing a quasi-experiment consisting of four groups (two product categories and two types of endorsers using data collected through an online survey. The results indicate that celebrity endorsements do have a positive impact on the evaluation of durable goods, but do not affect the evaluation of frequently purchased products. This finding largely confirms the assumptions of the match-up model, the meaning transfer model, and the ELM model.

  20. Manufacturing of mortars and concretes non-traditionals, by Portland cement, metakaoline and gypsum (15.05%

    Directory of Open Access Journals (Sweden)

    Talero, R.


    Full Text Available In a thorough previous research (1, it appeared that creation, evolution and development of the values of compressive mechanical strength (CS and flexural strength (FS, measured in specimens 1x1x6cm of mortar type ASTM C 452-68 (2, manufactured by ordinary Portland cement P-1 (14.11% C3A or PY-6 (0.00% C3A, metakaolin and gypsum (CaSO4∙2H2O -or ternary cements, CT-, were similar to the ones commonly developed in mortars and concretes of OPC. This paper sets up the experimental results obtained from non-traditional mortars and concretes prepared with such ternary cements -TC-, being the portland cement/metakaolin mass ratio, as follows: 80/20, 70/30 and 60/40. Finally, the behaviour of these cements against gypsum attack, has been also determined, using the following parameters: increase in length (ΔL%, compressive, CS, and flexural, FS, strengths, and ultrasound energy, UE. Experimental results obtained from these non-traditional mortars and concretes, show an increase in length (ΔL, in CS and FS, and in UE values, when there is addition of metakaolin.

    En una exhaustiva investigación anterior (1, se pudo comprobar que la creación, evolución y desarrollo de los valores de resistencias mecánicas a compresión, RMC, y flexotracción, RMF, proporcionados por probetas de 1x1x6 cm, de mortero 1:2,75, selenitoso tipo ASTM C 452-68 (2 -que habían sido preparadas con arena de Ottawa, cemento portland, P-1 (14,11% C3A o PY- 6 (0,00% C3A, metacaolín y yeso (CaSO4∙2H2O-, fue semejante a la que, comúnmente, desarrollan los morteros y hormigones tradicionales de cemento portland. En el presente trabajo se exponen los resultados experimentales obtenidos de morteros y hormigones no tradicionales, preparados con dichos cementos ternarios, CT, siendo las proporciones porcentuales en masa ensayadas, cemento portland/metacaolín, las siguientes: 80/20, 70

  1. Comparative evaluation of feldespatic crowns fitness made from additional silicon impression and gypsum cast by CAD/CAM

    Directory of Open Access Journals (Sweden)

    Faramarz Zakavi


    Full Text Available Background and Aims: Marginal fit is one of the key factors in the success of fixed restoration. The aim of this study was to evaluate the fitness of feldespatic crowns made from additional silicon impression and gypsum cast by CAD/CAM.   Materials and Methods: 10 intact extracted upper premolar teeth were used for this experimental study. After preparation of the mounted teeth with radial shoulder finish line, 2 Vita Mark II feldespatic CAD/CAM machined crowns were fabricated for each tooth (one from scanning the additional silicone impression of the prepared tooth and the other one from the plaster model. Marginal gap of each crown was measured using SEM in two points on the mesial and 2 points on the buccal surface. Data were analyzed using Paired t-test with SPSS version 17 software (P<0.05.   Results: The mean of marginal gaps in crowns fabricated from additional silicone and model plaster were (155.13±37.11 and (130.18±12.35, respectively. However, no significant difference emerged between marginal gaps of the two methods (P=0.055. Also, the mean of marginal gaps in crowns fabricated from additional silicone and model plaster was higher in mesial (157.82±44.41 compared to buccal (127.50±24.26 region (P=0.003.   Conclusion: Marginal fit was not significantly differen ce between crown s made of the plaster casts and silicone molds and both methods showed the same results .

  2. Microbial characterization of microbial ecosystems associated to evaporites domes of gypsum in Salar de Llamara in Atacama desert. (United States)

    Rasuk, Maria Cecilia; Kurth, Daniel; Flores, Maria Regina; Contreras, Manuel; Novoa, Fernando; Poire, Daniel; Farias, Maria Eugenia


    The Central Andes in northern Chile contains a large number of closed basins whose central depression is occupied by saline lakes and salt crusts (salars). One of these basins is Salar de Llamara (850 m a.s.l.), where large domed structures of seemingly evaporitic origin forming domes can be found. In this work, we performed a detailed microbial characterization of these domes. Mineralogical studies revealed gypsum (CaSO(4)) as a major component. Microbial communities associated to these structures were analysed by 454 16S rDNA amplicon sequencing and compared between winter and summer seasons. Bacteroidetes Proteobacteria and Planctomycetes remained as the main phylogenetic groups, an increased diversity was found in winter. Comparison of the upper air-exposed part and the lower water-submerged part of the domes in both seasons showed little variation in the upper zone, showing a predominance of Chromatiales (Gammaproteobacteria), Rhodospirillales (Alphaproteobacteria), and Sphingobacteriales (Bacteroidetes). However, the submerged part showed marked differences between seasons, being dominated by Proteobacteria (Alpha and Gamma) and Verrucomicrobia in summer, but with more diverse phyla found in winter. Even though not abundant by sequence, Cyanobacteria were visually identified by scanning electron microscopy (SEM), which also revealed the presence of diatoms. Photosynthetic pigments were detected by high-performance liquid chromatography, being more diverse on the upper photosynthetic layer. Finally, the system was compared with other endoevaporite, mats microbialite and Stromatolites microbial ecosystems, showing higher similitude with evaporitic ecosystems from Atacama and Guerrero Negro. This environment is of special interest for extremophile studies because microbial life develops associated to minerals in the driest desert all over the world. Nevertheless, it is endangered by mining activity associated to copper and lithium extraction; thus, its

  3. Calcium Sulfate Hemihydrate Whiskers Obtained from Flue Gas Desulfurization Gypsum and Used for the Adsorption Removal of Lead

    Directory of Open Access Journals (Sweden)

    Xiaoshu Wang


    Full Text Available Abstract: As a recycled material, flue gas desulfurization gypsum has been used to prepare calcium sulfate hemihydrate whisker (CSHW through hydrothermal synthesis for several decades. However, the subsequent utilization of this resultant material has not yet received considerable attention. In the present research, CSHW was successfully synthesized at a certain region, and was used for the adsorption of lead ions from aqueous solutions, thereby broadening the research field for the practical application of CSHW. Its adsorption capacity was significantly influenced by various parameters, particularly, the pH level and initial lead concentration. The pH value highly affected the hydrolysis degree of lead ions and dominated the adsorption of lead. The equilibrium isotherms under two different temperatures were simulated using Langmuir, Freundlich, and Temkin models. Both Langmuir and Temkin models showed a good fit to the data. Combined with the well-fitted pseudo-second-order model, the adsorption mechanism was thought to be a chemisorption process that was enforced by the ion exchange reaction. In addition, the specific crystal structure of CSHW revealed that ion exchange reaction occurred on the (010 and (100 facets due to their preferential growth and negatively charged property. The residual solid phase after adsorption was collected and detected using X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy. Results revealed that PbSO4 was formed on the surface of CSHW. The alkaline condition introduced the tribasic lead sulfate, and thus reduced the stability of the adsorption system.


    Chemical disinfection of water is a major public health advance that has decreased dramatically water-borne disease. Chemical disinfectants react with naturally occurring organic and inorganic matter in water to produce a wide variety of disinfection byproducts (DBPs). DBP num...

  5. Sampling from stochastic reservoir models constrained by production data

    Energy Technology Data Exchange (ETDEWEB)

    Hegstad, Bjoern Kaare


    When a petroleum reservoir is evaluated, it is important to forecast future production of oil and gas and to assess forecast uncertainty. This is done by defining a stochastic model for the reservoir characteristics, generating realizations from this model and applying a fluid flow simulator to the realizations. The reservoir characteristics define the geometry of the reservoir, initial saturation, petrophysical properties etc. This thesis discusses how to generate realizations constrained by production data, that is to say, the realizations should reproduce the observed production history of the petroleum reservoir within the uncertainty of these data. The topics discussed are: (1) Theoretical framework, (2) History matching, forecasting and forecasting uncertainty, (3) A three-dimensional test case, (4) Modelling transmissibility multipliers by Markov random fields, (5) Up scaling, (6) The link between model parameters, well observations and production history in a simple test case, (7) Sampling the posterior using optimization in a hierarchical model, (8) A comparison of Rejection Sampling and Metropolis-Hastings algorithm, (9) Stochastic simulation and conditioning by annealing in reservoir description, and (10) Uncertainty assessment in history matching and forecasting. 139 refs., 85 figs., 1 tab.

  6. Health impact of disinfection by-products in swimming pools

    Directory of Open Access Journals (Sweden)

    Cristina M. Villanueva


    Full Text Available This article is focused on the epidemiological evidence on the health impacts related to disinfection by-products (DBPs in swimming pools, which is a chemical hazard generated as an undesired consequence to reduce the microbial pathogens. Specific DBPs are carcinogenic, fetotoxic and/or irritant to the airways according to experimental studies. Epidemiological evidence shows that swimming in pools during pregnancy is not associated with an increased risk of reproductive outcomes. An epidemiological study suggested an increased risk of bladder cancer with swimming pool attendance, although evidence is inconclusive. A higher prevalence of respiratory symptoms including asthma is found among swimming pool workers and elite swimmers, although the causality of this association is unclear. The body of evidence in children indicates that asthma is not increased by swimming pool attendance. Overall, the available knowledge suggests that the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimising potential risks.

  7. Appraisal of the groundwater conceptual model of the gypsum coastal karst of Lesina Marina (Puglia, Southern Italy) aiming at density-dependent modeling. (United States)

    Campana, C.; Fidelibus, M. D.


    Inhabited coastal areas are site of many risks, because in terms of geomorphology, hydraulics, hydrogeology and mass transport, they are at the lowest level of potential energy. Moreover, considering that at land-sea interface brackish/salt waters enhance in general the effects of water-rock interactions, the number of possible risks increases. This is the case of the gypsum coastal karst of Lesina Marina (Puglia, Southern Italy), where, starting from 1993, a number of sinkholes developed mostly along an artificial canal, excavated in 1927 to connect a brackish lagoon with the sea. The excavation diverted groundwater flow, with increase of hydraulic gradients and filtration velocity, amplitude of the groundwater level oscillations and, locally, tidal efficiency, causing continuous "flooding and draining" cycles, largely controlled by tides. These factors, on the whole, favored internal erosion and flushing of cave deposits, and amplified, due to increased hydraulic connectivity between fresh and brackish/salt water, gypsum dissolution. After many years it is still not likely to assess the relative role played by internal erosion and dissolutional enlargement of cavities in the sinkhole development. With the final aim of defining the subsidence risk in the Lesina Marina area, recently the Puglia River Basin Authority realized new bore-holes, geophysical logs and a continuous piezometric monitoring. To the aims of the reconstruction of the aquifer conceptual model and of the identification of key factors for a reliable numerical density-dependent modeling (of flow, solute-transport and reactions), in the period from September to December 2011 we realized Electrical Conductivity and Temperature logs, samplings (at different depths) and chemical analyses along two transects perpendicular to the canal. Apart from the recognition of the main water-rock interaction processes (as gypsum solution and inverse Na/Ca ion-exchange), and the reconstruction of the trends of

  8. User community vs. producer innovation development efficiency

    DEFF Research Database (Denmark)

    Hienerth, Christoph; von Hippel, Eric; Jensen, Morten Berg


    In this paper we report upon a first empirical exploration of the relative efficiency of innovation development by product users vs. product producers. In a study of over 50 years of product innovation in the whitewater kayaking field, we find users in aggregate were approximately 3× more efficie...

  9. Solar Grade Silicon from Agricultural By-products

    Energy Technology Data Exchange (ETDEWEB)

    Laine, Richard M


    In this project, Mayaterials developed a low cost, low energy and low temperature method of purifying rice hull ash to high purity (5-6Ns) and converting it by carbothermal reduction to solar grade quality silicon (Sipv) using a self-designed and built electric arc furnace (EAF). Outside evaluation of our process by an independent engineering firm confirms that our technology greatly lowers estimated operating expenses (OPEX) to $5/kg and capital expenses (CAPEX) to $24/kg for Sipv production, which is well below best-in-class plants using a Siemens process approach (OPEX of 14/kg and CAPEX of $87/kg, respectively). The primary limiting factor in the widespread use of photovoltaic (PV) cells is the high cost of manufacturing, compared to more traditional sources to reach 6 g Sipv/watt (with averages closer to 8+g/watt). In 2008, the spot price of Sipv rose to $450/kg. While prices have since dropped to a more reasonable $25/kg; this low price level is not sustainable, meaning the longer-term price will likely return to $35/kg. The 6-8 g Si/watt implies that the Sipv used in a module will cost $0.21-0.28/watt for the best producers (45% of the cost of a traditional solar panel), a major improvement from the cost/wafer driven by the $50/kg Si costs of early 2011, but still a major hindrance in fulfilling DOE goal of lowering the cost of solar energy below $1/watt. The solar cell industry has grown by 40% yearly for the past eight years, increasing the demand for Sipv. As such, future solar silicon price spikes are expected in the next few years. Although industry has invested billions of dollars to meet this ever-increasing demand, the technology to produce Sipv remains largely unchanged requiring the energy intensive, and chlorine dependent Siemens process or variations thereof. While huge improvements have been made, current state-of-the-art industrial plant still use 65 kWh/kg of silicon purified. Our technology offers a key distinction to other technologies as it

  10. Human-induced hydrological changes and sinkholes in the gypsum karst of Lesina Marina area (Foggia Province, Italy) (United States)

    Fidelibus, M. D.; Gutierrez, F.; Spilotro, G.


    The Lesina Lagoon is located in the East-West-trending northern cost of Gargano (southern Italy). The lagoon is fed by springs draining the northern side of the Gargano Mesozoic carbonate aquifer and is connected with the sea by three channels, including the 2.2 km long Acquarotta Canal with a N-S orientation. The sea-side mouth of this canal was frequently clogged by sand accumulation. In 1927, the path of the northern section of this canal was changed to improve the water exchange between the lagoon and the Adriatic Sea for environmental and fish-farming purposes. The new portion of the canal, 8.5 m wide and 1.5 m deep, was excavated in evaporite bedrock and in a small outcrop of igneous rocks situated in the coast that inhibits sand accumulation. The Acquarotta Canal conveys water in both directions depending on the relative water levels of the lagoon and the sea. Initially the reach of the canal dug in gypsum was lined with concrete, which was replaced in 1993 by gabions for scenery improvement. The northern reach of the canal is dug in Upper Triassic gypsiferous sediments of the Burano Anhydrite Formation. The evaporite bedrock is mantled by unconsolidated deposits a few meters thick, largely made up of loose sand. The exposures found in the banks of the canal and in some sinkholes reveal that the gypsum has a high density of dissolutional conduits and cavities. Locally, it also shows open fractures and brecciated structure (crackle, mosaic and chaotic packbreccias) caused by dissolution-induced collapse processes. These voids, either of solutional or mechanical origin, are partially filled with detrital sediments derived from the mantling deposits. These features seem to correspond to a paleokarst, probably developed at several depths controlled by different and much lower sea level stands during the Quaternary. The construction Acquarotta Canal has caused significant changes in the local hydrology. According to the piezometric series recorded at several


    Energy Technology Data Exchange (ETDEWEB)

    Prof. Harold H. Schobert; Dr. M. Mercedes Maroto-Valer; Ms. Zhe Lu


    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, this report evaluates and compares several routes for the production of activated carbons from unburned carbon in fly ash, including physical and chemical activation methods. During the present reporting period (June 30, 2001-June 29, 2002), additional characterization work was conducted under Task 1 ''Procurement and characterization of CCBPs''. The suite collected includes samples from pulverized utility boilers, a utility cyclone unit equipped with a beneficiation technology, a stoker, and a fluidized bed combustor. Proximate, ultimate, and petrographic analyses of the fly ash samples previously collected were measured. Furthermore, the surface areas of the samples assembled were characterized by N{sub 2} adsorption isotherms at 77 K. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt%), while volatile matter contents of the samples varied between 0.45 to 24.8 wt%. The ultimate analyses of all the fly ash samples showed that they contained primarily carbon, while the hydrogen contents of all the samples were very low. In addition, during the current reporting period, also Task 2 ''Development of activated carbons'' and Task 3 ''Characterization of activated carbons'' were continued.

  12. The Environmental Impact and Cost Analysis of Concrete Mixing Blast Furnace Slag Containing Titanium Gypsum and Sludge in South Korea

    Directory of Open Access Journals (Sweden)

    Tae Hyoung Kim


    Full Text Available This study assessed the environmental effects and cost of the Industrial Waste addictive Blast Furnace Slag (W-BFS using Life Cycle Assessment (LCA and compared it to general BFS. The environmental impacts of W-BFS were as follows: 1.12 × 10−1 kg-CO2 eq/kg, 3.18 × 10−5 kg-Ethylene eq/kg, 4.79 × 10−4 kg-SO2 eq/kg, 7.15 × 10−4 kg-PO43− eq/kg, 7.15 × 10−4 kg-CFC11 eq/kg and 3.94 × 10−3 kg-Antimony eq/kg. Among the environmental impact category, GWP and AP were 9.28 × 10−2 kg-CO2 eq/kg and 3.33 × 10−4 kg-SO2 eq/kg at a raw material stage, accounting for 80% and 70% of total environmental impact respectively. In EP, POCP and ADP, in addition, raw material stage accounted for a great portion in total environmental impact because of “W” among input materials. In ODP, however, compared to the environmental impact of raw materials, oil, which was used in transporting BFS to the W-BFS manufacturing factory, was more influential. In terms of GWP, POCP and ODP, W-BFS was higher than general BFS. In terms of AP, EP and ADP, in contrast, the former was lower than the latter. In terms of cost, W-BFS (41.7 US$/ton was lower than general BFS by about 17% because of the use of waste additives comprised of industrial wastes instead of natural gypsum ,which has been commonly used in general BFS. In terms of GWP and POCP, the W-BFS mixed (30% concrete was lower than plain concrete by 25%. In terms of AP and EP, the former was lower than the latter by 30%. In terms of ADP, furthermore, W-BFS mixed (30% concrete was lower than plain concrete by 11%. In aggregate-related ODP, however, almost no change was found. In terms of cost, when W-BFS was added by 10% and 30%, it was able to reduce cost by 3% and 7% respectively, compared to plain concrete. Compared to BFS-mixed concrete as well, cost could be saved by 1% additionally because W-BFS (US$41.7/ton is lower than common cement (US$100.3/ton by about 60% in terms of production costs.

  13. Effects of spray drying on antioxidant capacity and anthocyanidin content of blueberry by-products. (United States)

    Lim, Kar; Ma, Mitzi; Dolan, Kirk D


    The effect of spray drying on degradation of nutraceutical components in cull blueberry extract was investigated. Samples collected before and after spray drying were tested for antioxidant capacity using oxygen radical absorbance capacity (ORAC(FL) ) and total phenolics; and for individual anthocyanidins. In Study 1, four different levels of maltodextrin (blueberry solids to maltodextrin ratios of 5: 95, 10: 90, 30: 70, and 50: 50) were spray dried a pilot-scale spray dryer. There was significantly higher retention of nutraceutical components with increased levels of maltodextrin indicating a protective effect of maltodextrin on the nutraceutical components during spray drying. In Study 2, the air inlet temperature of the spray dryer was kept constant for all runs at 150 °C, with 2 different outlet temperatures of 80 and 90 °C. The degradation of nutraceutical components was not significantly different at the 2 selected outlet temperatures. ORAC(FL) reduction for blueberry samples after spray drying was 66.3% to 69.6%. After spray drying, total phenolics reduction for blueberry was 8.2% to 17.5%. Individual anthocyanidin reduction for blueberry was 50% to 70%. The experimental spray dried powders compared favorably to commercial blueberry powders. Results of the study show that use of blueberry by-products is feasible to make a value-added powder. Results can be used by producers to estimate final nutraceutical content of spray-dried blueberry by-products. © 2011 Institute of Food Technologists®

  14. Utilisation of biomass gasification by-products for onsite energy production. (United States)

    Vakalis, S; Sotiropoulos, A; Moustakas, K; Malamis, D; Baratieri, M


    Small scale biomass gasification is a sector with growth and increasing applications owing to the environmental goals of the European Union and the incentivised policies of most European countries. This study addresses two aspects, which are at the centre of attention concerning the operation and development of small scale gasifiers; reuse of waste and increase of energy efficiency. Several authors have denoted that the low electrical efficiency of these systems is the main barrier for further commercial development. In addition, gasification has several by-products that have no further use and are discarded as waste. In the framework of this manuscript, a secondary reactor is introduced and modelled. The main operating principle is the utilisation of char and flue gases for further energy production. These by-products are reformed into secondary producer gas by means of a secondary reactor. In addition, a set of heat exchangers capture the waste heat and optimise the process. This case study is modelled in a MATLAB-Cantera environment. The model is non-stoichiometric and applies the Gibbs minimisation principle. The simulations show that some of the thermal energy is depleted during the process owing to the preheating of flue gases. Nonetheless, the addition of a secondary reactor results in an increase of the electrical power production efficiency and the combined heat and power (CHP) efficiency. © The Author(s) 2016.

  15. Transforming beef by-products into valuable ingredients: which spell/recipe to use?

    Directory of Open Access Journals (Sweden)

    Maeve Mary Henchion


    Full Text Available Satisfying the increasing global demand for protein results in challenges from a supply perspective. Increased use of animal proteins, through greater use of meat by-products, could form part of the solution, subject to consumer acceptance. This research investigates consumer evaluations of food products that incorporate ingredients derived from offals that have been produced through a range of food processing technologies. Using focus groups incorporating product stimuli representing various combinations of offals, processing and carrier products, the research finds that the physical state and perceived naturalness of the ingredients influences acceptance. It also highlights the impact of life experiences, linked to demographic characteristics, on interpretations and evaluations of products and processes. Ideational influences, i.e. knowledge of the nature or origin of the substance, are reasons for rejecting some concepts, with misalignment between nature of processing and the product resulting in rejection of others. Lack of perceived necessity also results in rejection. Alignment of ingredients with existing culinary practices and routines, communication of potential sensory or other benefits as well as naturalness are factors likely to promote acceptance, and generate repeat purchase, in some consumer segments. Trust in oversight that the products are safe is a prerequisite for acceptance in all cases. These findings have implications for pathways to increase sustainability of beef production and consumption through increased use of beef by-products.

  16. Pectic oligosaccharides from agricultural by-products: production, characterization and health benefits. (United States)

    Babbar, Neha; Dejonghe, Winnie; Gatti, Monica; Sforza, Stefano; Elst, Kathy


    Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc. However, extensive research is needed to establish the role of POS, both as a prebiotic as well as therapeutic agent. This review comprehensively covers different facets of POS, including the nature and chemistry of pectin and POS, potential agricultural residual sources of pectin, pre-treatment methods for facilitating selective extraction of pectin, identification and characterization of POS, health benefits and important applications of POS in food and feed. This review has been compiled to establish a platform for future research in the purification and characterization of POS and for in vivo and in vitro studies of important POS, so that they could be commercially exploited.

  17. Cellulose Nanocrystals Obtained from Rice By-Products and Their Binding Potential to Metallic Ions

    Directory of Open Access Journals (Sweden)

    Vanessa L. Albernaz


    Full Text Available The present study aimed to develop and optimize a method to obtain cellulose nanocrystals from the agricultural by-products rice husk and straw and to evaluate their electrostructural modifications in the presence of metallic ions. First, different particle formation conditions and routes were tested and analyzed by spectrophotometry, dynamic light scattering (DLS, and Zeta potential measurements. Then, electrostructural effects of ions Na(I, Cd(II, and Al(III on the optimized nanoparticles were analyzed by atomic force microscopy (AFM, scanning electron microscopy (SEM, and electrical conductivity (EC assessments. The produced cellulose nanocrystals adopted a rod-like shape. AFM height distribution and EC data indicated that the nanocrystals have more affinity in binding with Na(I > Al(III > Cd(II. These data suggest that the use of these cellulose nanocrystals in the bioremediation field is promising, both in metal sorption from wastewater and as an alternative for water desalination.

  18. The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water


    Glòria Carrasco-Turigas; Villanueva, Cristina M.; Fernando Goñi; Panu Rantakokko; Nieuwenhuijsen, Mark J.


    Disinfection by-products (DBPs) are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4) (chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)), MX, and bromate were tested when boiling and filtering high bromine-conta...

  19. Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes. (United States)

    Pagliano, Giorgia; Ventorino, Valeria; Panico, Antonio; Pepe, Olimpia


    Recently, issues concerning the sustainable and harmless disposal of organic solid waste have generated interest in microbial biotechnologies aimed at converting waste materials into bioenergy and biomaterials, thus contributing to a reduction in economic dependence on fossil fuels. To valorize biomass, waste materials derived from agriculture, food processing factories, and municipal organic waste can be used to produce biopolymers, such as biohydrogen and biogas, through different microbial processes. In fact, different bacterial strains can synthesize biopolymers to convert waste materials into valuable intracellular (e.g., polyhydroxyalkanoates) and extracellular (e.g., exopolysaccharides) bioproducts, which are useful for biochemical production. In particular, large numbers of bacteria, including Alcaligenes eutrophus, Alcaligenes latus, Azotobacter vinelandii, Azotobacter chroococcum, Azotobacter beijerincki, methylotrophs, Pseudomonas spp., Bacillus spp., Rhizobium spp., Nocardia spp., and recombinant Escherichia coli, have been successfully used to produce polyhydroxyalkanoates on an industrial scale from different types of organic by-products. Therefore, the development of high-performance microbial strains and the use of by-products and waste as substrates could reasonably make the production costs of biodegradable polymers comparable to those required by petrochemical-derived plastics and promote their use. Many studies have reported use of the same organic substrates as alternative energy sources to produce biogas and biohydrogen through anaerobic digestion as well as dark and photofermentation processes under anaerobic conditions. Therefore, concurrently obtaining bioenergy and biopolymers at a reasonable cost through an integrated system is becoming feasible using by-products and waste as organic carbon sources. An overview of the suitable substrates and microbial strains used in low-cost polyhydroxyalkanoates for biohydrogen and biogas production is

  20. Fluosorbent injection by-products. Final report, January 1997 through December 1999

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Sid [Sorbent Technologies Corp., Twinsburg, OH (United States)


    Few, if any, economical alternatives exist for small coal-fired boilers that require a flue-gas desulfurization (FGD) system which does not generate wastes. A new duct-injection technology, called "Fluesorbent," was developed to help fill this gap. Fluesorbent was intentionally designed so that the saturated S02-sorbent materials can be used as beneficial soil amendments after they were used for FGD. A. Project Objective: The objective of this project was to demonstrate in the field that saturated Fluesorbent materials can be utilized beneficially on agricultural and grass lands. B. Project Results: The results of this project suggest that, indeed, saturated Fluesorbent has excellent potential as a commercial soil amendment for crops, such as alfalfa and soybeans, and for turf. Yields of alfalfa and turf were substantially increased in field testing on acidic soils by one-time applications of Fluesorbent FGD by-products. In the first two years of field testing, alfalfa yields on field plots with the FGD by-products were approximately 40% greater than on plots treated with an equivalent amount of agricultural lime. In a third, drought-influenced year, the gains were smaller. Turf grass growth was fully twice that of untreated plots and more than 10% greater than with ag-lime. A small farm trial with a modified version of the Fluesorbent by-product increased soybean yield by 25%. A small trial with corn, however, indicated no significant improvement. Even though the Fluesorbent contained fly ash, the alfalfa and turf grown in FGD-treated plots contained significantly lower levels of heavy metals than that grown in untreated or lime-treated plots. In a project greenhouse experiment, the fly ashes from five different coal boilers from around Ohio produced equivalent yields when mixed with Fluesorbent, indicating wide potential applicability of the new technology. The Fluesorbent materials were also found to be easy to extrude into pellets for use with mixed fertilizers

  1. Optimization of the level and range of working temperature of the PCM in the gypsum-microencapsulated PCM thermal energy storage unit for summer conditions in Central Poland (United States)

    Łapka, P.; Jaworski, M.


    In this paper thermal energy storage (TES) unit in a form of a ceiling panel made of gypsum-microencapsulated PCM composite with internal U-shaped channels was considered and optimal characteristics of the microencapsulated PCM were determined. This panel may be easily incorporated into, e.g., an office or residential ventilation system in order to reduce daily variations of air temperature during the summer without additional costs related to the consumption of energy for preparing air parameters to the desired level. For the purpose of the analysis of heat transfer in the panel, a novel numerical simulator was developed. The numerical model consists of two coupled parts, i.e., the 1D which deals with the air flowing through the U-shaped channel and the 3D which deals with heat transfer in the body of the panel. The computational tool was validated based on the experimental study performed on the special set-up. Using this tool an optimization of parameters of the gypsum-microencapsulated PCM composite was performed in order to determine its most appropriate properties for the application under study. The analyses were performed for averaged local summer conditions in Warsaw, Poland.

  2. Sulfate and organic matter concentration in relation to hydrogen sulfide generation at inert solid waste landfill site - Limit value for gypsum. (United States)

    Asakura, Hiroshi


    In order to suggest a limit value for gypsum (CaSO4) for the suppression of hydrogen sulfide (H2S) generation at an inert solid waste landfill site, the relationship between raw material (SO4 and organic matter) for H2S generation and generated H2S concentration, and the balance of raw material (SO4) and product (H2S) considering generation and outflow were investigated. SO4 concentration should be less than approximately 100mg-SO4/L in order to suppress H2S generation to below 2000ppm. Total organic carbon (TOC) concentration should be less than approximately 200mg-C/L assuming a high SO4 concentration. The limit value for SO4 in the ground is 60mg-SO4/kg with 0.011wt% as gypsum dihydrate, i.e., approximately 1/10 of the limit value in inert waste as defined by the EU Council Decision (560mg-SO4/kg-waste). The limit value for SO4 in inert waste as defined by the EU Council Decision is high and TOC is strictly excluded. The cumulative amount of SO4 outflow through the liquid phase is much larger than that through the gas phase. SO4 concentration in pore water decreases with time, reaching half the initial concentration around day 100. SO4 reduction by rainfall can be expected in the long term. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Production of polyhydroxyalkanoates (PHAs) from waste materials and by-products by submerged and solid-state fermentation. (United States)

    Castilho, Leda R; Mitchell, David A; Freire, Denise M G


    Polyhydroxyalkanoates are biodegradable polymers produced by prokaryotic organisms from renewable resources. The production of PHAs by submerged fermentation processes has been intensively studied over the last 30 years. In recent years, alternative strategies have been proposed, such as the use of solid-state fermentation or the production of PHAs in transgenic plants. This paper gives an overview of submerged and solid-state fermentation processes used to produce PHAs from waste materials and by-products. The use of these low-cost raw materials has the potential to reduce PHA production costs, because the raw material costs contribute a significant part of production costs in traditional PHA production processes.

  4. Organic amendments derived from a pharmaceutical by-product: benefits and risks (United States)

    Gigliotti, Giovanni; Cucina, Mirko; Zadra, Claudia; Pezzolla, Daniela; Sordi, Simone; Carla Marcotullio, Maria; Curini, Massimo


    The application of organic amendments to soils, such as sewage sludge, anaerobic digestate and compost is considered a tool for improving soil fertility and enhancing C stocks. The addition of these different organic materials allows a good supply of nutrients for plants but also contributes to C sequestration, affects the microbial activity and the transformation of soil organic matter (SOM). Moreover, the addition of organic amendment has gained importance as a source of CO2 emissions and then as a cause of the "Global Warming". Therefore, it is important to investigate the factors controlling the SOM mineralization in order to improve the soil C sequestration and decreasing at the same time CO2 emissions. Moreover, the quality of organic matter added to the soil will play an important role in these dynamics. Based on these considerations, the aim of the present work was to investigate the effect of the application to an arable soil of different organic materials derived from a pharmaceutical by-product which results from the fermentative biomass after the separation of the lipopolypeptidic antibiotic produced. A microcosm soil experiment was carried out using three different materials: a sewage sludge derived from the stabilization process of the by-product, a digestate obtained from the anaerobic treatment of the by-product and a compost produced by the aerobic treatment of the same digestate. To achieve this aim, the short-term variations of CO2 emissions, enzymatic soil activities (Dehydrogenase total activity and Fluoresceine diacetate hydrolysis), SOM quantity and quality were studied. In addition, process-related residues of antibiotic and decanoic acid (a precursor added during the fermentation) were analyzed on the organic materials to assess their possible presence. Through these analyses it was possible to state that the application to the soil of sewage sludge and anaerobic digestate may have a strong influence on the short-term variations of the

  5. Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production

    Energy Technology Data Exchange (ETDEWEB)

    Donal F. Day


    The work conducted in this project is an extension of the developments itemized in DE-FG-36-04GO14236. This program is designed to help the development of a biorefinery based around a raw sugar mill, which in Louisiana is an underutilized asset. Some technical questions were answered regarding the addition of a biomass to ethanol facility to existing sugar mills. The focus of this work is on developing technology to produce ethanol and valuable by-products from bagasse. Three major areas are addressed, feedstock storage, potential by-products and the technology for producing ethanol from dilute ammonia pre-treated bagasse. Sugar mills normally store bagasse in a simple pile. During the off season there is a natural degradation of the bagasse, due to the composting action of microorganisms in the pile. This has serious implications if bagasse must be stored to operate a bagasse/biorefinery for a 300+ day operating cycle. Deterioration of the fermentables in bagasse was found to be 6.5% per month, on pile storage. This indicates that long term storage of adequate amounts of bagasse for year-round operation is probably not feasible. Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of

  6. Chemical production from industrial by-product gases: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lyke, S.E.; Moore, R.H.


    The potential for conservation of natural gas is studied and the technical and economic feasibility and the implementation of ventures to produce such chemicals using carbon monoxide and hydrogen from byproduct gases are determined. A survey was performed of potential chemical products and byproduct gas sources. Byproduct gases from the elemental phosphorus and the iron and steel industries were selected for detailed study. Gas sampling, preliminary design, market surveys, and economic analyses were performed for specific sources in the selected industries. The study showed that production of methanol or ammonia from byproduct gas at the sites studied in the elemental phosphorus and the iron and steel industries is technically feasible but not economically viable under current conditions. Several other applications are identified as having the potential for better economics. The survey performed identified a need for an improved method of recovering carbon monoxide from dilute gases. A modest experimental program was directed toward the development of a permselective membrane to fulfill that need. A practical membrane was not developed but further investigation along the same lines is recommended. (MCW)

  7. Conversion of agricultural by-products to sugars. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, P.J.


    ..beta..-xylosidase was immobilized by various methods to a number of different carriers. After efficiencies of coupling and after activities and stabilities of the resulting immobilized enzymes were measured, alumina and porous silica were chosen as preferred carriers and conditions for binding ..beta..-xylosidase to them were optimized. The effects of temperature and pH on the activity of both alumina- and silica-bound ..beta..-xylosidase were found to be similar to those affecting the activity of the soluble form of the enzyme. The effects of pH and temperature on stability of ..beta..-xylosidase immobilized to alumina were determined. While optimum pH for stability and the extraordinary effect of temperature on stability were similar to results with native ..beta..-xylosidase, the immobilized enzyme was appreciably less stable than the soluble one. The xylanase that previously had been partially purified was further purified and found to be a polygalacturonase. Another xylanase was purified to the point of homogeneity, and its specificity and the effects of temperature and pH on its activity were determined. Several other xylanases were partially purified and their characteristics partially determined. Xylobiose, xylotriose, xylotetraose, and an arabinosyl-xylosyl-xylose were produced, the first three by both acid and enzyme hydrolysis of xylan; all four were purified by charcoal-Celite column chromatography.

  8. Gypsum effects on soil chemical properties under two management systemsEfeito do gesso nas propriedades químicas do solo sob dois sistemas de manejo

    Directory of Open Access Journals (Sweden)

    Yara Brito Chaim Jardim Rosa


    Full Text Available The combination of gypsum application and soil management may influence soil chemical properties. In this context, the aim of this paper was to evaluate soil chemical properties under two management systems and residual gypsum in soil after 55 months from treatment application. This experiment was developed in FCA/UFGD in Dourados-MS, Brazil under a randomized block design with subdivided plots and four replications. Main plots, subplots and subsubplots consisted of tillage systems (conventional and no tillage, gypsum application and soil depth (0-0,05, 0,05-0,10, 0,10-0,15, 0,15-0,20 and 0,20-0,30 m, respectively. There were no effects of residual gypsum on calcium levels. The combination of no tillage system and residual gypsum increased potassium and sulfur as well as reduced potential acidity. However, residual gypsum increased soil potential acidity in conventional system. No tillage system increased calcium levels in the depths 0-0.05 and 0.05-0.10 m, organic matter down to 0.05 m, sulfur accumulation in the depths 0.05-0.10 and 0.10-0.15 m, sum of bases and base saturation in the depth 0.05-0.10. Conversely, magnesium levels in the depth 0.10-0.15 m, phosphorus from 0.05 to 0.15 m, potential acidity from 0.05 to 0.10 m and ECC in the depth 0.10-0.15 m were decreased. Effects of residual gypsum increased sulfur and base saturation from 0.20 to 0.30 m, but decreased magnesium and phosphorus levels in the depth 0.05-0.10 m. Soil active acidity and potassium levels were decreased in deeper soil layers. A combinação de gessagem e manejo do solo podem influenciar as propriedades químicas do solo. Neste contexto, o objetivo deste trabalho foi avaliar as propriedades químicas do solo submetido a dois manejos do solo e ao efeito residual de gesso, após 55 meses de implantação dos tratamentos. Desenvolvido em uma área experimental da FCA/UFGD de Dourados, MS, o experimento foi disposto no delineamento de blocos casualizados com os fatores

  9. Properties of chars obtained with pyrolysis of Castanea sativa by product

    Directory of Open Access Journals (Sweden)

    Pehlivan Eylem


    Full Text Available The application of biomass derived energy is gaining importance due to the decreasing supply of fossil fuels and growing environmental concerns. This study described the possibility of utilizing Castanea sativa’s by-product as biofuels by producing char via pyrolysis. The process was carried out in a fixed-bed reactor at different heating rates of 10°C, 100°C, and 200°C per minute at temperatures ranging from 400°C to 700°C, and a nitrogen flow rate of 100 cm3 per minute. The produced chars were characterized by proximate and elemental analyses, Brunauer-Emmett-Teller surface area, nuclear magnetic resonance, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray fluorescence analyses. The char yield was found to decrease as both pyrolysis temperature and heating rate increases. The carbon content of char ranged from 68 to 87 wt.%, which correspond to approximately 43% of carbon in the biomass. The char obtained at 700°C had high fixed carbon content (79.90% as well as high heating value, and hence, it could be used as a solid fuel or as a precursor in the activated carbon production with its 268 m2 per gram surface area.

  10. Development and characterization of couscous-like product using bulgur flour as by-product. (United States)

    Yuksel, Ayse Nur; Öner, Mehmet Durdu; Bayram, Mustafa


    Couscous is produced traditionally by agglomeration of Triticum durum semolina with water. The aims of this study were: to produce couscous-like product by substitution of semolina with bulgur by-product (undersize bulgur); to find optimum quantity of bulgur flour and processing conditions. In order to determine the optimum processing parameters and recipes; 0, 25 and 50% of bulgur containing couscous-like samples were prepared. The color, yield, sensory properties, total phenol and flavonoid contents, bulk density, protein and ash content, texture properties were determined. Two different types of dryer e.g. packed bed and microwave were used. Optimum parameters were predicted as 50% of bulgur flour for packed bed (60 °C) and microwave (180 W) drying with 50% (w/w) of water according to yields, color (L*, a*, b*) values and sensory properties (color, odor, general appearance). For packed bed drying at 60 °C yields were 54.28 ± 3.78, 47.70 ± 1.73 and 52.57 ± 7.04% for 0, 25 and 50% bulgur flour containing samples, respectively. Lightness (L*) values of couscous-like samples were decreased with increasing the quantity of bulgur flour after both drying processes. Results of sensory analysis revealed that couscous-like bulgur were more preferable for consumers.

  11. Late-stage anhydrite-gypsum-siderite-dolomite-calcite assemblages record the transition from a deep to a shallow hydrothermal system in the Schwarzwald mining district, SW Germany (United States)

    Burisch, Mathias; Walter, Benjamin F.; Gerdes, Axel; Lanz, Maximilian; Markl, Gregor


    The majority of hydrothermal vein systems of economic interest occur at relatively shallow crustal levels, although many of them formed at significantly greater depths. Their present position is a consequence of uplift and erosion. Although, many aspects of their formation are well constrained, the temporal chemical evolution of such systems during uplift and erosion is still poorly understood. These vein minerals comprise calcite, dolomite-ankerite, siderite-magnesite, anhydrite and gypsum forming the last gangue assemblages in Jurassic and Tertiary sulphide-fluorite-quartz-barite veins of the Schwarzwald mining district, SW Germany. Mineral textures of samples from nine localities reveal that in these sequences, mineral precipitation follows a recurring pattern: early calcite is followed by anhydrite or gypsum, siderite and/or dolomite. This succession may repeat up to three times. In-situ (LA-ICP-MS) U-Pb age dating of 15 carbonates from three subsequent generations of the late-stage vein assemblage yield robust ages between 20 and 0.6 Ma. Each mineral sequence forms in a distinctive period of about 2-5 Ma. These ages clearly relate these late-stage mineral phases to the youngest geological episode of the Schwarzwald, which is associated with the Cenozoic Rhine Graben rifting and basement uplift. Based on thermodynamic modelling, the formation of the observed mineral assemblages required an deeply sourced Mg-, Fe- and SO4-rich fluid (b), which was episodically mixed with a shallow crustal HCO3-rich fluid (a). As a consequence of fluid mixing, concentrations of Mg, Fe and SO4 temporarily increased and initiated the formation of the observed sulphate-carbonate mineral sequences. This discontinuous large-scale vertical fluid mixing was presumably directly related to episodes of active tectonics associated with the Cenozoic strike-slip regime of the Upper Rhine Graben. Analogously, episodic fluid mixing is a major key in the formation of older (Jurassic to early

  12. Opportunities, perspectives and limits in lactic acid production from waste and industrial by-products

    Directory of Open Access Journals (Sweden)

    Mladenović Dragana D.


    Full Text Available In line with the goals of sustainable development and environmental protection today great attention is directed towards new technologies for waste and industrial by-products utilization. Waste products represent potentially good raw material for production other valuable products, such as bioethanol, biogas, biodiesel, organic acids, enzymes, microbial biomass, etc. Since the first industrial production to the present, lactic acid has found wide application in food, cosmetic, pharmaceutical and chemical industries. In recent years, the demand for lactic acid has been increasing considerably owing to its potential use as a monomer for the production of poly-lactic acid (PLA polymers which are biodegradable and biocompatible with wide applications. Waste and industrial by-products such are whey, molasses, stillage, waste starch and lignocellulosic materials are a good source of fermentable sugars and many other substances of great importance for the growth of microorganisms, such as proteins, minerals and vitamins. Utilization of waste products for production of lactic acid could help to reduce the total cost of lactic acid production and except the economic viability of the process offers a solution of their disposal. Fermentation process depends on chemical and physical nature of feedstocks and the lactic acid producer. This review describes the characteristics, abilities and limits of microorganisms involved in lactic acid production, as well as the characteristics and types of waste products for lactic acid production. The fermentation methods that have been recently reported to improve lactic acid production are summarized and compared. In order to improve processes and productivity, fed-batch fermentation, fermentation with immobilized cell systems and mixed cultures and opportunities of open (non-sterilized fermentation have been investigated.

  13. Pseudomonas pseudoalcaligenes CECT5344, a cyanide-degrading bacterium with by-product (polyhydroxyalkanoates) formation capacity. (United States)

    Manso Cobos, Isabel; Ibáñez García, María Isabel; de la Peña Moreno, Fernando; Sáez Melero, Lara Paloma; Luque-Almagro, Víctor Manuel; Castillo Rodríguez, Francisco; Roldán Ruiz, María Dolores; Prieto Jiménez, María Auxiliadora; Moreno Vivián, Conrado


    Cyanide is one of the most toxic chemicals produced by anthropogenic activities like mining and jewelry industries, which generate wastewater residues with high concentrations of this compound. Pseudomonas pseudoalcaligenes CECT5344 is a model microorganism to be used in detoxification of industrial wastewaters containing not only free cyanide (CN(-)) but also cyano-derivatives, such as cyanate, nitriles and metal-cyanide complexes. Previous in silico analyses suggested the existence of genes putatively involved in metabolism of short chain length (scl-) and medium chain length (mcl-) polyhydroxyalkanoates (PHAs) located in three different clusters in the genome of this bacterium. PHAs are polyesters considered as an alternative of petroleum-based plastics. Strategies to optimize the bioremediation process in terms of reducing the cost of the production medium are required. In this work, a biological treatment of the jewelry industry cyanide-rich wastewater coupled to PHAs production as by-product has been considered. The functionality of the pha genes from P. pseudoalcaligenes CECT5344 has been demonstrated. Mutant strains defective in each proposed PHA synthases coding genes (Mpha(-), deleted in putative mcl-PHA synthases; Spha(-), deleted in the putative scl-PHA synthase) were generated. The accumulation and monomer composition of scl- or mcl-PHAs in wild type and mutant strains were confirmed by gas chromatography-mass spectrometry (GC-MS). The production of PHAs as by-product while degrading cyanide from the jewelry industry wastewater was analyzed in batch reactor in each strain. The wild type and the mutant strains grew at similar rates when using octanoate as the carbon source and cyanide as the sole nitrogen source. When cyanide was depleted from the medium, both scl-PHAs and mcl-PHAs were detected in the wild-type strain, whereas scl-PHAs or mcl-PHAs were accumulated in Mpha(-) and Spha(-), respectively. The scl-PHAs were identified as homopolymers of 3

  14. Lobster processing by-products as valuable bioresource of marine functional ingredients, nutraceuticals, and pharmaceuticals. (United States)

    Nguyen, Trung T; Barber, Andrew R; Corbin, Kendall; Zhang, Wei


    The worldwide annual production of lobster was 165,367 tons valued over $3.32 billion in 2004, but this figure rose up to 304,000 tons in 2012. Over half the volume of the worldwide lobster production has been processed to meet the rising global demand in diversified lobster products. Lobster processing generates a large amount of by-products (heads, shells, livers, and eggs) which account for 50-70% of the starting material. Continued production of these lobster processing by-products (LPBs) without corresponding process development for efficient utilization has led to disposal issues associated with costs and pollutions. This review presents the promising opportunities to maximize the utilization of LPBs by economic recovery of their valuable components to produce high value-added products. More than 50,000 tons of LPBs are globally generated, which costs lobster processing companies upward of about $7.5 million/year for disposal. This not only presents financial and environmental burdens to the lobster processors but also wastes a valuable bioresource. LPBs are rich in a range of high-value compounds such as proteins, chitin, lipids, minerals, and pigments. Extracts recovered from LPBs have been demonstrated to possess several functionalities and bioactivities, which are useful for numerous applications in water treatment, agriculture, food, nutraceutical, pharmaceutical products, and biomedicine. Although LPBs have been studied for recovery of valuable components, utilization of these materials for the large-scale production is still very limited. Extraction of lobster components using microwave, ultrasonic, and supercritical fluid extraction were found to be promising techniques that could be used for large-scale production. LPBs are rich in high-value compounds that are currently being underutilized. These compounds can be extracted for being used as functional ingredients, nutraceuticals, and pharmaceuticals in a wide range of commercial applications

  15. Lime and gypsum to improve root depth of orange crop in an Ultisol of the Coastal Tablelands Calcário e gesso no aprofundamento radicular da laranjeira em um Argissolo dos Tabuleiros Costeiros

    Directory of Open Access Journals (Sweden)

    Lafayette F. Sobral


    Full Text Available Coastal Tableland is a landscape unit in the North East of Brazil in which the main soils are Ultisols. In these soils, a compacted layer denominated "cohesive horizon" occurs and root growth is limited by it. An experiment with five treatments and six replications was set up in order to study how liming and gypsum could improve root depth of orange (Citrus sinensis L. Osbeck crop in an Ultisol in which a compacted layer was found at 0.3 m. Treatments were: A - No liming and no gypsum; B - Liming to achieve 60% base saturation; C - B + 1 t of gypsum ha-1 ; D - B + 2 t of gypsum ha-1 and E - B + 3 t of gypsum ha-1. Gypsum increased calcium and sulfate in the cohesive horizon. Surface application of lime and gypsum did not cause changes in soil density and total porosity in the cohesive horizon. An improvement of root length was observed at the cohesive horizon.Os tabuleiros costeiros são uma unidade de paisagem em que um dos principais solos são os Argissolos, nos quais, uma camada compactada, denominada "horizonte coeso" ocorre e o crescimento radicular é por ela limitado. Um experimento com cinco tratamentos e seis repetições foi implantado para se estudar os efeitos da calagem e do gesso no aprofundamento radicular da laranjeira (Citrus sinensis L. Osbeck em um Argissolo onde o horizonte coeso está a 0,3 m de profundidade. Os tratamentos foram: A - Sem gesso e sem calagem; B - Calagem para atingir 60% de saturação por bases; C - B + 1 t ha-1 de gesso ; D - B + 2 t ha-1 de gesso; e E - B + 3 t ha-1 de gesso. A calagem e o gesso aumentaram significativamente os teores de sulfato e de calcio no solo até a profundidade de 0,40 m. A aplicação a lanço de calcário e gesso não causaram modificações na densidade do solo e na porosidade total da camada compactada "horizonte coeso". Foi observado um aumento do comprimento das raízes da laranjeira na camada compactada.

  16. Methylene Blue Removal by Biochars from Food Industry By-Products (United States)

    Orfanos, Alexis; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.


    Biomass produced by food industries is mainly used as feedstock or in composting. In recent years, considerable research effort has been focused on the production of biochar under oxygen-limited conditions from carbon-rich biomass, such as food industry by-products, as mitigation measure for global warming once it is used as a soil amendment. The present study presents the findings of an experimental work, which investigated the use of different biochars for the removal of methylene blue (MB) from aqueous solutions. Biochars were produced from malt spent rootlets (MSR) from brewering and espresso coffee residue from coffee shops. MSR was pyrolyzed at temperatures of 300, 400, 500, 750, 850, and 900oC and the coffee residue was pyrolyzed at 850oC. The charring process was performed under limited-oxygen conditions using specialized containers. The surface area and the porosity of the materials were determined. Batch experiments were conducted in order to evaluate the sorption capacity of the above materials, and samples were agitated for 24 h at 25oC, at an optimum pH of about 7. Kinetic analysis was conducted over a period of 24 h, and isotherm studies were also constructed. The surface area of biochar produced from MSR and the MB removal were considerably increased at pyrolysis temperatures higher than 500oC. At 850oC, the maximum surface area value (300 m2 g-1) was observed, and the MB sorption capacity was 99 mg g-1. Based on the kinetic experimental data, sorption capacities at 120 min were over 58% of their equilibrium values for the biochars used. The maximum MB sorption capacity, based on the isotherm data, was 130 mg g-1, for the two biochars employed.

  17. Aqueous photodegradation of 4-tert-butylphenol: By-products, degradation pathway and theoretical calculation assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yanlin [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Shi, Jin; Chen, Hongche [Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433 (China); Zhao, Jianfu [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Dong, Wenbo, E-mail: [Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200433 (China)


    4-tert-butylphenol (4-t-BP), an endocrine disrupting chemical, is widely distributed in natural bodies of water but is difficult to biodegrade. In this study, we focused on the transformation of 4-t-BP in photo-initiated degradation processes. The steady-state photolysis and laser flash photolysis (LFP) experiments were conducted in order to elucidate its degradation mechanism. Identification of products was performed using the GC–MS, LC-MS and theoretical calculation techniques. The oxidation pathway of 4-t-BP by hydroxyl radical (HO·) was also studied and H{sub 2}O{sub 2} was added to produce HO·. 4-tert-butylcatechol and 4-tert-butylphenol dimer were produced in 4-t-BP direct photolysis. 4-tert-butylcatechol and hydroquinone were produced by the oxidation of HO·. But the formation mechanism of 4-tert-butylcatechol in the two processes was different. The benzene ring was fractured in 4-t-BP oxidation process and 29% of TOC was degraded after 16 h irradiation. - Highlights: • Photodegradation of 4-t-BP, an endocrine disrupting chemical, has been investigated. • 3 stable byproducts were identified from photolysis and oxidation processes. • 5 transient by-products were concluded from LFP experiments. • The theoretical calculation was performed to confirm the byproducts. • 4-t-BP was degraded with increasing efficiency: 254 nm < H{sub 2}O{sub 2}/313 nm < H{sub 2}O{sub 2}/254 nm.

  18. Near infrared spectroscopy for enforcement of European legislation concerning the use of animal by-products in animal feeds

    Directory of Open Access Journals (Sweden)

    Martnez A.


    Full Text Available The paper summarises the work done in the framework of two R&D projects aimed to demonstrate the contribution of Near Infrared Spectroscopy (NIRS to help the enforcement of the European legislation governing the use of animal by-products in animal feeds. Three different types of animal feed products were studied: compound feeds (CFs, animal protein byproducts meals (APBPs and animal fats by-products (AFBPs. The quantitative and qualitative chemometric models produced with a large collection of compound feed samples (n = 1005 ground and 523 unground have demonstrated, that NIRS can be used for the detection and quantification of the meat and bone meal (MBM added to compound feeds. Discriminant models produced with unground samples produced 100% of correctly classified samples in two cloned instruments placed in two different locations. The results also show that two dimensions NIR spectra of Animal By-Products (ABP, animal meals and fats may contain information about the animal species or group of species from which the ABPs were produced. However, further work is needed to enlarge the sample bank and the spectral libraries with well authenticated samples in order to increase the robustness of the quantitative and qualitative NIRS models. The paper opens expectations for using NIRS for the enforcement of legislation concerning the use of ABPs in animal feeds. More research and demonstration efforts have to be done in order to obtain more definitive and robust predictive models and for optimising its implementation either at-line, on-line and in-line in feed factories and inspection laboratories.

  19. Exploration of collagen recovered from animal by-products as a precursor of bioactive peptides: Successes and challenges. (United States)

    Fu, Yu; Therkildsen, Margrethe; Aluko, Rotimi E; Lametsch, René


    A large amount of food-grade animal by-products is annually produced during industrial processing and they are normally utilized as animal feed or other low-value purposes. These by-products are good sources of valuable proteins, including collagen or gelatin. The revalorization of collagen may lead to development of a high benefit-to-cost ratio. In this review, the major approaches for generation of collagen peptides with a wide variety of bioactivities were summarized, including antihypertensive, antioxidant and antidiabetic activities, and beneficial effects on bone, joint and skin health. The biological potentials of collagen peptides and their bioavailability were reviewed. Moreover, the unique advantages of collagen peptides over other therapeutic peptides were highlighted. In addition, the current challenges for development of collagen peptides as functional food ingredients were also discussed. This article discusses the opportunity to utilize collagen peptides as high value-added bio-functional ingredients in the food industry.

  20. Corrosion resistance of various bio-films deposited on austenitic cast steel casted by lost-wax process and in gypsum mould

    Directory of Open Access Journals (Sweden)

    J. Gawroński


    Full Text Available This work is the next of a series concerning the improvement of austenitic cast steel utility predicted for use in implantology for complicated long term implants casted by lost-wax process and in gypsum mould. Austenitic cast steel possess chemical composition of AISI 316L medical steel used for implants. In further part of present work investigated cast steel indicated as AISI 316L medical steel. Below a results of electrochemical corrosion resistance of carbon layer and bi-layer of carbon/HAp deposited on AISI 316L researches are presented. Coatings were manufactured by RF PACVD and PLD methods respectively. Obtained results, unequivocally indicates on the improvement of this type of corrosion resistance by substrate material with as deposited carbon layer. While bi-layer of carbon/HAp are characterized by very low corrosion resistance.

  1. The Potential Ability of Plaster to Cause Breast Cancer as Indicated by CA15-3 and CEA Antigens in Women Working in Gypsum Factory

    Directory of Open Access Journals (Sweden)

    Ali Abdul Hussein S. AL-Janabi


    Full Text Available Plaster is an important form of gypsum that mainly used in building construction. Breast cancer was investigated among women exposure to the dust of such material. The levels of CA15-3 and carcinoembryonic antigens (CEA as indicators for breast cancer were measured in the serum of 120 women working in a plaster factory. All of involved women showed a normal level of CEA, while 12.5% of them had moderately elevated levels of CA15-3. In conclusion; plaster dust has no significant effect to cause breast cancer in working women. Moderately high levels of CA15-3 in some of exposed women may relate to liver diseases. Key words: Breast Cancer, Plaster, CA15-3, CEA

  2. Land application uses for dry FGD by-products. Phase 1, [Annual report], December 1, 1991--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Bigham, J.; Dick, W.; Forster, L.; Hitzhusen, F.; McCoy, E.; Stehouwer, R.; Traina, S.; Wolfe, W. [Ohio State Univ., Columbus, OH (United States); Haefner, R. [Geological Survey, Columbus, OH (United States). Water Resources Div.


    The 1990 amendments to the Clean Air Act have spurred the development of flue gas desulfurization (FGD) processes, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. Presently FGD by-product materials are treated as solid wastes and must be landfilled. However, landfill sites are becoming more scarce and tipping fees are constantly increasing. It is, therefore, highly desirable to find beneficial reuses for these materials provided the environmental impacts are minimal and socially acceptable. Phase 1 results of a 4 and 1/2 year study to demonstrate large volume beneficial uses of FGD by-products are reported. The purpose of the Phase 1 portion of the project was to characterize the chemical, physical, mineralogical and engineering properties of the FGD by-product materials obtained from various FGD technologies being developed in the state of Ohio. Phase 1 also involved the collection of baseline economic data related to the beneficial reuse of these FGD materials. A total of 58 samples were collected and analyzed. In summary Phase 1 results revealed that FGD by-product materials are essentially coal fly ash materials diluted with unreacted sorbent and reaction products. High volume beneficial reuses will depend on the economics of their substituting for existing materials for various types of applications (e.g. as an agricultural liming material, soil borrow for highway embankment construction, and reclamation of active and abandoned surface coal mines). Environmental constraints to the beneficial reuse of dry FGD byproduct materials, based on laboratory and leachate studies, seem to be less than for coal fly ash.

  3. Solubility Measurements and Predictions of Gypsum, Anhydrite, and Calcite Over Wide Ranges of Temperature, Pressure, and Ionic Strength with Mixed Electrolytes (United States)

    Dai, Zhaoyi; Kan, Amy T.; Shi, Wei; Zhang, Nan; Zhang, Fangfu; Yan, Fei; Bhandari, Narayan; Zhang, Zhang; Liu, Ya; Ruan, Gedeng; Tomson, Mason B.


    Today's oil and gas production from deep reservoirs permits exploitation of more oil and gas reserves but increases risks due to conditions of high temperature and high pressure. Predicting mineral solubility under such extreme conditions is critical for mitigating scaling risks, a common and costly problem. Solubility predictions use solubility products and activity coefficients, commonly from Pitzer theory virial coefficients. However, inaccurate activity coefficients and solubility data have limited accurate mineral solubility predictions and applications of the Pitzer theory. This study measured gypsum solubility under its stable phase conditions up to 1400 bar; it also confirmed the anhydrite solubility reported in the literature. Using a novel method, the virial coefficients for Ca2+ and {{SO}}4^{2 - } (i.e., β_{{{{CaSO}}4 }}^{(0)} ,β_{{{{CaSO}}4 }}^{(2)} ,C_{{{{CaSO}}4 }}^{φ }) were calculated over wide ranges of temperature and pressure (0-250 °C and 1-1400 bar). The determination of this set of virial coefficients widely extends the applicable temperature and pressure ranges of the Pitzer theory in Ca2+ and SO 4 2- systems. These coefficients can be applied to improve the prediction of calcite solubility in the presence of high concentrations of Ca2+ and SO 4 2- ions. These new virial coefficients can also be used to predict the solubilities of gypsum and anhydrite accurately. Moreover, based on the derived β_{{{{CaSO}}4 }}^{(2)} values in this study, the association constants of {{CaSO}}4^{( 0 )} at 1 bar and 25 °C can be estimated by K_{{assoc}} = - 2β_{{{{CaSO}}4 }}^{(2)}. These values match very well with those reported in the literature based on other methods.

  4. On-line quantification and human health risk assessment of organic by-products from the removal of toluene in air using non-thermal plasma. (United States)

    Guo, Teng; Li, Xueshuang; Li, Jianquan; Peng, Zhen; Xu, Li; Dong, Junguo; Cheng, Ping; Zhou, Zhen


    Harmful organic by-products, produced during the removal of volatile organic compounds (VOCs) from the air by treatment with non-thermal plasma (NTP), hinder the practical applications of NTP. An on-line quantification and risk assessment method for the organic by-products produced by the NTP removal of toluene from the air has been developed. Formaldehyde, methanol, ketene, acetaldehyde, formic acid, acetone, acetic acid, benzene, benzaldehyde, and benzoic acid were determined to be the main organic by-products by proton transfer reaction mass spectrometry (PTR-MS), a powerful technique for real-time and on-line measurements of trace levels of VOCs, and a health-related index (HRI) was introduced to assess the health risk of these organic by-products. The discharge power (P) is a key factor affecting the formation of the organic by-products and their HRI values. Higher P leads to a higher removal efficiency (η) and lower HRI. However, higher P also means higher cost and greater production of discharge by-products, such as NO x and O 3 , which are also very dangerous to the environment and human health. In practical applications P, HRI, and η must be balanced, and sometimes the risks posed by the organic by-products are even greater than those of the removed compounds. Our mechanistic study reveals that acetone is a crucial intermediate for the removal of toluene by NTP, and we found that toluene molecules first fragment into acetone molecules, followed by other by-products. These observations will guide the study of the mechanism of aromatic molecule dissociation in plasma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Brookhaven Linac Isotope Producer (United States)

    Federal Laboratory Consortium — The Brookhaven Linac Isoptope Producer (BLIP)—positioned at the forefront of research into radioisotopes used in cancer treatment and diagnosis—produces commercially...

  6. Potential for methane production from typical Mediterranean agro-industrial by-products

    Energy Technology Data Exchange (ETDEWEB)

    Fountoulakis, M.S.; Drakopoulou, S.; Terzakis, S.; Georgaki, E.; Manios, T. [Laboratory of Solid Waste and Wastewater Management, School of Agricultural Technology, Technological Educational Institute of Crete, GR-71004 Iraklio, Crete (Greece)


    This work examines the potential for methane production from anaerobic co-digestion of olive mill wastewater and wine-grape residues with slaughterhouse wastewater. Continuous (mesophilic) and batch (mesophilic and thermophilic) experiments were studied, both with the separate types of by-products and with mixtures. Methane yields from olive oil wastewater, winery residues and slaughterhouse wastewater were 108, 147 and 297 L CH{sub 4} kg{sup -1} COD fed respectively. Co-digestion with 50% olive oil wastewater and 50% slaughterhouse wastewater or 50% winery residues gave a methane yield of 184 and 214 L CH{sub 4} kg{sup -1} COD, respectively. Furthermore, the methane yield was 188 L CH{sub 4} kg{sup -1} COD added, co-digesting a mixture of 50% winery residues and slaughterhouse wastewater. Finally, the same mixtures under thermophilic conditions gave methane yields of 282, 301 and 219 L CH{sub 4} kg{sup -1} COD, respectively. These results suggest that methane can be produced very efficiently by co-digesting olive oil wastewater, wine-grape residues and slaughterhouse wastewater. (author)

  7. In vitro toxicity and genotoxicity assessment of disinfection by-products, organic N-chloramines. (United States)

    Laingam, S; Froscio, S M; Bull, R J; Humpage, A R


    Disinfection by-products (DBPs) are of concern to both water industries and health authorities. Although several classes of DBPs have been studied, and there are regulated safe levels in disinfected water for some, a large portion of DBPs are not characterized, and need further investigation. Organic N-chloramines are a group of DBPs, which can be formed during common disinfection processes such as chlorination and chloramination, but little is known in terms of their toxicological significance if consumed in drinking water. Only a few in vitro studies using bacterial assays have reported some genotoxic potential of organic N-chloramines, largely in the context of inflammatory processes in the body rather than exposure through drinking water. In this study, we investigated 16 organic N-chloramines produced by chlorination of model amino acids and amines. It was found that within the drinking water-relevant micromolar concentration range, four compounds were both cytotoxic and genotoxic to mammalian cells. A small reduction of cellular GSH was also observed in the treatment with these four compounds, but not of a magnitude to account for the cytotoxicity and genotoxicity. The results presented in this study demonstrate that some organic N-chloramines, at low concentrations that might be present in disinfected water, can be harmful to mammalian cells.

  8. Evaluation of several microcrystalline celluloses obtained from agricultural by-products

    Directory of Open Access Journals (Sweden)

    John Rojas


    Full Text Available Microcrystalline cellulose (MCCI has been widely used as an excipient for direct compression due to its good flowability, compressibility, and compactibility. In this study, MCCI was obtained from agricultural by-products, such as corn cob, sugar cane bagasse, rice husk, and cotton by pursuing acid hydrolysis, neutralization, clarification, and drying steps. Further, infrared spectroscopy (IR, X-ray diffraction (XRD, optical microscopy, degree of polymerization (DP, and powder and tableting properties were evaluated and compared to those of Avicel PH101, Avicel PH102, and Avicel PH200. Except for the commercial products, all materials showed a DP from 55 to 97. Particles of commercial products and corn cob had an irregular shape, whereas bagasse particles were elongated and thick. Rice and cotton particles exhibited a flake-like and fiber-like shape, respectively. MCCI as obtained from rice husk and cotton was the most densified material, while that produced from corn cob and bagasse was bulky, porous, and more compressible. All products had a moisture content of less than 10% and yields from 7.4% to 60.4%. MCCI as obtained from bagasse was the most porous and compressible material among all materials. This product also showed the best tableting properties along with Avicel products. Likewise, all MCCI products obtained from the above-mentioned sources showed a more rapid disintegration time than that of Avicel products. These materials can be used as a potential source of MCCI in the production of solid dosage forms.

  9. Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products

    NARCIS (Netherlands)

    Broekhoven, van S.; Oonincx, D.G.A.B.; Huis, van A.; Loon, van J.J.A.


    Insects receive increasing attention as an alternative protein-rich food source for humans. Producing edible insects on diets composed of organic by-products could increase sustainability. In addition, insect growth rate and body composition, and hence nutritional quality, can be altered by diet.

  10. Use of fish hydrolysates and fishmeal by-products of the Alaskan fishing industry in diets for Pacific white shrimp (Litopenaeus vannamei) (United States)

    The suitability of four fish hydrolysates and two fishmeals derived from by-products of the Alaskan fishing industry, as menhaden fishmeal replacements in shrimp diets was determined. A control diet (30% crude protein and 8.5% crude lipid) was produced with menhaden meal (13% of diet). Experimental ...

  11. Characterization of Hanwoo Bovine By-products by Means of Yield, Physicochemical and Nutritional Compositions (United States)

    Moon, Sung Sil


    Though the edible bovine by-products are widely used for human consumption in most countries worldwide but the scientific information regarding the nutritional quality of these by-products is scarce. In the present study, the basic information regarding the yields, physicochemical and nutritional compositions of edible Hanwoo bovine by-products was studied. Our results showed that the yields, physicochemical and nutritional composition widely varied between the by-products examined. The highest pH values were found in rumen, reticulum, omasum and reproductive organ. Heart, liver, kidney and spleen had the lowest CIE L* values and highest CIE a* values. Liver had the highest vitamin A, B2 and niacin contents whereas the highest B1 and B5 contents were found in kidney. The highest Ca content was found in rumen, reticulum, omasum, head and leg while the highest Mn and Fe contents were found in rumen, omasum and spleen, respectively. Liver had the highest Cu content. Total essential amino acids (EAA)/amino acids (AA) ratios ranged between the by-products from 38.37% to 47.41%. Total polyunsaturated fatty acids (PUFA) levels ranged between the by-products from 2.26% to 26.47%, and most by-products showed favorable PUFA/SFA ratios. It is concluded that most of by-products examined are good sources of essential nutrients and these data will be of great importance for promotion of consumption and utilization of beef by-products in future. PMID:26761281

  12. By-products from ethanol production - the forgotten part of the equation. Possibilities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Grinsted Jensen, H.; Bjoernsson, A.H.; Lind, K.M.


    Conventional bioethanol is produced from starch based feedstocks either via dry or wet milling, using typically maize or wheat. One by-product from bioethanol production is dried distiller's grain with solubles (DDGS), which has proven to be a valuable feed commodity for animal husbandry. Particularly, DDGS replaces expensive protein feed at a competitive price for farmers, which has hitherto led to a rapidly increasing market for distiller's grain with solubles in the US, who is by far the largest producer of grain-based bioethanol in the world. The US also exports DDGS since it has a long shelf-life and can therefore be shipped overseas. Exports of DDGS from the US are increasingly taking place with Asia but also Europe and South-America as international destinations. Studies indicate that the price of DDGS in the US follows the corn price and is roughly at the same price level, even though protein contents in distiller's grain with solubles are higher than for cereals. With this price relationship, feed diets incorporating DDGS produce cost savings for farmers. An example for a Danish dairy farm shows that with this price relationship profits would increase by around 5 % per dairy cow if DDGS is included in the fodder plan, accounting for roughly 10 % of the energy content. Given that the US exports large amounts of DDGS it would be expected that the price level in Denmark would be highly influenced by US export prices, if Danish farmers adopt DDGS in their feed rations. One major barrier for increased acceptance of DDGS by potential buyers/farmers is the absence of a standard for the product. Pre-tested and pre-blended food diets with DDGS could lead to greater certainty of effects and acceptance by farmers. This could presumably increase the price of DDGS from current levels, which is lower than the feed value appears to suggest, due to uncertainty around the product as well as varying quality of DDGS. When DDGS replaces traditional animal feed

  13. Quantification and human health risk assessment of by-products of photo catalytic oxidation of ethylbenzene, xylene and toluene in indoor air of analytical laboratories. (United States)

    Dhada, Indramani; Sharma, Mukesh; Nagar, Pavan Kumar


    The by-products of TiO2-based photocatalytic oxidation (PCO) of ethylbenze, p,m-xylene, o-xylene and toluene (EXT) in vapour phase and those adsorbed on the catalyst surface (solid phase) were identified and quantified on GC/GC-MS. A factor was developed in terms of μg of by-product produced per mg of EXT removed per sq-meter surface area of catalyst for estimating the mass of by-products produced. The by-products quantified were: acetone, hexane, cyclohexane, benzene, crotonaldehyde, toulene, 1,4-benzoquinone, benzaldehyde, phenol, benzylalcohol, cresol, hydroquinone and benzoic acid. The by-products accounted for 2.3-4.2% of the total mass of EXT treated. For treating concentrations of 220μg/m(3) (ethylbenzene), 260μg/m(3) (p,m-xylene), 260μg/m(3) (o-xylene) and 320μg/m(3) (toluene), at a flow rate of 7L/min for 12h in a laboratory of volume 195m(3), the estimated cancer risks of by-products to the occupants were 1.51×10(-6), 1.06×10(-6), 4.69×10(-7), and 1.58×10(-9) respectively. The overall hazard index (HI) of the by-products for EXT was of the order 10(-4); which is much less than desired level of 1.0. The estimated risks were within the acceptable level. This study has also suggested the photocatalytic degradation pathways for EX which are through formation of toluene. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. In situ flash X-ray observation of projectile penetration processes and crater cavity growth in porous gypsum target analogous to low-density asteroids (United States)

    Yasui, Minami; Arakawa, Masahiko; Hasegawa, Sunao; Fujita, Yukihiro; Kadono, Toshihiko


    Recent studies of impact craters formed on low-density asteroids led to the proposal of a new crater formation mechanism dominated by pore collapse and compaction. Thus, it is important to study the crater formation process associated with the projectile penetration on porous cohesive targets. Laboratory impact experiments were conducted for a porous gypsum target with porosity of 50%, and flash X-rays were used to visualize the interior of the target for in situ observation of crater formation and projectile penetration. Spherical projectiles made of three different materials, stainless steel, aluminum, and nylon were impacted at 1.9-2.4 km/s (low-velocity impact) and 5.6-6.4 km/s (high-velocity impact) by using a two-stage light-gas gun. Two imaging plates were used to take two X-ray images at a different delay time from the impact moment for one shot. Two types of crater cavity shape were found on the porous gypsum target, that is, penetration holes or hemispherical cavities, depending on the projectile size and density, and the impact velocity. The drag coefficient of a projectile was determined by measuring the penetration depth changing with time, and we found that it was closely related to the crater cavity shape: it was about 0.9 for a penetration hole, while it was 2.3-3.9 for a hemispherical cavity. This large value for a hemispherical cavity could have been caused by the deformation or the disruption of the projectile. The cratering efficiency, ρtVcr(t)/mp, was found to have a power law relationship to the scaling time for crater growth, πt = vit/rp, where vi is the impact velocity, rp is the projectile radius, and t is the time after the impact, and all data for stainless steel and aluminum projectiles merged completely and could be fitted by a power-law equation of ρtVcr(t)/mp=2.69×10-1πt1.10. Furthermore, the scaled crater volume, πV = Vcr_finalρt/mp, where Vcr_final is the final crater cavity volume, ρt is the target density, and mp is the

  15. Effects of inorganic amendments (urea, gypsum) on seed germination and seedling recruitment of 20 native plant species used in dryland restoration (United States)

    Bateman, Amber; E Erickson, Todd; Merritt, David J.; Muñoz-Rojas, Miriam


    Introduction Soil health and functionality are major determining factors for restoration of degraded arid and semi-arid ecosystems. These highly nutrient impoverished soil substrates with low water retention capabilities dictate plant growth and survival in these landscapes that are subject to variable rainfall event and high temperatures (Muñoz-Rojas et al., 2016). Anthropogenic disturbances derived from mining activities have contributed to the degradation of soil functionality and have altered plant-soil-water interactions. With unknown positive or negative rehabilitation outcomes, inorganic amendments in the form of urea and gypsum are commonly added to reconstructed soil substrates disturbed by mining to replenish soil nutrients (nitrogen) and improve soil water holding capacity to improve seedling establishment and survival. Methods Using existing protocols for amendment addition to soil substrates, two experiments assessed the effects of urea and gypsum at multiple doses in reconstructed soil substrates (topsoil (TS), waste (W) and, 50:50 blend of both materials (TW) to evaluate its effectiveness as a supplement to improve seed germination, seedling recruitment and plant growth. In the first experiment, 20 species native to the resource-rich biodiverse Pilbara region of Western Australia were grown in 30 °C glasshouse facilities under well-watered conditions for three weeks with seedling emergence scored daily. At the end of the trial, seedlings were harvested and biomass was assessed. In the second experiment, five of the original 20 species (e.g. Acacia bivenosa, Gossypium robinsonii, Eucalyptus gamophylla, Triodia wiseana and, Senna notabilis) were assessed for germination in amended soils by burying nylon sachets in the reconstructed substrates. After three weeks, the sachets were retrieved and seeds were assessed for germination (i.e. radicle emergence was evident). Results and Discussion Total emergence and biomass of seedlings was negatively

  16. 40 CFR 63.302 - Standards for by-product coke oven batteries. (United States)


    ... batteries. 63.302 Section 63.302 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... National Emission Standards for Coke Oven Batteries § 63.302 Standards for by-product coke oven batteries... oven emissions from each affected existing by-product coke oven battery that exceed any of the...

  17. Hazard Analysis and identification of Critical Control Points of collagen extraction from cod by-products

    NARCIS (Netherlands)

    Aalberts, C.H.J.


    The aim of the European research project “UTILISATION AND STABILISATION OF BY-PRODUCTS FROM COD SPECIES” (QLK1-CT-2000-01017 QLRT-2001-02829) is to investigate whether collagen from fish by-products could serve as an important raw material in high quality food. Since Atlantic cod is a major

  18. By-Product Formation in Repetitive PCR Amplification of DNA Libraries during SELEX

    DEFF Research Database (Denmark)

    Tolle, Fabian; Wilke, Julian; Wengel, Jesper


    -recognizing aptamers. Little is known about the formation of such by-products when employing nucleic acid libraries as templates. We report on the formation of two different forms of by-products, named ladder- and non-ladder-type observed during repetitive amplification in the course of in vitro selection experiments...... and improving the success rate of aptamer selection....

  19. Nutritional diversity of agricultural and agro-industrial by-products for ruminant feeding

    Directory of Open Access Journals (Sweden)

    J.A.G. Azevêdo


    Full Text Available Fifty-seven by-products were collected from regions throughout Brazil. Chemical composition, in vitro neutral detergent fiber digestibility (IVNDFD, and total digestible nutrients (TDN were determined with the objective of grouping by-products with similar nutritional characteristics. The by-products belonging to group one (G1 presented the highest content of neutral detergent fiber exclusive of ash and nitrogenous compounds [aNDFom(n] and lowest energy content, with 42.5% and 38.8% of IVNDFD and TDN, respectively. A new cluster analysis was carried in order to better characterize G2 by-products, six subgroups (SGs were established (SG1 to SG6. SG1 by-products had the highest and the lowest values for lignin and TDN, respectively. SG2 by-products had the highest aNDFom(n value, with TDN and IVNDFD values greater than 600 and 700g/kg, respectively, and crude protein (CP value below 200g/kg in dry matter (DM. Among all the subgroups, SG3 had the highest TDN (772g/kg and IVNDFD (934g/kg values and the lowest lignin (23g/kg in DM value. The ether extract was what most influenced the hierarchical establishment of residual grouping in SG4. SG5 by-products had the highest concentration of non-fibrous carbohydrate. Different from the other subgroups, SG6 by-products had the highest value of available CP.

  20. 40 CFR Table 1 to Subpart C - VOC Content Limits by Product Category (United States)


    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false VOC Content Limits by Product Category..., Table 1 Table 1 to Subpart C—VOC Content Limits by Product Category Product category VOC content limit (weight-percent VOC) Air fresheners: Single-phase 70 Double-phase 30 Liquids/pump sprays 18 Solids/gels 3...

  1. Approach for a pro-active emerging risk system on biofuel by-products in feed

    NARCIS (Netherlands)

    Asselt, van E.D.; Meuwissen, M.P.M.; Asseldonk, van M.A.P.M.; Sterrenburg, P.; Mengelers, M.J.B.


    Worldwide biofuel products have rapidly entered the market and consequently so did the availability of their by-products for feed production. A pro-active emerging risk system for biofuel by-products is essential in order to prevent the occurrence of emerging hazards in feed and livestock

  2. In situ ruminal crude protein degradability of by-products from cereals, oilseeds and animal origin

    NARCIS (Netherlands)

    Habib, G.; Khan, N.A.; Ali, M.; Bezabih, M.


    The aim of this study was to establish a database on in situ ruminal crude protein (CP) degradability characteristics of by-products from cereal grains, oilseeds and animal origin commonly fed to ruminants in Pakistan and South Asian Countries. The oilseed by-products were soybean meal, sunflower

  3. An assessment of surface properties and moisture uptake of nonwoven fabrics from ginning by-products (United States)

    Greige (raw) cotton by-products resulting from cotton ginning and mill processes have long been bleached for using them in absorbent nonwoven products. Other than that, the greige cotton by-products mostly had limited material applications, and used as an alternative feedstock for biomass and as a ...

  4. Improvement in the nutritive quality of cassava and its by-products ...

    African Journals Online (AJOL)



    Dec 29, 2008 ... A review of the extent of fermentation of cassava and its by-products was made in order to highlight the role played by fermentation on the bio-conversion of cassava and cassava by-products for improved nutrient quality. The reasons for cassava products fermentation mentioned were synonymous with the.

  5. Optimization of extrusion variables for the production of snacks from by-products of rice and soybean

    Directory of Open Access Journals (Sweden)

    Lairy Silva Coutinho


    Full Text Available This study aimed to define the process conditions to obtain snacks from the by-products of rice and soybean with physical characteristics suitable for marketing. Therefore, the effects of moisture and extrusion temperature on the expansion and color of the products obtained experimentally obtained were evaluated, and the proximate composition of the by-products and that of the snack with greater desirability were determined. Response surface methodology and rotational central composite design were used, and desirability test based on the regression models adjusted was applied. The most desirable snack, with the highest expansion index (3.39, specific volume (13.5 mL.g-1, and the chromaticity coordinate a* (2.79, was obtained under 12 g.100 g-1 moisture and 85ºC of temperature in the third zone of the extruder. The snack produced under these conditions attained content of protein and lipid content 41 and 64% higher than that of the traditional corn snack. It can be concluded that producing extruded snack made form a mixture of broken grains, rice bran, and soybean okara (81:9:10 is technologically feasible, enabling the development of a new product with good nutritional value that can improve the diet of children, the main consumers of this type of food.

  6. Consumers and Producers

    NARCIS (Netherlands)

    E. Maira (Elisa)


    markdownabstractIn the last few decades, advances in information and communication technology have dramatically changed the way consumers and producers interact in the marketplace. The Internet and social media have torn down the information barrier between producers and consumers, leading to

  7. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 4, A laboratory study conducted in fulfillment of Phase 2, Objective 1 titled. Inhibition of acid production in coal refuse amended with calcium sulfite and calcium sulfate - containing FGD solids

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Y. L. [Ohio State Univ., Wooster, OH (United States); Dick, W. A. [Ohio State Univ., Wooster, OH (United States); Stehouwer, R. C. [Ohio State Univ., Wooster, OH (United States); Bigham, J. M. [Ohio State Univ., Wooster, OH (United States)


    Control of S02 emission from coal combustion requires desulfurization of coal before its combustion to produce coal refuse. Alternatively, gaseous emissions from coal combustion may be scrubbed to yield flue gas desulfurization (FGD) by-products that include calcium sulfite (CaSO3∙0.5H2O or simply CaS03). Acid production in coal refuse due to pyrite oxidation and disposal of large amounts of FGD can cause environmental degradation. Addition of CaS03 and CaS03-containing FGD to coal refuse may reduce the amounts of oxygen and ferric ion available to oxidize pyrite because the sulfite moiety in CaS03 is a strong reductant and thus may mitigate acid production in coal refuse. In Chapter 1, it was shown that CaS03 efficiently scavenged dissolved oxygen and ferric ion in water under the conditions commonly encountered in a coal refuse disposal environment. In the presence ofCaS03, the concentration of dissolved oxygen in water exposed to the atmosphere declined to below 0.01 mg L"1 at pH <8.0. In Chapter 2, it was demonstrated that CaS03 prevented a pH drop in coal refuse slurry when 0.2 gCaS03 was added to a 2% fresh coal refuse slurry every three days. Calcium sulfite also inhibited acid leaching from fresh coal refuse in bench-scale columns under controlled conditions. During the initial 13 weeks of leaching, the total amounts of titratable acidity, soluble H\\ Fe, and Al from CaS03-treated refuse (6.4 gin 50 g fresh coal refuse) were only 26%,10%, 32%, and 39% of those of the control columns, respectively. A combination of CaS03 with CaC03 or fly ash enhanced the inhibitory effect of CaS03 on acid leaching. Calcium sulfite-containing FGD which combined CaS03, CaC03, fly ash, and gypsum showed a much stronger inhibitory effect on acid leaching than CaS03 alone. This

  8. Aplicação de gesso e calcário na recuperação de solos salino-sódicos do Estado de Pernambuco Application of gypsum and limestone in the reclamation of saline-sodic soils of the Pernambuco State

    Directory of Open Access Journals (Sweden)

    Maria de F. C. Barros


    Full Text Available Experimento em colunas de solo foi conduzido, objetivando-se avaliar o efeito da aplicação de gesso e gesso + calcário, na recuperação de solos salino-sódicos do Perímetro Irrigado de Custódia, PE. Os tratamentos foram dispostos em um delineamento em blocos casualizados, com arranjo fatorial de quatro solos, dois métodos de aplicação de gesso e gesso + calcário (aplicados na superfície e incorporados aos primeiros 5 cm da coluna de solo, duas combinações dos corretivos (100% de gesso + 0% de calcário e 80% de gesso + 20% de calcário, calculados com base na necessidade de gesso dos solos, e quatro faixas de granulometria de gesso (2,0-1,0, 1,0-0,5, 0,5-0,3 e An experiment was carried out in soil columns with the objective of evaluating the effect of application of gypsum and limestone on reclamation of the saline-sodic soils in the Irrigation district of Custódia, PE. The treatments were arranged in a randomized block design in a factorial scheme of four soils, two methods for applications of gypsum and gypsum plus limestone (applied on surface and incorporated into the first five cm of the soil column, two combinations of the chemical amendments (100% gypsum plus 0% limestone and 80% gypsum plus 20% limestone, calculated on the basis of gypsum requirement of soil and four granulometry gypsum strips (2.0-1.0; 1.0-0.5; 0.5-0.3 and < 0.3 mm with three replications. The gypsum amount determined by the method of Schoonover M-1, under laboratory conditions, shows to be adequate in the displacement of the exchangeable sodium of the soil exchange complex. The efficiency of the gypsum as well as the gypsum plus lime mixture in reclamation of the soils shows to be superior, when the amendments are incorporated into the first 5 cm of the soil columns. Among the gypsum granulometry, the finest fractions, (0.5-0.3 mm and < 0.3 mm, presented better performance in replacing the exchangeable sodium of the exchange complex.

  9. Evolution of mechanical properties of a residue from the secondary aluminium remelting industry stabilized with gypsum; Evolucion de las propiedades mecanicas de un residuo de la metalurgia secundaria del aluminio estabilizado con yeso

    Energy Technology Data Exchange (ETDEWEB)

    Tayibi, H.; Perez, C.; Lopez, F. A.; Lopez-Delgado, A.


    Aluminium dust from aluminium remelting industry is a hazardous residue because of its high reactivity in the presence of water (production of ammonia, methane, hydrogen sulphide...) potential aluminothermy and its content in leaching heavy metals. In order to apply the new European Directive about landfill of waste, a Stabilization/Solidification (S/S) process was developed in the CENIM with the aim of decreasing its reactivity and to assure an easy transport and storage of the residue. Gypsum was used as a binder material. This work summarizes the study of the mechanical properties of the stabilized residue en comparison with the gypsum ones. The reactivity of the dust, before and after the S/S process was investigated by analysing the ammonia and metallic aluminium. (Author) 16 refs.

  10. Integrated Disinfection By-Products Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection By-Products from Water Disinfected by Chlorination and Ozonation/Postchlorination (United States)

    To conduct the health-effect studies described in subsequent articles in this series, concentrated aqueous mixtures of disinfection by-products were required for the two water treatment trains described in the preceding article (Miltner et al., 2008). To accomplish this, the fini...

  11. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water (United States)

    Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.


    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (˜3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na-Mg-SO4 salts more soluble than gypsum. Irrigation with high SAR (˜24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.


    Imhoff, D.H.; Harker, W.H.


    This patent relates to a method of producing neutrons in which there is produced a heated plasma containing heavy hydrogen isotope ions wherein heated ions are injected and confined in an elongated axially symmetric magnetic field having at least one magnetic field gradient region. In accordance with the method herein, the amplitude of the field and gradients are varied at an oscillatory periodic frequency to effect confinement by providing proper ratios of rotational to axial velocity components in the motion of said particles. The energetic neutrons may then be used as in a blanket zone containing a moderator and a source fissionable material to produce heat and thermal neutron fissionable materials. (AEC)

  13. Quantification of bioactive compounds in pulps and by-products of tropical fruits from Brazil. (United States)

    Ribeiro da Silva, Larissa Morais; Teixeira de Figueiredo, Evania Altina; Silva Ricardo, Nagila Maria Pontes; Pinto Vieira, Icaro Gusmao; Wilane de Figueiredo, Raimundo; Brasil, Isabella Montenegro; Gomes, Carmen L


    This study aimed to quantify the levels of resveratrol, coumarin, and other bioactives in pulps and by-products of twelve tropical fruits from Brazil obtained during pulp production process. Pineapple, acerola, monbin, cashew apple, guava, soursop, papaya, mango, passion fruit, surinam cherry, sapodilla, and tamarind pulps were evaluated as well as their by-products (peel, pulp's leftovers, and seed). Total phenolic, anthocyanins, yellow flavonoids, β-carotene and lycopene levels were also determined. Resveratrol was identified in guava and surinam cherry by-products and coumarin in passion fruit, guava and surinam cherry by-products and mango pulp. These fruit pulp and by-products could be considered a new natural source of both compounds. Overall, fruit by-products presented higher (P<0.05) bioactive content than their respective fruit pulps. This study provides novel information about tropical fruits and their by-products bioactive composition, which is essential for the understanding of their nutraceutical potential and future application in the food industry. Published by Elsevier Ltd.

  14. The Potential of Animal By-Products in Food Systems: Production, Prospects and Challenges

    Directory of Open Access Journals (Sweden)

    Babatunde O. Alao


    Full Text Available The consumption of animal by-products has continued to witness tremendous growth over the last decade. This is due to its potential to combat protein malnutrition and food insecurity in many countries. Shortly after slaughter, animal by-products are separated into edible or inedible parts. The edible part accounts for 55% of the production while the remaining part is regarded as inedible by-products (IEBPs. These IEBPs can be re-processed into sustainable products for agricultural and industrial uses. The efficient utilization of animal by-products can alleviate the prevailing cost and scarcity of feed materials, which have high competition between animals and humans. This will also aid in reducing environmental pollution in the society. In this regard, proper utilization of animal by-products such as rumen digesta can result in cheaper feed, reduction in competition and lower cost of production. Over the years, the utilization of animal by-products such as rumen digesta as feed in livestock feed has been successfully carried out without any adverse effect on the animals. However, there are emerging gaps that need to be further addressed regarding the food security and sustainability of the products. Therefore, the objective of this review highlights the efficacy and effectiveness of using animal by-products as alternative sources of feed ingredients, and the constraints associated with their production to boost livestock performance in the industry at large.

  15. An Overview of the Utilisation of Brewery By-Products as Generated by British Craft Breweries

    Directory of Open Access Journals (Sweden)

    Clare Kerby


    Full Text Available There is a wide range of information available on by-product disposal methods used by large national breweries. However, little information is available on the methods of by-product disposal used by craft breweries. An investigation was carried out in which 200+ British craft brewers were contacted, of which 90 craft brewers provided basic information about their brewery operations and by-product disposal. Representatives of eleven breweries were interviewed to provide an in-depth case study of their by-product disposal methods. The research found that urban craft brewers use a wider range of disposal methods compared to rural craft brewers; urban brewers dispose of more waste through sewage and landfill, as well as using external companies, such as bio-recycling and anaerobic digester plants, whereas rural brewers have relationships with farmers who dispose of the by-products in various ways. Craft brewers tend to have a direct relationship with the by-product users. Even though they do not have all disposal options available to them which the large industrial breweries have, due to their small scale of by-product production, craft brewers appear to find alternative means of sustainability.

  16. Effect of 3D woven fabrics on the microwave absorbing and mechanical properties of gypsum composites using carbon black as an absorbent (United States)

    Xie, Shuai; Ji, Zhijiang; Shui, Zhonghe; Li, Bin; Hou, Guoyan; Wang, Jing


    In order to improve the S and X band microwave absorbing properties of gypsum based composites with carbon black (CB) as an absorbent, three-dimensional (3D) woven fabric was embedded into the composites and the effects of 3D woven fabric on the dielectric properties, wave absorption, and mechanical properties were investigated. The results show that the microwave absorbing properties of the composites are visibly enhanced after being embedded with the 3D woven fabric. The minimum reflection loss reaches  -16 dB and the bandwidth for  -10 dB is 1.4 GHz in the S band; and in the X band the minimum reflection loss of  -25 dB can be obtained and the bandwidth for  -10 dB reaches 2.5 GHz. The introduction of the 3D woven fabrics can decrease the complex permittivity of the composites, resulting in the improvement of impedance matching. Moreover, a new microwave attenuation path is provided by the ‘hollow fibers’ of 3D woven fabric, which can enhance the microwave attenuation capacity. Thus, using 3D woven fabric is an effective way to improve the microwave absorption of an absorber with a dielectric loss absorbent. In addition, the flexural strength of the composites can be evidently enhanced by 3D woven fabrics.

  17. The Jettencave, Southern Harz Mountains, Germany: Geophysical observations and a structural model of a shallow cave in gypsum/anhydrite-bearing rocks (United States)

    Kaufmann, Georg; Romanov, Douchko


    Gypsum and anhydrite are soluble rocks, where fissures and bedding partings can be enlarged with time by the dissolution of the mineral species through water. The selective enlargement results in sub-surface voids acting as preferential flow path for the drainage of the rock. With time, larger cavities develop, and a network of cave passages can evolve. If the enlarged cave voids are not too deep under the surface, geophysical measurements can be used to detect, identify and trace these structures. We have used gravity measurements (GRAV), electrical resistivity imaging (ERI), self-potential measurements (SP), electrical conductivity measurements (EC), and ground-penetrating radar (GPR) above the cave Jettenhöhle, a cave located in the southern Harz Mountains in Germany. The Jettencave is developed in the Hauptanhydrit formation of the Permian Zechstein sequence, characterised by large breakdown rooms and an exposed water table. The overburden of the cave is only around 10-15 m, and dolomitic rocks are located in close vicinity. We present results from our geophysical surveys in vicinity of the cave. We are able to identify the cave geometry from GRAV, ERI, and GPR measurements, which distinguish the local lithology of the Permian Zechstein rocks in the area. From the ERI and EC measurements, we derive information on the void volume in the soluble rocks. We finally present a three-dimensional structural model of the Jettencave and its surroundings, based on our geophysical results and the hydrological interpretation.

  18. Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, ) in the presence of gypsum and varying amounts of calcium hydroxide

    KAUST Repository

    Hargis, Craig W.


    Suspensions of synthetic ye\\'elimite (C4A3S̄) in a saturated gypsum (CS̄H2) and calcium hydroxide (CH) solution were examined in-situ in a wet cell by soft X-ray transmission microscopy and ex-situ by scanning electron microscopy. The most voluminous hydration product observed was ettringite. Ettringite commonly displayed acicular, filiform, reticulated, and stellate crystal habits. Additionally, pastes with C 4A3S̄, 15% CS̄H2, and varying amounts of CH were prepared and examined with X-ray diffraction (XRD) and isothermal calorimetry. The XRD experiments showed that increasing CH content caused more solid solution (SO4 2 -/OH-) AFm phases to form at early ages (< 1 d) and more monosulfate to form at later ages (> 1 d). Calorimetry indicated that the increased production of solid solution AFm was accompanied with an increase in the initial (< 30 min) rate of heat evolution, and increasing CH generally reduced the time till the second maximum rate of heat evolution due to the formation of ettringite and monosulfate. © 2013 Elsevier Ltd.

  19. Speciation and distribution of vanadium in drinking water iron pipe corrosion by-products. (United States)

    Gerke, Tammie L; Scheckel, Kirk G; Maynard, J Barry


    Vanadium (V) when ingested from drinking water in high concentrations (>15 μg L(-1)) is a potential health risk and is on track to becoming a regulated contaminant. High concentrations of V have been documented in lead corrosion by-products as Pb(5)(V(5+)O(4))(3)Cl (vanadinite) which, in natural deposits is associated with iron oxides/oxyhydroxides, phases common in iron pipe corrosion by-products. The extent of potential reservoirs of V in iron corrosion by-products, its speciation, and mechanism of inclusion however are unknown. The aim of this study is to assess these parameters in iron corrosion by-products, implementing synchrotron-based μ-XRF mapping and μ-XANES along with traditional physiochemical characterization. The morphologies, mineralogies, and chemistry of the samples studied are superficially similar to typical iron corrosion by-products. However, we found V present as discrete grains of Pb(5)(V(5+)O(4))(3)Cl likely embedded in the surface regions of the iron corrosion by-products. Concentrations of V observed in bulk XRF analysis ranged from 35 to 899 mg kg(-1). We calculate that even in pipes with iron corrosion by-products with low V concentration, 100 mg kg(-1), as little as 0.0027% of a 0.1-cm thick X 100-cm long section of that corrosion by-product needs to be disturbed to increase V concentrations in the drinking water at the tap to levels well above the 15 μg L(-1) notification level set by the State of California and could adversely impact human health. In addition, it is likely that large reservoirs of V are associated with iron corrosion by-products in unlined cast iron mains and service branches in numerous drinking water distribution systems. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Sodic soils reclaimed with by-product from flue gas desulfurization: corn production and soil quality. (United States)

    Chun, S; Nishiyama, M; Matsumoto, S


    Interest is growing in the use of by-product from flue gas desulfurization (FGD) to reclaim sodic soils by controlling the pH and excessive Na+. This study evaluated the effects on corn (Zea mays) production and pH and electrical conductivity (EC) of calcareous sodic soil during four times of cultivation when the by-product was applied once at the first cultivation (Study I) and the impacts on plant and soil quality at first cultivation when the by-product was applied to the soil at 23,000 kg ha-1 (Study II). In Study I, the germination rate and corn production increased by applying the by-product (0, 5,800, 11,600, and 23,100 kg ha-1), and the greatest total amounts of corn production during the four times of cultivation was when the by-product was applied at 23,100 kg ha-1. In Study II, the pH, exchangeable sodium percentage (ESP), clay dispersion and soluble Na+ in the soil decreased and soluble Mg2+ and soluble K+ in the soil increased. The soil pH was reduced from 9.0 to 7.7 by applying the by-product. However, the by-product decreased the concentrations of total N and P in corn leaves in this study. No significant difference in the concentrations of Mo, Zn, Pb, Ni, Cd, Mn, Cr, Cu, and Al in corn leaves and the soil was observed between the by-product addition and the control except for B in the soil and Fe in corn leaves. The concentration of B in the soil was reduced from 28.7 mg kg-1 to 25.4 mg kg-1 and the concentration of Fe in corn leaves increased from 17.5 mg kg-1 to 22.6 mg kg-1 by applying the by-product in our study.

  1. Agricultural Producer Certificates (United States)

    Montgomery County of Maryland — A Certified Agricultural Producer, or representative thereof, is an individual who wishes to sell regionally-grown products in the public right-of-way. A Certified...

  2. Polygalacturonase activity of Penicillum sp 7/4B/EI 1 mutant grown on some by-products of food industry. (United States)

    Szajer, I


    Pectolytic activity of the Penicillum sp 7/4B/E11 mutant, which synthesized effectively PG and was not capable of producing PE, was studied on some by-products of food industries (apple pulp, beet pulp, and mixtures of apple pulp or beet pulp with wheat bran) supplemented in some experiments with mineral salts of the Czapek's medium. The strain showed good growth but a low PG activity when grown on by-products without mineral salts and an increase in PG activity after cultivation on these by-products (mainly on beet pulp) enriched with mineral salts. The highest PG activity was obtained after 6-8 days cultivation on beet pulp (3%) with mineral salts. Among the tested salts, NaNO3 influenced PG activity most effectively, K2HPO4 and MgSO4 to a smaller degree whereas others were ineffective. The mutant did not synthesize PE under these culture conditions.

  3. Landslide remediation on Ohio State Route 83 using clean coal combustion by-products

    Energy Technology Data Exchange (ETDEWEB)

    Payette, R. [Ohio Dept. of Transportation, Jacksontown, OH (United States); Chen, Xi You; Wolfe, W. [Ohio State Univ., Columbus, OH (United States); Beeghly, J. [Dravo Lime Co., Pittsburgh, PA (United States)


    The disposal of flue gas desulfurization (FGD) by-products has become a major concern as issues of emission cleansing and landfill costs continue to rise. Laboratory tests conducted at the Ohio State University have shown that dry FGD by-products possess certain engineering properties that have proven desirable in a number of construction uses. As a follow on to the laboratory program, a field investigation into engineering uses of dry FGD wastes was initiated. In the present work, an FGD by-product was used to reconstruct the failed portion of a highway embankment. The construction process and the stability of the repaired embankment are examined.

  4. Recovery and characterization of by-products from egg processing plant wastewater using coagulants

    National Research Council Canada - National Science Library

    Xu, L J; Sheldon, B W; Carawan, R E; Larick, D K; Chao, A C


    ...%, respectively, for all coagulants tested. Protein and fat recoveries were over 95% for all coagulants. The optimal coagulant concentration for maximum by-product recovery depended on initial wastewater concentrations of protein, total solids, and fat...


    This paper discusses the identification of organic disinfection by-products (DBPs) at a pilot plant in Evansville, Indiana, that uses chlorine dioxide as a primary disinfectant. nconventional multispectral identification techniques (gas chromatography combined with high and low r...

  6. Incineration By-Products of AA2, NC Fines, and NG Slums

    National Research Council Canada - National Science Library

    Cropek, Donald


    ...) and associated energetic wastes (EW). Knowledge of the by-products from incineration is invaluable for the proper design of emission control systems and selection of operating parameters to ensure maximum destruction efficiency...


    Shorter Menstrual Cycles Associated with Chlorination by-Products in Drinking Water. Gayle Windham, Kirsten Waller, Meredith Anderson, Laura Fenster, Pauline Mendola, Shanna Swan. California Department of Health Services.In previous studies of tap water consumption we...


    Reactions between chlorine disinfectants, dissolved organic matter, and other chemicals in water form a series of disinfection by-products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs), that are toxic and subject to increasingly stringent regulations. Th...

  9. Aqueous chlorination of mefenamic acid: kinetics, transformation by-products and ecotoxicity assessment. (United States)

    Adira Wan Khalit, Wan Nor; Tay, Kheng Soo


    Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and free available chlorine (FAC) was determined at 25 ± 0.1 °C. The result indicated that the degradation of Mfe by FAC is highly pH-dependent. When the pH was increased from 6 to 8, it was found that the kapp for the reaction between Mfe and FAC was decreased from 16.44 to 4.4 M(-1) s(-1). Characterization of the transformation by-products formed during the chlorination of Mfe was carried out using liquid chromatography-quadrupole time-of-flight accurate mass spectrometry. Four major transformation by-products were identified. These transformation by-products were mainly formed through hydroxylation, chlorination and oxidation reactions. Ecotoxicity assessment revealed that transformation by-products, particularly monohydroxylated Mfe which is more toxic than Mfe, can be formed during aqueous chlorination.

  10. Biochars made from agro-industrial by-products remove chlorine and lower water toxicity (United States)

    Tzachristas, Andreas; Xirou, Maria; Manariotis, Ioannis D.; Dailianis, Stefanos; Karapanagioti, Hrissi K.


    .5 mg/g. For the two commercial activated carbons, removal efficiencies were 11.4 ± 0.2 mg/g. The column experiment also showed positive results; no breakthrough has been observed after 1L of chlorine solution has passed through a column packed with 4 g of biochar made from the pyrolysis of grape seeds. Toxicity tests were also performed with the chlorine solution before and after passing through this column. The toxicity of the solution decreased after passing through the column packed with biochar suggesting that no toxic compounds are formed during the removal of chlorine by the biochar. The overall idea of this study is the sustainable use of the solid by-products of a food industry or producer to treat water or treated wastewater in order to enhance its quality and lower its toxicity. American Water Works Association (AWWA) 1990 Water quality and treatment, a handbook of community water supplies, Fourth edition.

  11. Evaluation of wastewater treatment by-products as soil amendment: Growth of sorghum-sudan grass and trace elements concentrations. (United States)

    Sivapatham, Paramasivam; Potts, Mariel C; Delise, Jeffrey A; Sajwan, Kenneth S; Alva, Ashok K; Jayaraman, Kuppuswamy; Chakraborty, Paromita


    Wastewater treatment by-products (WTBP), such as sewage sludge (SS) may be used to enhance soil chemical, physical, and biological properties. These enhanced soil properties, in turn, could from its source of production to its site of application. These concerns may be mitigated by incineration of the SS to produce ash (SSA) and dissolved in water and stored in ponds as contribute to an increase in plant growth, production, mineral nutrition. Some SS is difficult to handle due to bad odor in its raw state and has large mass, hence expensive for transportation weathered SSA (WSSA). A greenhouse study was conducted using Candler fine sand CFS; (CFS; pH = 6.8) and Ogeechee loamy sand OLS; (pH = 5.2) with application of either 0, 24.7, 49.4, 98.8, or 148.2 Mg ha(-1) as either SS, SSA, or WSSA to evaluate the biomass production and elemental composition responses of sorghum-sudan grass (Sorghum vulgaris var. Sudanese hitche). Shoot and root biomass were 2 to 3 fold greater in the soil amended with SS, than either SSA or WSSA. Concentrations of nutrient and trace elements in the shoots and roots increased with increasing rates of amendments. Application of these by-products up to 98.8 Mg ha(-1) rate did not adversely affect growth or accumulation of trace elements in sorghum-sudan grass. Long-term field studies are recommended to investigate the potential leaching of various elements from the amended soils in addition to evaluation of plant growth and production responses to determine the acceptable rates of these by-products as amendments to agricultural soils.

  12. Mineralogical features of size and density fractions in Sasol coal gasification ash, South Africa and potential by-products

    Energy Technology Data Exchange (ETDEWEB)

    R.H. Matjie; C. Van Alphen [Sasol Technology (Pty) Ltd., Sasolburg (South Africa)


    Bulk gasification ash (a mixture of coarse and fine ash particles), a by-product of coal gasification, is formed at elevated temperatures and pressures by the interaction of included minerals present in the coal and 'stone'. From the detailed mineralogical and chemical analyses of the pulverised screened size fractions and one density float fraction ({lt}1.9 g/cm{sup 3}) a number of potential viable by-products were identified. Screening and density separation produced a high ash, low volatile carbon-rich by-product, which is potentially suitable as an energy source for the cement industry. In addition, this carbon-rich product has included devolatilised kaolinite and quartz that are a source of Al{sub 2}O{sub 3} and SiO{sub 2}. This product could potentially replace the amount of clay required in the cement process. This high ash carbon product is not suitable as a reductant in the metallurgical industry. The -38 + 20 {mu}m ash size fraction is characterised by a comparatively high proportion of aluminosilicate (transformed product of kaolinite) and Ca-oxide/CaMg-oxide (transformed product of calcite/dolomite). These phases will enhance the pozzolanic reactivity of this ash size fraction and provide material suitable for the cement/concrete industry. The coarse ash size fractions are used as aggregate in road construction and in the manufacture of bricks. If economically and technically feasible, anorthite in the coarse ash size fractions could be beneficiated and used in a refractory. 12 refs., 9 figs., 2 tabs.

  13. Feeding of by-products completely replaced cereals and pulses in dairy cows and enhanced edible feed conversion ratio. (United States)

    Ertl, P; Zebeli, Q; Zollitsch, W; Knaus, W


    When fed human-edible feeds, such as grains and pulses, dairy cows are very inefficient in transforming them into animal products. Therefore, strategies to reduce human-edible inputs in dairy cow feeding are needed to improve food efficiency. The aim of this feeding trial was to analyze the effect of the full substitution of a common concentrate mixture with a by-product concentrate mixture on milk production, feed intake, blood values, and the edible feed conversion ratio (eFCR), defined as human-edible output per human edible input. The experiment was conducted as a change-over design, with each experimental period lasting for 7wk. Thirteen multiparous and 5 primiparous Holstein cows were randomly assigned to 1 of 2 treatments. Treatments consisted of a grass silage-based forage diet supplemented with either conventional ingredients or solely by-products from the food processing industry (BP). The BP mixture had higher contents of fiber and ether extract, whereas starch content was reduced compared with the conventional mixture. Milk yield and milk solids were not affected by treatment. The eFCR in the BP group were about 4 and 2.7 times higher for energy and protein, respectively. Blood values did not indicate negative effects on cows' metabolic health status. Results of this feeding trial suggest that by-products could replace common concentrate supplements in dairy cow feeding, resulting in an increased eFCR for energy and protein which emphasizes the unique role of dairy cows as net food producers. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Functional properties and dietary fiber characterization of mango processing by-products (Mangifera indica L., cv Ataulfo and Tommy Atkins). (United States)

    García-Magaña, María de Lourdes; García, Hugo S; Bello-Pérez, Luis A; Sáyago-Ayerdi, Sonia G; de Oca, Miguel Mata-Montes


    Several reports have focused on utilization of post-harvest residues of crops, while neglecting those residues produced by mango processing. These residues represent a waste of nutrients and a source of environmental contaminants. Such by-products could be valuable sources of dietary fiber (DF), antioxidant compounds, and single carbohydrates. The aim of this study was to evaluate some functional properties (FP), and the content of DF and polyphenols (PP) of the peel and coarse material obtained from residues during the industrial processing of Ataulfo and Tommy Atkins mangoes. The total dietary fiber (TDF) content was about 225 mg/g and 387 mg/g (dry weight) for the coarse material and the peel, respectively, from which soluble dietary fiber represented 23 and 42%, respectively. The main neutral sugar identified was rhamnose, especially in peels; the klason lignin (KL) content was 92 mg/g, which highlights the Ataulfo peel (Ataulfo-P) and the Tommy Atkins peel (Tommy Atkins-P). The extractable PP content in Ataulfo-P was higher than in Tommy-Atkins-P, and interesting data for non-extractable PP were obtained in the residues. FP as swelling, water holding, oil holding, and glucose absorption in the residues was studied, obtaining better functional properties when compared to cellulose fiber. The results show that mango industrial by-products, mainly from the Ataulfo-P variety, could be used as ingredients in food products because of their functional properties as well as their DF and PP content.

  15. Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination. (United States)

    Oh, Byung Soo; Oh, Sang Guen; Hwang, Youn Young; Yu, Hye-Weon; Kang, Joon-Wun; Kim, In S


    From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Assessment of Antioxidant Potential of Pomegranate Fruit By-Products via a Direct Approach Using a Simple QUENCHER Method. (United States)


    Fruit and vegetable processing industries produce substantial quantities of phenolic-rich by-products that could be potential sources of natural antioxidants. The measurement of antioxidant activity in plant materials is mostly limited to extraction-based procedures that have several limitations. In this study, a relatively new direct approach, the QUENCHER (quick, easy, new, cheap, and reproducible) procedure was applied to measure total antioxidant capacity in pomegranate fruit by-products, including peel, pith, carpellary membranes, and seeds. Freeze-dried ground samples were directly mixed with free radical solvents in a single operation rather than separating the extract from solid samples. Efficacy of the direct procedure was evaluated against a routine extraction-based procedure using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS); 2,2-diphenyl-1-picrylhydrazyl (DPPH); and ferric reducing antioxidant power assays. Pomegranate peel showed the highest total antioxidant capacity, followed by pith, carpellary membranes, and seeds. Total antioxidant capacity values determined by the direct procedure were significantly higher (P unit extraction operations. The conversion of industrial waste into valuable ingredients would be advantageous for development of pomegranate supplements and added-value products.

  17. New ceramics incorporated with industrial by-products as pore formers for sorption of toxic chromium from aqueous media (United States)

    Domopoulou, Artemi


    The incorporation of secondary resources including various industrial wastes as pore-forming agents into clayey raw material mixtures for the development of tailored porous ceramic microstructures is currently of increasing interest. In the present research, sintered ceramic compacts were developed incorporated with industrial solid by-products as pore formers, and then used as new sorbents for chromium removal from aqueous media. The microstructures obtained were characterized through X-ray diffraction (XRD) analysis as well as scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). Sorption potential of chromium from synthetic solutions on the porous ceramics was studied by static adsorption experiments as a function of the pore-former percentage in the ceramic matrix as well as the initial heavy metal (chromium) concentration, solution pH and temperature. Kinetic studies were conducted and adsorption isotherms of chromium were determined using the Langmuir equation. Preliminary experimental results concerning the adsorption characteristics of chromium on the ceramic materials produced appear encouraging for their possible beneficial use as new sorbents for the removal of toxic chromium from aqueous media. Keywords: sorbents, ceramics, industrial solid by-products, pore-former, chromium. Acknowledgements: This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program ARCHIMEDES III: Investing in knowledge society through the European Social Fund.

  18. Production of FucoPol by Enterobacter A47 using waste tomato paste by-product as sole carbon source. (United States)

    Antunes, Sílvia; Freitas, Filomena; Sevrin, Chantal; Grandfils, Christian; Reis, Maria A M


    Out-of-specification tomato paste, a by-product from the tomato processing industry, was used as the sole substrate for cultivation of the bacterium Enterobacter A47 and production of FucoPol, a value-added fucose-rich extracellular polysaccharide. Among the different tested fed-batch strategies, pH-stat, DO-stat and continuous substrate feeding, the highest production (8.77gL(-1)) and overall volumetric productivity (2.92gL(-1)d(-1)) were obtained with continuous substrate feeding at a constant flow rate of 11gh(-1). The polymer produced had the typical FucoPol composition (37mol% fucose, 27mol% galactose, 23mol% glucose and 12mol% glucuronic acid, with an acyl groups content of 13wt%). The average molecular weight was 4.4×10(6)Da and the polydispersity index was 1.2. This study demonstrated that out-of-specification tomato paste is a suitable low-cost substrate for the production of FucoPol, thus providing a route for the valorization of this by-product into a high-value microbial product. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Tunisian date (Phoenix dactylifera L.) by-products: Characterization and potential effects on sensory, textural and antioxidant properties of dairy desserts. (United States)

    Jridi, Mourad; Souissi, Nabil; Salem, Marwa Ben; Ayadi, M A; Nasri, Moncef; Azabou, Samia


    Three Tunisian date varieties, Deglet Nour, Kentichi and Allig, served to produce syrups and powders, which were then examined for their physico-chemical composition and antioxidant properties. Different proportions of these sweetening-like agents were incorporated to produce nine different formulations of dairy desserts, with lower amount of added sugars to avoid any artificial flavoring or coloring agents. Sensory and color evaluation data revealed that incorporating Deglet Nour and Kentichi syrup offers the most desirable formulation. Furthermore, syrup polysaccharides and fibers contribute to better maintain the final product texture. In addition, date by-products create a good source of natural thickening agents, involved in enhancing apparent viscosity and spontaneous exudation. Thanks to their high content in phenolic compounds, date by-products considerably improve antioxidant activities of the formulated desserts. Therefore, they could be valued as natural ingredients in the formulation of novel dairy products with high nutritional-properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Produce Sanitation System Evaluation (United States)


    was also expected to improve food safety (i.e., reduce microbes) and reduce premature spoilage while minimizing environmental impact and unpleasant...PRECISION REDUCTION VEGETABLES CONTAMINATION TEST AND EVALUATION SAFETY PH FACTOR SANITATION FRESH FOODS MICROORGANISMS ...fruits and vegetables (FF&V) aboard Navy vessels, The sink saves labor associated with the washing of produce in food service operations by

  1. Effect Of Laboratory Produced Xylanase From Aspergillus niger On ...

    African Journals Online (AJOL)

    The efficacy of laboratory produced xylanase enzyme from Aspergillus niger on highly fibrous feeds and feedstuffs was investigated. Guinea grass (Panicum maximum) from grass hay and rice husk (Oryza sativa) from crop by-product characterised with high fibre content served as substrates (Feeds and Feedstuffs) for the ...

  2. AFCI Transmutation Fuel Processes and By-Products Planning: Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Eric L. Shaber


    dictates the need for detailed process flows, mass balances, batch size data, and radiological dose estimates. Full definition of the materials that will need to be handled in the facility as feed material inputs, in-process fuel, scrap recycle, scrap requiring recovery, and by-product wastes is required. The feed material for demonstrating transmutation fuel fabrication will need to come from the separations of actinides from spent nuclear fuel processed in the same AFCF.

  3. Detecting animal by-product intake using stable isotope ratio mass spectrometry (IRMS). (United States)

    da Silva, D A F; Biscola, N P; Dos Santos, L D; Sartori, M M P; Denadai, J C; da Silva, E T; Ducatti, C; Bicudo, S D; Barraviera, B; Ferreira, R S


    Sheep are used in many countries as food and for manufacturing bioproducts. However, when these animals consume animal by-products (ABP), which is widely prohibited, there is a risk of transmitting scrapie - a fatal prion disease in human beings. Therefore, it is essential to develop sensitive methods to detect previous ABP intake to select safe animals for producing biopharmaceuticals. We used stable isotope ratio mass spectrometry (IRMS) for (13)C and (15)N to trace animal proteins in the serum of three groups of sheep: 1 - received only vegetable protein (VP) for 89 days; 2 - received animal and vegetable protein (AVP); and 3 - received animal and vegetable protein with animal protein subsequently removed (AVPR). Groups 2 and 3 received diets with 30% bovine meat and bone meal (MBM) added to a vegetable diet (from days 16-89 in the AVP group and until day 49 in the AVPR group, when MBM was removed). The AVPR group showed (15)N equilibrium 5 days after MBM removal (54th day). Conversely, (15)N equilibrium in the AVP group occurred 22 days later (76th day). The half-life differed between these groups by 3.55 days. In the AVPR group, (15)N elimination required 53 days, which was similar to this isotope's incorporation time. Turnover was determined based on natural (15)N signatures. IRMS followed by turnover calculations was used to evaluate the time period for the incorporation and elimination of animal protein in sheep serum. The δ(13)C and δ(15)N values were used to track animal protein in the diet. This method is biologically and economically relevant for the veterinary field because it can track protein over time or make a point assessment of animal feed with high sensitivity and resolution, providing a low-cost analysis coupled with fast detection. Isotopic profiles could be measured throughout the experimental period, demonstrating the potential to use the method for traceability and certification assessments. Copyright © 2016 Elsevier Ltd. All rights

  4. Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilizaton

    Energy Technology Data Exchange (ETDEWEB)

    David Hassett; Loreal Heebink; Debra Pflughoeft-Hassett; Tera Buckley; Erick Zacher; Mei Xin; Mae Sexauer Gustin; Rob Jung


    The University of North Dakota Energy & Environmental Research Center (EERC) conducted a multiyear study to evaluate the impact of mercury and other air toxic elements (ATEs) on the management of coal combustion by-products (CCBs). The ATEs evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Samples of fly ash and flue gas desulfurization (FGD) materials were collected preferentially from full-scale coal-fired power plants operating both without and with mercury control technologies in place. In some cases, samples from pilot- and bench-scale emission control tests were included in the laboratory studies. Several sets of 'paired' baseline and test fly ash and FGD materials collected during full-scale mercury emission control tests were also included in laboratory evaluations. Samples from mercury emission control tests all contained activated carbon (AC) and some also incorporated a sorbent-enhancing agent (EA). Laboratory release experiments focused on measuring releases of mercury under conditions designed to simulate CCB exposure to water, ambient-temperature air, elevated temperatures, and microbes in both wet and dry conditions. Results of laboratory evaluations indicated that: (1) Mercury and sometimes selenium are collected with AC used for mercury emission control and, therefore, present at higher concentrations than samples collected without mercury emission controls present. (2) Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. (3) The presence of carbon either from added AC or from unburned coal can result in mercury

  5. Characterization and disinfection by-product formation potential of natural organic matter in surface and ground waters from Northern Florida (United States)

    Rostad, C.E.; Leenheer, J.A.; Katz, B.; Martin, B.S.; Noyes, T.I.


    Streamwaters in northern Florida have large concentrations of natural organic matter (NOM), and commonly flow directly into the ground water system through karst features, such as sinkholes. In this study NOM from northern Florida stream and ground waters was fractionated, the fractions characterized by infrared (IR) and nuclear magnetic resonance (NMR), and then chlorinated to investigate their disinfection by-product (DBP) formation potential (FP). As the NOM character changed (as quantified by changes in NOM distribution in various fractions, such as hydrophilic acids or hydrophobic neutrals) due to migration through the aquifer, the total organic halide (TOX)-FP and trihalomethane (THM)-FP yield of each of these fractions varied also. In surface waters, the greatest DBP yields were produced by the colloid fraction. In ground waters, DBP yield of the hydrophobic acid fraction (the greatest in terms of mass) decreased during infiltration.

  6. Occurrence of ochratoxin A in cocoa by-products and determination of its reduction during chocolate manufacture. (United States)

    Copetti, Marina V; Iamanaka, Beatriz T; Nester, Melanie A; Efraim, Priscilla; Taniwaki, Marta H


    This work reports an investigation carried out to assess the natural occurrence of ochratoxin A in 168 samples from different fractions obtained during the technological processing of cocoa (shell, nibs, liquor, butter, cake and cocoa powder) and the reduction of ochratoxin A during chocolate manufacture. Ochratoxin A analyses were performed with immunoaffinity columns and detection by high performance liquid chromatography. Concerning the natural ochratoxin A contamination in cocoa by-products, the highest levels of ochratoxin A were found in the shell, cocoa powder and cocoa cake. The cocoa butter was the least contaminated, showing that ochratoxin A seems to remain in the defatted cocoa solids. Under the technological conditions applied during the manufacture of chocolate in this study and the level of contamination present in the cocoa beans, this experiment demonstrated that 93.6% of ochratoxin A present in the beans was reduced during the chocolate producing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Gas Chromatography Analyses for Trihalomethanes: An Experiment Illustrating Important Sources of Disinfection By-Products in Water Treatment (United States)

    Olson, Terese M.; Gonzalez, Alicia C.; Vasquez, Victor R.


    Chlorination processes are an important disinfection strategy in drinking water treatment. Side-reactions of chlorine species with naturally present organic matter, however, are known to produce toxic disinfection by-products (DBPs). One important class of DBPs is trihalomethanes. This experiment demonstrates how trihalomethanes form in a chlorination process by using a model substrate, resorcinol, to mimic the reactive moieties present in natural organic matter. To further simulate how bromo-substituted trihalomethanes are typically obtained in a chlorination process, bromide is also added to the resorcinol solution. Reaction pathways and yields for the formation of trihalomethanes are discussed. The experiment provides a meaningful example of gas chromatography analyses of mixtures of environmentally relevant compounds and is suitable for an undergraduate junior/senior level or graduate environmental chemistry course.

  8. Neutralization/prevention of acid rock drainage using mixtures of alkaline by-products and sulfidic mine wastes. (United States)

    Alakangas, Lena; Andersson, Elin; Mueller, Seth


    Backfilling of open pit with sulfidic waste rock followed by inundation is a common method for reducing sulfide oxidation after mine closure. This approach can be complemented by mixing the waste rock with alkaline materials from pulp and steel mills to increase the system's neutralization potential. Leachates from 1 m3 tanks containing sulfide-rich (ca.30 wt %) waste rock formed under dry and water saturated conditions under laboratory conditions were characterized and compared to those formed from mixtures. The waste rock leachate produced an acidic leachate (pH9). The decrease of elemental concentration in the leachate was most pronounced