WorldWideScience

Sample records for by-product gypsum produced

  1. Gypsum blocks produced from TiO2 production by-products.

    Science.gov (United States)

    Zhang, Yihe; Wang, Fan; Huang, Hongwei; Guo, Yuxi; Li, Baoying; Liu, Yangyang; Chu, Paul K

    2016-01-01

    Calcined titanium gypsum was investigated by the ways of XRD (powder X-ray diffraction), XRF (X-ray fluorescence) and TG-DTA (thermogravimetric-differential thermal analyses). It was employed as raw material for making lightweight materials. The influence of cement, amount of water/solid (W/S) ratio, water-reducing agent, citric acid content and the hydration age on the gypsum blocks was investigated. The results showed that the optimum W/S ratio, cement content and water-reducing agent are 0.9, 10% and 2 wt% for the calcined gypsum from titanium gypsum, respectively. The 5.96 MPa was attained after 7 days of ageing. It was also found that the citric acid is inappropriate to be used in the production of gypsum blocks from TiO2 production by-products. PMID:26495867

  2. Problems and possible remedies concerning NORM in by-Product gypsum produced by the phosphate industry

    International Nuclear Information System (INIS)

    Large quantities (∼ 30 million tons/year) of phosphogypsum are produced as a by-product of fertilizer production in Florida. The sedimentary phosphate rock, used as the raw material for phosphoric acid production, is enriched in uranium and daughter products. Relatively high concentrations of some of these U-series daughters, particularly 226 Ra (av. = 910 Bq.Kg-1), prevent use of the by-product gypsum for construction or other purposes. The material is thus stockpiled on huge stacks which are unsightly and a potential threat to the surrounding air and especially groundwater resources. It is estimated that ∼ 109 tons of this material will be on Florida stacks by the turn of the century. We have been investigating the detailed radiochemistry of phosphogypsum in the hope that can understanding of how these radionuclides are fixed in the material may lead to cost-effective purification schemes. Our work has focused on the distribution of 226 Ra but has also included 210 Pb and 210 Po (av. = 860 Bq.Kg-1) which are also enriched in phosphogypsum. This paper summarizes the problems associated with this material and reviews its radiochemistry as elucidated by sequential extraction and other methodologies. We also present some possible alternatives to long-term storage as a solution to the phosphogypsum problem. (author)

  3. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

    1999-04-30

    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.

  4. 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)

    1997-01-31

    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

  5. REUSAGE OF GYPSUM TAILING BINDER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Gypsum tailings, slag, cement, and other additives are used to produce gypsum building material products with simple technological processes and low costs. It provides a new effective approach to reuse gypsum tailings.

  6. Gypsum karst in Great Britain

    OpenAIRE

    Cooper A.H.

    1996-01-01

    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 recor...

  7. Sustainable Uses of FGD Gypsum in Agricultural Systems: Introduction.

    Science.gov (United States)

    Watts, Dexter B; Dick, Warren A

    2014-01-01

    Interest in using gypsum as a management tool to improve crop yields and soil and water quality has recently increased. Abundant supply and availability of flue gas desulfurization (FGD) gypsum, a by-product of scrubbing sulfur from combustion gases at coal-fired power plants, in major agricultural producing regions within the last two decades has attributed to this interest. Currently, published data on the long-term sustainability of FGD gypsum use in agricultural systems is limited. This has led to organization of the American Society of Agronomy's Community "By-product Gypsum Uses in Agriculture" and a special collection of nine technical research articles on various issues related to FGD gypsum uses in agricultural systems. A brief review of FGD gypsum, rationale for the special collection, overviews of articles, knowledge gaps, and future research directions are presented in this introductory paper. The nine articles are focused in three general areas: (i) mercury and other trace element impacts, (ii) water quality impacts, and (iii) agronomic responses and soil physical changes. While this is not an exhaustive review of the topic, results indicate that FGD gypsum use in sustainable agricultural production systems is promising. The environmental impacts of FGD gypsum are mostly positive, with only a few negative results observed, even when applied at rates representing cumulative 80-year applications. Thus, FGD gypsum, if properly managed, seems to represent an important potential input into agricultural systems. PMID:25602557

  8. Potential use of gypsum and lime rich industrial by-products for induced reduction of Pb, Zn and Ni leachability in an acid soil

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Jorda, M.P. [Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115 dpdo, 28006 Madrid (Spain); Garrido, F., E-mail: fernando.garrido@ccma.csic.es [Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115 dpdo, 28006 Madrid (Spain); Garcia-Gonzalez, M.T. [Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115 dpdo, 28006 Madrid (Spain)

    2010-03-15

    This study evaluates the potential use of four industrial by-products (phosphogypsum (PG), red gypsum (RG), sugar foam (SF), and ashes from biomass combustion (ACB)), applied at two rates in single and combined amendments to reduce the mobility and availability of Pb, Zn and Ni in a metal-spiked acid soil. Leaching experiments were done to estimate leachability indexes and assess their effectiveness. Most of the treatments significantly reduced the metal leachability although only a few were effective for all metals. Based on principal component and cluster analysis, sugar foam (SF) and a mixture of RG and ACB (RG+ACB), both applied at high rate, were selected as first choices to reduce mobility and availability of the three metals. Metal sorption mechanisms involved in the reduction of their leachability were identified using scanning electron microscopy. In the SF-treated samples, the metals were found associated to amorphous Al-hydroxy polymers deposited on phyllosilicates and organic matter particles. In the (RG+ACB)-treated samples, Pb, Zn, and traces of Ni were found associated to Fe/Ti oxide phases with a significant concentration of S, suggesting the formation of metal-sulfate ternary complexes.

  9. Potential use of gypsum and lime rich industrial by-products for induced reduction of Pb, Zn and Ni leachability in an acid soil

    International Nuclear Information System (INIS)

    This study evaluates the potential use of four industrial by-products (phosphogypsum (PG), red gypsum (RG), sugar foam (SF), and ashes from biomass combustion (ACB)), applied at two rates in single and combined amendments to reduce the mobility and availability of Pb, Zn and Ni in a metal-spiked acid soil. Leaching experiments were done to estimate leachability indexes and assess their effectiveness. Most of the treatments significantly reduced the metal leachability although only a few were effective for all metals. Based on principal component and cluster analysis, sugar foam (SF) and a mixture of RG and ACB (RG+ACB), both applied at high rate, were selected as first choices to reduce mobility and availability of the three metals. Metal sorption mechanisms involved in the reduction of their leachability were identified using scanning electron microscopy. In the SF-treated samples, the metals were found associated to amorphous Al-hydroxy polymers deposited on phyllosilicates and organic matter particles. In the (RG+ACB)-treated samples, Pb, Zn, and traces of Ni were found associated to Fe/Ti oxide phases with a significant concentration of S, suggesting the formation of metal-sulfate ternary complexes.

  10. Utilization of desulfurization gypsum to producing SO{sub 2} and CaO in multi-stage fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhu; Wang, Tao; Yang, Hairui; Zhang, Hai; Zhang, Zuyi [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering

    2013-07-01

    With emission control becomes more and more stringent, flue gas desulphurization (FGD) is commonly employed for desulfurization. However, the product of FGD, gypsum, causes the unexpected environmental problems. How to utilize the byproduct of FGD effectively and economically is a challenging task. This paper proposed the new technical process to produce SO{sub 2} and CaO by reducing the gypsum in multi-stage fluidized bed reactor with different atmosphere. In addition, some preliminary experiments were carried out in PTGA. The results show that CO concentration has little effect on the initial decomposing temperature, but affect the decomposing rate of phosphogypsum obviously. The decomposing product composed of CaS and CaO simultaneously. The ratio of the two products was determined by CO concentration. Lower CO content benefits to produce more CO product and more SO{sub 2}. The decomposition reaction of phosphogypsum in reducing atmosphere is parallel competition reaction. Therefore, it is necessary to eliminate the effect of CaS and other byproduct efficiently by the new technology, which utilize multi-atmosphere in multistage fluidized bed reactors.

  11. Producing Fish Protein Hydrolysates from Mackerel By-Products

    OpenAIRE

    Ana Luísa De Sousa Augusto

    2014-01-01

    Portugal is one of the largest consumers of fishery products in Europe. This consumption involves a large amount of discarded raw material, such as rejected fish in selling auctions and the generation of by-products in industrial production processes. The by-products in the canning industry alone reach 40% of the raw material, while the frozen fish industries may reach 10-50% of the raw material (INE, 2013). Fish protein hydrolysates (FPH) are one of the most promising technologies for th...

  12. Research Progress of the Application of Several Types of Industrial By-product Gypsums as the New Wall Materials Based on Gypsum%几种化学副产石膏在新型石膏基墙体材料研究中的进展

    Institute of Scientific and Technical Information of China (English)

    李书琴; 杜晟连; 王展光

    2012-01-01

    In advocate building energy efficiency and develop wall body reform, building new systems and energy saving and environmental protection type wall body material used to build the ecological architecture and the benefit of human. Gypsum as the main body of the green building materials in the construction industry pays close attention to doubly. This paper elaborates on the research progress of the application of several chemical by-product gypsums as the new wall materials based on gypsum, and arrives at the conclusion that gypsum as the new type of the raw materials of wall is the green building material which should be fully developed and promoted.%在倡导建筑节能和开展墙体改革形势下,新型建筑体系和节能环保型墙体材料的使用打造了生态建筑并造福于人类.以石膏为主体的绿色建材原料在建筑行业倍加关注.本文阐述了主要几种化学副产石膏做为新型石膏基墙体材料原料的研究进展,得出石膏作为新型石膏基墙体材料原料是一种首先应该大力发展的绿色建筑材料原料.

  13. Gypsum karst in Great Britain

    Directory of Open Access Journals (Sweden)

    Cooper A.H.

    1996-01-01

    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.

  14. Hydrogeology of Gypsum formations

    Directory of Open Access Journals (Sweden)

    Klimchouk A.

    1996-01-01

    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.

  15. Hydrogeology of Gypsum formations

    OpenAIRE

    Klimchouk A.

    1996-01-01

    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.

  16. Flue gas desulfurization gypsum agricultural network alabama (bermudagrass)

    Science.gov (United States)

    Synthetic gypsum is being produced in large quantities each year as a byproduct of SO2 removal from flue gas stream at coal-fired utility plants. This synthetic gypsum which is believed to be comparable or better than mined gypsum may enhance crop production. However, there is a paucity of informati...

  17. Candoluminescence of cave gypsum

    OpenAIRE

    Sweet John R.; Hess John W.; White William B.

    2010-01-01

    A selection of gypsum specimens from a variety of caves as well as CaSO4 synthesized in the laboratory emit both a green and yellow candoluminescence when excited by a hydrogen diffusion flame. The green emission is attributed to dehydration of gypsum to bassanite and the yellow emission appears upon further dehydration to anhydrite. The source of the luminescence is ascribed to minor concentrations of Mn2+ in the gypsum.

  18. An accelerator-produced short-lived radionuclide for the tracer-technique of gypsum in a large-scale production plant of gas concrete

    International Nuclear Information System (INIS)

    The inhomogeneous distribution of gypsum in gas concrete causes disturbances in the cutting process in gas concrete production. The mixing behaviour of gypsum was investigated by means of the tracer technique: first by measurements of the activity upon the mixer wall, second by scanning measurements of the activity at the surface of gas concrete blocks, and third the distribution of the activity in the micro areas is determined by autoradiography. The radionuclide production was accomplished on the cyclotron U120 by means of the nuclear reactions: 40Ca(α,n)43Ti -(0.5 s) → 43Sc 40Ca(α,p)43Sc. The activation of the powdery material was effected in a target machine which prevents the destruction of the gypsum. (author)

  19. Gypsum karst of France

    OpenAIRE

    Chardon M.; Nicod J.

    1996-01-01

    Many small and scattered areas of gypsum karst are present in France. They occur in the plains and plateaux (Paris, Lorraine, Provence) as well as in the mountains, especially the Alps. Typical gypsum karst landforms are well developed and widespread, but underground cavities are scarce, despite much exploration and the apparent existence of subsurface waterflow. The Alps and Provence contain the largest karstic areas.

  20. Effects of gypsum on trace metals in soils and earthworms.

    Science.gov (United States)

    Chen, Liming; Kost, Dave; Tian, Yongqiang; Guo, Xiaolu; Watts, Dexter; Norton, Darrell; Wolkowski, Richard P; Dick, Warren A

    2014-01-01

    Mined gypsum has been beneficially used for many years as an agricultural amendment. A large amount of flue gas desulfurization (FGD) gypsum is produced by removal of SO from flue gas streams when fuels with high S content are burned. The FGD gypsum, similar to mined gypsum, can enhance crop production. However, information is lacking concerning the potential environmental impacts of trace metals, especially Hg, in the FGD gypsum. Flue gas desulfurization and mined gypsums were evaluated to determine their ability to affect concentrations of Hg and other trace elements in soils and earthworms. The study was conducted at four field sites across the United States (Ohio, Indiana, Alabama, and Wisconsin). The application rates of gypsums ranged from 2.2 Mg ha in Indiana to 20 Mg ha in Ohio and Alabama. These rates are 2 to 10 times higher than typically recommended. The lengths of time from gypsum application to soil and earthworm sampling were 5 and 18 mo in Ohio, 6 mo in Indiana, 11 mo in Alabama, and 4 mo in Wisconsin. Earthworm numbers and biomass were decreased by FGD and mined gypsums in Ohio. Among all the elements examined, Hg was slightly increased in soils and earthworms in the FGD gypsum treatments compared with the control and the mined gypsum treatments. The differences were not statistically significant except for the Hg concentration in the soil at the Wisconsin site. Selenium in earthworms in the FGD gypsum treatments was statistically higher than in the controls but not higher than in the mined gypsum treatments at the Indiana and Wisconsin sites. Bioaccumulation factors for nondepurated earthworms were statistically similar or lower for the FGD gypsum treatments compared with the controls for all elements. Use of FGD gypsum at normal recommended agricultural rates seems not to have a significant impact on concentrations of trace metals in earthworms and soils. PMID:25602559

  1. Comparison of soil applied flue gas desulfurization (FGD) and agricultural gypsum on soil physical properties

    Science.gov (United States)

    Gypsum can come from different sources. Agricultural gypsum is typically mined and used to supply calcium to crops. Flue gas desulfurization (FGD) gypsum is a by-product of coal power plants. Although their chemical formulas are the same, different trace elements and materials are present in them....

  2. PRIMUS(reg. sign), a new process for recyling by-products and producing virgin iron

    Energy Technology Data Exchange (ETDEWEB)

    Roth, J.L.; Frieden, R.; Hansmann, T.; Monai, J.; Solvi, M.

    2001-11-01

    For years, the iron and steel industry has been in search of new processes for an efficient production of virgin steel as well as for the recycling of its by-products, especially for those containing zinc. Considering these objectives, Paul Wurth S.A., in cooperation with ProfilARBED, has developed a process using the multiple-hearth furnace and coal fines as the reductant and main energy source. A trial plant with a capacity of 2 t/h was built and has been operated for more than one year at the ProfilARBED Belval site. This paper reports on the trial campaigns, which have given most promising results.

  3. Gypsum karst geohazards in China

    OpenAIRE

    Yaoru, Lu; Cooper, A.H.

    1997-01-01

    China has the worlds largest proven gypsum (CaSO4.2H2O) resources in the world. The gypsum ranges from pre-Cambrian to Quaternary in age and occurs in varied geological environments. The rapid dissolution rate of gypsum means that gypsum karst development can be very fast, resulting in progressively worsening geohazards. This paper reviews the characteristics of the gypsum deposits and their associated geohazards in China.Three kinds of gypsum karst are discussed. These include karst in mass...

  4. Utilization of a by-product produced from oxidative desulfurization process over Cs-mesoporous silica catalysts.

    Science.gov (United States)

    Kim, Hyeonjoo; Jeong, Kwang-Eun; Jeong, Soon-Yong; Park, Young-Kwon; Kim, Do Heui; Jeon, Jong-Ki

    2011-02-01

    We investigated the use of Cs-mesoporous silica catalysts to upgrade a by-product of oxidative desulfurization (ODS). Cs-mesoporous silica catalysts were characterized through N2 adsorption, XRD, CO2-temperature-programmed desorption, and XRF. Cs-mesoporous silica prepared by the direct incorporation method showed higher catalytic performance than a Cs/MCM-41 catalyst by impregnation method for the catalytic decomposition of sulfone compounds produced from ODS process. PMID:21456272

  5. Hydrogen sulfide release from dairy manure storages containing gypsum bedding

    Science.gov (United States)

    Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

  6. Some parameters of uranium hexafluoride plasma produced by products of nuclear reaction

    International Nuclear Information System (INIS)

    The probe experimental results of investigation of uranium hexafluoride plasma produced in the centre of nuclear reactor core were demonstrated. Study of uranium hexafluoride plasma is continued by the following reasons: a possibility of U F6 utilization as nuclear fuel, the utilization of U F6 as volume source o ionization, search of active laser media compatible with U F6 that is complicated by lack of constant rates data for most of plasma-chemical reactions with U F6 and his dissociation products. Cylindrical probe volt-ampere characteristics (VAC) measured in U F6 plasma at pressure 20 Torr and different thermal neutron fluxes and have following features: -firstly, it is possible to choose a linear part in the field of small positive potentials of probe (0-1) V; - secondary, ion branches of VAC have typical break which current of satiation corresponds to; -thirdly, probe VAC measured at small values of thermal neutron flux density are symmetrical. Diagnostics approaches were used for interpretation VAC of probe. The values of satiation current and linear part of electron branch were calculated, and such plasma parameters as conductivity, diffusion coefficient values of positive and negative ions were determined. The resonance recharge cross section was estimated on diffusion coefficient value

  7. FGD [flue gas desulfurization] gypsum in research, development, production and application

    International Nuclear Information System (INIS)

    The research, development, production and application activities concerning flue gas desulfurization (FGD) gypsum in Germany are reviewed. Possibilities for the utilization of FGD gypsum were investigated in numerous laboratory and pilot plant tests. An agglomerating process was developed to dry the moist, fine gypsum powder into briquettes similar to natural crushed gyspum rock, and suitable for use alone or in conjunction with natural gypsum in existing factories producing plaster or Portland cement. After calcination, the FGD gypsum briquettes showed very good rheological properties in plaster with no thixotropy. The briquettes have a uniform 1 ton/m3 density and can be easily transported and stored outdoors. Utilization of FGD gypsum as a beta-hemihydrate plaster for production of prefabricated gypsum building components is now standard in Germany. A new factory was built in the early eighties using 50% FGD gypsum briquettes and 50% moist, finely divided FGD gypsum, producing 350,000 tonnes of projection plaster annually. A process was also developed for the production of alpha gypsum plaster from the moist, fine FGD gypsum. FGD gypsum has been found suitable for a wide range of filler applications currently filled by calcium carbonate and china clay. Main expenditures to be considered when performing economic assessments include: drying expenditure (ca 550,000 kJ/ton); energy consumption for briquetting (ca 10 kWh/ton); FGD gypsum transportation between power station and factory and associated handling; intermediate storage facilities; service and maintenance; and additive costs. 8 refs., 14 figs., 1 tab

  8. Gypsum at Olympia Undae

    Science.gov (United States)

    2006-01-01

    This Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) 'targeted image' shows a region of sand dunes surrounding the Martian north polar cap. CRISM, an instrument on NASA's Mars Reconnaissance Orbiter, acquired the image at 1811 UTC (2:11 p.m. EDT) on Oct. 1, 2006. The imaged site is near 80.0 degrees north latitude, 240.7 degrees east longitude. It covers an area about 12 kilometers (7.5 miles) square. At the center of the image, the spatial resolution is as good as 20 meters (65 feet) per pixel. The image was taken in 544 colors covering 0.36 to 3.92 micrometers. CRISM's sister instrument on the Mars Express spacecraft, OMEGA, has spectrally mapped Mars at lower spatial resolution and discovered that several regions of the planet are rich in sulfate minerals formed by liquid water. Surprisingly, one of the sulfate-rich deposits is a part of the giant field of sand dunes surrounding the north polar cap. CRISM is remapping the dune field at about five times higher resolution than OMEGA, and imaging selected regions at 50 times higher resolution. This image is the first of the high-resolution images of the dune field. This visualization includes two renderings of the data, both map-projected. The left images are false-color representations showing brightness of the surface at selected infrared wavelengths. The right images show strength of an absorption band at 1900 nanometers wavelength, which indicates the relative abundance of the sulfate mineral gypsum. Brighter areas have more gypsum, and darker areas have less gypsum. The bottom views are enlargements of the central part of the two versions of the image shown at top. Gypsum is a light-colored, whitish mineral, so it was anticipated that gypsum-rich parts of the sand dunes would be light in color. In fact, there are light-colored areas in the left images, but the images of the gypsum absorption at right show that the light areas have only low gypsum abundance. The dark sand dunes contain most of the

  9. Measuring the gypsum content of C&D debris fines.

    Science.gov (United States)

    Musson, Stephen E; Xu, Qiyong; Townsend, Timothy G

    2008-11-01

    Construction and demolition (C&D) debris recycling facilities often produce a screened material intended for use as alternative daily cover (ADC) at active landfills or for shaping and grading at closed landfills. This product contains soil and small pieces of wood, concrete, gypsum drywall, shingles and other components of C&D debris. Concerns have been raised over the contribution of gypsum drywall in C&D debris fines to odor problems at landfills where the product is used. To address such concerns, limitations may be placed on the percentage of gypsum (or sulfate) that can occur, and standardized testing procedures are required to permit valid compliance testing. A test procedure was developed for measuring the gypsum content in C&D debris fines. The concentration of sulfate leached in an aqueous solution was used to estimate the initial gypsum content of the sample. The impact of sample size and leaching time were evaluated. Precision and accuracy increased with increasing gypsum content. Results from replicate samples had an average relative standard deviation of 9%. The gypsum content of fines obtained from different facilities in the US varied widely from 1% to over 25%. These variations not only occurred between differing facilities, but within batches produced within a single facility. PMID:17980573

  10. Flue gas desulfurization gypsum and fly ash

    International Nuclear Information System (INIS)

    The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority's newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must be considered from an environmental perspective

  11. The gypsum karst of Italy

    OpenAIRE

    Forti P.; Sauro U.

    1996-01-01

    Gypsum karst has been studied in Italy since the last decades of the l9th Century. In 1917 the geographer Olinto Marinelli published �Fenomeni carsici delle regioni gessose d�Italia�, a fundamental synthesis of the early research. He distinguished 56 different morpho-karstic gypsum units and/or areas, which are all different in size and character, and described them, paying special attention to their surface morphology and hydrology. Marinelli listed all the main gypsum units and only a few s...

  12. Economics of Gypsum Production in Iran

    Science.gov (United States)

    Esmaeili, Abdoulkarim

    The purpose of this research is to analyze the economics of gypsum production in Iran. The trend in production cost, selling price and profit are used to investigate economics of gypsum production. In addition, the multivariate time series method is used to determine factors affecting gypsum price in domestic market. The results indicated that due to increase in production and inflation, profitability of gypsum production has decreased during recent years. It is concluded that tariff and non-tariff barriers on mines machinery are among reasons for increasing production cost in Iranian gypsum mines. Decreasing such barriers could increase profitability of gypsum production in Iran.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Sanderson

    2007-12-31

    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. Environmental evaluation of flue gas desulfurization gypsum as a BMP for erosion control

    Science.gov (United States)

    Flue Gas Desulfurization Gypsum (FGDG) is produced from pollution control systems reducing sulfur dioxide emissions from thermo-electric coal-fired power plants. Natural gypsum and FGDG both have been shown to be useful in control of soil erosion. However, concerns have been raised recently by envir...

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

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Marshall Sanderson

    2006-06-01

    This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. 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 developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being 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 includes five discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The five tasks were to include (1) a baseline 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, which was to evaluate gypsum produced from an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to a previous task, Task 3, although with gypsum from an alternate FGD system. In this project, process stacks in the wallboard plant have been sampled using the Ontario

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

    Science.gov (United States)

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

    2013-09-01

    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. Speleothems and cave minerals in gypsum caves

    OpenAIRE

    Forti P.

    1996-01-01

    For many years gypsum karst was considered to contain little of interest from the point of view of chemical deposits. Relatively recently a general study of speleothems has begun within gypsum karst areas in different climatic zones around the world. So far this ongoing research has shown that gypsum karst can be very interesting in terms of its contained chemical deposits. In this chapter, all that is currently known about speleothems in gypsum caves is reported systematically, and the disti...

  18. C12 derivatives of the hydroperoxide lyase pathway are produced by product recycling through lipoxygenase-2 in Nicotiana attenuata leaves

    NARCIS (Netherlands)

    M. Kallenbach; P.A. Gilardoni; S. Allmann; I.T. Baldwin; G. Bonaventure

    2011-01-01

    In response to diverse stresses, the hydroperoxide lyase (HPL) pathway produces C(6) aldehydes and 12-oxo-(9Z )-dodecenoic acid ((9Z )-traumatin). Since the original characterization of (10E )-traumatin and traumatic acid, little has been added to our knowledge of the metabolism and fluxes associate

  19. Hydro fuel is produce through aqueous-phase reforming process by using glycerol as by-product from oil palms

    International Nuclear Information System (INIS)

    Full text: The research is aim to study the type of catalysts (e.g. Pt-Ni, Pt and Ni catalysts) that are use to increase the yield of hydrogen gas in the reaction of aqueous-phase reforming (APR) process ,that use glycerol to produce hydrogen gas using steam. The output product of aqueous-phase reforming (APR) process are hydrogen, carbon monoxide and carbon dioxide gases. (author)

  20. Converting SDAP into gypsum in a wet limestone scrubber

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

    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)

  1. Fundamental and molecular composition characteristics of biochars produced from sugarcane and rice crop residues and by-products.

    Science.gov (United States)

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

    2016-01-01

    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. PMID:26058554

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

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Kiil, Søren

    2012-01-01

    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...... 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...... to produce low quality gypsum. The crystals formed in the pilot plant, on the basis of the full-scale slurry did, however, show acceptable filtration rates and crystal morphologies closer to the prismatic crystals from after pilot plant experiments with demineralized water. The gypsum slurry filtration rates...

  3. Polymer composites based on gypsum matrix

    Science.gov (United States)

    Mucha, Maria; Mróz, Patrycja; Kocemba, Aleksandra

    2016-05-01

    The role of polymers as retarder additives is to prolong the workability connected with setting time of gypsum. Various cellulose derivatives, soluble in water in concentration up to 1,5% by weight were applied taking different water/binder ratio. The hydration process of calcium sulfate hemihydrate (gypsum binder) into dihydrate (gypsum plaster) was observed by setting and calorimetric techniques. Scanning electron microscopy confirmed that the gypsum microstructure was varied when polymers are used. The mechanical properties of gypsum plasters were studied by bending strength test and they are correlated with sample microstructure

  4. Utilization Alternatives and Potentiality for FGD Gypsum from Coal-Fired Power Plants

    Institute of Scientific and Technical Information of China (English)

    Tian Hezhong; Hao Jiming; Zhao Zhe; Kong Xiangying; Yang Chao; Lu Guangjie; Liu Hanqiang; Xu Fenggang; Chu Xue

    2006-01-01

    @@ It is estimated that an installed capacity of thermal power units with desulphurization equipment will come up to 40-50 GW by the end of 2020, which affords a good opportunity for opening up and development of the market of the by-product gypsum from thermal power desulphurization. Therefore, it is necessary to research the present situation and restrictive factors in the comprehensive utilization of FGD gypsum.

  5. New eco-friendly gypsum materials for civil construction

    OpenAIRE

    Eires, R.; Camões, Aires; Jalali, Said

    2007-01-01

    The sustainable world’s economic growth and people’s life improvement greatly depend on the use of alternative products in the architecture and construction, such as industrial wastes conventionally called “green materials”. This paper concerns the main results of an experimental work carried out with the objective of developing new composite materials based on gypsum and incorporating waste material as granulated cork, a by-product of cork industry, and cellulose fibres, a waste of pap...

  6. Odour characteristics of seafood flavour formulations produced with fish by-products incorporating EPA, DHA and fish oil.

    Science.gov (United States)

    Peinado, I; Miles, W; Koutsidis, G

    2016-12-01

    Thermal degradation of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids was investigated. As a novelty, EPA, DHA or fish oil (FO) were incorporated as ω-fatty acid sources into model systems containing fish powder produced via Maillard reactions. Aroma composition of the resulting products was determined and complemented with sensory evaluation. Heating of the oils led to a fast decrease of both, EPA and DHA, and to the development of characteristic volatile compounds including hexanal, 2,4-heptadienal and 4-heptenal, the most abundant being (E,E)-2,4-heptadienal (132±44-329±122μmol/g). EPA and DHA addition to the model systems increased the concentration of these characteristic volatile compounds. However, it did not have a considerable impact on the development of characteristic Maillard reaction products, such as pyrazines and some aldehydes. Finally, the results of the sensory evaluation illustrated that panellists would chose samples fortified with FO as the ones with a more pleasant aroma. PMID:27374575

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

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Sanderson; Gary M. Blythe; Mandi Richardson

    2006-12-01

    This report presents and discusses results from Task 6 of the study 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,' performed at a full-scale commercial wallboard plant. 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 is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being 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 now includes six discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The project was originally composed of five tasks, which were to include (1) a baseline 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, which was to include testing with an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to Task 3, although with gypsum from an alternate FGD system. Subsequent to conducting Task 5 under these revised conditions, an opportunity arose to test gypsum produced at the same FGD system, but with an additive (Degussa Corporation's TMT-15) being used in the FGD system. TMT-15

  8. Identifying inhibitory effects of lignocellulosic by-products on growth of lactic acid producing micro-organisms using a rapid small-scale screening method.

    Science.gov (United States)

    van der Pol, Edwin C; Vaessen, Evelien; Weusthuis, Ruud A; Eggink, Gerrit

    2016-06-01

    Sugars obtained from pretreated lignocellulose are interesting as substrate for the production of lactic acid in fermentation processes. However, by-products formed during pretreatment of lignocellulose can inhibit microbial growth. In this study, a small-scale rapid screening method was used to identify inhibitory effects of single and combined by-products on growth of lactic acid producing micro-organisms. The small-scale screening was performed in 48-well plates using 5 bacterial species and 12 by-products. Large differences were observed in inhibitory effects of by-products between different species. Predictions can be made for growth behaviour of different micro-organisms on acid pretreated or alkaline pretreated bagasse substrates using data from the small-scale screening. Both individual and combined inhibition effects were shown to be important parameters to predict growth. Synergy between coumaric acid, formic acid and acetic acid is a key inhibitory parameter in alkaline pretreated lignocellulose, while furfural is a key inhibitor in acid pretreated lignocellulose. PMID:26990397

  9. THERMAL CONDUCTIVITY OF RUBBERIZED GYPSUM BOARD

    Directory of Open Access Journals (Sweden)

    Taher Abu-Lebdeh

    2014-01-01

    Full Text Available The disposal of scrap tires is a challenging task and hence an innovative solution to meet these challenges is needed. Extensive work has been done on the utilization of waste tires in a variety of applications in asphalt pavements and concrete. However, previous investigations focus only on the mechanical properties of the rubberized materials, but few on the thermal performance. This is especially true for rubberized gypsum. Limited or no experimental data on the thermal performance of rubberized gypsum board are available. In this study, an experimental program is established to investigate the effect of amount and size of crumb rubber on the thermal properties of gypsum materials. Gypsum is replaced by four different percentage of crumb rubber: 10, 20, 30 and 40% by weight of gypsum and two sizes of crumb rubber (#30, #10_20 to make eight rubberized gypsum specimens. The prepared specimens were tested for thermal conductivity using an apparatus specially designed and constructed for this purpose. The experimental program was concluded by proposing an empirical equation to predict the thermal conductivity of rubberized gypsum board. Results indicated better thermal performance of the gypsum board due to the addition of crumb rubber. Thermal conductivity of the rubberized gypsum was 18-38% lower than the ordinary gypsum. It is concluded that thermal conductivity of rubberized gypsum decreases with the increase of crumb rubber regardless the size of the rubber and that thermal conductivity of mixtures contained 40% of rubber was about 38% lower than conventional mixture when crumb rubber #10_20 was added, while the thermal conductivity reduced by 22% when crumb rubber #30 was added. The study suggested for future work to investigate the effect of air voids size and ratio on the thermal conductivity of rubberized gypsum.

  10. Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams

    Science.gov (United States)

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

    2014-01-01

    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.

  11. Environmental problems in gypsum karst terrains

    OpenAIRE

    Klimchouk A.; Andrejchouk V.

    1996-01-01

    Description of environmental problems in gypsum karst areas, especially of the effects related to human impacts that are unique to gypsum karst systems or most commonly occur herein. The paper deals with pollution (oil, radioactive substances and fertilizers), mining activity, underground water abstraction, construction of dams and reservoirs, collapse and subsidence hazards giving examples of former Soviet Union.

  12. Study of gypsum crystal nucleation and growth rates in simulated flue gas desulfurization liquors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, A.D.; Etherton, D.

    1981-06-01

    The kinetics of gypsum crystal nucleation and growth rates were measured in flue gas desulfurization (FGD) scrubber liquors. Variables studied were parent seed crystal size and mass; the organic additives citric acid, adipic acid, sodium dodecylbenzene sulfonate, and Calgon CL246 polyacrylic acid formulation; and pH. Citric acid produced gypsum crystals with a more favorable columnar structure. Lower pH resulted in increased nucleation rates. Stable secondary nucleation was observed in the presence of retained parent gypsum seed crystals of size >150 ..mu..m. Growth and nucleation rates were correlated using reaction kinetic models. These kinetics were then used in rigorous computer simulations to predict crystal-size distribution (CSD) with different scrubber configurations. Scrubber process configurations employing classified product removal were calculated to produce a gypsum sludge having a mean particle size up to twice as large as the particle size with unclassified operation.

  13. Attenuation characteristics of gypsum wallboard

    International Nuclear Information System (INIS)

    Increased cost of lead is promoting enhanced usage of common building materials for shielding in diagnostic medical and dental facilities where only a few half-value layers (HVLs) are needed. Attenuation of primary beam X-ray photons in gypsum wallboard as a function of kVp, filtration, and wallboard thickness have been measured. Findings, obtained using a Victoreen 555 with an 0.1 DAS probe in poor geometry, are substantially in agreement with the sparse data in the literature but extend to thicker wall configurations and different kVp and filtration parameters. These findings are of value in maximizing the benefit/cost ratio for diagnostic shielding, and strengthen the conviction that, where used for shielding purposes, common building materials must be installed carefully and HVL-depth dependence considered thoroughly. (author)

  14. 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.

    1997-10-01

    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.

  15. Separation And Purification Of Radioiodine 131I by Means of wet Distillation Method From By-Product of U-235 Fission Produced 99Mo Process

    International Nuclear Information System (INIS)

    The production of 99Mo from 235U fission also produces radioiodine fraction as by product. The radioiodine fraction can be expected to be a complement for radioiodine 131I produced by neutron activation on TeO2 target. Separation and purification were therefore carried out from radioiodine fraction obtained from production process of 99Mo fission product. The radioiodine 131I fraction was separated and purified by means of wet distillation method that is often used for separating 131I from post-neutron activated TeO2. The quality control of the resulting products indicates that the resulting radioiodine 131I solution was suitable to be used for labelling or synthesis of 131I labelled compounds. Although the efficiencies of separation and purification were found to be low ranging between 25 to 37%, the result of the presented experiment generally affirm the consideration to exploit the 131I fission product for labelling or synthesis of 131I radiopharmaceuticals. Key word : distillation, radioiodine 131I , 235U

  16. 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 for...

  17. Activation of Anhydrate Phosphogypsmn by K2SO4 and Hemihydrate Gypsum

    Institute of Scientific and Technical Information of China (English)

    YANG Min; QIAN Jueshi

    2011-01-01

    Lime pretreated phosphogypsum(PG) was calcined at 500 ℃ to produce anhydrate gypsum cement.Due to the slow hydration of anhydrate gypsum,additives,K2SO4 and hemihydrate gypsum were selected to accelerate the hydration of anhydrate.The hydration characteristics,the resistance to hydrodynamic water,and the mineralogical studies were investigated.The experimental results suggest that activated by K2SO4 and hemihydrate,anhydrate PG hydrates much more rapidly than that in the presence of only K2SO4 or in the absence of additives.The binder has proper setting time,good strength development,and relatively better resistance to water.The hardened binder has hydrated products of rod or stick like shaped dihydrate gypsum crystals.

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

    Science.gov (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...

  19. The air permeability of gypsum insulating structures

    Energy Technology Data Exchange (ETDEWEB)

    Krikunenko, V.K.; Denisova, G.F.; Omelchenko, A.S.

    1980-01-01

    The air permeability of materials made from gypsum binders used to build insulation and blast-resistant crosspieces is studied, and it is established that the materials tested provided reliable insulation due to the low air permeability factor.

  20. Deformation processes in polycrystalline aggregates of gypsum

    OpenAIRE

    S Meer

    1995-01-01

    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 densification behaviour of polycrystalline gypsum aggregates, and the underlying microphysical processes which control deformation, thus form a subject of considerable interest in a number of areas of s...

  1. AGAPUTE - Advanced gas purification technologies for co-gasification of coal, refinery by-products, biomass & waste, targeted to clean power produced from gas & steam turbine generator sets and fuel cells. FINAL REPORT

    OpenAIRE

    Di Donato, Antonello; Puigjaner Corbella, Lluís; Velo García, Enrique; Nougués, José María; Pérez Fortes, María del Mar; Bojarski, Aarón David

    2010-01-01

    Informe Final del Projecte ECSC RFC-CR-04006: AGAPUTE - Advanced gas purification technologies for co-gasification of coal, refinery by-products, biomass & waste, targeted to clean power produced from gas & steam turbine generator sets and fuel cells

  2. Dehydration Kinetics of Volterra Gypsum: Experiments and Overview

    Science.gov (United States)

    Llana-Funez, S.; Wheeler, J.; Faulkner, D.

    2007-12-01

    Dehydration reactions are often envisaged as a triggering mechanism for seismicity in rocks under tectonic loads due to the reduction in effective pressure during the release of fluids that may eventually produce mechanical embrittlement. Understanding of metamorphic transformation in deforming rocks is even more important in fault zones where periods of seismic slip are reported. Dehydration of gypsum under controlled conditions, in laboratory experiments and in numerical models, provides information on deformation processes operating in seismically active regions and may be of help in understanding their cyclicity and their evolution. Two series of simple heating experiments of Volterra gypsum samples at room pressure, using intact and powdered specimens, provide reference data for further experiments under confining and differential stress during dehydration. Heating experiments were run at constant temperature between 80 degC and 140 °C in intact specimens and at 86 °C and 97 °C using powders with five different grain size fractions: 0.5 mm. The complete dehydration of 1 mol of gypsum produces 1 mol of anhydrite and two moles of water generating a porosity of about 38% and implying a weight loss of 21% upon removal of water. The progressive loss of weight during dehydration was used as the method to estimate the progress of the reaction. The reaction is characterized by an initial stage under 10% reaction were reaction rate accelerates, which is followed by a linear stage for about 50 to 70% of the reaction and a final third stage with decelerating reaction rates. All tests run above 85 °C reached about 90% reaction. Those below 85 °C seem to converge to a lower final fraction (75%) suggesting partial dehydration, very likely to bassanite. The temperature dependence of the linear rates indicates in an Arrhenius plot that the full dehydration of gypsum has an activation enthalpy of 96 kJ/mol. The two temperatures tested with powdered specimens are

  3. 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

    2012-09-01

    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.

  4. Flue gas desulfurization gypsum and coal fly ash as basic components of prefabricated building materials.

    Science.gov (United States)

    Telesca, Antonio; Marroccoli, Milena; Calabrese, Daniela; Valenti, Gian Lorenzo; Montagnaro, Fabio

    2013-03-01

    The manufacture of prefabricated building materials containing binding products such as ettringite (6CaO·Al2O3·3SO3·32H2O) and calcium silicate hydrate (CSH) can give, in addition to other well-defined industrial activities, the opportunity of using wastes and by-products as raw materials, thus contributing to further saving of natural resources and protection of the environment. Two ternary mixtures, composed by 40% flue gas desulfurization (FGD) gypsum or natural gypsum (as a reference material), 35% calcium hydroxide and 25% coal fly ash, were submitted to laboratory hydrothermal treatments carried out within time and temperature ranges of 2h-7days and 55-85°C, respectively. The formation of (i) ettringite, by hydration of calcium sulfate given by FGD or natural gypsum, alumina of fly ash and part of calcium hydroxide, and (ii) CSH, by hydration of silica contained in fly ash and residual lime, was observed within both the reacting systems. For the FGD gypsum-based mixture, the conversion toward ettringite and CSH was highest at 70°C and increased with curing time. Some discrepancies in the hydration behavior between the mixtures were ascribed to differences in mineralogical composition between natural and FGD gypsum. PMID:23219474

  5. GYPSUM DEPOSITS IN THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Anto Gabrić

    2002-12-01

    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.

  6. Origin of zoning within dedolomite and calcitized gypsum of the Mississippian Arroyo Penasco Group

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, D.S.

    1985-01-01

    The Mississippian Arroyo Penasco Group carbonates are the oldest Paleozoic rocks present in north-central New Mexico. These supratidal to shallow,subtidal sediments exhibit complex diagenetic fabrics produced by periods of pre-Pennsylvanian subaerial exposure. Both extensive recrystallization of the Espiritu Santo carbonates and brecciation of the overlying Macho Member of the Tererro Formation resulted from an extended period of Mississippian subaerial exposure of broad, low-relief tidal flats. Cathodoluminescent petrography indicates that the recrystallized limestones consist of calcite pseudomorphs of dolomite and gypsum. Dedolomite and calcitized gypsum crystals, with /sup 13/C//sup 12/C ratios of -2 to +1.5% PDB, range from highly zoned to uniformly luminescent. Electron microprobe analyses reveals variable Mn and Fe contents across the pseudomorphs which are responsible for differences in observed luminosity. These features are interpreted to reflect a period of subaerial exposure after deposition of Macho Member sediments, which caused dissolution of gypsum and dolomite by sulfate and Mg depleted meteoric fluids and produced the collapse breccia. Preservation of zoning within some pseudomorphs required simultaneous dissolution of gypsum and dolomite and precipitation of calcite. C-isotope data indicates a meteoric to mixed phreatic origin for pore fluids which precipitated calcite; repetitive zoning within dolomite and gypsum pseudomorphs is indicative of interactions between marine and meteoric phreatic fluids in the intertidal environment.

  7. Gypsum karst in Italy: a review

    Science.gov (United States)

    De Waele, Jo; Chiarini, Veronica; Columbu, Andrea; D'Angeli, Ilenia M.; Madonia, Giuliana; Parise, Mario; Piccini, Leonardo; Vattano, Marco; Vigna, Bartolomeo; Zini, Luca; Forti, Paolo

    2016-04-01

    Although outcropping only rarely in Italy, gypsum karst has been described in detail since the early XXth century (Marinelli, 1917). Gypsum caves are now known from almost all Italian regions (Madonia & Forti, 2003), but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche regions), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum quarries in Piedmont (Vigna et al., 2010). During the late 80s and 90s several multidisciplinary studies have been carried out in many gypsum areas. All this work converged into a comprehensive overview in 2003 (Madonia & Forti, 2003). Further detailed studies focused on the gypsum areas of Emilia Romagna (Chiesi et al., 2010; Forti & Lucci, 2010; Demaria et al., 2012; De Waele & Pasini, 2013; Ercolani et al., 2013; Columbu et al., 2015; Lucci & Piastra, 2015; Tedeschi et al., 2015) and of Sicily (Madonia & Vattano, 2011). Sinkholes related to Permo-Triassic gypsum have been studied in Friuli Venezia Giulia (Zini et al., 2015). This presentation will review the state of the art regarding different aspects of evaporite karst in Italy focusing on the main new results. References Chiesi M., et al. (2010) - Origin and evolution of a salty gypsum/anhydrite karst spring: the case of Poiano (Northern Apennines, Italy). Hydrogeology Journal, 18, pp. 1111-1124. Columbu A. et al. (2015) - Gypsum caves as indicators of climate-driven river incision and aggradation in a rapidly uplifting region. Geology, 43(6), 539-542. Demaria D. et al. (Eds.) (2012), Le Grotte Bolognesi, GSB-USB, 431 p. De Waele J., Pasini G. (2013) - Intra-messinian gypsum palaeokarst in the northern Apennines and its palaeogeographic implications. Terra Nova 25, pp. 199-205. Ercolani M., et al. (Eds.) (2013), I Gessi e la Cave i Monte Tondo. Studio multidisciplinare di un'area carsica nella Vena del Gesso Romagnola. Memorie Ist. It. Spel. II(26), 559 p

  8. Flue gas desulfurization gypsum agricultural network alabama (cotton)

    Science.gov (United States)

    Flue gas desulfurization gypsum (FGDG) is an excellent source of gypsum (CaSO4•2H2O) that can be beneficially used in agriculture. Research was conducted as part of the Flue Gas Desulfurization Gypsum Agricultural Network program sponsored by the Electric Power Research Institute in collaboration wi...

  9. Deformation processes in polycrystalline aggregates of gypsum

    NARCIS (Netherlands)

    de Meer, S.

    1995-01-01

    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 densi

  10. Dissolution of Gypsum from field observations

    OpenAIRE

    Klimchouk A.; Cucchi F.; Calaforra J.M.; Aksem S.; Finocchiaro F.; Forti P.

    1996-01-01

    The paper reports the results of field measurements of gypsum dissolution in various countries (Ukraine, Spain, Italy and others) and in different environments (river waters, precipitation, vadose zone, unconfined aquifer, perched cave lakes, ephemeral streams in caves, confined aquifer, cave air).

  11. Formation mechanism of authigenic gypsum in marine methane hydrate settings: Evidence from the northern South China Sea

    Science.gov (United States)

    Lin, Qi; Wang, Jiasheng; Algeo, Thomas J.; Su, Pibo; Hu, Gaowei

    2016-09-01

    During the last decade, gypsum has been discovered widely in marine methane hydrate-bearing sediments. However, whether this gypsum is an in-situ authigenic precipitate remains controversial. The GMGS2 expedition carried out in 2013 by the Guangzhou Marine Geological Survey (GMGS) in the northern South China Sea provided an excellent opportunity for investigating the formation of authigenic minerals and, in particular, the relationship between gypsum and methane hydrate. In this contribution, we analyzed the morphology and sulfur isotope composition of gypsum and authigenic pyrite as well as the carbon and oxygen isotopic compositions of authigenic carbonate in a drillcore from Site GMGS2-08. These methane-derived carbonates have characteristic carbon and oxygen isotopic compositions (δ13C: -57.9‰ to -27.3‰ VPDB; δ18O: +1.0‰ to +3.8‰ VPDB) related to upward seepage of methane following dissociation of underlying methane hydrates since the Late Pleistocene. Our data suggest that gypsum in the sulfate-methane transition zone (SMTZ) of this core precipitated as in-situ authigenic mineral. Based on its sulfur isotopic composition, the gypsum sulfur is a mixture of sulfate derived from seawater and from partial oxidation of authigenic pyrite. Porewater Ca2+ ions for authigenic gypsum were likely generated from carbonate dissolution through acidification produced by oxidation of authigenic pyrite and ion exclusion during methane hydrate formation. This study thus links the formation mechanism of authigenic gypsum with the oxidation of authigenic pyrite and evolution of underlying methane hydrates. These findings suggest that authigenic gypsum may be a useful proxy for recognition of SMTZs and methane hydrate zones in modern and ancient marine methane hydrate geo-systems.

  12. Tri-calcium phosphate (ß-TCP) can be artificially synthesized by recycling dihydrate gypsum hardened.

    Science.gov (United States)

    Han-Cheol, Cho; Hori, Masaharu; Yoshida, Takakazu; Yamada, Naoko; Komada, Yuko; Tamaki, Yukimichi; Miyazaki, Takashi

    2014-01-01

    Calcium phosphate is known as a major component of biological hard tissues. This study aimed to produce calcium phosphate by recycling kneaded surplus gypsum. β-dihydrate gypsum was derived from commercial dental β-hemihydrate gypsum, which was mechanically powdered and mixed with the liquid component of a commercial zinc phosphate cement. This mixture was fired at 1,200°C and evaluated by XRD analysis, thermal analysis and scanning electron microscopy (SEM). An acceptable ratio of mixing was 4 g of β-dihydrate gypsum powder to 1.5 mL of phosphoric acid liquid. XRD peaks were monotonic below 800°C, but new ß-TCP was formed by firing at 900°C or more, although TG-DTA analysis of synthetic ß-TCP suggested that some residual dihydrate gypsum remained in the sample. SEM images indicated a fused-block bone-like structure covered with phosphorus and calcium. These results suggest that production of synthetic β-TCP is possible through ecological techniques using recycled materials. PMID:25483384

  13. 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

    2011-01-01

    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...... 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 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...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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 r...

  15. Assessment of Mercury in Soils, Crops, Earthworms, and Water when Soil is Treated with Gypsum

    Science.gov (United States)

    Flue gas desulfurization (FGD) gypsum from fossil fuel combustion has many potential uses in agriculture, but there is concern about the potential environmental effects of its elevated mercury (Hg) concentration. The wet limestone scrubbing process that removes sulfur from flue gas (and produces gyp...

  16. Field studies on the use of flue gas desulfurization (FGD) gypsum in agriculture

    Science.gov (United States)

    Flue gas desulfurization gypsum (FGDG) is a product of precipitation of sulfur from stack gases from coal-fired electric power plants. This material is produced in increasingly large quantities by electric power companies to meet clean air standards. We have evaluated this material for beneficial us...

  17. Ancient gypsum mortars from Cyprus: characterization and reinvention

    Science.gov (United States)

    Theodoridou, M.; Ioannou, I.

    2012-04-01

    confirms the phenomena of crystallisation and recrystallisation closed to the exposed surfaces due to long-term weathering. As anticipated, the results of this study have proven useful in reinventing gypsum-based materials based on the production technology of the past and the use of local raw materials. It is worth noting that gypsum is a widely available mineral in Cyprus due to the extensive evaporite deposits on the island. In the mortars designed and produced in the laboratory, ratios of binder to aggregates were based on the results of the analysed ancient samples. Gypsum and lime based materials were used in different proportions both as binder and aggregates. The new mixtures were tested in fresh and dry conditions at 7, 28, 56 and 90 days after their production. The results indicated higher mechanical strengths (7.6-9.6 MPa) when only gypsum based materials were used both as binder and aggregates. Porosity and average pore diameter tended to increase as the percentage of calcite increased in the mixtures. The variability of the results enhances the possibility of selecting the appropriate repair mortar depending on the nature of the material which may demand a conservation treatment.

  18. THERMAL CONDUCTIVITY OF RUBBERIZED GYPSUM BOARD

    OpenAIRE

    Taher Abu-Lebdeh; Ellie Fini; Ashraf Fadiel

    2014-01-01

    The disposal of scrap tires is a challenging task and hence an innovative solution to meet these challenges is needed. Extensive work has been done on the utilization of waste tires in a variety of applications in asphalt pavements and concrete. However, previous investigations focus only on the mechanical properties of the rubberized materials, but few on the thermal performance. This is especially true for rubberized gypsum. Limited or no experimental data on the thermal performance of rubb...

  19. Tunisian gypsums: Characteristics and use in cement

    Science.gov (United States)

    Mahmoudi, Salah; Bennour, Ali; Chalwati, Youssef; Souidi, Khouloud; Thabet, Manel; Srasra, Ezzedine; Zargouni, Fouad

    2016-09-01

    Gypsum materials of hundred meters thickness and interbedded with marine claystones and limestones from different paleogeographic sectors in the Tunisian territory are studied to assess their suitability for cement production. For this reason, thirty representative samples are analysed by chemical, physical and geotechnical tests. The obtained results for the studied gypsum materials are compared to Tunisian and European norms and with the local cements, currently marketed and which obey international norms. Indeed, for all samples hydraulic modulus HM, silica modulus SM and alumina modulus AM vary from (2.37-2.44), (2.48-2.68) and (1.45-2.5), respectively; whereas the required values for these modulus are (1.5-2.5), (2-3) and (1.5-2.5). The same behavior is observed for mineralogical analyses of C3S, C2S, C3A and C4AF and compressive strength at different ages. Briefly, Tunisia contains important reserves of gypsum scattered and spread over the Tunisian territory and can be used for cement production.

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

    Directory of Open Access Journals (Sweden)

    Garcia Santos, A.

    2004-03-01

    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.

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

    International Nuclear Information System (INIS)

    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 (FeSO4, ZnSO4, MnSO4, MgSO4). 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 109 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. CL50 for medium 3 was 8.4 x 106 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)

  2. 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: valicent@cnpms.embrapa.br; Mourao, Andre H.C. [Curso de Meio Ambiente, Sete Lagoas, MG (Brazil)

    2008-11-15

    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)

  3. DEVELOPMENT OF HYDRAULIC GYPSUM THAT CONTAINS CEMENTS THAT HAVE SULPHATED CLINKER PHASES

    Directory of Open Access Journals (Sweden)

    Mikheenkov Mikhail Arkad'evich

    2012-10-01

    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 %.

  4. Gypsum scaling and cleaning in forward osmosis: measurements and mechanisms.

    Science.gov (United States)

    Mi, Baoxia; Elimelech, Menachem

    2010-03-15

    This study investigates gypsum scaling and cleaning behavior in forward osmosis (FO). The results show that gypsum scaling in FO is almost fully reversible, with more than 96% recovery of permeate water flux following a water rinse without addition of chemical cleaning reagents. Parallel comparisons of fouling and cleaning were made between FO (without hydraulic pressure) and RO (under high hydraulic pressure) modes. The shape of the water flux decline curves during gypsum scaling is similar in the two modes, but the flux recovery in FO mode is higher than that in RO mode by about 10%. This behavior suggests that operating in FO mode may reduce the need for chemical cleaning. The role of membrane materials in controlling gypsum scaling and cleaning was investigated using cellulose acetate (CA) and polyamide (PA) membranes. Gypsum scaling of PA membranes causes more severe flux decline and is harder to clean than that of CA membranes. AFM force measurements were performed between a gypsum particle probe and the membrane surfaces to elucidate gypsum scaling mechanisms. Analysis of adhesion force data indicates that gypsum scaling of the PA membrane is dominated by heterogeneous/surface crystallization, while gypsum scaling of the CA membrane is dominated by bulk crystallization and subsequent particle deposition.This finding implies that membrane surface modification and new material development can be an effective strategy to mitigate membrane scaling. PMID:20151636

  5. Separation of Mercury from Flue Gas Desulfurization Scrubber Produced Gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Hensman, Carl, E., P.h.D; Baker, Trevor

    2008-06-16

    Frontier Geosciences (Frontier; FGS) proposed for DOE Grant No. DE-FG02-07ER84669 that mercury control could be achieved in a wet scrubber by the addition of an amendment to the wet-FGD scrubber. To demonstrate this, a bench-scale scrubber and synthetic flue-gas supply was designed to simulate the limestone fed, wet-desulfurization units utilized by coal-fired power plants. Frontier maintains that the mercury released from these utilities can be controlled and reduced by modifying the existing equipment at installations where wet flue-gas desulfurization (FGD) systems are employed. A key element of the proposal was FGS-PWN, a liquid-based mercury chelating agent, which can be employed as the amendment for removal of all mercury species which enter the wet-FGD scrubber. However, the equipment design presented in the proposal was inadequate to demonstrate these functions and no significant progress was made to substantiate these claims. As a result, funding for a Phase II continuation of this work will not be pursued. The key to implementing the technology as described in the proposal and report appears to be a high liquid-to-gas ratio (L/G) between the flue-gas and the scrubber liquor, a requirement not currently implemented in existing wet-FGD designs. It may be that this constraint can be reduced through parametric studies, but that was not apparent in this work. Unfortunately, the bench-scale system constructed for this project did not function as intended and the funds and time requested were exhausted before the separation studies could occur.

  6. 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.

    1997-03-01

    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.

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

    International Nuclear Information System (INIS)

    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 (CaSO4), calcium sulfite (CaSO3), calcium carbonate (CaCO3), calcium hydroxide [Ca(OH)2], and fly ash. Some scrubbing processes produce almost pure gypsum (CaSO42H2O). 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

  8. The Thermal Damage Properties of Mudstone, Gypsum and Rock Salt from Yingcheng, Hubei, China

    Directory of Open Access Journals (Sweden)

    Jie Chen

    2015-03-01

    Full Text Available The impacts of temperature on the surface thermal damage of rock salt, gypsum and mudstone from the Yingcheng salt mine, China were investigated by the surface crack growth and propagation tests at different temperatures. We found that: (a high temperature could strengthen the rock salt molecular thermal motion and weaken the cohesion among the rock salt grains, so that the grain boundaries were more prone to slip and thus develop into cracks; (b high temperature could make the water molecules evaporate from rock specimens, which should change the physical properties of gypsum and mudstone; and (c high temperature had a significant effect on the interface between rock salt and gypsum and mudstone, therefore it should be easy to produce cracks with white or light yellow cumulate powder here. The surface crack growth and propagation of the rock salt, gypsum and mudstone have a positive correlation with the temperature by stereo microscope and the method of binary images, which could observe the surface thermal damage properties. Finally, the fractal dimension of the rock salt surface cracks was calculated based on fractal theory, and the evolution of the surface thermal damage was found from 50 to 260 °C.

  9. Health survey in gypsum mines in India

    Directory of Open Access Journals (Sweden)

    Nandi Subroto

    2009-01-01

    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.

  10. Properties study of cotton stalk fiber/gypsum composite

    International Nuclear Information System (INIS)

    This manuscript addresses treating cotton stalk fiber surface with styrene acrylic emulsion, which improves the interfacial combined state of cotton stalk fiber/gypsum composite effectively and improves its mechanical properties notably. Mixes less slag, ordinary Portland cement, etc., to modify gypsum base. The electron microscope was utilized to analyze and research on the effect on composite properties of the abovementioned mixtures

  11. Gypsum-based management practises to prevent phosphorus transportation

    OpenAIRE

    Pietola, Liisa

    2008-01-01

    Significant agricultural P load decrease on waters is observed. Practical methods to achieve the load decrease is developed; provide solutions for farmers, are included into the Finnish agri-environmental support scheme. Practical methods includes: gypsum as soil amendment for erosion and soluble P control, gypsum-based precipitate in manure treatment to fractionate P.

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

    OpenAIRE

    Tesárek, P.; J. Drchalová; J. Kolísko; P. Rovnaníková; R. Černý

    2004-01-01

    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. 

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

    Directory of Open Access Journals (Sweden)

    P. Tesárek

    2004-01-01

    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. 

  14. The production and utilization of by-product agricultural fertilizer from flue gases

    International Nuclear Information System (INIS)

    The electron-beam process is one of the most effective methods for removing SO2 and NOX from industrial flue gases and producing a usable by-product. This paper surveys the potential for production and consumption of alternative, usable, commercial by-products, in conjunction with major reductions in the inventory of emissions of SO2 and NOX. An examination is made of the important limitations in the annual consumptive use or price of and/or net revenues from commonplace, electric utility, by-product types such as gypsum, sulfuric acid, etc. A principal focus of the work is an analysis and quantification of the major large-scale, growing and profitable markets for utility solid wastes that can be generated in agricultural fertilizer forms, including ammonium sulfate and other compounds that are available through stack-gas cleaning operations at large, coal-fired boilers. Cost study data is arranged to define the impact of commercial by-product yield and revenue on the economics of full scale SO2 and NOX emission reduction activity. (author)

  15. 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.

    2007-05-01

    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.

  16. Corrosion of bare and galvanized steel in gypsum

    Directory of Open Access Journals (Sweden)

    Gómez, Mercedes

    1988-12-01

    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

  17. Carbonate speleothems from western Mediterranean gypsum karst: palaeoclimate implications

    Science.gov (United States)

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

    2016-04-01

    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

  18. Influence of three types of superplasticizers on tricalciumaluminate hydration in presence of gypsum.

    OpenAIRE

    Pourchet, Sylvie; Comparet, Cedric; NONAT, A; Maitrasse, Philippe

    2006-01-01

    Different types of superplasticizers have been widely used over the past few decades in order to produce a more fluid or very high strength and durable concrete. These chemical admixtures interfere with the various physico-chemical processes occurring in early cement paste. In this paper we present results from a study on the influence of superplasticizers on pure tricalciumaluminate hydration in presence of gypsum. The suspensions hydration has been investigated by conductimetry, isothermal ...

  19. Impact of welan gum on tricalcium aluminate-gypsum hydration

    Energy Technology Data Exchange (ETDEWEB)

    Ma Lei, E-mail: malei198713@163.com; Zhao Qinglin, E-mail: zhaoqinglin@whut.edu.cn; Yao Chukang; Zhou Mingkai

    2012-02-15

    The retarding effect of welan gum on tricalcium aluminate-gypsum hydration, as a partial system of ordinary Portland cement (OPC) hydration, was investigated with several methods. The tricalcium aluminate-gypsum hydration behavior in the presence or absence of welan gum was researched by field emission gun scanning electron microscopy, X-ray diffraction and zeta potential analysis. Meanwhile, we studied the surface electrochemical properties and adsorption characteristics of welan gum by utilizing a zeta potential analyzer and UV-VIS absorption spectrophotometer. By adding welan gum, the morphology change of ettringite and retardation of hydration stages in tricalcium aluminate-gypsum system was observed. Moreover, we detected the adsorption behavior and zeta potential inversion of tricalcium aluminate and ettringite, as well as a rapid decrease in the zeta potential of tricalcium aluminate-gypsum system. The reduction on nucleation rate of ettringite and hydration activity of C{sub 3}A was also demonstrated. Thus, through the adsorption effect, welan gum induces a retarding behavior in tricalcium aluminate-gypsum hydration. Highlights: Black-Right-Pointing-Pointer Adsorption characteristics of welan gum on C{sub 3}A and ettringite have been studied. Black-Right-Pointing-Pointer C{sub 3}A-gypsum hydration behavior and the hydration products are examined in L/S = 3. Black-Right-Pointing-Pointer Welan gum retards the process of C{sub 3}A-gypsum hydration. Black-Right-Pointing-Pointer The addition of welan gum changes the nucleation growth of ettringite.

  20. Impact of welan gum on tricalcium aluminate–gypsum hydration

    International Nuclear Information System (INIS)

    The retarding effect of welan gum on tricalcium aluminate–gypsum hydration, as a partial system of ordinary Portland cement (OPC) hydration, was investigated with several methods. The tricalcium aluminate–gypsum hydration behavior in the presence or absence of welan gum was researched by field emission gun scanning electron microscopy, X-ray diffraction and zeta potential analysis. Meanwhile, we studied the surface electrochemical properties and adsorption characteristics of welan gum by utilizing a zeta potential analyzer and UV–VIS absorption spectrophotometer. By adding welan gum, the morphology change of ettringite and retardation of hydration stages in tricalcium aluminate–gypsum system was observed. Moreover, we detected the adsorption behavior and zeta potential inversion of tricalcium aluminate and ettringite, as well as a rapid decrease in the zeta potential of tricalcium aluminate–gypsum system. The reduction on nucleation rate of ettringite and hydration activity of C3A was also demonstrated. Thus, through the adsorption effect, welan gum induces a retarding behavior in tricalcium aluminate–gypsum hydration. Highlights: ► Adsorption characteristics of welan gum on C3A and ettringite have been studied. ► C3A–gypsum hydration behavior and the hydration products are examined in L/S = 3. ► Welan gum retards the process of C3A–gypsum hydration. ► The addition of welan gum changes the nucleation growth of ettringite.

  1. Gypsum-karst problems in constructing dams in the USA

    Science.gov (United States)

    Johnson, Kenneth S.

    2008-01-01

    Gypsum is a highly soluble rock and is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are also present in limestones and dolomites. Gypsum karst is widespread in the USA and has caused problems at several sites where dams were built, or where dam construction was considered. Gypsum karst is present (at least locally) in most areas where gypsum crops out, or is less than 30-60 m below the land surface. These karst features can compromise on the ability of a dam to hold water in a reservoir, and can even cause collapse of a dam. Gypsum karst in the abutments or foundation of a dam can allow water to pass through, around, or under a dam, and solution channels can enlarge quickly, once water starts flowing through such a karst system. The common procedure for controlling gypsum karst beneath the dam is a deep cut-off trench, backfilled with impermeable material, or a close-spaced grout curtain that hopefully will fill all cavities. In Oklahoma, the proposed Upper Mangum Dam was abandoned before construction, because of extensive gypsum karst in the abutments and impoundment area. Catastrophic failure of the Quail Creek Dike in southwest Utah in 1989 was due to flow of water through an undetected karstified gypsum unit beneath the earth-fill embankment. The dike was rebuilt, at a cost of US 12 million, with construction of a cut-off trench 600 m long and 25 m deep. Other dams in the USA with severe gypsum-karst leakage problems in recent years are Horsetooth and Carter Lake Dams, in Colorado, and Anchor Dam, in Wyoming.

  2. Gypsum-karst problems in constructing dams in the USA

    Science.gov (United States)

    Johnson, K.S.

    2008-01-01

    Gypsum is a highly soluble rock and is dissolved readily to form caves, sinkholes, disappearing streams, and other karst features that typically are also present in limestones and dolomites. Gypsum karst is widespread in the USA and has caused problems at several sites where dams were built, or where dam construction was considered. Gypsum karst is present (at least locally) in most areas where gypsum crops out, or is less than 30-60 m below the land surface. These karst features can compromise on the ability of a dam to hold water in a reservoir, and can even cause collapse of a dam. Gypsum karst in the abutments or foundation of a dam can allow water to pass through, around, or under a dam, and solution channels can enlarge quickly, once water starts flowing through such a karst system. The common procedure for controlling gypsum karst beneath the dam is a deep cut-off trench, backfilled with impermeable material, or a close-spaced grout curtain that hopefully will fill all cavities. In Oklahoma, the proposed Upper Mangum Dam was abandoned before construction, because of extensive gypsum karst in the abutments and impoundment area. Catastrophic failure of the Quail Creek Dike in southwest Utah in 1989 was due to flow of water through an undetected karstified gypsum unit beneath the earth-fill embankment. The dike was rebuilt, at a cost of US $12 million, with construction of a cut-off trench 600 m long and 25 m deep. Other dams in the USA with severe gypsum-karst leakage problems in recent years are Horsetooth and Carter Lake Dams, in Colorado, and Anchor Dam, in Wyoming. ?? 2007 Springer-Verlag.

  3. Preparation of Thermal Insulation Plaster with FGD Gypsum

    OpenAIRE

    Yi-Chao Zhang; Shao-Bin Dai; Jun Huang; Sheng-Gang Duan; Zhen-Zhen Zhi

    2016-01-01

    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 effic...

  4. Effect of Industrial By-Products on Unconfined Compressive Strength of Solidified Organic Marine Clayey Soils

    Directory of Open Access Journals (Sweden)

    Chan-Gi Park

    2015-08-01

    Full Text Available The use of industrial by-products as admixture to ASTM Type I cement (ordinary Portland cement (OPC was investigated with the objective of improving the solidification of organic marine clayey soils. The industrial by-products considered in this paper were oyster-shell powder (OSP, steelmaking slag dust (SMS and fuel-gas-desulfurized (FGD gypsum. The industrial by-products were added to OPC at a ratio of 5% based on dry weight to produce a mixture used to solidify organic marine clayey soils. The dosage ratios of mixtures to organic marine clayey soils were 5, 10 and 15% on a dry weight basis. Unconfined compressive strength (UCS test after 28 days revealed that the highest strength was obtained with the OPC + SMS 15% mixing ratio. The UCS of specimens treated with this mixture was >500 kPa, compared with 300 kPa for specimens treated with a 15% OPC + OSP mixture and 200 kPa when 15% of OPC was used alone. These results were attributed to the more active hydration and pozzolanic reaction of the OPC + SMS mixture. This hypothesis was verified through X-ray diffraction (XRD and scanning electron microscopy (SEM analyses, and was confirmed by variations in the calcium carbonate (CaCO3 content of the materials during curing.

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

    Directory of Open Access Journals (Sweden)

    Sanna Laura

    2010-01-01

    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.

  6. Weathering crust and karren on exposed gypsum surfaces

    OpenAIRE

    Macaluso T.; Sauro U.

    1996-01-01

    The evolution of gypsum bare rock surfaces is the result both of volume changes of the outer rock layer and mass wasting by dissolutional processes. Some unusual weathering processes induce an increase in the volume of the outer gypsum layer, resulting in the development of a "weathering crust" and of characteristic forms such as small ridges and bubbles. However, the more typical erosional forms are dissolutional ones of karren type, which are commonly interconnected, or superimposed upon th...

  7. Effect of gypsum content on sulfoaluminate mortars stability

    OpenAIRE

    DESBOIS, Tiffany; Le Roy, Robert; PAVOINE, Alexandre; PLATRET, Gérard; FERAILLE-FRESNET, Adélaïde; ALAOUI, Amina

    2010-01-01

    Calcium sulfoaluminate clinker is one of the most promising cements that would lower the greenhouse gas effect accompanying cement production. This article examines the effect of gypsum content on the dimensional stability of sulfoaluminate mortars. Mechanical properties as chemical evolution are studied. Our results show that the mortar with the greatest gypsum content expands without a decrease of its mechanical properties when it is cured in water. Two hypotheses about the mortars hydratio...

  8. Effect of Gypsum Application on Enzymatic Browning Activity in Lettuce

    Directory of Open Access Journals (Sweden)

    Prasit Chutichudet

    2009-01-01

    Full Text Available 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.

  9. Experimental deformation tests on natural gypsum in simple shear

    Science.gov (United States)

    Barberini, V.; Burlini, L.; Rutter, E.; Dapiaggi, M.

    2003-04-01

    Gypsum, together with anhydrite and halite, is the main mineral forming evaporitic rocks. These rocks, interlayered within sedimentary sequences, play an important role in structural development in several ways on accounts of their particular physical properties. Evaporites are more plastic and less permeable compared to sandstones, limestones and shales. Moreover, gypsum starts to dehydrate at less than 100 °C. High plasticity at relatively low temperature, together with the possible presence of pressurised water, imply that, when sedimentary sequences are involved in thrust tectonics, deformation is often localised in evaporitic levels (Apennines, South Alpine region, Zagros, Gulf of Mexico, etc.); in some cases the deformation is accompanied by seismicity as in the Northern Apennines extensional systems. Low permeability of evaporitic rocks allow them to be a good sealing rock for oil reservoirs and a very efficient rock to localise waste disposal. In this framework, a set of experiments was performed on gypsum samples from Volterra (Tuscany, Italy) in order to investigate how gypsum behaves at increasing stress/strain conditions. Experimental deformation tests were performed at confining pressures up to 300 MPa, at different temperatures (20, 70, 90 and 130 °C) and at strain rates ranging between 1*10-4 and 5*10-6 s-1. In order to reach high shear strain values (up to gamma = 4), we used: 1) gypsum cores deformed using the newly developed torsion technique in a Paterson-type apparatus and 2) both gypsum slices and powder in sawcut assembly at 35°, deformed in a Heard-type triaxial apparatus. All the deformed samples have been studied both by optical microscopy, to investigate the evolution of the microstructure with strain, and by XRD analysis, to determine if and to what extent gypsum dehydrated during deformation. A peak in the shear stress value (60-120 MPa) was reached at shear strains between gamma = 0.2 and gamma = 1, followed by strain softening or

  10. Effect of gypsum content on soil water retention

    Science.gov (United States)

    Moret-Fernández, D.; Herrero, J.

    2015-09-01

    Many gypsiferous soils occur in arid lands, where the water retention capacity of the soil is vital to plant life and crop production. This study investigated the effect of gypsum content on the gravimetric soil water retention curve (WRC). We analyzed calcium carbonate equivalent (CCE), equivalent gypsum content (EG), soil organic carbon content (SOC), and electrical conductivity of 43 samples collected from various horizons in soils in the Ebro Valley, NE Spain. The WRC of the fine earth was determined using the pressure-plate method (pressure heads = 0, -33, -100, -200, -500, and -1500 kPa), and the gravimetric water retention curves were fitted to the unimodal van Genuchten function. Soil gypsum content had a significant effect on water retention. Soils that had high gypsum content made WRC with higher water retention at near saturation conditions, and steeper WRC slopes. The EG threshold at which gypsum content had an effect on WRC was about 40%, and EG was positively and negatively correlated with the α and n parameters of the WRC, respectively.

  11. 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

    2009-07-01

    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)

  12. 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)

    2000-11-30

    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.

  13. Arctic Gypsum Endoliths: a biogeochemical characterization of a viable and active microbial community

    Directory of Open Access Journals (Sweden)

    L. A. Ziolkowski

    2013-02-01

    Full Text Available Extreme environmental conditions such as those found in the polar regions on Earth are thought to test the limits of life. Microorganisms living in these environments often seek protection from environmental stresses such as high UV exposure, desiccation and rapid temperature fluctuations, with one protective habitat found within rocks. Such endolithic microbial communities, which often consist of bacteria, fungi, algae and lichens, are small-scale ecosystems comprised of both producers and consumers. However, the harsh environmental conditions experienced by polar endolithic communities are thought to limit microbial diversity and the rate at which they cycle carbon. In this study, we characterized the microbial community diversity, turnover, and microbe-mineral interactions of a gypsum-based endolithic community in the polar desert of the Canadian high Arctic. 16S/18S rRNA pyrotag sequencing demonstrated the presence of a diverse community of phototrophic and heterotrophic bacteria, algae and fungi. Stable carbon isotope analysis of the viable microbial membranes, as phospholipid fatty acids and glycolipid fatty acids, confirmed the diversity observed by molecular techniques and indicated that atmospheric carbon is assimilated into the microbial community biomass. Uptake of radiocarbon from atmospheric radioweapons testing during the 1960s into microbial lipids was used as a pulse label to determine that the microbial community turns over carbon on the order of 10 yr, equivalent to 4.4 g C m−2 yr−1 gross primary productivity. SEM micrographs indicated that mechanical weathering of gypsum by freeze-thaw cycles leads to increased porosity, which ultimately increases the habitability of the rock. In addition, while bacteria were adhered to these mineral surfaces there was little evidence for microbial alteration of minerals, which contrasts with other gypsum endolithic habitats. While it is possible that these

  14. Calcium isotopic fractionation in microbially mediated gypsum precipitates

    Science.gov (United States)

    Harouaka, Khadouja; Mansor, Muammar; Macalady, Jennifer L.; Fantle, Matthew S.

    2016-07-01

    Gypsum (CaSO4·2H2O) precipitation experiments were carried out at low pH in the presence of the sulfur oxidizing bacterium Acidithiobacillus thiooxidans. The observed Ca isotopic fractionation (expressed as Δ44/40Cas-f = δ44/40Casolid-δ44/40Cafluid) at the end of each experimental time period (∼50 to 60 days) was -1.41‰ to -1.09‰ in the biotic experiments, -1.09‰ in the killed control, and -1.01‰ to -0.88‰ in the abiotic controls. As there were no strong differences in the solution chemistry and the rate at which gypsum precipitated in the biotic and abiotic controls, we deduce a biological Ca isotope effect on the order of -0.3‰. The isotope effect correlates with a difference in crystal aspect ratios between the biotic experiments (8.05 ± 3.99) and abiotic controls (31.9 ± 8.40). We hypothesize that soluble and/or insoluble organic compounds selectively inhibit crystal growth at specific crystal faces, and that the growth inhibition affects the fractionation factor associated with gypsum precipitation. The experimental results help explain Ca isotopic variability in gypsum sampled from a sulfidic cave system, in which gypsum crystals exhibiting a diversity of morphologies (microcrystalline to cm-scale needles) have a broad range of δ44/40Ca values (∼1.2-0.4‰) relative to the limestone wall (δ44/40Ca = 1.3‰). In light of the laboratory experiments, the variation in Ca isotope values in the caves can be interpreted as a consequence of gypsum precipitation in the presence of microbial organic matter and subsequent isotopic re-equilibration with the Ca source.

  15. Mechanical strength and thermal conductivity of low-porosity gypsum plates

    Directory of Open Access Journals (Sweden)

    Conceição de Maria Pinheiro Correia

    2009-03-01

    Full Text Available The thermal conductivity and mechanical strength of gypsum and gypsum-cellulose plates made from commercial plaster by a new process have been measured. The gypsum parts made by the new process, 'novogesso', have high mechanical strength and low porosity. The gypsum strength derives from both the high aspect ratio of the gypsum crystals and the strong adhesion among them by nano-flat layers of confined water, which behaves as supercooled water. Another contribution to the strength comes from the nano-flatness of the lateral surfaces of the gypsum single crystals. The bending and compression strengths, σB and σc, of gypsum plates prepared by this new technique can be as high as 30 and 100 MPa, respectively. The way gypsum plates have been assembled as well as their low thermal conductivity allowed for the construction of a low-cost experimental house with thermal and acoustic comfort.

  16. Determination of Gypsum Content in Dryland Soils Exploiting the Gypsum–Bassanite Phase Change

    OpenAIRE

    Lebrón Hernando, Inmaculada; Herrero Isern, Juan; Robinson, D A

    2009-01-01

    The presence of gypsum in soil, even in small amounts, is relevant from the genetic, taxonomic, and applied points of view. Moreover, those soils having gypsum as the main component, for example gypseous soils, host a number of rare and endangered organisms. Determining gypsum content in soils is crucial to understanding their behavior; however, current methods of determination are cumbersome or imprecise. This study was conducted to develop an accurate new method to determine soil gypsum con...

  17. Microstructure and mechanical properties of gypsum composites reinforced with recycled cellulose pulp

    OpenAIRE

    Magaly Araújo Carvalho; Carlito Calil Júnior; Holmer Savastano Junior; Rejane Tubino; Michele Tereza Carvalho

    2008-01-01

    The use of waste fibers for the reinforcement of brittle matrices is considered opportune for the sustainable management of urban solid residues. This paper examines the microstructure and mechanical properties of a composite material made of gypsum reinforced with cellulose fibers from discarded Kraft cement bag. Two different kinds of gypsum were used, natural gypsum (NG) and recycled gypsum (RG), both with an addition of 10% by mass of limestone. For the production of samples, slurry vacuu...

  18. The crystallization water of gypsum rocks is a relevant water source for plants

    OpenAIRE

    Palacio, Sara; J. Azorín; Montserrat-Martí, Gabriel; J. P. Ferrio

    2014-01-01

    Some minerals, like gypsum, hold water in their crystalline structure. Although still unexplored, the use of such crystallization water by organisms would point to a completely new water source for life, critical under dry conditions. Here we use the fact that the isotopic composition of free water differs from gypsum crystallization water to show that plants can use crystallization water from the gypsum structure. The composition of the xylem sap of gypsum plants during summer shows closer v...

  19. Physicochemical Properties and Cellular Responses of Strontium-Doped Gypsum Biomaterials

    Directory of Open Access Journals (Sweden)

    Amir Pouria

    2012-01-01

    Full Text Available This paper describes some physical, structural, and biological properties of gypsum bioceramics doped with various amounts of strontium ions (0.19–2.23 wt% and compares these properties with those of a pure gypsum as control. Strontium-doped gypsum (gypsum:Sr was obtained by mixing calcium sulfate hemihydrate powder and solutions of strontium nitrate followed by washing the specimens with distilled water to remove residual salts. Gypsum was the only phase found in the composition of both pure and gypsum:Sr, meanwhile a shift into lower diffraction angles was observed in the X-ray diffraction patterns of doped specimens. Microstructure of all gypsum specimens consisted of many rod-like small crystals entangled to each other with more elongation and higher thickness in the case of gypsum:Sr. The Sr-doped sample exhibited higher compressive strength and lower solubility than pure gypsum. A continuous release of strontium ions was observed from the gypsum:Sr during soaking it in simulated body fluid for 14 days. Compared to pure gypsum, the osteoblasts cultured on strontium-doped samples showed better proliferation rate and higher alkaline phosphatase activity, depending on Sr concentration. These observations can predict better in vivo behavior of strontium-doped gypsum compared to pure one.

  20. Examination of the system fly ash lime calcined gypsum water

    Science.gov (United States)

    Marinkovic, S.; Kostic-Pulek, A.

    2007-05-01

    The feasibility of the utilization of the system fly ash lime calcined gypsum (β-hemihydrate) water (the mass ratio 2:1:2:2.5) for the production of building ceramics was investigated. The system was cured under different conditions, i.e., tap water and ambient air. It was confirmed by X-ray diffraction analysis that three hydration products (gypsum, portlandite and ettringite) were formed in the water-cured system and two (gypsum and portlandite) in the air-cured system. Due to the formation of these products, a compressive strength of 4.01 MPa in the water-cured and 7.83 MPa in air-cured system developed. When the air-cured system was exposed to three alternate heating cooling or three alternate cooling heating cycles, the compressive strength increased (from 7.83 to 9.47 and 10.55 MPa, respectively). The fly ash lime calcined gypsum water systems prepared in this work can be applied for the manufacture of products for internal walls (bricks and blocks).

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

    OpenAIRE

    Andrew S. Blasetti; David W. Dinehart

    2012-01-01

    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 c...

  2. Physicochemical Properties and Cellular Responses of Strontium-Doped Gypsum Biomaterials

    OpenAIRE

    Amir Pouria; Hadis Bandegani; Milad Pourbaghi-Masouleh; Saeed Hesaraki; Masoud Alizadeh

    2012-01-01

    This paper describes some physical, structural, and biological properties of gypsum bioceramics doped with various amounts of strontium ions (0.19–2.23 wt%) and compares these properties with those of a pure gypsum as control. Strontium-doped gypsum (gypsum:Sr) was obtained by mixing calcium sulfate hemihydrate powder and solutions of strontium nitrate followed by washing the specimens with distilled water to remove residual salts. Gypsum was the only phase found in the composition of both pu...

  3. 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.

    Science.gov (United States)

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

    2012-01-01

    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

  4. Glomalin Production and Microbial Activity in Soils Impacted by Gypsum Mining in a Brazilian Semiarid Area

    Directory of Open Access Journals (Sweden)

    Adalia C.E.S. Mergulhao

    2010-01-01

    Full Text Available Problem statement: Mining activities involve the removal of the vegetal cover and the soil organic layer, causing a severe environmental impact. In Northeast Brazil, 40% of the worlds crude gypsum is found in a semiarid area, making this region responsible for 95% of the gypsum demand in the national market. Although economically important, this activity is harmful to the environment. Studies of soil microbiological and biochemical attributes can help in the identification of the limitations of impacted ecosystems, providing data to define strategies for sustainability of such environments. Approach: To evaluate and compare the biological state of preserved and mining degraded semiarid soils, a native preserved area and areas impacted by gypsum mining were selected at the Araripina Experimental Station, located in the semiarid region of Pernambuco State, Northeast Brazil. The four sampling areas included: (1 A native, preserved �caatinga� area with spine bearing trees and shrubs and some characteristic xerophytic plants (AN; (2 An area surrounding the mine, presenting the same type of vegetation although already degraded (AM; (3 A waste deposit area (AR; (4 Interface area between the waste deposit and a mining degraded area (AI. Samples were taken in each area (1000 m2 during two periods: wet (December/2003, Rainfall = 28.7 mm and dry (September/2004, Rainfall = 1.3 mm. Results: Fluorescein diacetate hydrolysis values, microbial biomass C and basal respiration were higher in the preserved caatinga than in the impacted areas. The gypsum mining activity reduced the concentration of easily extractable glomalin in relation to the native caatinga area in both sampling periods. Higher deposits of total glomalin also occurred in the native area, however, mainly during the wet period. Conclusion: The mining activity produced a negative impact on the soil microbiota, reducing the total enzymatic activity. The microbial

  5. Arctic gypsum endoliths: a biogeochemical characterization of a viable and active microbial community

    Science.gov (United States)

    Ziolkowski, L. A.; Mykytczuk, N. C. S.; Omelon, C. R.; Johnson, H.; Whyte, L. G.; Slater, G. F.

    2013-11-01

    Extreme environmental conditions such as those found in the polar regions on Earth are thought to test the limits of life. Microorganisms living in these environments often seek protection from environmental stresses such as high UV exposure, desiccation and rapid temperature fluctuations, with one protective habitat found within rocks. Such endolithic microbial communities, which often consist of bacteria, fungi, algae and lichens, are small-scale ecosystems comprised of both producers and consumers. However, the harsh environmental conditions experienced by polar endolithic communities are thought to limit microbial diversity and therefore the rate at which they cycle carbon. In this study, we characterized the microbial community diversity, turnover rate and microbe-mineral interactions of a gypsum-based endolithic community in the polar desert of the Canadian high Arctic. 16S/18S/23S rRNA pyrotag sequencing demonstrated the presence of a diverse community of phototrophic and heterotrophic bacteria, archaea, algae and fungi. Stable carbon isotope analysis of the viable microbial membranes, as phospholipid fatty acids and glycolipid fatty acids, confirmed the diversity observed by molecular techniques and indicated that present-day atmospheric carbon is assimilated into the microbial community biomass. Uptake of radiocarbon from atmospheric nuclear weapons testing during the 1960s into microbial lipids was used as a pulse label to determine that the microbial community turns over carbon on the order of 10 yr, equivalent to 4.4 g C m-2 yr-1 gross primary productivity. Scanning electron microscopy (SEM) micrographs indicated that mechanical weathering of gypsum by freeze-thaw cycles leads to increased porosity, which ultimately increases the habitability of the rock. In addition, while bacteria were adhered to these mineral surfaces, chemical analysis by micro-X-ray fluorescence (μ-XRF) spectroscopy suggests little evidence for microbial alteration of minerals

  6. 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: andrea.ferraz@univasf.edu.br [Universidade Federal do Vale do Sao Francisco (UNIVASF), Juazeiro, BA (Brazil)

    2014-08-15

    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)

  7. Lime and gypsum application on the wheat crop

    Directory of Open Access Journals (Sweden)

    Caires Eduardo Fávero

    2002-01-01

    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.

  8. Bacterial Life and Dinitrogen Fixation at a Gypsum Rock

    OpenAIRE

    Boison, Gudrun; Mergel, Alexander; Jolkver, Helena; Bothe, Hermann

    2004-01-01

    The organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. The cyanobacterial consortium consisted almost exclusively of Chroococcidiopsis spp. The organisms of the shards expressed nitrogenase activity (C2H2 reduction) aerobically and in light. After a prolonged period of drought at the rock, the cells were inactive, but they resumed nitrogenase activity 2 to 3 days after the addition of water. In a suspension culture of Chroococcidi...

  9. 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.

    2016-08-01

    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)

  10. Preparation of Thermal Insulation Plaster with FGD Gypsum

    Directory of Open Access Journals (Sweden)

    Yi-Chao Zhang

    2016-05-01

    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.

  11. 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

    2012-06-01

    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.

  12. Synthesis of Fluorite (CaF2 Crystal from Gypsum Waste of Phosphoric Acid Factory in Silica Gel

    Directory of Open Access Journals (Sweden)

    Mohammad Misbah Khunur

    2012-06-01

    Full Text Available This paper report the synthesis and characterization of fluorite single crystal prepared from gypsum waste of phosphoric acid production in silica gel. Instead of its high calcium, gypsum was used to recycle the waste which was massively produces in the phosphoric acid production. The gypsum waste, the raw material of CaCl2 supernatant, was dissolved in concentrated HCl and then precipitated as calcium oxalate (CaC2O4 by addition of ammonium oxalate. The CaCl2 was obtained by dissolving the CaC2O4 with HCl 3M. The crystals were grown at room temperature in silica gel and characterized by AAS, FTIR and powder XRD. The optimum crystal growth condition, which is pH of gel, CaCl2 concentration and growth time, were investigated. The result shows that at optimum condition of pH 5.80, CaCl2 concentrations of 1.2 M, and growth time of 144 hours, colorless crystals with the longest size of 3 mm, were obtained (72.57%. Characterization of the synthesized crystal by AAS indicates that the obtained crystal has high purity. Meanwhile, analysis by FTIR spectra shows a Ca–F peak at 775 cm-1, and powder-XRD analysis confirms that the obtained crystal was fluorite (CaF2. © 2012 BCREC UNDIP. All rights reservedReceived: 11st April 2012; Revised: 4th June 2012; Accepted: 13rd June 2012[How to Cite: M.M. Khunur, A. Risdianto, S. Mutrofin, Y.P. Prananto. (2012. Synthesis of Fluorite (CaF2 Crystal from Gypsum Waste of Phosphoric Acid Factory in Silica Gel. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 71-77.  doi:10.9767/bcrec.7.1.3171.71-77 ][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.3171.71-77 ] | View in 

  13. 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

    2014-01-01

    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.

  14. Research on the Desulfurization Gypsum of the Rotary Kiln with the Finned Tube

    OpenAIRE

    Zhang, Zongyu; Xin, Zhaoxiang; Jie LI; Zhao, Hongming

    2010-01-01

    The calcination technology of the desulfurization gypsum decides the product quality directly. The production process and property of the desulfurization gypsum has been described and themerits and faults of the conventional calcination technologies have been analyzed. The calcination technology of the desulfurization gypsum of the rotary kiln with the finned tube was chose for the research. The structure and workflow of the calcinatory has been analyzed, and the results showed the advantages...

  15. Hydrology of marginal evaporitic basins during the Messinian Salinity Crisis: isotopic investigation of gypsum deposits

    Science.gov (United States)

    El Kilany, Aida; Caruso, Antonio; Dela Pierre, Francesco; Natalicchio, Marcello; Rouchy, Jean-Marie; Pierre, Catherine; Balter, Vincent; Aloisi, Giovanni

    2016-04-01

    The deposition of gypsum in Messinian Mediterranean marginal basins is controlled by basin restriction and the local hydrological cycle (evaporation/precipitation rates and relative importance of continental vs marine water inputs). We are using the stable isotopic composition of gypsum as a proxy of the hydrological cycle that dominated at the moment of gypsum precipitation. We studied the Messinian Caltanissetta (Sicily) and Tertiary Piedmont (north western Italy) basins where we carried out a high-resolution isotopic study of gypsum layers composing gypsum-marl cycles. These cycles are thought to be the sedimentary expression of astronomical precession cycles, lasting approximately 20 kyr, during which the marginal basins experienced a succession of arid and a wet conditions. We determined the isotopic composition of gypsum hydration water (18O and D), of the sulphate ion (34S, 18O) and of Strontium (87/86Sr), all of which are potentially affected by the hydrological cycle. In our samples, the mother water from which gypsum precipitated is considerably lighter (-4.0 planning a detailed petrographic investigation of gypsum crystals to look for evidence of dissolution/precipitation processes at the micro-scale. This is an essential step in interpreting the isotopic signals of gypsum because we can expect the 18O and D composition of Messinian continental input to be not too dissimilar from that of modern meteoric waters involved in diagenetic processes.

  16. On the origin of gypsum in the Mars north polar region

    Science.gov (United States)

    Fishbaugh, Kathryn E.; Poulet, François; Chevrier, Vincent; Langevin, Yves; Bibring, Jean-Pierre

    2007-07-01

    We describe the distribution and concentration of the largest Martian gypsum deposit discovered to date by the Mars Express OMEGA (Observatoire pour le Mineralogie, l'Eau, les Glaces et l'Activité) imaging spectrometer, its relationship to the late Amazonian-aged north polar dunes in which it is found, and its likely origin. Gypsum has not been discovered anywhere within the north polar region outside of the Olympia Undae dune sea. In the areas of highest gypsum a concentration, 35% pure gypsum grains of a few tens of micrometers in size, mixed with 65% millimeter-sized gypsum grains containing, dark, spectrally featureless inclusions best fit the OMEGA observations. The gypsum-rich dunes contain no significant average albedo, temperature, or morphological anomalies. We propose that water emanating from nearby channels, carved during melting of the polar layered deposits, infiltrated the eastern end of the polar dune sea, percolating through the dunes. Deposits of gypsum resulted from a combination of direct, in situ alteration of sulfide- and high-calcium-pyroxene-bearing dunes and from formation of evaporitic gypsum crystals in the pore spaces of these dunes. This gypsum deposit formed in a unique local environment and is disconnected from sulfate-forming events elsewhere on Mars which are thought to have occurred much earlier, during the late Noachian and Hesperian, by various means. Sulfates have not been discovered in any other collection of dunes on Mars.

  17. FGD [flue gas desulfurization] gypsum in the United Germany: Trends of demand and supply

    International Nuclear Information System (INIS)

    1990 was the first year in which all flue gas desulfurization (FGD) units in West Germany suplied the gypsum industry in Germany and some other European countries with FGD-gypsum. The effect on the gypsum market was not as significant as anticipated, mainly due to wrong estimates based on the most conservative conditions assumed by the power stations in their applications for permission. These estimates generally assumed high sulfur coal at full load throughout the year, whereas most West German boilers fire low sulfur coal and run only at peak times, resulting in much less FGD gypsum on the market than the German gypsum industry had been prepared to use. The unification of Germany has changed the situation of the gypsum industry dramatically. Reserves of natural gypsum in the middle of Germany are now much more accessible, and a great number of lignite-fired power stations must be fitted with FGD equipment as soon as possible. At the same time, the market for gypsum building products will improve dramatically due to the poor condition of many buildings in east Germany, which will require rehabilitation. These circumstances imply a bright future for both natural and FGD-based gypsum in Germany. 8 refs., 5 figs

  18. 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: elena.montero@cimav.edu.mx [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)

    2015-07-23

    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.

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

    OpenAIRE

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

    2014-01-01

    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...

  20. Luminescence of Speleothems in Italian Gypsum Caves: Preliminary Report

    CERN Document Server

    Shopov, Yavor Y; Forti, Paolo

    2009-01-01

    The luminescence of 3 speleothem samples from the Acquafredda karst system and 1 from the Novella Cave (Gessi Bolognesi Natural Park, Italy) has been recorded using excitation by impulse Xe- lamp. All these carbonate speleothems are believed to be formed only from active CO2 from the air, because the bedrock of the cave consist of gypsum and does not contain carbonates. The obtained photos of luminescence record the climate changes during the speleothem growth. U/Th and 14C dating proved that studied speleothems started to grow since about 5,000 years ago. The detailed analyses of the luminescence records is still in progress.

  1. Water of Hydration Dynamics in Minerals Gypsum and Bassanite: Ultrafast 2D IR Spectroscopy of Rocks.

    Science.gov (United States)

    Yan, Chang; Nishida, Jun; Yuan, Rongfeng; Fayer, Michael D

    2016-08-01

    Water of hydration plays an important role in minerals, determining their crystal structures and physical properties. Here ultrafast nonlinear infrared (IR) techniques, two-dimensional infrared (2D IR) and polarization selective pump-probe (PSPP) spectroscopies, were used to measure the dynamics and disorder of water of hydration in two minerals, gypsum (CaSO4·2H2O) and bassanite (CaSO4·0.5H2O). 2D IR spectra revealed that water arrangement in freshly precipitated gypsum contained a small amount of inhomogeneity. Following annealing at 348 K, water molecules became highly ordered; the 2D IR spectrum became homogeneously broadened (motional narrowed). PSPP measurements observed only inertial orientational relaxation. In contrast, water in bassanite's tubular channels is dynamically disordered. 2D IR spectra showed a significant amount of inhomogeneous broadening caused by a range of water configurations. At 298 K, water dynamics cause spectral diffusion that sampled a portion of the inhomogeneous line width on the time scale of ∼30 ps, while the rest of inhomogeneity is static on the time scale of the measurements. At higher temperature, the dynamics become faster. Spectral diffusion accelerates, and a portion of the lower temperature spectral diffusion became motionally narrowed. At sufficiently high temperature, all of the dynamics that produced spectral diffusion at lower temperatures became motionally narrowed, and only homogeneous broadening and static inhomogeneity were observed. Water angular motions in bassanite exhibit temperature-dependent diffusive orientational relaxation in a restricted cone of angles. The experiments were made possible by eliminating the vast amount of scattered light produced by the granulated powder samples using phase cycling methods. PMID:27385320

  2. 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: double@ntu.edu.tw [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Division of Medical Engineering Research, National Health Research Institute, Zhunan, Miaoli County, Taiwan (China)

    2012-10-01

    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.

  3. Synthesis of partial stabilized cement–gypsum as new dental retrograde filling material

    International Nuclear Information System (INIS)

    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: ► A new dental retrograde filling material PSC–gypsum was developed. ► PSC–gypsum cement has shown excellent initial and final setting time as 15–35 min. ► It not only improved the setting time but also retain the viscosity, 2 Pa·s. ► High alkaline pH of the cement had a remarkable antibacterial activity. ► Cytotoxicity studies revealed that the synthesized material is highly biocompatible.

  4. Preparation of pure calcium carbonate by mineral carbonation using industrial byproduct FGD gypsum

    Science.gov (United States)

    Song, K.; Kim, W.; Bang, J. H.; Park, S.; Jeon, C. W.

    2015-12-01

    Mineral carbonation is one of the geological approaches for the sequestration of anthropogenic CO2 gas. Its concept is based on the natural weathering processes in which silicate minerals containing divalent cations such as Ca or Mg are carbonated to CaCO3 or MgCO3 in the reaction with CO2gas. Raw materials for the mineral carbonation have been extended to various industrial solid wastes such as steel slag, ashes, or FGD (flue gas desulfurization) gypsum which are rich in divalent cations. These materials have economic advantages when they are produced in CO2 emission sites. Flue gas desulfurization (FGD) gypsum is such a byproduct obtained in at coal-fired power plants. Recently, we carried out a research on the direct mineral carbonation of FGD gypsum for CO2sequestration. It showed high carbonation reactivity under ambient conditions and the process can be described as follows: CaSO4·2H2O + CO2(g) + 2NH4OH(aq) → CaCO3(s) + (NH4)2SO4(aq) (1) At the early stage of the process, calcium carbonate (CaCO3) exists as a dissolved ion pair during the induction period. High-purity CaCO3 could be precipitated from dissolved calcium carbonate solution extracted during the induction period. The effect of experimental parameters on pure CaCO3 was evaluated: CO2 flow rate (1-3 L/min), ammonia content (4-12%), and solid-to-liquid (S/L) ratio (5-300 g/L). FE-SEM (field-emission scanning electron microscopy) and XRD (X-ray diffraction) study revealed that the precipitated CaCO3 was round-shaped vaterite crystals. The induction time was inversely proportional to the CO2 flow rate and the yield for pure CaCO3 increased with the ammonia content. The formation efficiency for pure CaCO3 decreased with S/L (solid/liquid) ratio. It was 90% (mol/mol) when the S/L ratio was 5 g/L. However, S/L ratio didn't affect the maximum solubility limit of dissolved CaCO3.

  5. Permeability control on transient slip weakening during gypsum dehydration: Implications for earthquakes in subduction zones

    Science.gov (United States)

    Leclère, Henri; Faulkner, Daniel; Wheeler, John; Mariani, Elisabetta

    2016-05-01

    A conflict has emerged from recent laboratory experiments regarding the question of whether or not dehydration reactions can promote unstable slip in subduction zones leading to earthquakes. Although reactions produce mechanical weakening due to pore-fluid pressure increase, this weakening has been associated with both stable and unstable slip. Here, new results monitoring strength, permeability, pore-fluid pressure, reaction progress and microstructural evolution during dehydration reactions are presented to identify the conditions necessary for mechanical instability. Triaxial experiments are conducted using gypsum and a direct shear sample assembly with constant normal stress that allows the measurement of permeability during sliding. Tests are conducted with temperature ramp from 70 to 150 °C and with different effective confining pressures (50, 100 and 150 MPa) and velocities (0.1 and 0.4 μm s-1). Results show that gypsum dehydration to bassanite induces transient stable-slip weakening that is controlled by pore-fluid pressure and permeability evolution. At the onset of dehydration, the low permeability promoted by pore compaction induces pore-fluid pressure build-up and stable slip weakening. The increase of bassanite content during the reaction shows clear evidence of dehydration related with the development of R1 Riedel shears and P foliation planes where bassanite is preferentially localized along these structures. The continued production of bassanite, which is stronger than gypsum, provides a supporting framework for newly formed pores, thus resulting in permeability increase, pore-fluid pressure drop and fault strength increase. After dehydration reaction, deformation is characterized by unstable slip on the fully dehydrated reaction product, controlled by the transition from velocity-strengthening to velocity-weakening behaviour of bassanite at temperature above ∼140 °C and the localization of deformation along narrow Y-shear planes. This study

  6. Bacterial life and dinitrogen fixation at a gypsum rock.

    Science.gov (United States)

    Boison, Gudrun; Mergel, Alexander; Jolkver, Helena; Bothe, Hermann

    2004-12-01

    The organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. The cyanobacterial consortium consisted almost exclusively of Chroococcidiopsis spp. The organisms of the shards expressed nitrogenase activity (C2H2 reduction) aerobically and in light. After a prolonged period of drought at the rock, the cells were inactive, but they resumed nitrogenase activity 2 to 3 days after the addition of water. In a suspension culture of Chroococcidiopsis sp. strain PCC7203, C2H2 reduction required microaerobic conditions and was strictly dependent on low light intensities. Sequencing of a segment of the nitrogenase reductase gene (nifH) indicated that Chroococcidiopsis possesses the alternative molybdenum nitrogenase 2, expressed in Anabaena variabilis only under reduced O2 tensions, rather than the widespread, common molybdenum nitrogenase. The shards apparently provide microsites with reduced light intensities and reduced O2 tension that allow N2 fixation to proceed in the unicellular Chroococcidiopsis at the gypsum rock, unless the activity is due to minute amounts of other, very active cyanobacteria. Phylogenetic analysis of nifH sequences tends to suggest that molybdenum nitrogenase 2 is characteristic of those unicellular or filamentous, nonheterocystous cyanobacteria fixing N2 under microaerobic conditions only. PMID:15574902

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

    Science.gov (United States)

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

    2014-01-01

    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. PMID:25161860

  8. Microstructure and mechanical properties of gypsum composites reinforced with recycled cellulose pulp

    Directory of Open Access Journals (Sweden)

    Magaly Araújo Carvalho

    2008-12-01

    Full Text Available The use of waste fibers for the reinforcement of brittle matrices is considered opportune for the sustainable management of urban solid residues. This paper examines the microstructure and mechanical properties of a composite material made of gypsum reinforced with cellulose fibers from discarded Kraft cement bag. Two different kinds of gypsum were used, natural gypsum (NG and recycled gypsum (RG, both with an addition of 10% by mass of limestone. For the production of samples, slurry vacuum de-watering technique followed by pressing was evaluated revealing to be an efficient and innovative solution for the composites under evaluation. The composite was analyzed based on flexural strength tests, scanning electron microscopy (SEM imaging, secondary electron (SE detection, and pseudo-adiabatic calorimetry. The morphology of the fractured surfaces of flexural test samples revealed large gypsum crystals double the original size surrounding the fibers, but with the same overall aspect ratio. Natural fibers absorb large amounts of water, causing the water/gypsum ratio of the paste to increase. The predominance of fiber pullout, damaged or removed secondary layers and incrusted crystals are indicative of the good bonding of the fiber to the gypsum matrix and of the high mechanical resistance of composites. This material is a technically better substitute for the brittle gypsum board, and it stands out particularly for its characteristics of high impact strength and high modulus of rupture.

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

    Directory of Open Access Journals (Sweden)

    Juan Morales

    2016-03-01

    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.

  10. Geomorphological aspects of gypsum karst areas with special emphasis on exposed karst

    OpenAIRE

    Sauro U.

    1996-01-01

    Medium- to large-size forms in gypsum karst are described, including dolines, blind valleys, ploje-like depressions, collapses and positive and/or residual forms such as outliers, cone-like hills, dome-like hills, mesa-like tabular blocks and plateaux and breccia pipe hills. The similarities and/or difference between gypsum and carbonate forms are discussed.

  11. Effects of fluidized gas desulfurization (FGD) gypsum on non-target freshwater and sediment dwelling organims

    Science.gov (United States)

    Fluidized gas desulfurization gypsum is a popular agricultural soil amendment used to increase calcium and sulfur contents, and reduce aluminum toxicity. Due to its surface application in conservation tillage systems and high solubility, the soluble components of gypsum may be transferred with agri...

  12. Calcium sulfoaluminate (Ye'elimite) hydration in the presence of gypsum, calcite, and vaterite

    International Nuclear Information System (INIS)

    Six calcium sulfoaluminate-based cementitious systems composed of calcium sulfoaluminate, calcite, vaterite, and gypsum were cured as pastes and mortars for 1, 7, 28 and 84 days. Pastes were analyzed with X-ray diffraction, thermogravimetric and differential thermal analyses. Mortars were tested for compressive strength, dimensional stability and setting time. Furthermore, pastes with a water/cementitious material mass ratio of 0.80 were tested for heat evolution during the first 48 h by means of isothermal conduction calorimetry. It has been found that: (1) both calcite and vaterite reacted with monosulfoaluminate to give monocarboaluminate and ettringite, with vaterite being more reactive; (2) gypsum lowered the reactivity of both carbonates; (3) expansion was reduced by calcite and vaterite, irrespective of the presence of gypsum; and (4) both carbonates increased compressive strength in the absence of gypsum and decreased compressive strength less in the presence of gypsum, with vaterite's action more effective than that of calcite

  13. Environmental impacts of the gypsum mining operation at Maqna area, Tabuk, Saudi Arabia

    Science.gov (United States)

    Al-Harthi, Abbas

    2001-11-01

    The impacts of quarrying of the gypsum deposits on the environment at Maqna, Tabuk, were evaluated by intensive field studies including in situ testing, mapping and sampling of gypsum and well water. Field and laboratory tests were made to determine the engineering properties including tensile and compressive strengths, unit weight, fracture spacing and the rock quality designation (RQD) values. Results were used to determine the most suitable method for quarrying and extraction. Chemical analyses of gypsum and water well samples were conducted along with mineralogical analysis using X-ray diffraction analysis (XRD). Results show that there are no harmful impacts on the environment of the studied area associated with the extraction and quarrying of the gypsum deposits at the Maqna area. They also revealed that the gypsum can be quarried using a ripping technique, which does not create noise and/or vibration in the surrounding areas.

  14. Calcium sulfoaluminate (Ye'elimite) hydration in the presence of gypsum, calcite, and vaterite

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Craig W. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States); Telesca, Antonio [School of Engineering, University of Basilicata, Potenza (Italy); Monteiro, Paulo J.M., E-mail: monteiro@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States)

    2014-11-15

    Six calcium sulfoaluminate-based cementitious systems composed of calcium sulfoaluminate, calcite, vaterite, and gypsum were cured as pastes and mortars for 1, 7, 28 and 84 days. Pastes were analyzed with X-ray diffraction, thermogravimetric and differential thermal analyses. Mortars were tested for compressive strength, dimensional stability and setting time. Furthermore, pastes with a water/cementitious material mass ratio of 0.80 were tested for heat evolution during the first 48 h by means of isothermal conduction calorimetry. It has been found that: (1) both calcite and vaterite reacted with monosulfoaluminate to give monocarboaluminate and ettringite, with vaterite being more reactive; (2) gypsum lowered the reactivity of both carbonates; (3) expansion was reduced by calcite and vaterite, irrespective of the presence of gypsum; and (4) both carbonates increased compressive strength in the absence of gypsum and decreased compressive strength less in the presence of gypsum, with vaterite's action more effective than that of calcite.

  15. ESR Studies and Dating of Egyptian Gypsum at Ras Mala'ab, Sinai, Egypt

    International Nuclear Information System (INIS)

    A gypsum sample from the famous gypsum-anhydrite evaporitic deposit composing the Ras Mala'ab Formation, Upper Miocene, occurring at Ras Mala'ab, on the east coast of the Gulf of Suez, was subjected to (ESR) dosimetric studies. Also, (ESR) was used to date the formation or most recent recrystallization of that gypsum. The gypsum derivative (ESR) spectrum is characterized by the large broad Fe2+ signal (g=2.50) and HF-sixtet Mn2+ signals. Only the characteristic gypsum signal (G l, g=2.0040) was detected between the third and fourth lines of the HF-Mn2+ which is attributed to the electron-center SO3-. This signal was sensitive to artificial γ-irradiation and showed significant enhancement using a γ-dose of 550 Gy. Also, the signal was very stable up to 400 oC. The gypsum sample with a total dose (TD) of 1500 Gy, determined graphically by extrapolating the linear relationship between defect concentration and the artificial γ-doses for (G l, g=2.0040) and an annual dose (D) due to cosmic rays (0.3 mGy), yielded an age of 5.00 Ma. This could mean the age of formation or latest recrystallization of this gypsum deposit. The geologic age assignment of the Ras Mala'ab Group including the evaporitic gypsum unit, is Middle to Late Miocene. It is directly overlain by the Pliocene elastics at the locality of Ras Mala'ab. This might suggest that these evaporitic gypsum facies represent the top of the Miocene in the Gulf of Suez area, since the Miocene-Pliocene boundary is now put at 5.00-5.50 Ma ago. Therefore, the ESR age of the Ras Mala'ab gypsum is consistent with the geologic age assignment

  16. The Role of Biofilms in the Sedimentology of Actively Forming Gypsum Deposits at Guerrero Negro, Mexico

    Science.gov (United States)

    Vogel, Marilyn B.; Des Marais, David J.; Turk, Kendra A.; Parenteau, Mary N.; Jahnke, Linda L.; Kubo, Michael D. Y.

    2009-11-01

    Actively forming gypsum deposits at the Guerrero Negro sabkha and saltern system provided habitats for stratified, pigmented microbial communities that exhibited significant morphological and phylogenetic diversity. These deposits ranged from meter-thick gypsum crusts forming in saltern seawater concentration ponds to columnar microbial mats with internally crystallized gypsum granules developing in natural anchialine pools. Gypsum-depositing environments were categorized as forming precipitation surfaces, biofilm-supported surfaces, and clastic surfaces. Each surface type was described in terms of depositional environment, microbial diversity, mineralogy, and sedimentary fabrics. Precipitation surfaces developed in high-salinity subaqueous environments where rates of precipitation outpaced the accumulation of clastic, organic, and/or biofilm layers. These surfaces hosted endolithic biofilms comprised predominantly of oxygenic and anoxygenic phototrophs, sulfate-reducing bacteria, and bacteria from the phylum Bacteroidetes. Biofilm-supported deposits developed in lower-salinity subaqueous environments where light and low water-column turbulence supported dense benthic microbial communities comprised mainly of oxygenic phototrophs. In these settings, gypsum granules precipitated in the extracellular polymeric substance (EPS) matrix as individual granules exhibiting distinctive morphologies. Clastic surfaces developed in sabkha mudflats that included gypsum, carbonate, and siliclastic particles with thin gypsum/biofilm components. Clastic surfaces were influenced by subsurface brine sheets and capillary evaporation and precipitated subsedimentary gypsum discs in deeper regions. Biofilms appeared to influence both chemical and physical sedimentary processes in the various subaqueous and subaerially exposed environments studied. Biofilm interaction with chemical sedimentary processes included dissolution and granularization of precipitation surfaces, formation of

  17. Producing polymeric ferric sulfate from copperas by-products from titanium dioxide%用钛白废渣七水硫酸亚铁生产聚合硫酸铁

    Institute of Scientific and Technical Information of China (English)

    郭焦星

    2012-01-01

    硫酸法钛白粉排放大量FeSO4·7H2O废渣,目前主要用其生产铁黑、铁黄、铁红等铁系颜料及FeSO4·H2O饲料.但由于铁系颜料及FeSO4· H2O饲料的国内、国际市场容量有限,FeSO4·7H2O废渣的处理已成为我国硫酸法钛白粉快速发展的瓶颈之一.聚合硫酸铁是一种新型无机高分子絮凝剂,广泛用于各种工业污水的混凝净化处理,市场容量很大.利用钛白粉废渣作为原料,经过精制,将废渣所含的氧化钛回收返回钛白粉生产线,利用高效、节能、成熟的工装设备,采用催化及直接氧化法生产高质量的液体聚合硫酸铁,具有很好的经济效益和环境效益.%Titanium dioxide production processes in gulfuric acid method emit large quantities of copperas waste residue. At present,it is primarily used for production of iron series pigments such as iron oxide black, iron oxide yellow, iron oxide red, and the ferrous sulphate monohydrate feed. Because of domestic and international market capacity of iron series pigments and the ferrous sulphate monohydrate feed is not much enough, the treat-ment of the copperas waste residue has become one of die bottleneck of the rapid development of titanium dioxide production by sulfuric acid method in China. Polymeric ferric sulfate is a new type of inorganic polymer flocculant, it is widely used in flocculation treatment of various industrial wastewater. The market capacity is large. Extensive use of titanium dioxide waste residue as raw materials, recycles titamium oxide contains in the waste residue after refining and returns to the titanium dioxide production line, produces the high quality liquid folymeric ferric sulfate by catalytic and direct oxidation method with efficient, energy-saving, sophisticated equipment. It has good eco-nomic benefit and environmental benefit.

  18. PPF-reinforced, ESP-lightened gypsum plaster

    Directory of Open Access Journals (Sweden)

    García Santos, A.

    2009-03-01

    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

  19. XRD and mineralogical analysis of gypsum dunes at White Sands National Monument, New Mexico and applications to gypsum detection on Mars

    Science.gov (United States)

    Lafuente, B.; Bishop, J. L.; Fenton, L. K.; King, S. J.; Blake, D.; Sarrazin, P.; Downs, R.; Horgan, B. H.

    2013-12-01

    A field portable X-ray Diffraction (XRD) instrument was used at White Sands National Monument to perform in-situ measurements followed by laboratory analyses of the gypsum-rich dunes and to determine its modal mineralogy. The field instrument is a Terra XRD (Olympus NDT) based on the technology of the CheMin (Chemistry and Mineralogy) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity which is providing the mineralogical and chemical composition of scooped soil samples and drilled rock powders collected at Gale Crater [1]. Using Terra at White Sands will contribute to 'ground truth' for gypsum-bearing environments on Mars. Together with data provided by VNIR spectra [2], this study clarifies our understanding of the origin and history of gypsum-rich sand dunes discovered near the northern polar region of Mars [3]. The results obtained from the field analyses performed by XRD and VNIR spectroscopy in four dunes at White Sands revealed the presence of quartz and dolomite. Their relative abundance has been estimated using the Reference Intensity Ratio (RIR) method. For this study, particulate samples of pure natural gypsum, quartz and dolomite were used to prepare calibration mixtures of gypsum-quartz and gypsum-dolomite with the 90-150μm size fractions. All single phases and mixtures were analyzed by XRD and RIR factors were calculated. Using this method, the relative abundance of quartz and dolomite has been estimated from the data collected in the field. Quartz appears to be present in low amounts (2-5 wt.%) while dolomite is present at percentages up to 80 wt.%. Samples from four dunes were collected and prepared for subsequent XRD analysis in the lab to estimate their composition and illustrate the changes in mineralogy with respect to location and grain size. Gypsum-dolomite mixtures: The dolomite XRD pattern is dominated by an intense diffraction peak at 2θ≈36 deg. which overlaps a peak of gypsum, This makes low concentrations of dolomite

  20. Optically stimulated luminescence dosimetry with gypsum wallboard (drywall)

    International Nuclear Information System (INIS)

    Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm). It is necessary to decrease the optical stimulation power dramatically in order to adequately separate the RIS from the interfering background signal. The necessary protocols are developed for accurately measuring the absorbed dose as low as 500 mGy and demonstrate that the RIS decays logarithmically with storage time, with complete erasure expected within 1-4 d. (authors)

  1. Optically stimulated luminescence dosimetry with gypsum wallboard (drywall).

    Science.gov (United States)

    Thompson, Jeroen W; Burdette, Kevin E; Inrig, Elizabeth L; Dewitt, Regina; Mistry, Rajesh; Rink, W Jack; Boreham, Douglas R

    2010-09-01

    Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm). It is necessary to decrease the optical stimulation power dramatically in order to adequately separate the RIS from the interfering background signal. The necessary protocols are developed for accurately measuring the absorbed dose as low as 500 mGy and demonstrate that the RIS decays logarithmically with storage time, with complete erasure expected within 1-4 d. PMID:20447939

  2. Testing Carbon Sequestration in Soil Through the Addition of Gypsum

    Science.gov (United States)

    Han, Y.; Tokunaga, T. K.; Wan, J.; Conrad, M. E.; Salve, R.

    2011-12-01

    In order to help control adverse effects of increased atmospheric concentrations of CO2, effective methods for fixing carbon need to be developed. Given the large C inventories and fluxes associated with soils, it is important to identify cost- and energy-effective means for increasing long-term C retention within soil profiles. This study investigates the alternative strategy of increasing carbon retention in soils through accelerating calcite (CaCO3) precipitation and promoting soil organic carbon (SOC) complexation on mineral surfaces. With the addition of calcium ion to soils with pH > 8 often found in arid and semi-arid regions, the slow process of calcite precipitation may be accelerated. Calcium also promotes SOC binding onto mineral surfaces, diminishing leaching of SOC. Addition of flue gas desulfurization gypsum (FGDG) represents an inexpensive source of calcium to natural, slightly alkaline soil surfaces which might promote the fixation of CO2 as calcite and decrease leaching losses of organic carbon. To test this hypothesis, we prepared laboratory soil columns (7.5 cm in diameter and 85 cm in height) with and without calcium sulfate-amended layers. The distribution of carbon in the columns was monitored in gaseous, aqueous and solid phases over a period of several months to test the effect of adding calcium ions. In some columns, a relatively high fraction of 13C-labeled bicarbonate was injected to differentiate the newly precipitated calcite from the initial calcite present in the soil. The potential for more distinct calcite precipitation within the soil root zone will be investigated in vegetated soil columns. Through obtaining C mass balances in soil profiles, this study is quantifying the efficiency of gypsum amendments for mitigating C losses to the atmosphere.

  3. Enhanced gypsum scaling by organic fouling layer on nanofiltration membrane: Characteristics and mechanisms.

    Science.gov (United States)

    Wang, Jiaxuan; Wang, Lei; Miao, Rui; Lv, Yongtao; Wang, Xudong; Meng, Xiaorong; Yang, Ruosong; Zhang, Xiaoting

    2016-03-15

    To investigate how the characteristics of pregenerated organic fouling layers on nanofiltration (NF) membranes influence the subsequent gypsum scaling behavior, filtration experiments with gypsum were carried out with organic-fouled poly(piperazineamide) NF membranes. Organic fouling layer on membrane was induced by bovine serum albumin (BSA), humic acid (HA), and sodium alginate (SA), respectively. The morphology and components of the scalants, the role of Ca(2+) adsorption on the organic fouling layer during gypsum crystallization, and the interaction forces of gypsum on the membrane surface were investigated. The results indicated that SA- and HA-fouled membranes had higher surface crystallization tendency along with more severe flux decline during gypsum scaling than BSA-fouled and virgin membranes because HA and SA macromolecules acted as nuclei for crystallization. Based on the analyses of Ca(2+) adsorption onto organic adlayers and adhesion forces, it was found that the flux decline rate and extent in the gypsum scaling experiment was positively related to the Ca(2+)-binding capacity of the organic matter. Although the dominant gypsum scaling mechanism was affected by coupling physicochemical effects, the controlling factors varied among foulants. Nevertheless, the carboxyl density of organic matter played an important role in determining surface crystallization on organic-fouled membrane. PMID:26799710

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

    OpenAIRE

    Kirchheim, A. P.; Fernàndez-Altable, V.; Monteiro, P. J.; Dal Molin, D. C.; Casanova, I.

    2009-01-01

    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 cubi...

  5. Determination of Radium 226 in mexican phosphate fertilizers and gypsum by gamma spectrometry

    International Nuclear Information System (INIS)

    The 226 Ra isotope was determined in 17, 20 and 46% m/m phosphate fertilizers and gypsum. The samples of the fertilizers were dissolved in 10% v/v nitric acid solutions. The barium sulphate method was used for the precipitation of 226 Ra. On the other hand, alkaline fusion method was used to separate the 226 Ra from gypsum. The results indicated that 226 Ra was present in the phosphate fertilizers and gypsum. The 226 Ra concentrations present in these materials were between 10 -4 - 10 -5 μg g-1. (Author)

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

    Directory of Open Access Journals (Sweden)

    Silva Hermo, B.

    2010-03-01

    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.

  7. Rehabilitation of gypsum-mined lands in the Indian desert

    Science.gov (United States)

    Sharma, K.D.; Kumar, S.; Gough, L.P.

    2001-01-01

    The economic importance of mining in the Indian Desert is second only to agriculture. Land disturbed by mining, however, has only recently been the focus of rehabilitation efforts. This research assesses the success of rehabilitation plans used to revegetate gypsum mine spoils within the environmental constraints of the north-west Indian hot-desert ecosystem. The rehabilitation plan first examined both mined and unmined areas and established assessments of existing vegetative cover and the quality of native soils and mine spoils. Tests were made on the effect of the use, and conservation, of available water through rainwater harvesting, amendment application (for physical and chemical spoil modification), plant establishment protocols, and the selection of appropriate germ plasm. Our results show that the resulting vegetative cover is capable of perpetuating itself under natural conditions while concurrently meeting the needs of farmers. Although the mine spoils are deficient in organic matter and phosphorus, they possess adequate amounts of all other nutrients. Total boron concentrations (>5.0 mg kg-1) in both the topsail and mine spoil indicate potentially phytotoxic conditions. Electrical conductance of mine spoil is 6-10 times higher than for topsail with a near-neutral pH. Populations of spoil fungi, Azotobactor, and nitrifying bacteria are low. The soil moisture storage in rainwater harvesting plots increased by 8% over the control and 48% over the unmined area. As a result of rehabilitation efforts, mine spoils show a steady buildup in organic carbon, and P and K due to the decomposition of farmyard manure and the contribution of nitrogen fixation by the established leguminous plant species. The rehabilitation protocol used at the site appears to have been successful. Following revegetation of the area with a mixture of trees, shrubs, and grasses, native implanted species have become established. Species diversity, measured in terms of species richness

  8. Crystallization kinetics of gypsum from dense suspension of hemihydrate in water

    Science.gov (United States)

    Amathieu, L.; Boistelle, R.

    1988-04-01

    The crystallization kinetics of gypsum from a dense suspension of calcium sulfate hemihydrate (weight ratio water/hemihydrate = 20) are followed by a conductimetric method. All stages of the process are investigated. The dissolution of hemihydrate is very fast, achieving in a few seconds a supersaturation of 5.4 times the solubility product of gypsum. The dissolution rate varies as a quadratic function of undersaturation. The crystals of gypsum form immediately, due to heterogeneous nucleation onto the hemihydrate particles. Later, secondary or even homogeneous nucleation may occur. There is no steady state between hemihydrate dissolution and gypsum growth even in the first stages of the hydration process. The growth rate laws are either quadratic or linear according to whether supersaturation is small or large.

  9. Final Critical Habitat for the Gypsum wild-buckwheat (Eriogonum gypsophilum)

    Data.gov (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...

  10. Breakdown development in cover beds, and landscape features induced by intrastratal gypsum karst

    OpenAIRE

    Andrejchuk V.; Klimchouk A.

    1996-01-01

    Intrastratal karst is by far the predominant gypsum karst type. Its development may begin in deep-seated settings within rocks already buried by younger strata, and it proceeds increasingly rapidly as uplift brings gypsum sequences into progressively shallower positions. Such development commonly occurs under confined (artesian) hydrogeological conditions, that subsequently change to open conditions (phreatic-water table-vadose). The general evolutionary line of intrastratal karst is typified...

  11. Prospects of using gypsum to conserve water and improve wheat yield in rainfed aridisols

    International Nuclear Information System (INIS)

    A long term field study (2005- 10) was carried out at the farmer's field to evaluate the residual effect of gypsum on soil moisture conservation and wheat production under rainfed conditions. The treatments included application of gypsum 0, 1 and 2 t/ha, and its comparison with former practice (F.P). The basal dose of fertilizers NPK was applied at 120, 80, 60 kg/ha every year before the sowing of wheat. Soil samples were collected before the sowing of wheat every year for soil moisture determination. Gypsum application not only resulted in an increase in soil moisture contents (up to 41%) but also improved grain yield up to 23% and straw yield up to 19%. The effect of gypsum was noticeable during low rainfall years compared to control (0 t/ha gypsum). The results showed that the gypsum could be an effective additive for soil amendment, enhancing wheat yield in rainfed areas by conserving soil moisture and nutrients. (author)

  12. preparation of rubber gypsum composite by using cold method moulding and radiation finishing process

    International Nuclear Information System (INIS)

    Natural rubber latex (NRL) as a liquid rubber was mixed with anhydrous calcium sulphate (gypsum ) at room temperature using full hydrolyzed polyvinyl alcohol as a protective colloid for rubber part and cellulo sic stabilizer for gypsum part to stabilize and control the mixing process from the fast coagulation. the liquid mix ure was moulded in a 10 m3 cubic cavity to obtain rubber- gypsum blocks. the minimum amount of calcium sulphate which was required to induce moulding state of natural rubber latex was 3.97% of the total weight of formulation and 6.24% of rubber - gypsum total ratio. radiation finishing process was applied on the dried composite blocks for three different reasons. first was to sterilize the prepared mould, second was to activate the mould surface to be self adhesive product, the third was to obtain a soft rubber mould with 7% dioctyl phthalate as a plasticizer. the prepared rubber - gypsum moulds were passed through a serious of measurements such as setting time , weight loss, bulk density, abrasion surface ,hardness, scanning electron microscopy (sem), tensile strength, elongation at break, compression set and water absorption . the use of the prepared rubber gypsum moulds as wet moulding and dry articles via extrusion processes for auto motives and machines and also hygienic sterilized products as nontoxic rubber tools for kids and children

  13. Hyperspectral sensor for gypsum detection on monumental buildings

    International Nuclear Information System (INIS)

    A portable hyperspectral device (ASD-FieldSpec FR Pro) has been employed for the characterization of alterations affecting the marble facade of the Santa Maria Novella church (XIII cent.) in Florence (Italy). The ASD-FieldSpec FR Pro collects the reflectance spectra of a selected target area (about 1.5 cm2). The spectra of calcite, gypsum and other mineral phases commonly occurring on outdoor surfaces exposed to the urban atmosphere were collected and presented. The spectral features of alteration minerals (depth of reflectance minima) appear to be affected by grain size, phase abundance in addition to lightness (L*) of the target area. Notwithstanding these limitations, the spectra may be used for a qualitative screening of the alteration and, under reasonable assumptions, the reflectance band depth may be used also for quantitative estimation of phase abundance. The monitoring of the conservation state of outdoor surfaces is considered of fundamental importance to plan conservative interventions on historical buildings. Our results point out that portable hyperspectral instruments may be considered as powerful tools for characterizing historical surfaces in a nondestructive and noninvasive way

  14. Manufacture of ammonium sulfate fertilizer from gypsum-rich byproduct of flue gas desulfurization - A prefeasibility cost estimate

    Science.gov (United States)

    Chou, I.-Ming; Rostam-Abadi, M.; Lytle, J.M.; Achorn, F.P.

    1996-01-01

    Costs for constructing and operating a conceptual plant based on a proposed process that converts flue gas desulfurization (FGD)-gypsum to ammonium sulfate fertilizer has been calculated and used to estimate a market price for the product. The average market price of granular ammonium sulfate ($138/ton) exceeds the rough estimated cost of ammonium sulfate from the proposed process ($111/ ton), by 25 percent, if granular size ammonium sulfate crystals of 1.2 to 3.3 millimeters in diameters can be produced by the proposed process. However, there was at least ??30% margin in the cost estimate calculations. The additional costs for compaction, if needed to create granules of the required size, would make the process uneconomical unless considerable efficiency gains are achieved to balance the additional costs. This study suggests the need both to refine the crystallization process and to find potential markets for the calcium carbonate produced by the process.

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

    Directory of Open Access Journals (Sweden)

    Jackson D.S. Paz

    2006-09-01

    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

  16. Antioxidant properties of extracts from buckwheat by-products

    OpenAIRE

    Marzanna Hęś; Danuta Górecka; Krzysztof Dziedzic

    2012-01-01

    Background. In the course of production of buckwheat groats by-products are produced, such as bran and hull, which apart from high content of dietary fi ber, may also constitute valuable sources of antioxidants. The aim of these investigations was to determine the antioxidant activity of extracts from by-products produced during processing of buckwheat for groats. Material and method. Analyses were conducted on bran and hull of buckwheat cv. Kora. Extraction was run using acetone, methanol an...

  17. Distinctive Accessory Minerals, Textures and Crystal Habits in Biofilm Associated Gypsum Deposits

    Science.gov (United States)

    Vogel, M.; Des Marais, D.; Jahnke, L.; Parenteau, M.

    2008-12-01

    Gypsum-depositing environments near Guerrero Negro, Baja California Sur, Mexico were investigated in order to differentiate the influence of microbial activity versus nonbiological processes upon sedimentary fabrics and minerals. Field sites were located in sabkhas (mudflats and anchialine pools) and in seawater concentration ponds in the salt production facility operated by Exportadora de Sal, S. A. Gypsum (CaSO4.2H2O) was classified according to sedimentary environment (e.g., mudflats, anchialine pools, saltern ponds, surface and subsurface sediments), sedimentary texture, mineral composition, crystal habit, brine composition and other geochemical and biological factors. Gypsum types that develop in the absence of biofilms include water column precipitates (pelagic grains) and subsedimentary crystalline discs that form from phreatic brine ripening. Subsedimentary gypsum forming in sabkha environments had a sinuous axial microtexture and poikilitically enclosed detrital particles whereas water column precipitates exhibited euhedral prismatic habits and extensive penetrative twinning. Gypsum that was influenced by biofilms included cumulate crusts and gypsooids / gypsolite developing in anchialine pools and in saltern concentration ponds. Gypsum precipitating within subaqueous benthic microbial mats, or biofilm/sediment surfaces offered compelling evidence of biofilm influence on crystal textures and habits. Biofilm effects include irregular high relief surface textures, accessory minerals (elemental sulfur, Ca-carbonate, Sr/Ca-sulfate, Mg-oxide and Mg- sulfate) and distinctive crystal habits. Elemental sulfur, Ca-carbonate, and Sr/Ca-sulfate are known byproducts of bacterially mediated sulfate reduction (BSR). Populations of gypsum crystals within biofilms exhibited euhedral to lensoidal morphologies with unique equant and distorted prismatic forms. These forms had been shown to arise from form- and face-specific inhibition by bioorganic functional groups (Cody

  18. Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder.

    Science.gov (United States)

    Zhong, Shiyun; Ni, Kun; Li, Jinmei

    2012-07-01

    A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO(4)(2-) from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO(4)(2-) releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO(4)(2-) from the mortar with 20% FGD gypsum is 9200 mg·m(-2), which is lower than that from the mortar with 95% cement clinker and 5% FGD gypsum. PMID:22440404

  19. Modularity Reveals the Tendency of Arbuscular Mycorrhizal Fungi To Interact Differently with Generalist and Specialist Plant Species in Gypsum Soils

    OpenAIRE

    Torrecillas, Emma; del Mar Alguacil, Maria; Roldán, Antonio; Díaz, Gisela; Montesinos-Navarro, Alicia; Torres, Maria Pilar

    2014-01-01

    Patterns in plant–soil biota interactions could be influenced by the spatial distribution of species due to soil conditions or by the functional traits of species. Gypsum environments usually constitute a mosaic of heterogeneous soils where gypsum and nongypsum soils are imbricated at a local scale. A case study of the interactions of plants with arbuscular mycorrhizal fungi (AMF) in gypsum environments can be illustrative of patterns in biotic interactions. We hypothesized that (i) soil char...

  20. Peanut by-products fed to cattle.

    Science.gov (United States)

    Hill, Gary M

    2002-07-01

    Peanut by-products supply substantial quantities of feedstuffs to beef cattle grown in the same region where peanuts are produced. Included in the list of products fed to cattle are peanuts and peanut meal, peanut skins, peanut hulls, peanut hay, and silages. Residual peanut hay is by far the most widely used peanut by-product fed to beef cattle, and if it is properly harvested with minimal leaf shatter, it is comparable to good-quality grass hays in nutrient content. Peanut skins are often included in small quantities in cattle and pet foods, supplying both protein and energy. High tannin content of peanut skins can cause severe performance depressions in beef cattle if peanut skins are included at levels higher than 10% of the diet, unless diets contain relatively high CP (above 15% CP), or additional N sources are added such as ammonia or urea. Because dairy cattle diets are often above 16% CP in the total dietary DM, peanut skins may increase milk production when added at levels up to 16% of the dry matter. Peanut hulls are effectively used as a roughage source at levels up to 20% of beef finishing diets, for bedding in dairy cattle loafing sheds (if tested and found to contain low aflatoxin levels), and in a variety of manufactured products. Peanut hulls are economically priced because of their quantity, their inherent high fiber, and low CP content, and they should not be fed as a primary feedstuffs for beef cattle. Peanut by-products are generally priced below other by-products, and they can be incorporated into a variety of supplements and diets for cow herds, growing-finishing cattle, and dairy cattle. PMID:12235662

  1. Messinian Salinity Crisis' Primary Evaporites: the shallow gypsum vs. deep dolomite formation paradox solved

    Science.gov (United States)

    De Lange, G. J.; Krijgsman, W.

    2015-12-01

    The Messinian Salinity Crisis (MSC) is a dramatic event that took place ~ 5.9 Ma ago, resulting in deposition of 1-3 km thick evaporites at the Mediterranean seafloor. A considerable, long-lasting controversy existed on the modes of their formation, including the observed shallow gypsum versus deep dolostone deposits for the early phase of MSC. The onset of MSC is marked by deposition of gypsum/sapropel-like alternations, thought to relate to arid/humid climate conditions at a precessional rhythm. Gypsum precipitation only occurred at marginal- and dolomite formation at deeper settings. A range of potential explanations was given, most of which cannot satisfactorily explain all observations. Biogeochemical processes during MSC are commonly neglected but may explain that different deposits formed in shallow vs deep environments without exceptional physical boundary conditions for each. A unifying mechanism is presented in which gypsum formation occurs at all shallow water depths but its preservation is limited to shallow sedimentary settings. In contrast, ongoing deep-basin anoxic organic matter (OM) degradation processes result in dolomite formation. Gypsum precipitation in evaporating seawater takes place at 3-7 times concentrated seawater; seawater is always oversaturated relative to dolomite but its formation is inhibited by the presence of dissolved sulphate. Thus conditions for formation of gypsum exclude those for formation of dolomite and vice versa. Another process linking the saturation states of gypsum and dolomite is that of OM degradation by sulphate reduction. In stagnant deep water, ongoing OM-degradation may result in reducing the sulphate and enhancing the dissolved carbonate content. Such low-sulphate / high carbonate conditions in MSC deepwater are. unfavorable for gypsum preservation and favorable for dolomite formation, and always coincide with anoxic, i.e. oxygen-free conditions. Including dynamic biogeochemical processes in the thusfar static

  2. The influence of composition of gypsum plaster on its technological properties

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2010-10-01

    Full Text Available Gypsum plasters used in art and precision foundry always are the composition of gypsum-silica-cristobalite. It is necessary considering the specifity of plaster during heating stage. Plaster undergoes then, structural transformations causing significant variations of its volume which are nonuniform and proceed with different intensity. The content of silica and cristobalite reduces dimensional variations of setted gypsum plaster what increases dimensional accuracy and significant stresses reduction limiting the possibility of mould cracks occurrence during heating.The influence of cristobalite and silica addition on basic gypsum plaster properties like setting time, dimensional changes after setting, bending strength and permeability in raw and heat treated state are presented in this paper. Experiments were done for mixes containing 30÷70% of the gypsum. It was proven that cristobalite has the biggest influence on the bounding time and expansion of the sandmix and the strength and permeability do not depend on the type of additions and only on theirs total amount in the composition.

  3. The effect of magnesium on partial sulphate removal from mine water as gypsum.

    Science.gov (United States)

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

    2015-08-15

    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. PMID:26067895

  4. STRUCTURE AND PROPERTIES OF COMPOSITE MATERIAL BASED ON GYPSUM BINDER AND CARBON NANOTUBES

    Directory of Open Access Journals (Sweden)

    CHUMAK Anastasia Gennadievna

    2013-04-01

    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.

  5. Use of flue gas desulfurization gypsum for leaching Cd and Pb in reclaimed tidal flat soil.

    Science.gov (United States)

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

    2016-04-01

    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. PMID:26758303

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

    KAUST Repository

    Kirchheim, A. P.

    2009-02-26

    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.

  7. Testing CO2 Sequestration in an Alkaline Soil Treated with Flue Gas Desulfurization Gypsum (FGDG)

    Science.gov (United States)

    Han, Y.; Tokunaga, T. K.

    2012-12-01

    Identifying effective and economical methods for increasing carbon storage in soils is of interest for reducing soil CO2 fluxes to the atmosphere in order to partially offset anthropogenic CO2 contributions to climate change This study investigates an alternative strategy for increasing carbon retention in soils by accelerating calcite (CaCO3) precipitation and promoting soil organic carbon (SOC) complexation on mineral surfaces. The addition of calcium ion to soils with pH > 8, often found in arid and semi-arid regions, may accelerate the slow process of calcite precipitation. Increased ionic strength from addition of a soluble Ca source also suppresses microbial activity which oxidizes SOC to gaseous CO2. Through obtaining C mass balances in soil profiles, this study is quantifying the efficiency of gypsum amendments for mitigating C losses to the atmosphere. The objective of this study is to identify conditions in which inorganic and organic C sequestration is practical in semi-arid and arid soils by gypsum treatment. As an inexpensive calcium source, we proposed to use flue gas desulfurization gypsum (FGDG), a byproduct of fossil fuel burning electric power plants. To test the hypothesis, laboratory column experiments have been conducted in calcite-buffered soil with addition of gypsum and FGDG. The results of several months of column monitoring are demonstrating that gypsum-treated soil have lowered amounts of soil organic carbon loss and increased inorganic carbon (calcite) production. The excess generation of FGDG relative to industrial and agricultural needs, FGDG, is currently regarded as waste. Thus application of FGDG application in some soils may be an effective and economical means for fixing CO2 in soil organic and inorganic carbon forms.Soil carbon cycle, with proposed increased C retention by calcite precipitation and by SOC binding onto soil mineral surfaces, with both processes driven by calcium released from gypsum dissolution.

  8. Agricultural residues based composites II-gypsum plaster-fiber composites

    International Nuclear Information System (INIS)

    It is planned to get rid of some agricultural wastes, which form major environmental problems, to be used for the production of some valuable economic composites with gypsum plaster for wide important applications. Bagasse, cotton stalks, rice straw or linen fibers were blended with gypsum plaster to form the composites. Effect of each of the fiber type, length, content, and modification on the physicomechanical properties of the resulted composites were followed after different hydration conditions. Moreover, some selected composites were further investigated for their microstructure and thermal insulation properties. Results indicated that addition of fibers decreased the bulk density and mechanical properties of the composites. Density of composites with long fibers is lower than those contain short varieties although the compressive strength (CS)gave the reverse trend. Density and mechanical properties decreased as the added fibers ratio was increased. Strength of all composites increased on ageing. Cotton stalks composites gave 23 % increase in CS on using 2 % of 1.25 mm fiber than neat plaster. 2 % fiber addition of 0.8 mm gave almost the same results as the neat. The results of composites with more than 2 % fiber addition were lower than the neat gypsum. The CS of gypsum with 2 % linen fibers (1.25 mm) was higher than that of neat gypsum plaster, whereas, at 4 % fiber addition the CS was nearly the same as neat gypsum pastes. The composites with higher linen fiber contents than 4 % showed lower CS than neat gypsum paste. The modulus of rupture (MOR) of rice straw or Bagasse composites with 1.25 mm were slightly higher than that of 0.8 mm fiber length, but lower than the neat gypsum. Heat treatment at 105 degree C for 24 hours of cotton stalks decreased their properties. Acetylation of rice straw for different acetylation contents decreased their density, unaffected the CS and improved the MOR of the composites. Addition of CMC to cotton stalks has no benefit

  9. Two distinctive new species of Commicarpus (Nyctaginaceae) from gypsum outcrops in eastern Ethiopia

    DEFF Research Database (Denmark)

    Friis, Ib; Gilbert, Michael G.; Weber, Odile;

    2016-01-01

    During field trips in 2013 and 2014, two distinctive plants belonging to the genus Commicarpus were collected in the Lele Hills, Bale Zone, eastern Ethiopia, on outcrops of sedimentary rock belonging to the Gorrahei Formation with high contents of gypsum. The plants are here described as two new....... leleensis, only known from the type, should remain Data Deficient (DD). Outcrops of gypsum with restricted-range species are well known from eastern Ethiopia and Somalia, but the locality with the two new species of Commicarpus is the most north-western and one of the highest sites recorded so far for...

  10. Gypsum addition to soils contaminated by red mud: implications for aluminium, arsenic, molybdenum and vanadium solubility.

    Science.gov (United States)

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

    2013-10-01

    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

  11. 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.

    -Godavari basin, eastern continental margin of India at a water depth of 1691 m. X-ray diffraction and energy dispersive spectrum studies confirm presence of pyrite, gypsum, calcite, and other mineral aggregates. The occurrence of gypsum in such deep sea...

  12. Analysis of gypsum ore conversion with aid of gamma-ray transmission and CCRD

    International Nuclear Information System (INIS)

    Nowadays, except for very few kettles imported, the monitoring of the conversion of the produced plaster at the Pole Plaster of Araripe is not done with aid of on-line techniques. It shows a simulation of operational conditions with an online meter of chemically combined water in plaster, by means of Central Composite Rotatable Designs (CCRD) and nuclear technique of gamma-ray transmission. In the family of central composite rotatable designs, the CCRD is more efficient than the others, regarding uniformity of variances of the points at the same distance from the center of the design. It is a simulation of operational conditions with an online meter of chemically combined water in plaster, by means of nuclear technique of gamma radiation transmission. Such determination can be achieved by the effect caused by the variation of the mass attenuation coefficient of the dehydrated partially material. An Americium-241 gamma source (60 keV) was simulated in the implementation of the Beer-Lambert equation. The nuclear data required for simulation were obtained from XMuDat software, available from site of the International Atomic Energy Agency. A program in Matlab programming language has demonstrated the possibility of monitoring at all stages of the dehydration process with measures of the specific mass of the sample having an estimated error of the order of 1%. To verify the operating conditions suitable for the process, experiments were simulated using a CCRD. The independent variables were the thickness sample and chemically combined water in plaster. Optimal conditions of the process were determined (STATISTICA software, Release 7.0), which allowed the derivation of a model represented by response surface of the gypsum conversion. (author)

  13. By-products of palm oil extraction and refining

    OpenAIRE

    Tan Yew-Ai

    2006-01-01

    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.

  14. By-products of palm oil extraction and refining

    Directory of Open Access Journals (Sweden)

    Tan Yew-Ai

    2006-01-01

    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.

  15. Biosignatures in modern sulfates: texture, composition and depositional environments of gypsum deposits at Guerrero Negro, Baja, Mexico

    Science.gov (United States)

    Vogel, M. B.; Des Marais, D. J.; Jahnke, L. L.; Turk, K.; Kubo, M.

    2007-12-01

    Gypsum (CaSO4·H2O) is an important phase in biogeochemistry and sedimentology as a mineral sink for sulfur, a paleoclimatic indicator, and an endolithic niche for phototrophic and chemotrophic bacteria. Sulfate deposits are also important targets of exploration for evidence of habitable environments and life on Mars. Gypsum deposits from a range of sedimentary environments at the Guerrero Negro crystallizer ponds and sabkha settings were investigated for microscale structure and composition to differentiate fabrics formed under microbial influence from those formed under abiogenic conditions. Sub-sedimentary gypsum forms in sabkha environments as mm to cm scale selenite discs (termed bird beak gypsum; Warren, 2006) and selenite disc aggregates. Selenite discs and other sub-sedimentary gypsum are characterized by a sinuous axial microtexture and poikilitically enclosed detrital particles. Sub-aqueous gypsum forms as cements, granules (termed gypsooids), and massive botryoidal crusts that line the sediment water interface and margins of managed crystallizer ponds and natural anchialine pools. Sub-aqueous gypsum exhibits a wide range of textures and mineral/biofilm associations that include amorphous to euhedral, tabular, needle and lensoidal morphologies. Elemental sulfur forms rinds on prismatic, growth aligned gypsum twins and reticulate magnesian carbonate is interspersed with both twinned crystals and rosette aggregates in stratified sub-aqueous environments. Intracrystalline biofilms and cell material was observed in association with nearly all sub-aqueous morphologies but only scarce evidence has been found for intercrystalline microbial communities. Columnar microbial communities living in anchialine pools were found to host precipitation of mm scale gypsum granules in their EPS matrix. Fine scale gypsum textures are unlikely to persist through diagenetic alteration, but understanding their primary associations with sulfur and carbonates is necessary for

  16. Constraining the origin of the Messinian gypsum deposits using coupled measurement of δ^{18}O$/δD in gypsum hydration water and salinity of fluid inclusions

    Science.gov (United States)

    Evans, Nicholas P.; Gázquez, Fernando; McKenzie, Judith A.; Chapman, Hazel J.; Hodell, David A.

    2016-04-01

    We used oxygen and hydrogen isotopes of gypsum hydration water (GHW) coupled with salinity deduced from ice melting temperatures of primary fluid inclusions in the same samples (in tandem with 87Sr/86Sr, δ34S and other isotopic measurements) to determine the composition of the mother fluids that formed the gypsum deposits of the Messinian Salinity Crisis from shallow and intermediate-depth basins. Using this method, we constrain the origin of the Messinian Primary Lower Gypsum (PLG) of the Sorbas basin (Betic foreland) and both the Upper Gypsum (UG) and the Lower Gypsum of the Sicilian basin. We then compare these results to measurements made on UG recovered from the deep Ionian and Balearic basins drilled during DSDP Leg 42A. The evolution of GHW δ18O/δD vs. salinity is controlled by mixing processes between fresh and seawater, coupled with the degree of evaporation. Evaporation and subsequent precipitation of gypsum from fluids dominated by freshwater will result in a depressed 87Sr/86Sr values and different trajectory in δ18O/δD vs. salinity space compared to fluids dominated by seawater. The slopes of these regression equations help to define the end-members from which the fluid originated. For example, salinity estimates from PLG cycle 6 in the Sorbas basin range from 18 to 51ppt, and after correction for fractionation factors, estimated δ18O and δD values of the mother water are low (-2.6 salinity) are within error of the average isotope composition of the modern precipitation and groundwater in this region of SE Spain. This indicates there was a significant contribution of meteoric water during gypsum deposition, while 87Sr/86Sr (0.708942 salinities of fluid inclusions are higher averaging ˜100ppt. In contrast to cycle 6, the intercepts of the regression equations of cycle 2 display more positive δ18O/δD values. While the estimated range in δ18O and δD of the mother water and salinities fall below those expected from the evaporation of seawater

  17. Reduction of Interrill Erosion by different application methods of Polyacrylamide and Gypsum

    Science.gov (United States)

    Soil erosion has been studied from different perspectives. This paper presents results on interrill erosion for three different application methods of Polyacrylamide (PAM) and Gypsum. Small interrill plots (0.74 m2) were packed with a highly erodible sieved soil and surface was prepared for it to ha...

  18. Nitrogen and phosphorus leaching as affected by gypsum amendment and exchangeable calcium and magnesium

    Science.gov (United States)

    The movement of N and P from the soil by leaching contributes to losses from agricultural land and represents an important environmental and human health concern. The objective of this study was to evaluate the effect of gypsum amendment and the resultant impact of different levels of exchangeable C...

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

    Directory of Open Access Journals (Sweden)

    Fábio Régis de Souza

    2012-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Kolaitis Dionysios I.

    2013-11-01

    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.

  1. 40 CFR 436.50 - Applicability; description of the gypsum subcategory.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the gypsum subcategory. 436.50 Section 436.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY...

  2. Animal waste and FGD gypsum effects on bermudagrass and soil leachate nutrient contents

    Science.gov (United States)

    In previous experiments on newly relcaimed coal mine soils in northeastern Mississippi, applying poultry litter at 22.4 Mg ha-1 yr-1 enhanced bermudagrass (Cynodon dactylon L.) biomass and selected soil quality parameters. Additionally, co-application of 11.2 Mg ha-1 FGD gypsum and litter reduced so...

  3. Dynamic controls on accretion and lithification of modern gypsum-dominated thrombolites, Los Roques, Venezuela

    Science.gov (United States)

    Petrash, Daniel A.; Gingras, Murray K.; Lalonde, Stefan V.; Orange, François; Pecoits, Ernesto; Konhauser, Kurt O.

    2012-03-01

    Meter-sized thrombolites coated by well developed zonally differentiated microbial mats have been found growing in the shallow waters (depth metabolism of sulfide-oxidizing bacteria, Fourth, as the dissolved sulfide is oxidized into sulfate, the pore-water become saturated with respect to gypsum (CaSO4·2H2O). Fifth, as primary gypsum precipitates within the structures, endolithic sulfate-reducing bacteria metabolize the sulfate moiety in the mineral phase, while simultaneously oxidizing the EPS trapped during accretion. Sixth, as microbial EPS degradation proceeds, the anaerobic oxidation of specific protein fractions of the EPS matrix leads to increased alkalinity, the partial dissolution of gypsum, supersaturation with respect to calcium carbonate, and ultimately pseudomorphic aragonite replacement; this differs from secondary calcite cements in being enriched in 12C, and depleted in minor and trace metals initially associated with the EPS. The biogeochemical processes occurring in this thrombolite-constructing lagoon represent a novel field site for studying the chemical and isotopic processes characterizing early diagenetic gypsum and the role microbes play in its precipitation, dissolution and calcification. In this regard, insights gained from this modern field site will help to better understand mechanisms by which some Precambrian microbialites were lithified.

  4. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    Science.gov (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...

  5. Cause Analysis and Countermeasure of Gypsum Rain in Coal-fired Power Plants

    OpenAIRE

    Qizhen Liu; Yanjing Sun; Yi Sun

    2013-01-01

    Focusing on the phenomenon of gypsum rain while wet desulphurization(WFGD) were adopted in coal fired power plant without GGH, the paper studied and put forward the solutions : (1) desulfurization facilities related equipment modification; (2) optimal operation of existing desulfurization facilities.

  6. Comparison of gypsum and potassium silicate for reclamation of saline sodic soil

    International Nuclear Information System (INIS)

    Relative efficiency of gypsum, potassium silicate and their combinations at different levels for reclamation of saline sodic soil was tested. Treatments were replicated thrice. All pots were arranged according to completely randomized design and treatments were applied to the soil according to treatment plan. Appropriate time was given to achieve the reclamation of saline sodic soil and relative efficiency was assessed through laboratory analysis. After this, rice seedling (Shaheen Basmati) was transplanted in all the pots i.e., 3 plants per pot. Necessary N, P and K fertilizers were applied at the recommended rate. After crop harvest, soil samples were taken for analysis of pH, electrical conductivity (EC), sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) of soil. All the amendments when used alone or in combination with each other improved the chemical parameters of soil. All levels of gypsum (100%, 75% and 50% G.R) proved effective in lowering pH, EC, SAR and ESP of saline sodic soil. Similar trend was observed with the use of all levels of potassium -1 silicate (225, 150 and 75mg per kg soil) of soil. Combinations of gypsum and potassium silicate also remained better in this regard. The most effective treatment was application of the full required rate of gypsum. (author)

  7. Hydrologic transport of fecal bacteria attenuated by flue gas desulfurization gypsum

    Science.gov (United States)

    Flue gas desulfurization (FGD) gypsum is a byproduct of coal-fired power plants. As a soil amendment for crop and pasture production it may increase water infiltration, reduce soil erosion, and decrease nutrient losses from applications of animal manures. Broiler litter is used as a source of plan...

  8. Broiler litter ash and flue gas desulfurization gypsum effects on peanut yield and uptake of nutrients

    Science.gov (United States)

    Peanut (Arachis hypogaea L.) is an important crop that requires large amounts of soluble calcium and phosphorus. Flue gas desulfurization gypsum (FGDG) and super phosphate (SP) have been used for calcium and phosphorus fertilizer for peanut. Broiler litter ash (BLA), a high phosphorus byproduct pr...

  9. BUILDING MATERIALS MADE FROM FLUE GAS DESULFURIZATION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Michael W. Grutzeck; Maria DiCola; Paul Brenner

    2006-03-30

    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. Strategies For Turkish Automotive By-Products Industry

    Directory of Open Access Journals (Sweden)

    Hakan Bütüner

    2012-06-01

    Full Text Available Automotive industry is comprised of the industry which produces vehicles, and the industry which, as dominated by Small and Medium Scale Enterprises, produces parts, modules, and systems of such vehicles according to the technical documentation. Having been established through technical and economic supports of the major manufacturers, and developed in the course of time, the by products industry is involved its activities as a significant potential for the domestic economy at present. In this article, general characteristics of Turkish automative by products industry, its weak aspects, aspects need to be improved, and dominant strategies that need to be considered for the improvement are discussed.

  11. Permian paleogeography of west-central Pangea: Reconstruction using sabkha-type gypsum-bearing deposits of Parnaíba Basin, Northern Brazil

    Science.gov (United States)

    Abrantes, Francisco R.; Nogueira, Afonso C. R.; Soares, Joelson L.

    2016-07-01

    Extreme aridity during Late Permian - Early Triassic period was the main factor for resetting the entire paleoclimate of the planet. Permian evaporite basins and lacustrine red beds were widely distributed along the supercontinent of Pangea. Sulphate deposits in Western Pangea, particularly in Northern Brazil, accumulated in an extensive playa lake system. Outcrop-based facies and stratigraphic analysis of up to 20 m thick evaporite-siliciclastic deposits reveal the predominance of laminated reddish mudstone with subordinate limestone, marl and lenses of gypsum. The succession was deposited in shallow lacustrine and inland sabkha environments associated with saline pans and mudflats. Gypsum deposits comprise six lithofacies: 1) bottom-growth gypsum, 2) nodular/micronodular gypsum, 3) mosaic gypsum, 4) fibrous/prismatic gypsum, 5) alabastrine gypsum, and 6) rosettes of gypsum. Gypsum types 1 and 2 are interpreted as primary deposition in saline pans. Bottom-growth gypsum forms grass-like crusts while nodular/micronodular gypsum indicates displacive precipitation of the crust in shallow water and the groundwater capillary zone. Types 3 and 4 are early diagenetic precipitates. Abundant inclusions of tiny lath-like anhydrite crystals suggest a primary origin of anhydrite. Alabastrine gypsum, fibrous gypsum (satinspar) and rosettes of gypsum probably derived from near-surface hydration of anhydrite. The gypsum-bearing deposits in the Parnaíba Basin contribute towards understanding paleogeographic changes in Western Pangea. A progressive uplift of East Pangea, culminated in the forced regression and retreat of epicontinental seas to the West. Restricted seas or large lakes were formed before the definitive onset of desert conditions in Pangea, leading to the development of extensive ergs.

  12. Characterization of bacterial diversity associated with microbial mats, gypsum evaporites and carbonate microbialites in thalassic wetlands: Tebenquiche and La Brava, Salar de Atacama, Chile.

    Science.gov (United States)

    Farías, M E; Contreras, M; Rasuk, M C; Kurth, D; Flores, M R; Poiré, D G; Novoa, F; Visscher, P T

    2014-03-01

    In this paper, we report the presence of sedimentary microbial ecosystems in wetlands of the Salar de Atacama. These laminated systems, which bind, trap and precipitate mineral include: microbial mats at Laguna Tebenquiche and Laguna La Brava, gypsum domes at Tebenquiche and carbonate microbialites at La Brava. Microbial diversity and key biogeochemical characteristics of both lakes (La Brava and Tebenquiche) and their various microbial ecosystems (non-lithifying mats, flat and domal microbialites) were determined. The composition and abundance of minerals ranged from trapped and bound halite in organic-rich non-lithifying mats to aragonite-dominated lithified flat microbialites and gypsum in lithified domal structures. Pyrosequencing of the V4 region of the 16s rDNA gene showed that Proteobacteria comprised a major phylum in all of the microbial ecosystems studied, with a marked lower abundance in the non-lithifying mats. A higher proportion of Bacteroidetes was present in Tebenquiche sediments compared to La Brava samples. The concentration of pigments, particularly that of Chlorophyll a, was higher in the Tebenquiche than in La Brava. Pigments typically associated with anoxygenic phototrophic bacteria were present in lower amounts. Organic-rich, non-lithifying microbial mats frequently formed snake-like, bulbous structures due to gas accumulation underneath the mat. We hypothesize that the lithified microbialites might have developed from these snake-like microbial mats following mineral precipitation in the surface layer, producing domes with endoevaporitic communities in Tebenquiche and carbonate platforms in La Brava. Whereas the potential role of microbes in carbonate platforms is well established, the contribution of endoevaporitic microbes to formation of gypsum domes needs further investigation. PMID:24442191

  13. 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

    2014-10-01

    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.

  14. 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)

    2000-11-30

    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.

  15. Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions

    Institute of Scientific and Technical Information of China (English)

    I.Y.Elbeyli; S.Piskin

    2004-01-01

    Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

  16. Arsenic uptake by gypsum and calcite: Modeling and probing by neutron and x-ray scattering

    CERN Document Server

    Fernandez-Martinez, Alejandro; Roman-Ross, Gabriela; Johnson, Mark R; Bardelli, Fabrizio; Turrillas, Xavier; Charlet, Laurent

    2006-01-01

    Here we report on two structural studies performed on As-doped gypsum (CaSO4 2H2O) and calcite (CaCO3), using neutron (D20-ILL) and x-ray (ID11-ESRF) diffraction data and EXAFS (BM8-ESRF). The aim of this study is to determine whether As gets into the bulk of gypsum and calcite structures or is simply adsorbed on the surface. Different mechanisms of substitution are used as hypotheses. The combined Rietveld analysis of neutron and x-ray diffraction data shows an expansion of the unit cell volume proportional to the As concentration within the samples. DFT-based simulations confirm the increase of the unit cell volume proportional to the amount of carbonate or sulphate groups substituted. Interpolation of the experimental Rietveld data allows us to distinguish As substituted within the structure from that adsorbed on the surface of both minerals.

  17. Gypsum treated fly ash as a liner for waste disposal facilities

    Energy Technology Data Exchange (ETDEWEB)

    Baig, A.A.; Sivapullaiah, P.V. [Indian Inst. of Science, Bangalore (India)

    2009-07-01

    Fly ash is now being used in geotechnical engineering and construction applications as a means of reducing the environmental impacts of fly ash generated in thermal power plants. Various additions are used to improve fly ash properties. This abstract discussed a study conducted to investigate lime and gypsum additions to fly ash. Lime amendments ranged from 0 to 10 per cent, while gypsum additions ranged from 0 to 2.5 per cent. Laboratory experiments were conducted to determine the hydraulic conductivity of compacted samples in moulds. The study showed wide variations in hydraulic conductivity for the various samples. The physico-chemical, chemical, and mineralogical changes in the fly ash amended samples were discussed.

  18. ANALYSIS OF BY-PRODUCTS MARKET IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Keniyz N. V.

    2015-01-01

    Full Text Available Changing style of life, its rhythm and tendencies dictate their own conditions. The deficit of time makes us economize it on all, including the time for cooking. Among the main trends of the domestic meat market - switching consumers from frozen meat products to fresh cooled products. In connection with it the amount of consumers of meat semi-finished products grows. In the work there was considered the results of research of the Russian market of by-products. The market of frozen meat by-products is actively developed in large cities, where it has its own production. The participants of the market state that consumers have started to buy more frozen by-products by weight and the analysis of meat by-products assortment in retailing trade for 2014 testifies it. Trying to fasten their positions, operators of the market not only develop the production powers but work out new products and the analysis of dynamics of production volumes of meat by-products and shares of federal districts – producers of meat by-products testify it. The main players in this segment see the future market for complex, receipt, combined products and ready dishes that will lead to change of structure of meat semi-finished products sales

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

    Energy Technology Data Exchange (ETDEWEB)

    Renforth, P., E-mail: Phil.Renforth@earth.ox.ac.uk [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX3 0DP (United Kingdom); Mayes, W.M. [Centre for Environmental and Marine Sciences, University of Hull, Scarborough, YO11 3AZ (United Kingdom); Jarvis, A.P. [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Burke, I.T. [School of Earth and Environment, University of Leeds, Leeds, LS2 9JT (United Kingdom); Manning, D.A.C. [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Gruiz, K. [Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1111 Budapest, St. Gellert sq. 4 (Hungary)

    2012-04-01

    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{sub 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{sub 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. - Highlights: Black-Right-Pointing-Pointer Gypsum was dosed into a tributary of the river Danube, Hungary, following a red mud spill in 2010. Black-Right-Pointing-Pointer This remediation resulted in toxic element removal and atmospheric CO{sub 2} capture. Black-Right-Pointing-Pointer Red mud may have value for carbon capture and may be a resource rather than a waste.

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

    International Nuclear Information System (INIS)

    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 CO2. 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 CO2 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. - Highlights: ► Gypsum was dosed into a tributary of the river Danube, Hungary, following a red mud spill in 2010. ► This remediation resulted in toxic element removal and atmospheric CO2 capture. ► Red mud may have value for carbon capture and may be a resource rather than a waste.

  1. Influence of Flue Gas Desulfurization Gypsum on Reducing Soluble Phosphorus in Successive Runoff Events from a Coastal Plain Bermudagrass Pasture.

    Science.gov (United States)

    Watts, Dexter B; Torbert, H Allen

    2016-05-01

    Controlling the threat that pastures intensively managed with poultry litter (PL) pose to accelerating eutrophication is a major issue in the southeastern United States. Gypsum (CaSO) has been identified as a promising management tool for ameliorating litter P losses to runoff. Thus, research was conducted to elucidate gypsum's residual effects on P losses from a bermudagrass ( L.) pasture. Runoff events (60 min) were created using rainfall simulations. Treatments consisted of applying four flue gas desulfurization (FGD) gypsum rates (0, 2.2, 4.4, and 8.9 Mg ha) to bermudagrass fertilized with 13.4 Mg ha PL plus a nonfertilized check (no litter or gypsum) and 8.9 Mg ha FGD gypsum only as controls. Rainfall simulations (∼ 85 mm h) were conducted immediately, 5 wk, and 6 mo (i.e., at the end of growing season) after PL application to determine gypsum's effectiveness at controlling P loss over successive runoff events. The greatest dissolved P (DP) in runoff occurred immediately after PL application. Gypsum effectively reduced cumulative DP concentration losses (54%) compared with PL alone in initial runoff events. Gypsum reduced DP concentrations in succeeding runoff events also regardless of timing, suggesting that its effect is persistent and will not diminish over a growing season. Generally, maximum DP reductions were achieved with 8.9 Mg ha. However, it was surmised from this study that optimal P reduction in a bermudagrass pasture can be achieved with 4.4 Mg ha. Information ascertained from this study may be useful in aiding land managers making prescriptions for management practices that reduce DP losses from agricultural fields. PMID:27136176

  2. Fate of mercury in flue gas desulfurization gypsum determined by Temperature Programmed Decomposition and Sequential Chemical Extraction.

    Science.gov (United States)

    Zhu, Zhenwu; Zhuo, Yuqun; Fan, Yaming; Wang, Zhipeng

    2016-05-01

    A considerable amount of Hg is retained in flue gas desulfurization (FGD) gypsum from Wet Flue Gas Desulfurization (WFGD) systems. For this reason, it is important to determine the species of Hg in FGD gypsum not only to understand the mechanism of Hg removal by WFGD systems but also to determine the final fate of Hg when FGD gypsum is disposed. In this study, Temperature Programmed Decomposition (TPD) and Sequential Chemical Extraction (SCE) were applied to FGD gypsum to identify the Hg species in it. The FGD gypsum samples were collected from seven coal-fired power plants in China, with Hg concentrations ranging from 0.19 to 3.27μg/g. A series of pure Hg compounds were used as reference materials in TPD experiments and the results revealed that the decomposition temperatures of different Hg compounds increase in the order of Hg2Cl2gypsums identified by TPD included HgCl2, Hg2Cl2, Hg2SO4, black HgS and red HgS, of which mercury sulfides were the primary compounds. The results of SCE indicated that Hg was mainly distributed in the strongly complexed phase. The low Hg content in FGD gypsum increases the ambiguity of assigning extraction fractions to certain Hg species by SCE. The fact that the primary compounds in FGD gypsum are HgS phases leads the leaching of Hg in the natural environment to be quite low, but a considerable amount of Hg may be released during the industrial heating process. PMID:27155422

  3. Production of an Extracellular Matrix as an Isotropic Growth Phase of Penicillium rubens on Gypsum

    OpenAIRE

    Bekker, M.; Huinink, H.P.; Adan, O.C.G.; Samson, R.A.; Wyatt, T.; Dijksterhuis, J.

    2012-01-01

    Indoor mold represents an important environmental concern, but a fundamental knowledge of fungal growth stages is needed to limit indoor fungal proliferation on finishing materials used in buildings. The present study focused on the succession of germination stages of the common indoor fungus Penicillium rubens on a gypsum substrate. This substrate is used as a model system representing porous materials that are widely used in indoor environments. Imaging with cryo-scanning electron microscop...

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

    OpenAIRE

    Juan Morales; José Manuel Astilleros; Emilio Matesanz; Lurdes Fernández-Díaz

    2016-01-01

    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 ...

  5. Kajian Kuat Tekan Bebas pada Tanah Lempung yang Distabilisasi dengan Gypsum dan Abu Ampas Tebu

    OpenAIRE

    Gultom, Deddy Jhon Jonatan

    2015-01-01

    Stabilisasi tanah sering sekali digunakan dalam proyek konstruksi guna memperbaiki struktural tanah di lapangan. Proses stabilisasi tanah tersebut dapat dilakukan dengan cara mencampurkan bahan stabilisator sepertigypsum, semen, bitumen, dan bahan-bahan olahan limbah pabrik seperti abu ampas tebu, abu sekam padi, abu cangkang sawit. Penelitian ini meneliti suatu proses stabilisasi tanah dengan menggunakan bahan campuran gypsum yang telah ditetapkan kadarnya sebesar 2% dan abu ampas tebu y...

  6. STUDY OF HYDRATION PRODUCTS IN THE MODEL SYSTEMS METAKAOLIN-LIME AND METAKAOLIN-LIME-GYPSUM

    OpenAIRE

    Matus Zemlicka; Eva Kuzielova; Kuliffayova Marta; Tkacz Jakub; Palou Martin

    2015-01-01

    Possible preferential formation of ettringite instead of required calcium silicate hydrate (CSH) and calcium aluminosilicate hydrate (CASH) phases when aluminosilicates were added to the blended cements was investigated on the model systems comprising of metakaolin, lime and gypsum. Compressive strength, microstructure and phase composition of the samples were evaluated after 7 days of curing at 50oC, using thermal analysis, X-ray diffraction techniques and scanning electronic microscopy. Sam...

  7. Investigation on Mercury Reemission from Limestone-Gypsum Wet Flue Gas Desulfurization Slurry

    OpenAIRE

    2014-01-01

    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 discu...

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

    Directory of Open Access Journals (Sweden)

    Yasunori Ayukawa

    2015-01-01

    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.

  9. Developing biodiversity indicators on a stakeholders' opinions basis: the gypsum industry Key Performance Indicators framework.

    Science.gov (United States)

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

    2016-07-01

    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. PMID:26347416

  10. Thermal testing and numerical simulation of gypsum wallboards incorporated with different PCMs content

    Energy Technology Data Exchange (ETDEWEB)

    Borreguero, Ana M.; Luz Sanchez, M.; Valverde, Jose Luis; Carmona, Manuel; Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla - La Mancha, Av. Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)

    2011-03-15

    A mathematical model based on the Fourier heat conduction equation for one dimension was developed. The complexity of the mathematical solution of this stiff set of differential equations that use boundary conditions that move with the solid-liquid interface was simplified by using an apparent heat capacity (c{sub p}{sup ap}) dependent on temperature and obtained by Modulated Differential Scanning Calorimetry (MDSC). The performance of this model was confirmed by using a home-made experimental installation for the thermal characterization of solid materials. Theoretical curves obtained for gypsum blocks with three different contents of phase change materials (PCMs) were in agreement with experimental ones, indicating that this thermal process can be reproduced theoretically by using the c{sub p}{sup ap} of each block and a unique thermal conductivity of the pure gypsum. The other physical and thermal properties were taken from literature or supplied by the manufacturers. Results also indicated that the higher the PCM content, the higher the energy storage capacity of the wallboard and the lower the wall temperature variation. Furthermore, it was found that a block containing a 5 wt.% of microcapsule allows the reduction of gypsum thickness by 8.5%, maintaining the same insulating effect. Thus, these kind of material can be used to improve comfort, save energy in buildings and even reduce the weight of wallboards. (author)

  11. Mechanical properties of simulated Mars materials: gypsum-rich sandstones and lapilli tuff

    Science.gov (United States)

    Morrow, Carolyn; Lockner, David; Okubo, Chris

    2013-01-01

    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.

  12. Mineral potential of clays that cover the gypsum deposits in Araripina-PE region

    International Nuclear Information System (INIS)

    In the present work the applicability of the clays that cover the deposits of Gypsum Plaster in the region of Araripina - PE for use as the ceramic pigments and for bricks production in the red ceramic industry was analyzed. The clay minerals contained the illite, kaolinite and smectite, with high proportion of the last one. The possibility of industrial application of this mineral clay is considerable; however, the mining industries that mine and process the gypsum in the region do not take the clays into account as the potential mineral. In general, industries use the clay minerals in manufacturing processes or as key raw materials, or as the alternatives for some kinds of the chemical processing industries. This paper aims to highlight the potential of materials that cover the deposits of gypsum in reference. The material sampled from different deposit layers was characterized and the physical treatment of ore was applied. The results showed that the material analyzed can be used in various kinds of industry, such as the production of natural ceramic pigments. (author)

  13. Gypsum-hosted endolithic communities of the Lake St. Martin impact structure, Manitoba, Canada: spectroscopic detectability and implications for Mars

    Science.gov (United States)

    Rhind, T.; Ronholm, J.; Berg, B.; Mann, P.; Applin, D.; Stromberg, J.; Sharma, R.; Whyte, L. G.; Cloutis, E. A.

    2014-09-01

    There is increasing evidence that Mars may have once been a habitable environment. Gypsum is targeted in the search for Martian biosignatures because it can host extensive cryptoendolithic communities in extreme terrestrial environments and is widespread on Mars. In this study the viability of using different spectroscopy-based techniques to identify the presence of gypsum endolithic communities was investigated by analysing various cryptoendoliths collected from the Lake St. Martin impact crater (LSM), a Mars analogue site found in Manitoba, Canada. Concurrently, the cryptoendolithic microbial community structure present was also analysed to aid in assigning spectroscopic features to microbial community members. Two main morphologies of endolithic communities were collected from gypsum deposits at LSM: true cryptoendolithic communities and annular deposits on partially buried boulders and cobbles Endolithic communities were found to be visibly present only in gypsum with a high degree of translucency and could occur as deep as 3 cm below the exterior surface. The bacterial community was dominated by a phylum (Chloroflexi) that has not been previously observed in gypsum endoliths. The exterior surfaces of gypsum boulders and cobbles are devoid of spectroscopic features attributable to organic molecules and detectable by reflectance, Raman, or ultraviolet-induced fluorescence spectroscopies. However, exposed interior surfaces show unique endolithic signatures detectable by each spectroscopic technique. This indicates that cryptoendolithic communities can be detected via spectroscopy-based techniques, provided they are either partially or fully exposed and enough photon-target interactions occur to enable detection.

  14. Mercury transportation in soil via using gypsum from flue gas desulfurization unit in coal-fired power plant

    Institute of Scientific and Technical Information of China (English)

    Kelin Wang; William Orndorff; Yan Cao; Weiping Pan

    2013-01-01

    The mercury flux in soils was investigated,which were amended by gypsums from flue gas desulphurization (FGD) units of coalfired 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.

  15. Anaerobic digestion of slaughterhouse by-products

    DEFF Research Database (Denmark)

    Hejnfelt, Anette; Angelidaki, Irini

    2009-01-01

    Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 degrees C and for some experiments also at 37 degrees C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone...

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

    Directory of Open Access Journals (Sweden)

    Luis Clenio J. Moreira

    2014-03-01

    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.

  17. Fabrication and properties of microencapsulated-paraffin/gypsum-matrix building materials for thermal energy storage

    International Nuclear Information System (INIS)

    Graphical abstract: DSC curves of microPCMs/gypsum composite samples before and after a thermal cycling treatment. Highlights: ► Microcapsules containing paraffin was fabricated by in-situ polymerization. ► Methanol-modified melamine–formaldehyde (MMF) was used as shell material. ► MicroPCMs/gypsum-matrix building materials were applied for solar energy storage. ► The structure and thermal conductivity of composites had been investigated. - Abstract: Microencapsulated phase change materials (microPCMs) have been widely applied in solid matrix as thermal-storage or temperature-controlling functional composites. The aim of this work was to prepare and investigate the properties of microPCMs/gypsum-matrix building materials for thermal energy storage. MicroPCMs contain paraffin was fabricated by in situ polymerization using methanol-modified melamine–formaldehyde (MMF) as shell material. A series of microPCMs samples were prepared under emulsion stirring rates in range of 1000–3000 r min−1 with core/shell weight ratios of 3/1, 2/1, 1/1, 1/2 and 1/3, respectively. The shell of microPCMs was smooth and compact with global shape, its thickness was not greatly affected by the core/shell ratio and emulsion stirring rate. DSC tests showed that the shell of microPCMs did not influence the phase change behavior of pure paraffin. It was found from TGA analysis that microPCMs samples containing paraffin lost their weight at the temperature of nearly 250 °C, which indicated that the PCM had been protected by shell. More shell material in microPCMs could enhance the thermal stability and provide higher compact condition for core material. After a 100-times thermal cycling treatment, the microPCMs contain paraffin also nearly did not change the phase change behaviors of PCM. With the increasing of weight contents of microPCMs in gypsum board, the thermal conductivity (λ) values of composites had decreased. The simulation of temperature tests proved that the microPCMs/gypsum

  18. Reforestation and landscape reconstruction in gypsum mine area from the semiarid region of NE Brazil

    Science.gov (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.

    2012-04-01

    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

  19. Reproductive toxicology of disinfection by-products.

    OpenAIRE

    Smith, M. K.; Zenick, H; George, E L

    1986-01-01

    The chronic exposure of large segments of the population to disinfected drinking water has necessitated an evaluation of the health effects of the by-products of the chlorination process. This paper reviews the available information concerning the reproductive consequences associated with exposure to disinfection by-products. Four groups of compounds are discussed: the trihalomethanes, in particular chloroform; the chlorinated phenols; chlorinated humic substances; and the haloacetonitriles. ...

  20. Bacterial Communities and the Nitrogen Cycle in the Gypsum Soils of Cuatro Ciénegas Basin, Coahuila: A Mars Analogue

    OpenAIRE

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

    2012-01-01

    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...

  1. Preparation and properties of CSA type expansive cement using industrial by-products

    Energy Technology Data Exchange (ETDEWEB)

    Sone, J.T.; Cho, J.S. [Dankook University, Cheonan (Korea); Jeun, J.Y. [Hyundai Cement Co, Ltd., Tanyang-gun (Korea)

    2001-02-01

    3CaO{center_dot}3Al{sub 2}O{sub 3}{center_dot}CaSO{sub 4}(C{sub 4}A{sub 3}S) clinker was synthesized by using industrial by-product. The raw materials were used fly ash and blast furnace slag(water and air cooling) for Al{sub 2}O{sub 3} material, by-product gypsum for SO{sub 3} material and natural calcite for CaO material, respectively. The CSA type expansive was made by mixing C{sub 4}A{sub 3}S clinker, CaO and CaSO{sub 4}. The hydration and physical properties of ordinary portland cement substituted with 10 wt% CSA additive were investigated. The main hydration products were ettringite and Ca(OH){sub 2}. The densification and the expansion due to the formation of ettringite during hydration increased strength of compressive, tensile and flexural. But they reduced the drying shrinkage of hardened cement. (author). 19 refs., 3 tabs., 11 figs.

  2. 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

    2010-03-30

    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

  3. The impact of gypsum mine water: A case study on morphology and DNA integrity in the freshwater invertebrate, Gammarus balcanicus

    International Nuclear Information System (INIS)

    The aim of our study was to investigate how exposure to heavy metal-rich waters from gypsum mining affects the morphology and levels of primary DNA damage in Gammarus balcanicus. Chemical analysis revealed increased concentrations of metals in water and sediment collected at a site impacted by gypsum mine wastewaters. The specimens also showed elevated total tissue metal levels when compared with the organisms collected at the reference site. The most prominent increase was observed for strontium, followed by iron, nickel, vanadium, aluminium, and manganese. The major pathway of entry for these toxic substances was through the degraded exoskeleton as a consequence of excessive strontium input (unbalanced calcium/strontium ratio) and altered permeability. Disturbed exoskeleton integrity was observed only in individuals collected downstream of the gypsum mine, which was confirmed by electron microscopy. Levels of primary DNA damage were evaluated using the alkaline comet assay in the haemolymph of the specimens. - Highlights: • Our findings suggest toxic potential of gypsum mine wastewaters. • The Gammarus specimens showed elevated total tissue metal levels. • Strontium uptake disturbed exoskeleton integrity. • Corrupted cuticle altered permeability to other toxic substances. • Combined effects of all contaminants caused genotoxicity. - Gypsum mine wastewaters have genotoxic potential and affect the gammarid exoskeleton morphology and biochemistry associated with a high strontium uptake

  4. Anaerobic digestion of slaughterhouse by-products

    International Nuclear Information System (INIS)

    Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 oC and for some experiments also at 37 oC. 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 dm3 kg-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-3 and 7 g N dm-3 respectively. Pretreatment (pasteurization: 70 oC, sterilization: 133 oC, 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 oC showed 40% higher methane production compared to digestion of manure alone.

  5. Preparation and Absorption/Desorption Performance of Gypsum-based Humidity Controlling Materials

    Institute of Scientific and Technical Information of China (English)

    JIANG Hongyi; LUAN Congmei

    2011-01-01

    Absorption/desorption properties of some humidity controlling materials which contain gypsum as basic cement materials and activated Sepiolite powder as humidity controlling media were tested.The kinetics curve of moisture adsorption/desorption were drawn and humidity controlling performance in nature environment was verified.The experimental results show that moisture absorption/desorption rates are increased,and the speed is also accelerated.These materials,which can adjust environmental humidity effectively,are new ones with good humidity controlling performance.

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

    Directory of Open Access Journals (Sweden)

    Oliver-Ramírez, A.

    2011-09-01

    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.

  7. Radiation-induced signals of gypsum crystals analysed by ESR and TL techniques applied to dating

    Energy Technology Data Exchange (ETDEWEB)

    Aydas, Canan [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey); Engin, Birol, E-mail: birol_engin65@yahoo.co [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey); Aydin, Talat [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey)

    2011-02-15

    Natural crystals of terrestrial gypsum were investigated concerning the radiation effects on Electron spin resonance (ESR) and Thermoluminescence (TL) properties and their application for geological dating. ESR signals of Fe{sup 3+}, Mn{sup 2+}, G1 (SO{sub 3}{sup -}, g = 2.003) and G2 (SO{sub 4}{sup -}, g{sub ||} =2.018g{sub perpendicular} =2.009) centers were observed. The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal at g = 2.009. The intensity of this center increased with {gamma}-radiation and the additive dose method for this ESR center yielded accumulated dose GD of 67.4 {+-} 10.1 Gy. Using U, Th and K contents plus the cosmic-ray contribution, a dose rate of 1.92 {+-} 0.22 mGy/year has been obtained. We have determined the ESR age of the gypsums to be (35 {+-} 4) x 10{sup 3} years. TL peaks at 157 and 278 {sup o}C were observed. By using initial rise method the thermal activation energy of 278 {sup o}C TL peak was found to be underestimated, probably due to the thermal quenching. Activation energies and frequency factors obtained by the method of varying the heating rate indicate lifetime of 4.09 x 10{sup 7} years (at 15 {sup o}C) for 278 {sup o}C peak. The additive dose method applied to this TL peak yielded GD of 75 {+-} 11 Gy. The corresponding TL age using the 278 {sup o}C TL peak was found to be (39 {+-} 5) x 10{sup 3} years for gypsum sample. The TL age of this sample is consistent with the ESR age within experimental error limits. The obtained ESR and TL ages are not consistent with the expectations of geologists. This contradiction is probably due to the repeatedly recrystallisation of gypsum samples under the environmental conditions after their formation in the upper Miocene-Pliocene Epoch.

  8. Radiation-induced signals of gypsum crystals analysed by ESR and TL techniques applied to dating

    Science.gov (United States)

    Aydaş, Canan; Engin, Birol; Aydın, Talat

    2011-02-01

    Natural crystals of terrestrial gypsum were investigated concerning the radiation effects on Electron spin resonance (ESR) and Thermoluminescence (TL) properties and their application for geological dating. ESR signals of Fe 3+, Mn 2+, G1 ( SO3-, g = 2.003) and G2 ( SO4-, g∥=2.018g⊥=2.009) centers were observed. The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal at g = 2.009. The intensity of this center increased with γ-radiation and the additive dose method for this ESR center yielded accumulated dose GD of 67.4 ± 10.1 Gy. Using U, Th and K contents plus the cosmic-ray contribution, a dose rate of 1.92 ± 0.22 mGy/year has been obtained. We have determined the ESR age of the gypsums to be (35 ± 4) × 10 3 years. TL peaks at 157 and 278 °C were observed. By using initial rise method the thermal activation energy of 278 °C TL peak was found to be underestimated, probably due to the thermal quenching. Activation energies and frequency factors obtained by the method of varying the heating rate indicate lifetime of 4.09 × 10 7 years (at 15 °C) for 278 °C peak. The additive dose method applied to this TL peak yielded GD of 75 ± 11 Gy. The corresponding TL age using the 278 °C TL peak was found to be (39 ± 5) × 10 3 years for gypsum sample. The TL age of this sample is consistent with the ESR age within experimental error limits. The obtained ESR and TL ages are not consistent with the expectations of geologists. This contradiction is probably due to the repeatedly recrystallisation of gypsum samples under the environmental conditions after their formation in the upper Miocene-Pliocene Epoch.

  9. Coupled measurement of δ18O/δD in gypsum hydration water and salinity of fluid inclusions in gypsum: A novel tool for reconstructing parent water chemistry and depositional environment

    Science.gov (United States)

    Evans, Nick; Gázquez, Fernando; Turchyn, Alexandra; Chapman, Hazel; Hodell, David

    2015-04-01

    The measurement of oxygen and hydrogen isotopes in gypsum hydration water (CaSO4•2H2O) is a powerful tool to determine the isotopic composition of the parent fluid from which gypsum precipitated. To be useful, however, the hydration water must retain its original isotope signal and not have undergone postdepositional exchange. We developed a novel method to ascertain whether hydration waters have secondarily exchanged by coupling oxygen and hydrogen isotopes of gypsum hydration water with the salinities of fluid inclusions. Salinity is obtained through microthermometric analysis of the same gypsum crystals measured for hydration water by freezing the sample and then measuring the melting point of the fluid inclusions. We apply the method to Messinian gypsum deposits of Cycle 6 within the Yesares Member, Río de Aguas section, Sorbas Basin (SE Spain). After correction of oxygen and hydrogen isotopes of gypsum hydration water for fractionation factors, the estimated range of the mother water is -1.8o to 2.8o for δ18O and -12.5o to 16.3o for δD. In the same samples, estimated salinity of primary fluid inclusions range from 18 to 51ppt. Salinity is highly correlated with δ18O and δD, yielding an r2 of 0.88 and 0.87, respectively. The intercepts of the regression equations (i.e., at zero salinity) define the isotope composition of the freshwater endmember, and average -4.4±1.3o for δ18O and -28.9±8.7o for δD. These values are within error of the average isotope composition of precipitation and groundwater data from the local region of Almería today (-4.3o and -22.2o for δ18O and δD, respectively). This agreement provides strong evidence that the gypsum hydration water has retained its isotope composition and has not undergone postdepositional exchange. Furthermore, the isotope and salinity values indicate a significant contribution of meteoric water during gypsum deposition. This observation contrasts with sulfur and oxygen isotopes in sulfate (21.9 > δ34S

  10. Commercial use of coal combustion by-products in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Vom Berg, W. [VGB Technische Vereinigung der Grosskraftwerksbetreiber e.V., Essen (Germany)

    1997-12-31

    In 1994, front 57.5% million tonnes of by-products produced in coal-fired plants in the European Union, about 44% were utilized in the construction industry and as building material in the deep mining industry and 28% for the refilling and recultivating of lignite open cast mines and other artificial or natural depressions. The utilization of by-products has various advantages from the point of view of environmental protection, but leads in the most cases to increased waste management costs. In order to guarantee power plant waste management through utilization it is important to diversify as much as possible the ways of utilization. During the last 30 years, different utilization methods for by-products have been developed. The choice of the `right` utilization depends on the specific conditions of the power plant. The situation of utilization in Europe is shown in an exemplary way for the different by-products. A direct adoption to the Indian situation is surely not possible as options for utilization are to a large degree determined by historical, geographical, infrastructural and other factors. Some general considerations and practical experience in Europe, however, could help to avoid false developments in India. 1 ref., 2 figs., 2 tabs.

  11. Valorization of food processing by-products

    NARCIS (Netherlands)

    Chandrasekaran, M.; Nout, M.J.R.; Sarkar, P.K.

    2012-01-01

    Biotechnology has immense potential for resolving environmental problems and augmenting food production. Particularly, it offers solutions for converting solid wastes into value-added items. In food processing industries that generate voluminous by-products and wastes, valorization can help offset g

  12. Recycling flue gas desulphurization (FGD) gypsum for removal of Pb(II) and Cd(II) from wastewater.

    Science.gov (United States)

    Yan, Yubo; Li, Qiao; Sun, Xiuyun; Ren, Zhiyuan; He, Fei; Wang, Yalun; Wang, Lianjun

    2015-11-01

    The present study aims to verify the feasibility of directly reusing the flue gas desulphurization (FGD) gypsum generated from coal-fired power plants to adsorptively remove Pb(II) and Cd(II) from wastewater. The Toxicity Characteristic Leaching Procedure (TCLP) test was conducted to evaluate the leachability of toxic heavy metals from FGD gypsum. The adsorption behaviors of FGD gypsum for Pb(II) and Cd(II) such as pH impact, sorption kinetics, sorption isotherms and sorption thermodynamics were studied in a series of batch experiments. The pH studies indicated that the adsorption of Pb(II) and Cd(II) had their best adsorption amounts both at the pH values from 5.0 to 7.0. The kinetic analysis displayed that the adsorption processes both followed the pseudo-second order model well, and the FGD gypsum provided a higher sorption rate for Pb(II). Equilibrium studies showed that the adsorption of Pb(II) and Cd(II) could be properly described by Langmuir isotherms model, and the predicted maximum adsorption capacities were even greater than some specially prepared adsorbents. The thermodynamic investigation confirmed that the removal of Pb(II) and Cd(II) from aqueous medium could carry out spontaneously, and the higher temperature favored the processes. The instrument analysis techniques were also employed to deeply understand the mechanism involved in Pb(II) and Cd(II) removal by FGD gypsum. Overall, good sorption performance together with cost-effective characteristic makes FGD gypsum potentially attractive material for the Pb(II) and Cd(II) removal in industrial wastewater. PMID:26162902

  13. Breakdown development in cover beds, and landscape features induced by intrastratal gypsum karst

    Directory of Open Access Journals (Sweden)

    Andrejchuk V.

    1996-01-01

    Full Text Available Intrastratal karst is by far the predominant gypsum karst type. Its development may begin in deep-seated settings within rocks already buried by younger strata, and it proceeds increasingly rapidly as uplift brings gypsum sequences into progressively shallower positions. Such development commonly occurs under confined (artesian hydrogeological conditions, that subsequently change to open conditions (phreatic-water table-vadose. The general evolutionary line of intrastratal karst is typified by progressive emergence of a sequence into a shallower position, activation of groundwater circulation and development of cave systems within karst units, commencement of gravitational breakdown and its upward propagation through overlying beds, and development of a karst landscape. These processes and phenomena progress through the directed evolution of karst types as follows: deep-seated intrastratal karst (1K to subjacent 1K to entrenched 1K to denuded karst. One of the main characteristics of intrastratal karst is that it induces gravitational breakdown in cover beds. With the aid of processes other then simple breakdown, such effects may propagate upwards and may, or may not, reach the surface, depending upon the thickness and structure of the overburden. A karst landscape evolves when such features reach the surface. This paper considers the conditions and mechanisms of such development.

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

    Directory of Open Access Journals (Sweden)

    Vimmrová Alena

    2016-06-01

    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.

  15. Leaching characteristics of trace elements in desulfurization gypsum from a coal-fired power plant

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.K.; Zhuo, Y.Q.; Zhu, Z.W.; Chen, C.H. [Tsinghua Univ., Beijing (China). Inst. of Thermal Engineering

    2013-07-01

    The contents and leaching characteristics of Cr, Cd, As, Pb and Se in FGD gypsum from a 200 MW coal-fired power plant were investigated in this study. Experimental results revealed that: the leaching characteristics of As and Se were similar, both leaching rates were not obviously affected by pH but increased with increase of the liquid-solid ratio. Pb and Cr had similar leaching characteristics, their leaching rates were closely related with the pH of leaching solution and increased with the lowering of pH and both increased with the increasing of solid-liquid ratio. Along with the increase of the liquid-solid ratio, the leaching gradually achieved balance, and the balanced liquid-solid ratio was bigger when pH of leaching solution was lower. Cd content of leaching solution was below detect limit, and thus failed to get its leaching characteristics. The order of trace element content in leaching solution is Pb < Cr < As < Se, and the order of leaching rates is Cr < As < Pb < Se. BCR extraction procedure revealed that trace elements in FGD gypsum were mainly existed as available fraction and migration ability was stronger than that of trace elements in fly ash from coal-fired power plants.

  16. Detection of Defects in Acrylic and Steel Inclusions in Gypsum Using Compton Backscattered Gamma Rays

    Science.gov (United States)

    Boldo, Emerson M.; Appoloni, Carlos R.

    2011-08-01

    Compton scattering of gamma radiation is a nondestructive technique used for the detection of defects and inclusions in materials. The methodology allows one-side inspection of large structures, is relatively inexpensive and can be portable. The number of photons inelastically scattered within a well-defined volume element is linearly proportional to the electron density of the material. Targeting a sample with a collimated beam of gamma rays, the energy spectrum of backscattered photons can be used to determine local density perturbations. In this work we used the Compton backscattering technique to detection of small collinear defects in acrylic blocks and steel rods inclusions in gypsum blocks samples. The samples were irradiated with gamma rays from a O/2 mm collimated 241Am (100 mCi) source and the inelastically scattered photons were collected at an angle of 135° by a CdTe detector with a O/7 mm×30 mm collimation. Scanning was achieved by lateral movement of the sample blocks across the source and detector field of view in steps of 1 mm. The results showed that defects in the acrylic samples as small as 3 mm in size were visible in the intensity versus energy spectrum. The tests on gypsum blocks with steel rods inclusions suggest that, for a low energy and activity source, the effects of beam attenuation are more decisive to the scattered intensity than increasing of material density. An analysis of the density contrast is also presented.

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

    DEFF Research Database (Denmark)

    Sadrekarimi, Jamshid; Kiyani, Majid; Fakhri, Behnam;

    2011-01-01

    model locates the phreatic surface somewhat higher than the 2D model. This means that the 2D model estimates lower pore water pressure pattern in comparison with the 3D model. These may be attributed to the fact that with 2D model the lateral components of vectors of seepage velocity are ignored. In the......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...

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

    Science.gov (United States)

    Vimmrová, Alena; Kočí, Václav; Krejsová, Jitka; Černý, Robert

    2016-06-01

    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.

  19. Study on effects of wood fiber content on physical, mechanical, and acoustical properties of wood-fiber-filled gypsum composites

    Directory of Open Access Journals (Sweden)

    Hamed Ramezani

    2012-04-01

    Full Text Available The Acoustical model of wood-fiber-filled gypsum composites panel is presented. The transmission loss coefficients of the composite structures were calculated by an approximated approach. However, the physical and mechanical properties of board specimens including; water absorption, thickness swelling, bending modulus of elasticity, bending modulus of rupture, internal bond, and compression parallel to the surface obtained experimentally. Finally, the effects of wood fibers to gypsum mixing ratios on physical, mechanical and acoustical properties of composite flat structures were investigated and data analysis was done by use of statistical methods.

  20. Differing Abundances of Gypsum in the Primary and Secondary Dunes of the Martian Dune Field Olympia Undae

    Science.gov (United States)

    Szumila, I. T.; Bishop, J. L.; Fenton, L. K.; Brown, A. J.

    2012-12-01

    We report on a compositional study in Olympia Undae, located around the polar cap of Mars. Gypsum has been detected throughout the sand sea but with a decline in abundance westward (Langevin et al., 2005). Dune crests are the regions of highest apparent gypsum concentration in CRISM images. Olympia Undae consists of primary dunes formed transverse to circumpolar easterly winds and secondary dunes which lie almost orthogonal to the primary dunes (Ewing et al. 2010). METHODS: We examined a number of CRISM and HiRISE images across the dune field. We focused our preliminary study on FRT0000C31A and FRT0000C2FC, which exhibited the best spectral signatures. Gypsum was identified in CRISM images by its unique 1.45/1.49/1.54 μm triplet, ~1.94-1.95 μm band, 2.22/2.27 μm doublet and 2.49 μm band with a 2.42 μm shoulder. Spectra were acquired from regions of interest (ROIs) created along the crests of primary dunes and the low-relief crests of the secondary dunes (Fig. 1). FINDINGS: CRISM spectra of primary and secondary dune crest ROIs from FRT0000C2FC are compared with a gypsum-rich unit in FRT0000CA5C (Fig. 2). The I/F of gypsum-bearing regions is much darker than pure gypsum indicating a mixture composition containing darker components. The depth of the ~1.95 μm hydration band is ~20-30% stronger for primary dune crests relative to the secondaries, which suggests a similar relationship among the gypsum abundance of these features, assuming similar components and grain sizes. Semi-quantitative analyses are underway to measure this in more detail. Continuing studies are planned with additional images as well. Figure 1 A map-projected view of CRISM image FRT0000C2FC with ROI locations for the primary (P) and secondary (S) dune crests marked. Figure 2 CRISM I/F spectra of gypsum-bearing units in Olympia Undae compared with laboratory reflectance spectra of minerals.

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

    OpenAIRE

    Shao, Dezhi; Liu, Jinlong; Huang, Xin

    2015-01-01

    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...

  2. 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.)

    1993-04-01

    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. Sulfide weathering in the Werenskioldbreen, Spitsbergen - A polar terrestrial analogue for gypsum deposition in the North Polar Region of Mars

    Science.gov (United States)

    Szynkiewicz, A.; Modelska, M.; Buczynski, S.; Borrok, D.; Pratt, L.

    2010-12-01

    Hydrated sulfates such as gypsum are important constituents of the low-elevation areas around the North Polar residual ice cap on Mars, but the origin of hydrological process which led to the formation and accumulation of gypsum is poorly understood. To address this uncertainty, we investigated the origin of proglacial gypsum in the Werenskioldbreen, a polythermal glacier of Spitsbergen in the Svalbard archipelago east of Greenland. We measured S isotopes, major chemistry and surface water flow rates to calculate SO4 fluxes from sulfide weathering in this polar climate. Sulfides comprised 0.02 to 0.42 weight % of the fine-grained fraction of proglacial sediments and their δ34S varied over the range of +9 to +16 ‰. The δ34S of dissolved SO4 in glacier melt waters (+9 to +17 ‰) was consistent with SO4 generation being dominated by sulfide oxidation. In summer 2008, the calculated SO4 flux was ~6,200 kg/day in the main glacier stream of the Werenskioldbreen discharging to the Greenland Sea and it translated to 4.3 x 105 mol/yr-km2 based on the scale of the entire Werenskioldbreen catchment (~27.4 km2). Our measured polar SO4 flux was 6 times larger than reported estimates for pyrite-derived SO4 loading in a considerably larger (1.78 x 106 km2) watershed of Northern Canada. This implies that small glacier catchments can generate an important global-scale flux of sulfide-derived SO4. Both evaporation and freezing of glacial waters lead to precipitation, accumulation, and temporary storage of gypsum in the proglacial zone. Poor preservation of gypsum on the surface of proglacial sediments mainly results from its quick dissolution during warmer condition when the hydrological cycle is most active. The observed distribution of gypsum and hydrated sulfates around the north polar ice residual deposits of Planum Boreum on Mars matches the spatial and geochemical patterns of gypsum formation controlled by sulfide weathering in terrestrial polar environments like

  4. 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

    2009-01-30

    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

  5. Environmental impact of a coal combustion-desulphurisation plant: Abatement capacity of desulphurisation process and environmental characterisation of combustion by-products

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Ayuso, E.; Querol, X.; Tomas, A. [Inst. of Earth Science Jaume Almera, (CSIC), Barcelona (Spain). Dept. of Environmental Geology

    2006-12-15

    The fate of trace elements in a combustion power plant equipped with a wet limestone flue gas desulphurisation (FGD) installation was studied in order to evaluate its emission abatement capacity. With this aim representative samples of feed coal, boiler slag, fly ash, limestone, FGD gypsum and FGD process water and wastewater were analysed for major and trace elements using the following techniques: inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), ion chromatography (IC), ion selective electrode (ISE) and atomic absorption spectroscopy (AAS). Mass balances were established allowing to determine the element partitioning behaviour. It was found that, together with S, Hg, Cl, F, Se and As were those elements entering in the FGD plant primarily as gaseous species. The abatement capacity of the FGD plant for such elements offered values ranged from 96% to 100% for As, Cl, F, S and Se, and about 60% for Hg. The environmental characterisation of combustion by-products (boiler slag fly ash and FGD gypsum) were also established according to the Council Decision 2003/33/EC on waste disposal. To this end, water leaching tests (EN-12457-4) were performed, analysing the elements with environmental concern by means of the aforementioned techniques. According to the leaching behaviour of combustion by-products studied, these could be disposed of in landfills for non-hazardous wastes.

  6. Environmental impact of a coal combustion-desulphurisation plant: abatement capacity of desulphurisation process and environmental characterisation of combustion by-products.

    Science.gov (United States)

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

    2006-12-01

    The fate of trace elements in a combustion power plant equipped with a wet limestone flue gas desulphurisation (FGD) installation was studied in order to evaluate its emission abatement capacity. With this aim representative samples of feed coal, boiler slag, fly ash, limestone, FGD gypsum and FGD process water and wastewater were analysed for major and trace elements using the following techniques: inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), ion chromatography (IC), ion selective electrode (ISE) and atomic absorption spectroscopy (AAS). Mass balances were established allowing to determine the element partitioning behaviour. It was found that, together with S, Hg, Cl, F, Se and As were those elements entering in the FGD plant primarily as gaseous species. The abatement capacity of the FGD plant for such elements offered values ranged from 96% to 100% for As, Cl, F, S and Se, and about 60% for Hg. The environmental characterisation of combustion by-products (boiler slag, fly ash and FGD gypsum) were also established according to the Council Decision 2003/33/EC on waste disposal. To this end, water leaching tests (EN-12457-4) were performed, analysing the elements with environmental concern by means of the aforementioned techniques. According to the leaching behaviour of combustion by-products studied, these could be disposed of in landfills for non-hazardous wastes. PMID:16890268

  7. Lipid and Phylogenetic Analysis of a Gypsum-hosted Endoevaporitic Microbial Community

    Science.gov (United States)

    Turk, K. A.; Jahnke, L. L.; Green, S. J.; Kubo, M. D.; Vogel, M. B.; Des Marais, D. J.

    2007-12-01

    Gypsum evaporites host diverse, productive and volumetrically significant microbial communities and are relevant modern-day analogs to both Precambrian sabkha deposits and, potentially, Martian evaporites. Extensive evaporites form in subaqueous environments of high salinity ponds (>150 permil) maintained by the Exportadora de Sal, S. A. (ESSA) in Guerrero Negro, B.C.S., Mexico. A gypsarenite (reworked clastic gypsum) crust found along the southeast margin of ESSA's Pond 9 was collected in February 2004 and each vibrantly colored layer in the top centimeter was sampled. Extant microbial communities from each layer were characterized using complementary culture-independent molecular techniques, lipid biomarker analysis, and compound specific isotopic analysis. Coupling molecular analysis with lipid biomarker analysis revealed that oxygenic photosynthetic organisms dominate the surface layers (top 3 mm). Polar lipids from the surface layers consisted predominantly of glycolipids, which are characteristic of algae, cyanobacteria and green anoxygenic photosynthetic bacteria. Consistent with prior analyses of gypsum evaporites, 16S rRNA gene clone libraries indicate that cyanobacterial populations belong primarily to the genus Cyanothece. The bacterial community below the surface layers is more diverse and dominated by anaerobic organisms. Phototrophic purple sulfur bacteria, sulfate-reducing bacteria (SRB), and Bacteroidetes were particularly abundant. The relative abundances of SRB increased with depth; Desulfobacteraceae clones were distributed throughout the crust, but not at the surface, while Desulfovibrionaceae clones were found predominantly in the deepest layers. These molecular results are consistent with fatty acid biomarker analysis. δ13C values of major lipid classes in the crust and sediment range from 14 to 36‰, which is considerably lower than corresponding values for benthic Microcoleus-dominated cyanobacterial mats found at lower salinities at ESSA

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

    KAUST Repository

    Chen, Si Cong

    2013-11-08

    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.

  9. 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: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih. 31136 (Mexico)

    2015-07-23

    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.

  10. GYPSUM-WATER MANAGEMENT INTERACTIONS ON THE SURVIVAL, YIELD, AND PROTEIN CONTENT OF SELECTED SPECIES OF MARSH VEGETATION

    Science.gov (United States)

    A field study evaluating the effects of gypsum and water management on the survival, yield, and protein content of selected species of marsh vegetation was conducted on an open area inundated by brackish water near Hackberry, LA. The overall growth and yield responses of four species of marsh vegeta...

  11. A Study on the Effective Factors on the Development of Gypsum and Salt Export in Jenah in Hormozgan Province

    Directory of Open Access Journals (Sweden)

    Abbas Talebbeydokhti

    2014-04-01

    Full Text Available This study seeks to study the effective factors on the development of gypsum and salt export in Jenah region of Hormozgan Province. The statisitcal universe of this research comprises all managers and exporters in the gypsum and salt industry in Hormozgan Province. The studied sample size was estimated 130 by using Cochran formula. To measure export development, Da Silva and Da Rocha 30-item questionnaire was used; this questionnaire has been designed for measuring the effective factors on the development of export from five aspects namely, financial factors, political factors, managerial factors, cultural factors and technological factors. Having examined descriptive statistics of the research variables, validity and reliability of the questionnaire and data normality, the effect of each variable on the development of gypsum and salt export was studied by using t student test and the variables and their indices were prioritized by Friedman ranking. The resutls revealed that through the lens of respondents and by 99% confidence, technological and managerial factors are the mere obstacles to the development of gypsum and salt export in Hormozgan Province. The most important technological obstacles are namely, warehousing and control of physical goods flow in the destination country, access to the wholesalers or retailers in the destination country, difficulty of employing qualified persons or companies for the export-related activities and the most important managerial obstacles are namely, lack of managerial schedule and lack of export management skills.

  12. Biogas from by-products; Biogas aus Nebenprodukten

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

    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.

  13. Age and speleogenesis of epigenic gypsum caves in the northern Apennines (Italy)

    Science.gov (United States)

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

    2016-04-01

    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

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

    Directory of Open Access Journals (Sweden)

    K. Toshtay

    2013-05-01

    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.

  15. New insights into meat by-product utilization.

    Science.gov (United States)

    Toldrá, Fidel; Mora, Leticia; Reig, Milagro

    2016-10-01

    Meat industry generates large volumes of by-products like blood, bones, meat trimmings, skin, fatty tissues, horns, hoofs, feet, skull and viscera among others that are costly to be treated and disposed ecologically. These costs can be balanced through innovation to generate added value products that increase its profitability. Rendering results in feed ingredients for livestock, poultry and aquaculture as well as for pet foods. Energy valorization can be obtained through the thermochemical processing of meat and bone meal or the use of waste animal fats for the production of biodiesel. More recently, new applications have been reported like the production of polyhydroxyalkanoates as alternative to plastics produced from petroleum. Other interesting valorization strategies are based on the hydrolysis of by-products to obtain added value products like bioactive peptides with relevant physiological effects as antihypertensive, antioxidant, antidiabetic, antimicrobial, etc. with promising applications in the food, pharmaceutical and cosmetics industry. This paper reports and discusses the latest developments and trends in the use and valorisation of meat industry by-products. PMID:27156911

  16. Hydration effects on gypsum dissolution revealed by in situ nanoscale atomic force microscopy observations

    Science.gov (United States)

    Burgos-Cara, A.; Putnis, C. V.; Rodriguez-Navarro, C.; Ruiz-Agudo, E.

    2016-04-01

    Recent work has suggested that the rates of mineral dissolution in aqueous solutions are dependent on the kinetics of dehydration of the ions building the crystal. Dehydration kinetics will be ultimately determined by the competition between ion-water and water-water interactions, which can be significantly modified by the presence of background ions in solution. At low ionic strength, the effect of electrolytes on ion-water (electrostatic) interactions will dominate (Kowacz et al., 2007). By performing macroscopic and in situ, microscopic (atomic force microscopy) dissolution experiments, the effect of background electrolytes on the dissolution kinetics of gypsum (CaSO4·2H2O) {0 1 0} cleavage surfaces is tested at constant, low ionic strength (IS = 0.05) and undersaturation (saturation index, SI = -0.045). Dissolution rates are systematically lower in the presence of 1:1 background electrolytes than in an electrolyte-free solution, regardless of the nature of the electrolyte tested. We hypothesize that stabilization of the hydration shell of calcium by the presence of background ions can explain this result, based on the observed correlations in dissolution rates with the ionic surface tension increment of the background ion in solution. Stabilization of the cation hydration shell should favor dissolution. However, in the case of strongly hydrated ions such as Ca2+, this has a direct entropic effect that reduces the overall ΔG of the system, so that dissolution is energetically less favorable. Overall, these results provide new evidence that supports cation dehydration being the rate-controlling step for gypsum dissolution, as proposed for other minerals such as barite, dolomite and calcite.

  17. 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

    2015-06-01

    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.

  18. Antioxidant properties of extracts from buckwheat by-products

    Directory of Open Access Journals (Sweden)

    Marzanna Hęś

    2012-06-01

    Full Text Available Background. In the course of production of buckwheat groats by-products are produced, such as bran and hull, which apart from high content of dietary fi ber, may also constitute valuable sources of antioxidants. The aim of these investigations was to determine the antioxidant activity of extracts from by-products produced during processing of buckwheat for groats. Material and method. Analyses were conducted on bran and hull of buckwheat cv. Kora. Extraction was run using acetone, methanol and water at room temperature for 24 h. The level of phenolics was determined spectrophotometrically with the Folin-Ciocalteau reagent, using (+ catechin as a standard. Antioxidant activity of extracts was analysed in relation to linoleic acid, running incubation for 19 h, by scavenging of stable radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl and on the basis of metal chelating ability. Recorded results were compared with the activity of BHT (butylated hydroxytoluene. Results. The highest content of polyphenols was found in the methanol extract of hull (168.5 mg/g d.m., which was also characterised by the best antiradical properties. The lowest content of total phenols was found for water extracts of bran after grinding and fi nal bran, at 20.3 mg/g d.m. and 10.2 mg/g d.m. In the emulsion system the highest activity was found for methanol extracts of hull and bran after grinding (Wo = 0.89, as well as the extract of fi nal bran (Wo = 0.85. A higher chelating ability in relation to Fe (II ions was observed for bran extracts (after grinding – 76.1%, fi nal bran – 62.2% than for hull extracts (26%. Conclusions. Extracts obtained from by-products of buckwheat were characterised by high antioxidant activity in the applied model systems.

  19. Pseudomorphs of Neotethyan Evaporites in Anatolia's HP/LT belts - Aptian basin-wide pelagic gypsum deposits

    Science.gov (United States)

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

    2015-04-01

    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

  20. Origin and diagenetic evolution of gypsum and microbialitic carbonates in the Late Sag of the Namibe Basin (SW Angola)

    Science.gov (United States)

    Laurent, Gindre-Chanu; Edoardo, Perri; Ian, Sharp R.; Peacock, D. C. P.; Roger, Swart; Ragnar, Poulsen; Hercinda, Ferreira; Vladimir, Machado

    2016-08-01

    Ephemeral evaporitic conditions developed within the uppermost part of the transgressive Late Sag sequence in the Namibe Basin (SW Angola), leading to the formation of extensive centimetre- to metre-thick sulphate-bearing deposits and correlative microbialitic carbonates rich in pseudomorphs after evaporite crystals. The onshore pre-salt beds examined in this study are located up to 25 m underneath the major mid-Aptian evaporitic succession, which is typified at the outcrop by gypsiferous Bambata Formation and in the subsurface by the halite-dominated Loeme Formation. Carbonate-evaporite cycles mostly occur at the top of metre-thick regressive parasequences, which progressively onlap and overstep landward the former faulted (rift) topography, or fill major pre-salt palaeo-valleys. The sulphate beds are made up of alabastrine gypsum associated with embedded botryoidal nodules, dissolution-related gypsum breccia, and are cross-cut by thin satin-spar gypsum veins. Nodular and fine-grained fabrics are interpreted as being diagenetic gypsum deposits resulting from the dissolution and recrystallisation of former depositional subaqueous sulphates, whereas gypsum veins and breccia result from telogenetic processes. The carbonates display a broader diversity of facies, characterised by rapid lateral variations along strike. Thin dolomitic and calcitic bacterial-mediated filamentous microbialitic boundstones enclose a broad variety of evaporite pseudomorphs and can pass laterally over a few metres into sulphate beds. Dissolution-related depositional breccias are also common and indicate early dissolution of former evaporite layers embedded within the microbialites. Sulphate and carbonate units are interpreted as being concomitantly deposited along a tide-dominated coastal supra- to intertidal- sabkha and constitute high-frequency hypersaline precursor events, prior to the accumulation of the giant saline mid-Aptian Bambata and Loeme Formations. Petrographic and geochemical

  1. VNIR reflectance spectra of gypsum mixtures for comparison with White Sands National Monument, New Mexico (WSNM) dune samples as an analog study of the Olympia Undae region of Mars

    Science.gov (United States)

    King, S. J.; Bishop, J. L.; Fenton, L. K.; Lafuente, B.; Garcia, G. C.; Horgan, B. H.

    2013-12-01

    Dunes at WSNM are being used as an analog study area for gypsum-rich dunes near the northern polar region of Mars. Samples were collected from 4 dunes at WSNM for this study. In order to determine abundances of the gypsum, quartz and dolomite present in the dune sand, size separates (250 μm) were prepared for gypsum, quartz and dolomite, mixtures were prepared using the 90-150 μm size fraction, and all samples were characterized in the lab. Analyses of the VNIR spectral data are presented here (Figs. 1-2) and analyses of the XRD data are presented in a companion abstract [1]. The majority of the dune sand is dominated by gypsum, while the coarse grains at some ripples are largely dolomite. Mid-IR spectra will be evaluated as well. Gypsum/Dolomite Mixtures (Fig. 1) There is a clear progression of albedo and band strength in these mixture spectra as one mineral is increased and the other decreased. The mixture spectra are dominated by the gypsum bands for mixtures that are gypsum rich (≥50wt.% gypsum) including a triplet at 1.446-1.535 μm, plus bands at 1.749, 1.945, 2.217 and 2.267 μm. When mixtures become predominantly dolomite (10/90 & 20/80 mixtures), the gypsum bands are significantly weaker, while the dolomite band at 2.322 becomes much more visible. Gypsum/Quartz Mixtures (Fig. 2) The gypsum/quartz mixture spectra are dominated to an even greater extent by gypsum, resulting in readily observable gypsum features for spectra of samples with only 10 wt.% gypsum. [1] Lafuente et al. (2013) AGU, submitted.

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

    Directory of Open Access Journals (Sweden)

    Llamas Borrajo, J. F.

    2007-08-01

    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

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

    Directory of Open Access Journals (Sweden)

    Rodríguez-Orejón, A.

    2014-06-01

    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.

  4. Study of the Effect of Gypsum and Rice Straw Extract on the Control of Earthy-Musty Odor in Tilapia Culture Pond

    Directory of Open Access Journals (Sweden)

    Supannee SUWANPAKDEE

    2016-07-01

    Full Text Available The effect of gypsum and rice straw extract to reduce the levels of earthy-musty odor in tilapia earthen ponds was determined. Three treatments with 3 replicates in a completely randomized design were performed as follows: T1 - control; T2 - gypsum at 200 ppm, and T3 - rice straw tannin extract at 1 ppm. The results show that rice straw tannin extract treatment in tilapia ponds was the most effective method in reducing off-flavor in pond water. The use of 200 ppm gypsum in reducing off-flavor in ponds was also more effective than the control. Both rice straw extract and gypsum-treated ponds had increased fish biomass and %FCE. These methods have potential as alternative methods for the reduction of off-flavor, as well as the control of phytoplankton, turbidity, and TSS in tilapia ponds.

  5. 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

    2003-01-01

    estimating biomass 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......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 (3.2.1.52) 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 was...

  6. Precise timing of lacustrine gypsum in Luobubo, Xinjiang using the thermal ionization mass spectrometry U-series method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Dating techniques including gypsum dissolu tion in water, iron hydroxide co-precipitation with uranium and thorium and mass spectrometric determination have been investigated in this note. The ages of the gypsum sam ples in a CK core from Luobubo lacustrine sediments are in the range of (12.85 ± 0.21) kaBP (4 m distance from the top core) to (153.2± 7.2) kaBP (49 m distance from the top core) with the relative errors of ± 1.6%-± 4.7%. It indicates that the sedimental environment of the CK core was situated in the middle-late Pleistocene and Holocene periods, corre sponding to 1--6 stages of oxygen isotopes in the abyssal sediments and included much information from last inter glacial to Holocene warm periods.

  7. Astrobiological significance of minerals on Mars surface environment: UV-shielding properties of Fe (jarosite) vs. Ca (gypsum) sulphates

    CERN Document Server

    Amaral, G A; Vázquez, L; Amaral, Gabriel; Martinez-Frias, Jesus; Vazquez, Luis

    2005-01-01

    The recent discovery of liquid water-related sulphates on Mars is of great astrobiological interest. UV radiation experiments, using natural Ca and Fe sulphates (gypsum, jarosite), coming from two selected areas of SE Spain (Jaroso Hydrothermal System and the Sorbas evaporitic basin), were performed using a Xe Lamp with an integrated output from 220 nm to 500 nm of 1.2 Wm-2. The results obtained demonstrate a large difference in the UV protection capabilities of both minerals and also confirm that the mineralogical composition of the Martian regolith is a crucial shielding factor. Whereas gypsum showed a much higher transmission percentage, jarosite samples, with a thickness of only 500 microns, prevented transmission. This result is extremely important for the search for life on Mars as: a) jarosite typically occurs on Earth as alteration crusts and patinas, and b) a very thin crust of jarosite on the surface of Mars would be sufficient to shield microorganisms from UV radiation.

  8. 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

    2015-01-01

    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.

  9. Mutagenic activity of disinfection by-products.

    OpenAIRE

    Cognet, L; Courtois, Y; Mallevialle, J

    1986-01-01

    Data on raw water quality, disinfection treatment practices, and the resulting mutagenic properties of the treated water were compiled from pilot- and full-scale treatment experiments to evaluate that parameter which might produce variability in the results of a mutagenic study. Analysis of the data and comparison of treatment practices indicated that the measured mutagenic activity is strongly related to the characteristics of the organic matter in the raw water, the methodology used to samp...

  10. Evaluation and Comparison of High-Level Microwave Oven Disinfection with Chemical Disinfection of Dental Gypsum Casts

    OpenAIRE

    Meghashri, K; Kumar, Prasanna; Prasad, D. Krishna; Hegde, Rakshit

    2014-01-01

    Background: The aim of this study was to evaluate and compare microwave disinfection with chemical disinfection of dental gypsum casts. Materials and Methods: 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...

  11. Studi Experimental Perbandingan Perilaku Kuat Geser Pada Tanah Lempung Yang Distabilisasi Dengan Bahan Pencampur Gypsum Dan Semen

    OpenAIRE

    Purba, Elisa Dwijayanti

    2015-01-01

    Dalam dunia konstruksi masalah yang ditimbulkan oleh sifat fisik dan mekanis tanah sering ditemui. Salah satu upaya yang dilakukan untuk mengatasi masalah tersebut adalah dengan melakukan proses stabilisasi tanah untuk perbaikan tanah. Proses stabilisasi tanah tersebut dapat dilakukan dengan cara mencampurkan bahan stabilisator seperti semen, gypsum, fly ash, bitumen,kapur, dan bahan-bahan olahan limbah pabrik lainnya. Dalam penelitian ini akan dilakukan proses stabilisasi tanah denga...

  12. Factors affecting the precipitation of pure calcium carbonate during the direct aqueous carbonation of flue gas desulfurization gypsum

    International Nuclear Information System (INIS)

    The mineral carbonation of FGD (flue gas desulfurization) gypsum was carried out through CO2 sorption into ammonia solution containing FGD gypsum. High-purity calcium carbonate was precipitated from DCC (dissolved calcium carbonate) solution which was extracted during the induction period. The factors affecting the preparation of pure calcium carbonate were examined under the following conditions: CO2 flow rate (1–3 L/min), ammonia content (4–12%), and S/L (solid-to-liquid) ratio (5–300 g/L). X-Ray diffraction study revealed that the PCC (precipitated calcium carbonate) was round-shaped vaterite. The induction time for PCC decreased as the CO2 flow rate increased. The maximum formation efficiency for pure PCC was seen to increase linearly with the ammonia content. The formation efficiency for pure PCC was the highest (90%) for S/L ratio of 5 g/L but it decreased as S/L ratio increased. On the other hand, S/L ratio didn't affect the maximum solubility limit of DCC. It is believed that the pure PCC would add an economic value to the FGD gypsum carbonation for industrial CO2 sequestration. - Highlights: • Pure and white CaCO3 was synthesized using induction period during direct carbonation of FGD gypsum. • Its formation efficiency was increased with ammonia content but decreased with solid-to-liquid ratio. • This method is expected to extend to other industrial CO2 sequestration for the enhanced economic value of precipitated CaCO3

  13. Characterisation and partial purification of proteolytic enzymes from sardine by-products to obtain concentrated hydrolysates.

    Science.gov (United States)

    Castro-Ceseña, Ana Bertha; del Pilar Sánchez-Saavedra, M; Márquez-Rocha, Facundo J

    2012-11-15

    A procedure to recover proteases and lipases from the by-products of Monterey sardine (Sardinops sagax caerulea) has been developed, comprising 2 steps: a centrifugation at low temperature to eliminate more than 90% of the initial fat content, and an acetone precipitation step. After this treatment, enzymatic activity increased by 33.8% for lipase, 15.5% for trypsin, 14.8% for chymotrypsin, 93.4% for aminopeptidase, and 19.7% for pepsin. The extents of hydrolysis of fish by-product proteins by endogenous enzyme by-product extract, viscera concentrate extract, and commercial Alcalase® were 62%, 85%, and 28%, respectively. The two extract preparations from sardine by-product (viscera and by-product concentrate extracts) produced 3-fold greater hydrolysis than with the commercial enzyme. The recovery of enzyme concentrates from sardine waste has both ecological and economical advantages for the fish industry. PMID:22868132

  14. Establishment of trees on mixtures of pulverised fuel ash and gypsum. Part II: nutrition and trace elements

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P.J.A.; Moffat, A.J.

    1993-10-01

    Pulverised fuel ash (PFA) sites in Britain have traditionally been restored to agriculture, but with the current trend to taking agricultural land out of production there is renewed interest in alternative end uses such as forestry. PFA has been shown to be colonized naturally to trees after 20-plus-years. In a series of experiments, the authors tested the growth and chemical uptake of a variety of tree species ([ital Populus nigra] var 'Italica', [ital P.alba], [ital Pinus nigra] var maritima, [ital Betula pendula], [ital Acer pseudoplatanus], [ital Alnus glutinosa], [ital A. cordata], and [ital Robinia pseudoacacia]) in a variety of mixtures (PFA, flue gas desulphurization gypsum, a 1:1 PFA:gypsum mix and a 2:1 mix, and a compost control). In earlier research several of the species were shown to tolerate the unusual physical and chemical characteristics of the mixtures. Here, elemental content of leaves from the trees after one year indicated that PFA consistently increased foliar levels of K, B, and Mo. Poor performance of some of the tree species in pure PFA was attributed to boron toxicity. Adding gypsum with the PFA tended to reduce B uptake. Fertilizers tended to improve tree performance. The authors were encouraged by the performance of the nitrogen fixing species ([ital Alnus] and [ital Robinia]), indicating that it may be possible to establish a self-sustaining woodland on power plant wastes.

  15. Potential of soil amendments (Biochar and Gypsum) in increasing water use efficiency of Abelmoschus esculentus L. Moench

    Science.gov (United States)

    Batool, Aniqa; Taj, Samia; Rashid, Audil; Khalid, Azeem; Qadeer, Samia; Saleem, Aansa R.; Ghufran, Muhammad A.

    2015-01-01

    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 (WUE) and growth of Abelmoschus esculentus L. Moench (Lady’s Finger). A 6 weeks experiment was conducted under greenhouse conditions. Stress treatments were applied after 30 days of sowing. Plant height, leaf area, photosynthesis, transpiration rate (Tr), stomatal conductance and WUE were determined weekly under stressed [60% field capacity (F.C.)] and non-stressed (100% F.C.) conditions. Stomatal conductance and Tr decreased and reached near to zero in stressed plants. Stressed plants also showed resistance to water stress upto 5 weeks and gradually perished at sixth week. On the other hand, WUE 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 A. esculentus, compared to its application in combination with gypsum. PMID:26442046

  16. 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

    2015-09-01

    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.

  17. Composting of waste paint sludge containing melamine resin as affected by nutrients and gypsum addition and microbial inoculation

    International Nuclear Information System (INIS)

    Melamine formaldehyde resins have hard and durable properties and are found in many products, including automobile paints. These resins contain high concentrations of nitrogen and, if properly composted, can yield valuable products. We evaluated the effects of starter compost, nutrients, gypsum and microbial inoculation on composting of paint sludge containing melamine resin. A bench-scale composting experiment was conducted at 55 °C for 91 days and then at 30 °C for an additional 56 days. After 91 days, the composts were inoculated with a mixed population of melamine-degrading microorganisms. Melamine resin degradation after the entire 147 days of composting varied between 73 and 95% for the treatments with inoculation of microorganisms compared to 55–74% for the treatments without inoculation. Degradation was also enhanced by nutrients and gypsum additions. Our results infer that large scale composting of melamine resins in paint sludge is possible. - Highlights: ► Melamine resin in waste paint sludges could be efficiently composted at bench scale. ► Melamine resin degradation after 147 days of composting was 73–95% complete. ► Nutrients, gypsum and melamine-degrading microorganisms increased composting rate. ► Melamine degradation products first increased and then decreased in the compost. ► Final compost was enriched in nitrogen and other essential plant nutrients. - Melamine resin in waste paint sludges was efficiently composted at bench scale, with finished composts having low levels of heavy metals and enriched in plant nutrients.

  18. Uptake of Nutrients in Vegetables Grown on FGD-Gypsum-Amended Soils

    Directory of Open Access Journals (Sweden)

    Yutdanai Yodthongdee

    2013-10-01

    Full Text Available This research evaluated the effects of using flue gas desulphurization gypsum (FGDG for growing of some agronomic crops. The FGDG was added to soil at 0, 2.5, 5.0 and 7.5% by weight. The test plants, Chinese kale and green bean, were grown and harvested after 45 days and 60 days, respectively. Application of FGDG at all ratios significantly increased pH of the soil, due to the lime containing in FGDG. The heavy metals content in plants grown in the FGDG treated tanks were not significantly different from those of the control tank. From the ten studied elements in Chinese kale and green bean seed tissues (As, Ca, Cd, Cr, Cu, K, Mg, Na, Pb, and Zn, the content of five toxic elements (As, Cd, Cr, Cu, and Pb were very low and not significantly influenced by FGDG, while the content of some nutrient elements (K, Ca, Mg in the plant tissues growing in FGDG treated soil were higher than the control. Concentration of some micronutrients (Cu and Zn in plants decreased with increasing dose of FGDG. There has not been any negative effect from applying up to 5.0% FGDG in soil. The results showed possibility of using FGDG as soil amendment in terms of agricultural production and safety.

  19. Inhibition of hydrogen sulfide generation from disposed gypsum drywall using chemical inhibitors.

    Science.gov (United States)

    Xu, Qiyong; Townsend, Timothy; Bitton, Gabriel

    2011-07-15

    Disposal of gypsum drywall in landfills has been demonstrated to elevate hydrogen sulfide (H(2)S) concentrations in landfill gas, a problem with respect to odor, worker safety, and deleterious effect on gas-to-energy systems. Since H(2)S production in landfills results from biological activity, the concept of inhibiting H(2)S production through the application of chemical agents to drywall during disposal was studied. Three possible inhibition agents - sodium molybdate (Na(2)MoO(4)), ferric chloride (FeCl(3)), and hydrated lime (Ca(OH)(2)) - were evaluated using flask and column experiments. All three agents inhibited H(2)S generation, with Na(2)MoO(4) reducing H(2)S generation by interrupting the biological sulfate reduction process and Ca(OH)(2) providing an unfavorable pH for biological growth. Although FeCl(3) was intended to provide an electron acceptor for a competing group of bacteria, the mechanism found responsible for inhibiting H(2)S production in the column experiment was a reduction in pH. Application of both Na(2)MoO(4) and FeCl(3) inhibited H(2)S generation over a long period (over 180 days), but the impact of Ca(OH)(2) decreased with time as the alkalinity it contributed was neutralized by the generated H(2)S. Practical application and potential environmental implications need additional exploration. PMID:21592650

  20. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects

    Science.gov (United States)

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

    2016-03-01

    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.

  1. Combination of simvastatin, calcium silicate/gypsum, and gelatin and bone regeneration in rabbit calvarial defects.

    Science.gov (United States)

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

    2016-01-01

    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. PMID:26996657

  2. Ribosomal RNA gene fragments from fossilized cyanobacteria identified in primary gypsum from the late Miocene, Italy.

    Science.gov (United States)

    Panieri, G; Lugli, S; Manzi, V; Roveri, M; Schreiber, B C; Palinska, K A

    2010-03-01

    Earth scientists have searched for signs of microscopic life in ancient samples of permafrost, ice, deep-sea sediments, amber, salt and chert. Until now, evidence of cyanobacteria has not been reported in any studies of ancient DNA older than a few thousand years. Here, we investigate morphologically, biochemically and genetically primary evaporites deposited in situ during the late Miocene (Messinian) Salinity Crisis from the north-eastern Apennines of Italy. The evaporites contain fossilized bacterial structures having identical morphological forms as modern microbes. We successfully extracted and amplified genetic material belonging to ancient cyanobacteria from gypsum crystals dating back to 5.910-5.816 Ma, when the Mediterranean became a giant hypersaline brine pool. This finding represents the oldest ancient cyanobacterial DNA to date. Our clone library and its phylogenetic comparison with present cyanobacterial populations point to a marine origin for the depositional basin. This investigation opens the possibility of including fossil cyanobacterial DNA into the palaeo-reconstruction of various environments and could also be used to quantify the ecological importance of cyanobacteria through geological time. These genetic markers serve as biosignatures providing important clues about ancient life and begin a new discussion concerning the debate on the origin of late Miocene evaporites in the Mediterranean. PMID:20059556

  3. A microscopy study of hyphal growth of Penicillium rubens on gypsum under dynamic humidity conditions.

    Science.gov (United States)

    van Laarhoven, Karel A; Huinink, Hendrik P; Adan, Olaf C G

    2016-05-01

    To remediate indoor fungal growth, understanding the moisture relations of common indoor fungi is crucial. Indoor moisture conditions are commonly quantified by the relative humidity (RH). RH is a major determinant of the availability of water in porous indoor surfaces that fungi grow on. The influence of steady-state RH on growth is well understood. Typically, however, the indoor RH constantly changes so that fungi have to endure frequent periods of alternating low and high RH. Knowledge of how common indoor fungi survive and are affected by the low-RH periods is limited. In particular, the specific effects of a drop in RH on the growth of the mycelium remain unclear. In this work, video microscopy was used to monitor hyphal growth of Penicillium rubens on gypsum substrates under controlled dynamic humidity conditions. The effect of a single period of low RH (RH = 50-90%) interrupting favourable conditions (RH = 97%) was tested. It was found that hyphal tips ceased to extend when exposed to any tested decrease in RH. However, new hyphal growth always emerges, seemingly from the old mycelium, suggesting that this indoor fungus does not rely only on conidia to survive the humidity patterns considered. These findings are a fundamental step in unravelling the effect of RH on indoor fungal growth. PMID:26996401

  4. Development of materials that cover the deposits of gypsum exploited in the polo plasterer in Pernambuco

    International Nuclear Information System (INIS)

    The mineral clay found on the surface of gypsum deposits in the region of Recife - PE are considered mining tailings and job search reference in new industrial applications for these minerals, ores. In this context, we performed the characterization of these materials with the purpose of its use as inorganic pigments in the ceramic coating. These minerals present 'in locus' different colors ranging from beige to reddish. After heat treatment at 1000° C their colors have varied tones that can be used as natural pigments in the ceramic industry. The techniques of fluorescence X-ray diffraction X-ray, infrared and colorimetry were applied in the characterization of mineral-ore in question. Using mineral processing techniques we obtain a physical separation of clay minerals associated. The use of concentrated after processing showed that the material has the potential to replace traditional pigments used in ceramic industry, and thus represent a new alternative on the market of natural pigments. Another potential comprehensive analysis of the material is its use associated with polymers in order to develop new materials. (author)

  5. Inhibition of hydrogen sulfide generation from disposed gypsum drywall using chemical inhibitors

    International Nuclear Information System (INIS)

    Disposal of gypsum drywall in landfills has been demonstrated to elevate hydrogen sulfide (H2S) concentrations in landfill gas, a problem with respect to odor, worker safety, and deleterious effect on gas-to-energy systems. Since H2S production in landfills results from biological activity, the concept of inhibiting H2S production through the application of chemical agents to drywall during disposal was studied. Three possible inhibition agents - sodium molybdate (Na2MoO4), ferric chloride (FeCl3), and hydrated lime (Ca(OH)2) - were evaluated using flask and column experiments. All three agents inhibited H2S generation, with Na2MoO4 reducing H2S generation by interrupting the biological sulfate reduction process and Ca(OH)2 providing an unfavorable pH for biological growth. Although FeCl3 was intended to provide an electron acceptor for a competing group of bacteria, the mechanism found responsible for inhibiting H2S production in the column experiment was a reduction in pH. Application of both Na2MoO4 and FeCl3 inhibited H2S generation over a long period (over 180 days), but the impact of Ca(OH)2 decreased with time as the alkalinity it contributed was neutralized by the generated H2S. Practical application and potential environmental implications need additional exploration.

  6. By-products in earth construction. Assessment of acceptability

    Energy Technology Data Exchange (ETDEWEB)

    Mroueh, U.-M.; Maekelae, E.; Wahlstroem, M. [VTT Chemical Technology, Espoo (Finland); Kauppila, J.; Sorvari, J. [Finnish Environmental Institute, Helsinki (Finland); Heikkinen, P.; Salminen, R. [Geological Survey of Finland, Espoo (Finland); Juvankoski, M.; Tammirinne, M. [VTT Communities and Infrastructures, Espoo (Finland)

    2000-07-01

    About 70 million tonnes of natural mineral aggregates are used each year in Finland for road construction and earthworks. Depletion of the best materials, the need for resource conservation and longer transport distances have all increased the need to introduce substitute materials for natural aggregates. At the same time industry, construction and other similar activities produce large quantities of potentially usable by-products. Current waste legislation also supports the use of wastes as substitutes for natural raw materials. The use of secondary products of industry and other activities requires that they be proven to be environmentally friendly and technically suitable. In the project 'By-products in earthworks - assessment of applicability' guidance was developed for the assessment of the environmental and technical applicability of secondary products for use in earthworks and road construction. The project was a part of the Finnish Ecogeo Technology Programme. The guide was prepared in collaboration between several research institutes. The guide presents the legislative requirements for the utilisation of secondary products in earthworks, recommendations for the investigation of environmental and technical applicability, recommendations for environmental and technical criteria of the utilisation in earthworks and recommendations for product quality control procedures. A tiered system is presented for the assessment of environ- mental compliance. The assessment levels are as follows: 1. Concentrations of harmful components. 2. Leaching of harmful components from unpaved and paved constructions. 3. Risk assessment. During the preparation of the guide, the environmental, legal and technical preconditions for the use of the secondary materials were extensively investigated. The results of these studies were published in separate reports. The following aspects, amongst others, were studied during the project: The environmental and health risks of the

  7. Acid mine drainage treatment using by-products from quicklime manufacturing as neutralization chemicals.

    Science.gov (United States)

    Tolonen, Emma-Tuulia; Sarpola, Arja; Hu, Tao; Rämö, Jaakko; Lassi, Ulla

    2014-12-01

    The aim of this research was to investigate whether by-products from quicklime manufacturing could be used instead of commercial quicklime (CaO) or hydrated lime (Ca(OH)2), which are traditionally used as neutralization chemicals in acid mine drainage treatment. Four by-products were studied and the results were compared with quicklime and hydrated lime. The studied by-products were partly burnt lime stored outdoors, partly burnt lime stored in a silo, kiln dust and a mixture of partly burnt lime stored outdoors and dolomite. Present application options for these by-products are limited and they are largely considered waste. Chemical precipitation experiments were performed with the jar test. All the studied by-products removed over 99% of Al, As, Cd, Co, Cu, Fe, Mn, Ni, Zn and approximately 60% of sulphate from acid mine drainage. However, the neutralization capacity of the by-products and thus the amount of by-product needed as well as the amount of sludge produced varied. The results indicated that two out of the four studied by-products could be used as an alternative to quicklime or hydrated lime for acid mine drainage treatment. PMID:25193795

  8. Kojic Acid Production from Agro-Industrial By-Products Using Fungi

    OpenAIRE

    El-Kady, Ismael A.; Abdel Naser A. Zohri; Shimaa R. Hamed

    2014-01-01

    A total of 278 different isolates of filamentous fungi were screened using synthetic medium for respective ability to produce kojic acid. Nineteen, six, and five isolates proved to be low, moderate, and high kojic acid producers, respectively. Levels of kojic acid produced were generally increased when shaking cultivation was used rather than those obtained using static cultivation. A trial for the utilization of 15 agro-industrial wastes or by-products for kojic acid production by the five s...

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

    Directory of Open Access Journals (Sweden)

    Vitoldas Vaitkevičius

    2015-03-01

    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: http://dx.doi.org/10.5755/j01.ms.21.1.5635

  10. 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

    2006-08-31

    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

  11. 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

    2006-08-31

    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

  12. Dry matter yields of maize grown with coal combustion by-products

    International Nuclear Information System (INIS)

    Major coal combustion by-products (CCBPs) include fly ash, bottom ash, flue gas desulfurization (scrubber sludge) and fluidized bed combustion residues, and coal gasification ashes. Interest in using these products on agricultural land as soil amendments has recently arisen. However, the impact of these products on soils properties and plant growth are unknown. The new technologies in coal power plants are designed to reduce sulfur (S) emissions into the air. Flue Gas Desulfurization (FGD) (scrubber sludge) and Fluidized Bed Combustion (FBC) residues are CCBPs from this new technology. Both of these types of products have received only limited attention relative to agricultural use (Carlson and Adriano, 1992). The FGD products normally result from the addition of limestone slurries to flue gas streams to control sulfur emissions. The final product generally consists of fly ash and Ca-S (sometimes some Mg-S) salts containing different proportions of sulfite/sulfate/carbonate (Santhanam et al., 1979; Miller, 1987). Compositions of products vary extensively dependent on factors such as type of coal used, combustion conditions, and types of devices used for emission control. These products often contain high soluble salts and may contain enhanced amounts of heavy metals. In a few products, much of the sulfite is converted to sulfate and the resulting products contain high CaSO4, (gypsum hydrite). The FBC products normally result from mixing coal and limestone in the furnace in a fluidized bed created by the injection of air. This usually results in an alkaline final product, relatively high in Ca salts (sulfite/sulfate/oxide) with variable amounts of ash whose composition depends on the type of coal and specific boiler systems used (Terman et al., 1978; Korcak, 1980a, 1982). 20 refs., 3 figs

  13. Mechanical properties of nano SiO2 filled gypsum particleboard

    Institute of Scientific and Technical Information of China (English)

    LEI Wen; DENG Yu-he; ZHOU Mei; XUAN Ling; FENG Qian

    2006-01-01

    Nano SiO2 was filled into gypsum particleboard. Effect of the amount of nano SiO2 particles filled,ultrasonic dissipating duration and treating the nano particles with different coupling agents on the mechanical properties of the board were studied respectively. The results show that nano SiO2 is helpful for the improvement of the properties. Adding 3%(mass fraction) nano SiO2 is the best for the improvement of both modulus of rupture(MOR) and modulus of elasticity(MOE) of the boards formed at 30 ℃ or 40 ℃. For the boards formed at 30 ℃,their MOR and MOE can be improved by 8.77% and 12.24%,and MOR and MOE of the boards formed at 40 ℃ can be improved by 44.44% and 108.38%.3% is also the best addition proportion to improve internal bond(IB) of the boards formed at 30 ℃,while 5% is the best for that of the boards formed at 40 ℃. At room temperature,dissipating nano SiO2 into flake by ultrasonic has better effect on the properties of the final products. Through ultrasonic treating for 1 h and the best treating duration,the MOR and MOE can be increased by 41.99% and 47.80%. In addition,different coupling agents have different effects on the final properties too,and silane coupling agent KH570 is better for the improvement of properties of the boards formed at room temperature.

  14. Preparation and in vitro evaluation of strontium-doped calcium silicate/gypsum bioactive bone cement

    International Nuclear Information System (INIS)

    The combination of two or more bioactive components with different biodegradability could cooperatively improve the physicochemical and biological performances of the biomaterials. Here we explore the use of α-calcium sulfate hemihydrate (α-CSH) and calcium silicate with and without strontium doping (Sr-CSi, CSi) to fabricate new bioactive cements with appropriate biodegradability as bone implants. The cements were fabricated by adding different amounts (0–35 wt%) of Sr-CSi (or CSi) into the α-CSH-based pastes at a liquid-to-solid ratio of 0.4. The addition of Sr-CSi into α-CSH cements not only led to a pH rise in the immersion medium, but also changed the surface reactivity of cements, making them more bioactive and therefore promoting apatite mineralization in simulated body fluid (SBF). The impact of additives on long-term in vitro degradation was evaluated by soaking the cements in Tris buffer, SBF, and α-minimal essential medium (α-MEM) for a period of five weeks. An addition of 20% Sr-CSi to α-CSH cement retarded the weight loss of the samples to 36% (in Tris buffer), 43% (in SBF) and 54% (in α-MEM) as compared with the pure α-CSH cement. However, the addition of CSi resulted in a slightly faster degradation in comparison with Sr-CSi in these media. Finally, the in vitro cell-ion dissolution products interaction study using human fetal osteoblast cells demonstrated that the addition of Sr-CSi improved cell viability and proliferation. These results indicate that tailorable bioactivity and biodegradation behavior can be achieved in gypsum cement by adding Sr-CSi, and such biocements will be of benefit for enhancing bone defect repair. (paper)

  15. Disinfection by-product formation during seawater desalination: A review.

    Science.gov (United States)

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

    2015-09-15

    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. PMID:26099832

  16. Interaction of gypsum and the rhizome of Anemarrhena asphodeloides plays an important role in anti-allergic effects of byakkokakeishito in mice.

    Science.gov (United States)

    Makino, Toshiaki; Shiraki, Yusaku; Mizukami, Hajime

    2014-07-01

    Gypsum is a crude mineral drug used in the formulas of Japanese kampo medicine and traditional Chinese medicine. The present study aimed to evaluate the anti-allergic effect of byakkokakeishito extract (BKT), which consists of gypsum (natural hydrous calcium sulfate), Anemarrhena Rhizome (rhizome of Anemarrhena asphodeloides), Cinnamon Bark (bark of trunk of Cinnamomum cassia), Oriza Seed (seed of Oryza sativa), and Glycyrrhiza (root and stolon of Glycyrrhiza uralensis), and to clarify the role of gypsum in the formula. We prepared BKT by boiling a mixture of various quantities of gypsum and fixed amounts of the other four crude drugs in water. We evaluated the anti-allergic activity of the formulations using three different murine models of allergy: contact dermatitis induced by painting hapten onto skin; allergic dermatitis-like symptoms induced by cutaneous injection of mite-antigen; and skin passive cutaneous anaphylaxis (PCA) reaction using ovalbumin as antigen. The calcium content in the various BKT samples was dose-dependently increased up to 60 g/day of human dosage. BKT significantly suppressed the allergic symptoms in the three different experimental models. The effect of BKT was augmented by increasing the gypsum dosage only in the PCA reaction model. The extract prepared from a mixture of Anemarrhena Rhizome and gypsum exhibited an effect comparable to that of BKT. BKT exhibits an anti-allergic effect in several animal models, which may provide experimental evidence for the clinical use of BKT in allergic diseases. Gypsum may augment the anti-allergic activity of BKT, presumably through increasing intestinal absorption of Anemarrhena Rhizome-derived active constituents. PMID:24554438

  17. The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions.

    Science.gov (United States)

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

    2015-06-01

    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. PMID:26040733

  18. 石膏在有机物厌氧分解中的固碳效应%Effect of Gypsum on Carbon Sequestration of Organic Matter in Anaerobic Decomposition

    Institute of Scientific and Technical Information of China (English)

    何光亚; 陈天虎; 黎少杰; 张楠; 归显扬; 姚敦璠; 刘畅

    2011-01-01

    本文以牛肉膏蛋白胨为厌氧微生物的营养源,研究了石膏对厌氧微生物生化系统中甲烷释放量和有机物矿化的影响.根据溶液中总有机碳(TOC)、总无机碳(TIC)、硫酸根、硫化物、pH值以及气体中CO2,CH4和H2S的释放量的观测,以及固体产物的扫描电镜(SEM)、能谱(EDS)、X-射线衍射(XRD)分析结果,探讨了石膏对抑制甲烷菌活性的影响和机制.结果表明,添加石膏能有效降低甲烷释放量达40%以上,而对于CO2的释放量没有明显影响;固体中碳酸盐矿物的含量大幅度增加.石膏在该厌氧体系中的作用主要表现在如下几个方面:(1)石膏是微溶矿物,随着硫酸根的还原,体系中石膏溶解不饱和而不断溶解,石膏起到缓释硫酸根的作用;(2)石膏缓慢溶解使溶液中有稳定的硫酸根浓度,有足够的电子受体,促使硫酸盐还原菌(SRB)成为优势微生物,SRB通过对底物和电子的竞争抑制了产甲烷菌(MPB)和产甲烷能力;(3)硫酸盐还原菌在还原硫酸根的同时消耗有机碳,加速有机物的无机矿化,有机物无机矿化产生的碳酸根与石膏中的Ca2+结合形成方解石,提高了将有机碳固定为无机碳的速率,表现出固碳效应.%This paper investigated the affect of gypsum on methane emission and organic matter mineralization in anaerobic biochemical system by using beef extract peptone as the nutrient source. To explore the effect and mechanism of gypsum on suppressing the activity of methane-producing bacteria (MPB), three kinds of chemical and physical indexes were tested: 1) TOC, TIC, SO42-, sulfide and pH values of the aqueous phase; 2) volume of CO2, CH4 and H2S emissions in the gas phase, and 3) SEM, EDS and XRD analyses of the solid phase. Our results showed that addition of gypsum could effectively reduce methane emission by more than 40 %. However, no apparent impact on the release of CO2 was observed during this process. Furthermore, the content

  19. Carbon and nitrogen stable isotope measurements and X-ray photoabsorption spectroscopy of microbial-mat-containing gypsum crust in modern saline pan

    Science.gov (United States)

    Isaji, Yuta; Kawahata, Hodaka; Yoshimura, Toshihiro; Kuroda, Junichiro; Ogawa, Nanako O.; Jimenez-Espejo, Francis J.; Lugli, Stefano; Manzi, Vinicio; Roveri, Marco; Tamenori, Yusuke; Ohkouchi, Naohiko

    2015-04-01

    A gypsum crust collected from the Sosalt commercial salt work at Trapani (western Sicily, Italy), which was deposited in several years, has a remarkable layered structure with different colors and physical appearance (from the top to the bottom: transparent gypsum, green layer, and granulous layer containing black particles), each color representing a different microbial community. Previous studies suggest that the colored layers consist of different cyanobacterial communities, purple sulfur bacteria and sulfur reducing bacteria, respectively, and that their biochemical processes are intimately connected (e.g. Caumette et al., 1994; Canfield et al., 2004). In this study we performed stable carbon and nitrogen isotope measurements, elemental mapping, and bulk chemical analyses to describe geochemical characteristics of this layered evaporite deposit. Lower values of δ13C and δ15N in the colored layers compared to the topmost transparent layer indicate active biochemical processes by the bacterial communities, as expected. To further describe the differences between the layers, a synchrotron based micro-X-ray fluorescence (μ-XRF) was used to acquire the spatial distributions of Na, Mg, Sr, S, Cl, and P in the each layer of different color. The elemental mapping combined with chemical speciation of S K-edge X-ray absorption near edge structure (XANES) spectra of the gypsum crust showed that the transparent and the green layers were uniformly filled with gypsum crystals, while a somewhat high concentration of elements other than sulfur were observed in the interparticle realm of the bottom gypsum layer. This indicates an earliest alteration at the bottom layer probably as a result of sulfur reduction by sulfur reducing bacteria inhabiting the interparticle realm. It is noteworthy that no reduced sulfur compounds, except for gypsum, was detected in the sample by μ-XANES analysis, despite the presence of a layer inhabited by sulfur reducing bacteria. Since gypsum is

  20. Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

    Science.gov (United States)

    Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

    2002-05-01

    The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

  1. Bacterial communities and the nitrogen cycle in the gypsum soils of Cuatro Ciénegas Basin, coahuila: a Mars analogue.

    Science.gov (United States)

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

    2012-07-01

    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. PMID:22920518

  2. Experimental research on the local resistance characteristics of branch pipe in dense phase pneumatic conveying desulfurized gypsum

    Science.gov (United States)

    Liu, Zong Ming; Pan, Hong Li; Duan, Guang Bin; Wang, Yong

    2014-04-01

    Pneumatic conveying experiment was carried out in branch pipe branch whose angle would change. In the paper, compressed air was conveying power while dry desulfurized gypsum was conveying materials. The trend of local resistance whose gas-solid flow come through branches with different geometric structure was investigated with different gas-solid flow velocity and solids loading ratio. The result showed that the local resistance loss of branch pipe would increase with the increment of the angle between the branch pipe and the main pipe, the ratio of solid-gas in the pipe and the superficial gas velocity.

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

    OpenAIRE

    R. Biernacki; R. Haratym; J. Kwapisz

    2012-01-01

    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 resul...

  4. Comparative evaluation of feldespatic crowns fitness made from additional silicon impression and gypsum cast by CAD/CAM

    OpenAIRE

    Faramarz Zakavi; Hengameh Alinejad; Zahra Jowkar

    2015-01-01

    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 ...

  5. Moisture parameters and fungal communities associated with gypsum drywall in buildings.

    Science.gov (United States)

    Dedesko, Sandra; Siegel, Jeffrey A

    2015-01-01

    Uncontrolled excess moisture in buildings is a common problem that can lead to changes in fungal communities. In buildings, moisture parameters can be classified by location and include assessments of moisture in the air, at a surface, or within a material. These parameters are not equivalent in dynamic indoor environments, which makes moisture-induced fungal growth in buildings a complex occurrence. In order to determine the circumstances that lead to such growth, it is essential to have a thorough understanding of in situ moisture measurement, the influence of building factors on moisture parameters, and the levels of these moisture parameters that lead to indoor fungal growth. Currently, there are disagreements in the literature on this topic. A literature review was conducted specifically on moisture-induced fungal growth on gypsum drywall. This review revealed that there is no consistent measurement approach used to characterize moisture in laboratory and field studies, with relative humidity measurements being most common. Additionally, many studies identify a critical moisture value, below which fungal growth will not occur. The values defined by relative humidity encompassed the largest range, while those defined by moisture content exhibited the highest variation. Critical values defined by equilibrium relative humidity were most consistent, and this is likely due to equilibrium relative humidity being the most relevant moisture parameter to microbial growth, since it is a reasonable measure of moisture available at surfaces, where fungi often proliferate. Several sources concur that surface moisture, particularly liquid water, is the prominent factor influencing microbial changes and that moisture in the air and within a material are of lesser importance. However, even if surface moisture is assessed, a single critical moisture level to prevent fungal growth cannot be defined, due to a number of factors, including variations in fungal genera and

  6. Comparison of biochar formation from various agricultural by-products using FTIR spectroscopy

    Science.gov (United States)

    Biochar is charred material produced by the pyrolysis of organic biomass. In this work, Fourier transform infrared (FTIR) spectra of different agricultural by-products feedstock and their derived biochars were collected to explore the potential of FTIR technique as a simple and rapid method for char...

  7. UTILIZATION OF LOW NOx COAL COMBUSTION BY-PRODUCTS

    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

    1998-12-01

    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.

  8. Maximizing Utilization of Energy from Crop By-products

    OpenAIRE

    Budi Haryanto

    2014-01-01

    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 sou...

  9. Characterization and precipitation mechanism of α-calcium sulfate hemihydrate growing out of FGD gypsum in salt solution

    Institute of Scientific and Technical Information of China (English)

    YANG LiuChun; GUAN BaoHong; WU ZhongBiao

    2009-01-01

    Alpha-calcium sulfate hemihydrate (α-HH) has been prepared from flue gas desulfurization (FGD)gypsum with salt solution method under atmospheric pressure. X-ray diffraction (XRD), thermogra-vimetry and differential scanning calorimetry (TG-DSC), optical micrograph, X-ray photoelectron spec-troscopy (XPS), energy dispersive spectrometry (EDS), and scanning electron microscopy (SEM) have been employed to characterize the α-HH crystals, based on which the formation and growth mecha-nisms of the a-HH crystals have been discussed. The results show that FGD gypsum can be success-fully transformed into high purity α-HH in salt solution under mild conditions, and that a dissolu-tion-recrystallization route is most probably adopted by this transition. The growth of a-HH crystals in salt solution demonstrates a preferred direction along [001] and results in a bundle-of-sheets or bun-dle-of-raphide texture. The characteristics revealed in this study can help to understand and control the growth of the α-HH crystal from solution.

  10. Assessment of natural radiation exposure levels and mass attenuation coefficients of lime and gypsum samples used in Turkey.

    Science.gov (United States)

    Damla, Nevzat; Cevik, Uğur; Kobya, Ali Ihsan; Celik, Ahmet; Celik, Necati

    2010-11-01

    The activity concentrations of 226Ra, 232Th, and 40K in lime and gypsum samples used as building materials in Turkey were measured using gamma spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 38±16, 20±9, and 156±54 Bq kg(-1) for lime and found to be 17±6, 13±5, and 429±24 Bq kg(-1) for gypsum, respectively. The radiological hazards due to the natural radioactivity in the samples were inferred from calculations of radium equivalent activities (Raeq), indoor absorbed dose rate in the air, the annual effective dose, and gamma and alpha indices. These radiological parameters were evaluated and compared with the internationally recommended limits. The experimental mass attenuation coefficients (μ/ρ) of the samples were determined in the energy range 81-1,332 keV. The experimental mass attenuation coefficients were compared with theoretical values obtained using XCOM. It is found that the calculated values and the experimental results are in good agreement. PMID:19921450

  11. 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.

    1999-01-31

    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.

  12. Land application uses for dry flue gas desulfurization by-products. Executive summary

    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.

    1999-01-31

    Flue gas desulfurization (FGD) scrubbing technologies create several types of by-products. This project focused primarily on by-product materials obtained from what are commonly called ''dry scrubbers'' which produce a dry, solid material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Prior to this project, dry FGD by-products were generally treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing; The major objective of this project was to develop beneficial uses, via recycling, capable of providing economic benefits to both the producer and the end user of the FGD by-product. It is equally important, however, that the environmental impacts be carefully assessed so that the new uses developed are not only technically feasible but socially acceptable. Specific objectives developed for this project were derived over an 18-month period during extensive discussions with personnel from industry, regulatory agencies and research institutions. These were stated as follows: Objective 1: To characterize the material generated by dry FGD processes. Objective 2: To demonstrate the utilization of dry FGD by-product as a soil amendment on agricultural lands and on abandoned and active surface coal mines in Ohio. Objective 3: To demonstrate the use of dry FGD by-product as an engineering material for soil stabilization. Objective 4: To determine the quantities of dry FGD by-product that can be utilized in each of these applications. Objective 5. To determine the environmental and economic impacts of utilizing the material. Objective 6. To calibrate environmental, engineering, and economic models that can be used to determine the applicability and costs of utilizing these processes at other sites.

  13. Hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) into gypsum (CaSO 4·2H 2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight

    Science.gov (United States)

    Boisvert, Jean-Philippe; Domenech, Marc; Foissy, Alain; Persello, Jacques; Mutin, Jean-Claude

    2000-12-01

    The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO 4·2H 2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner.

  14. Kojic Acid Production from Agro-Industrial By-Products Using Fungi

    Directory of Open Access Journals (Sweden)

    Ismael A. El-Kady

    2014-01-01

    Full Text Available A total of 278 different isolates of filamentous fungi were screened using synthetic medium for respective ability to produce kojic acid. Nineteen, six, and five isolates proved to be low, moderate, and high kojic acid producers, respectively. Levels of kojic acid produced were generally increased when shaking cultivation was used rather than those obtained using static cultivation. A trial for the utilization of 15 agro-industrial wastes or by-products for kojic acid production by the five selected higher kojic acid producer isolates was made. The best by-product medium recorded was molasses for kojic acid. A. flavus numbers 7 and 24 were able to grow and produce kojic acid on only 12 out of 15 wastes or by-products media. The best medium used for kojic acid production by A. flavus number 7 was rice fragments followed by molasses, while the best medium used for kojic acid production by A. flavus number 24 was the molasses followed by orange, pea, and rice fragments. An attempt for production of kojic acid using a 1.5 L laboratory fermentor has been made. Aspergillus flavus number 7 was used and grown on molasses medium; maximum level (53.5 g/L of kojic acid was obtained after eight days of incubation.

  15. Utilization of Dairy by Product in the Production of Bioinsecticide

    Directory of Open Access Journals (Sweden)

    M. Fadel

    2002-01-01

    Full Text Available Locally available sugar cane molasses was utilized in the production of bioinseticide by cultivating four strains of Bacillus thuringiensis (B.t namely H-D 133, H-D 234, ENRC 60 and ENRC 63 under shaking culture. The highest yields obtained after 90 hour fermentation. Total viable counts, total spores and percent of spores were different between the four strains. The by product whey ultrafiltrate was utilized in spore crystal mixture recovery from the fermentation beer of the tested strains. Adjusted fermentation beer to pH 7.0 and pH 4.0 prior recovery showed the advantage in spore an crystal mixture recovered yield when the fermentation beer was adjusted to pH. 4.0 Comparison between lactose solution and whey ultrafiltrate contained the same amount of lactose for spores-crystals mixture recovery from fermentation beers showed increases in the yield where in whey ultrafiltrate was employed. Bioassay against the larvae of Spodoptera littoralis, Spodoptera exigua Phthorimaea operculella and Earias insulana were performed. The LC50, slopes, 95% confidence limits and potencies for both two spore-crystal mixtures obtained by lactose solution or whey ultrafiltrate of the four strains were determined. The bioassay showed that the larvae of potato tuber moth and spin boll worms were highly sensitive to the four produced pathogen than S. littoralis and S. eixigua. The spore-crystal mixture recovered in the presence of whey ultrafiltrate showed high toxic effect against the assayed larvae of S. exigua, E. insulana and S. littoralis, whereas, the recovered spore-crystal mixture in the presence of lactose solution was more toxic for P. operculella.

  16. Isotopic evidence for the source of Ca and S in soil gypsum, anhydrite and calcite in the Atacama Desert, Chile

    Science.gov (United States)

    Rech, Jason A.; Quade, Jay; Hart, William S.

    The origin of pedogenic salts in the Atacama Desert has long been debated. Possible salt sources include in situ weathering at the soil site, local sources such as aerosols from the adjacent Pacific Ocean or salt-encrusted playas (salars), and extra-local atmospheric dust. To identify the origin of Ca and S in Atacama soil salts, we determined δ 34S and 87Sr/ 86Sr values of soil gypsum/anhydrite and 87Sr/ 86Sr values of soil calcite along three east-west trending transects. Our results demonstrate the strong influence of marine aerosols on soil gypsum/anhydrite development in areas where marine fog penetrates inland. Results from an east-west transect located along a breach in the Coastal Cordillera show that most soils within 90 km of the coast, and below 1300 m in elevation, are influenced by marine aerosols and that soils within 50 km, and below 800 m in elevation, receive >50% of Ca and S from marine aerosols (δ 34S values > 14‰ and 87Sr/ 86Sr values >0.7083). In areas where the Coastal Cordillera is >1200 m in elevation, however, coastal fog cannot penetrate inland and the contribution of marine aerosols to soils is greatly reduced. Most pedogenic salts from inland soils have δ 34S values between +5.0 to +8.0‰ and 87Sr/ 86Sr ratios between 0.7070 and 0.7076. These values are similar to average δ 34S and 87Sr/ 86Sr values of salts from local streams, lakes, and salars (+5.4 ±2‰ δ 34S and 0.70749 ± 0.00045 87Sr/ 86Sr) in the Andes and Atacama, suggesting extensive eolian reworking of salar salts onto the surrounding landscape. Ultimately, salar salts are precipitated from evaporated ground water, which has acquired its dissolved solutes from water-rock interactions (both high and low-temperature) along flowpaths from recharge areas in the Andes. Therefore, the main source for Ca and S in gypsum/anhydrite in non-coastal soils is indirect and involves bedrock alteration, not surficially on the hyperarid landscape, but in the subsurface by ground water

  17. 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

    2014-12-01

    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

  18. Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine

    Science.gov (United States)

    Muirhead, Dean; Carrier, Christopher

    2012-01-01

    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

  19. Composting of sugar-cane waste by-products through treatment with microorganisms and subsequent vermicomposting.

    Science.gov (United States)

    Kumar, Rahul; Verma, Deepshikha; Singh, Bhanu L; Kumar, Umesh; Shweta

    2010-09-01

    The waste by-products of the sugar-cane industry, bagasse (b), pressmud (p) and trash (t) have been subjected to bioinoculation followed by vermicomposting to shorten stabilization time and improve product quality. Press-mud alone and in combination with other by-products of sugar processing industries was pre-decomposed for 30 days by inoculation with combination of Pleurotus sajorcaju, Trichoderma viridae, Aspergillus niger and Pseudomonas striatum. This treatment was followed by vermicomposting for 40 days with the native earthworm, Drawida willsi. The combination of both treatments reduced the overall time required for composting to 20 days and accelerated the degradation process of waste by-products of sugar processing industry, thereby producing a nutrient-enriched compost product useful for sustaining high crop yield, minimizing soil depletion and value added disposal of waste materials. PMID:20403689

  20. By-products of Opuntia ficus-indica as a source of antioxidant dietary fiber.

    Science.gov (United States)

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

    2010-09-01

    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. PMID:20623195

  1. X-ray absorption fine structure spectroscopy and X-ray diffraction study of cementitious materials derived from coal combustion by-products

    International Nuclear Information System (INIS)

    Cementitious materials derived from coal combustion by-products have been investigated by means of X-ray diffraction (XRD) and S and Ca K-edge X-ray absorption fine structure (XAFS) spectroscopy. The XRD analysis revealed that these materials are a complex mixture of a small amount of quartz [SiO2] and three calcium-bearing compounds: hannebachite [CaSO3·1/2H2O], gypsum [CaSO4·2H2O] and ettringite [(Ca6(Al(OH)6)2(SO4)3·26H2O)]. Analysis of the S XAFS data focused on deconvolution of the X-ray absorption near-edge structure (XANES) regions of the spectra. This analysis established that sulfate and sulfite are the two major sulfur forms, with a minor thiophenic component contained in unburned carbon in the fly ash. Increasing sulfate and decreasing sulfite correlated well with increasing gypsum and ettringite and decreasing hannebachite content in the samples. Different calcium compounds were identified primarily through simple comparison of the Ca K-edge XANES and radial structure functions (RSFs) of the cementitious samples with those of reference compounds. Because of the complex coordination chemistry of calcium in these materials, it was difficult to obtain detailed local atomic environment information around calcium beyond the first Ca-O peak. Analysis of the extended X-ray absorption fine structure (EXAFS) and the RSF gave average Ca-O distances in the range 2.44-2.5 A, with each calcium atom surrounded roughly by eight oxygen atoms. In certain samples, the average Ca-O distances were close to that in ettringite (2.51 A), suggesting that these samples have higher ettringite content. The results of S and Ca K-edges XAFS and the XRD data were in reasonable agreement

  2. Bioactive peptides generated from meat industry by-products

    OpenAIRE

    Mora, Leticia; Reig, Milagro; Toldrá, Fidel

    2014-01-01

    There is a large generation of meat by-products, not only from slaughtering but also in the meat industry from trimming and deboning during further processing. This results in extraordinary volumes of by-products that are primarily used as feeds with low returns or, more recently, to biodiesel generation. The aim of this work was to review the state of the art to generate bioactive peptides from meat industry by-products giving them an added value. Hydrolysis with commercial proteases constit...

  3. 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

    2012-06-01

    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

  4. Soil and broccoli head sulfur levels but not yields are improved by the application of gypsum to a light textured soil

    Science.gov (United States)

    Light textured soils in semi-arid areas can be deficient in sulfur (S). Thus, the objective of the present study was to evaluate the effects of cultivar type (open pollinated vs. hybrid), minimum (strip-tillage) vs. conventional (bedded) tilling practices, and gypsum rate (0, 500, 1000 and 2000 kg/...

  5. Fibrous gypsum veins as diffuse features and within fault zones: the case study of the Pisco Basin (Ica desert, southern Peru)

    Science.gov (United States)

    Rustichelli, Andrea; Di Celma, Claudio; Tondi, Emanuele; Baud, Patrick; Vinciguerra, Sergio

    2016-04-01

    New knowledge on patterns of fibrous gypsum veins, their genetic mechanisms, deformation style and weathering are provided by a field- and laboratory-based study carried out on the Neogene to Quaternary Pisco Basin sedimentary strata (porous sandstones, siltstones and diatomites) exposed in the Ica desert, southern Peru. Gypsum veins vary considerably in dimensions, attitudes and timing and can develop in layered and moderately fractured rocks also in the absence of evaporitic layers. Veins occur both as diffuse features, confined to certain stratigraphic levels, and localised within fault zones. Arrays formed by layer-bounded, mutually orthogonal sets of steeply-dipping gypsum veins are reported for the first time. Vein length, height and spacing depend on the thickness of the bed packages in which they are confined. Within fault zones, veins are partly a product of faulting but also inherited layer-bounded features along which faults are superimposed. Due to the different petrophysical properties with respect to the parent rocks and their susceptibility to textural and mineralogical modifications, water dissolution and rupture, gypsum veins may have a significant role in geofluid management. Depending on their patterns and grade of physical and chemical alteration, veins may influence geofluid circulation and storage, acting as barriers to flow and possibly also as conduits.

  6. Gypsum amendment to rice paddy soil stimulated bacteria involved in sulfur cycling but largely preserved the phylogenetic composition of the total bacterial community.

    Science.gov (United States)

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

    2016-06-01

    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. PMID:27085098

  7. 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

    2016-08-01

    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.

  8. 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)

    Science.gov (United States)

    Doğan, Uğur

    2005-11-01

    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.

  9. A low-temperature ductile shear zone: The gypsum-dominated western extension of the brittle Fella-Sava Fault, Southern Alps

    Science.gov (United States)

    Bartel, Esther Maria; Neubauer, Franz; Heberer, Bianca; Genser, Johann

    2014-12-01

    Based on structural and fabric analyses at variable scales we investigate the evaporitic gypsum-dominated Comeglians-Paularo shear zone in the Southern Alps (Friuli). It represents the lateral western termination of the brittle Fella-Sava Fault. Missing dehydration products of gypsum and the lack of annealing indicate temperatures below 100 °C during development of the shear zone. Despite of such low temperatures the shear zone clearly exhibits mylonitic flow, thus evidencing laterally coeval activity of brittle and viscous deformation. The dominant structures within the gypsum rocks of the Lower Bellerophon Formation are a steeply to gently S-dipping foliation, a subhorizontal stretching lineation and pure shear-dominated porphyroclast systems. A subordinate simple shear component with dextral displacement is indicated by scattered σ-clasts. Both meso- and microscale structures are characteristic of a subsimple shear type of deformation with components of both coaxial and non-coaxial strain. Shortening in a transpressive regime was accommodated by right-lateral displacement and internal pure shear deformation within the Comeglians-Paularo shear zone. The shear zone shows evidence for a combination of two stretching faults, where stretching occurred in the rheologically weaker gypsum member and brittle behavior in enveloping lithologies.

  10. Gypsum (CaSO4·2H2O Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis

    Directory of Open Access Journals (Sweden)

    Tai-Shung Chung

    2013-11-01

    Full Text Available 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.

  11. Geomorphological Evidence of Plausible Water Activity and Evaporatic Deposition in Interdune Areas of the Gypsum-rich Olympia Undae Dune Field

    Science.gov (United States)

    Szynkiewicz, A.; Ewing, R. C.; Fishbaugh, K. E.; Bourke, M. C.; Bustos, D.; Pratt, L. M.

    2009-03-01

    New morphological features (e.g., cross-bedding strata, bright patches), revealed by HiRISE for the gypsum-rich Olympia Undae Dune Field, appear to indicate the change(s) in paleoenvironmental conditions likely controlled by climate fluctuations in the North Pole of Mars.

  12. The Messinian marine to nonmarine gypsums of Jumilla (Northern Betic Cordillera, SE Spain): Isotopic and Sr concentration constraints on the origin of parent brines

    Science.gov (United States)

    Rossi, Carlos; Vilas, Lorenzo; Arias, Consuelo

    2015-10-01

    The origin of the Messinian Hoya de la Sima (HS) gypsum (Betic foreland) is constrained using 87Sr/86Sr, δ34S, Sr concentration, and petrographic data. The Lower and Middle HS units consist of subaqueous vertically-aligned and stromatolitic selenites, the latter containing unusual microbial depositional textures. The Upper Unit consists of very-shallow-water bioturbated lenticular gypsum with Paracamelus ichnites. 87Sr/86Sr and δ34S indicate precipitation from predominantly marine waters, with upward increasing continental influence. Mixing models between Messinian seawater and continental water that dissolved Triassic evaporites show that the percentages of seawater required to explain the measured 87Sr/86Sr are analogous to the percentages obtained using δ34S, supporting precipitation from such mixtures. 87Sr/86Sr and δ34S of Lower HS selenites resemble those of the Primary Lower Gypsum (PLG) of the Messinian Salinity Crisis (MSC), in both cases indicating precipitation from seawater-continental water mixtures in which most Sr and SO4 were supplied by Messinian seawater. In the Lower HS selenites, Sr concentrations indicate contributing continental waters with Sr/Ca ratios similar to seawater. However, Sr concentrations of PLG selenites from other Betic basins (Bajo Segura, Sorbas indicate parent waters with Sr/Ca ratios lower than seawater. If the Sr contents of the betic PLG selenites are representative, it is unlikely that the Lower HS selenites represent the PLG. However, we cannot completely discard that option since different LPG subbasins could have had variable Sr/Ca. The HS gypsums formed coevally to diapirism of Triassic evaporites, in a restricted lagoonal basin developed during or slightly after a phase of strike-slip faulting in the Betic Cordillera. More general implications of this work are that Sr concentrations, combined with 87Sr/86Sr and δ34S data, provide key constraints on the origin of parent brines, and using Sr concentrations as

  13. 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

    1996-03-01

    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.

  14. 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.

    1993-04-01

    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.

  15. Risk of groundwater inrush in subterranean gypsum quarries: the case study of Moncalvo near Asti (North Italy)

    Science.gov (United States)

    Banzato, Cinzia; Fiorucci, Adriano; Gianotti, Alberto; de Waele, Jo; Vigna, Bartolomeo

    2010-05-01

    During the realisation of underground excavations in gypsum bedrock there is a possibility of intercepting large karst voids that can be completely filled with water under a considerable hydraulic pressure. The casual breaching of such voids can cause sudden and abundant water inrushes with consequences concerning safety of the excavation area and flooding of the tunnels. The presence of air-filled caves of great dimensions can also cause problems related to collapse of walls, ceilings and floors. In the subterranean quarry of Moncalvo d'Asti (Central Piedmont, Italy) in January 2005 an important inrush (60,000 m3 overnight) occurred causing damage to machinery and the flooding of several kilometres of underground tunnels. This inrush was caused by the breaching of a thin diaphragm of rock that separated the quarry from a large water-filled cave with water pressure of around 300 kPa along the front of the excavation. The rapid emptying of this void has caused a partial collapse of the roof of one of the largest cave chambers with the formation at the surface of a 20 metre wide sinkhole. To prevent similar phenomena to happen in the future a hydrogeological study concerning the entire gypsum mass was carried out. These investigations included monitoring of water levels intercepted by a series of boreholes, measurements of flow rates of water veins encountered by the excavations and chemical analysis of the different types of water coming from several points. This study has evidenced the presence of different drainage networks and the existence of a main karst circuit fed by diffused infiltration and recharge from the overlying marly-silty deposits and from adjacent minor less karstified systems in particularly fractured sectors of the gypsum. The waters coming from the main karst circuit are chemically very different from the waters deriving from deeper pathways. To be able to continue the excavation of gypsum in safe conditions the water levels were lowered for a

  16. Assessment of by-products from fresh-cut products for reuse as bioactive compounds.

    Science.gov (United States)

    Tarazona-Díaz, M P; Aguayo, E

    2013-10-01

    The fresh-cut industry is constantly growing and generating wastes. The major challenge for this industry consists in an environmentally sustainable production through re-utilization of by-products, for instance, in extraction of bioactive compounds. In this paper, the nutritional and functional compounds of apple, potato, cucumber, melon and watermelon by-products were investigated. The amount of by-product produced was of 10.10 to 30.80% of initial fresh weight depending on the product. By-products were characterized by low protein (peel than in whole product. Apple peel was rich in carbohydrates, total dietary fibre, antioxidants and total polyphenols. Potato peel was high in iron. Melon was rich in magnesium. Watermelon peel was characterized by the level of potassium, and cucumber peel was rich in manganese, zinc, phosphorous, calcium and sodium. All these data demonstrate than natural by-product from fresh-cut industry could potentially be utilized as ingredients to design new functional foods with a future market. PMID:23733809

  17. Electrostatic enhancement of fabric filtration of fly ash and spray-dryer by-product

    Energy Technology Data Exchange (ETDEWEB)

    Hovis, L.S.; Daniel, B.E.; Donovan, R.P.

    1985-11-01

    The paper describes small pilot-scale experiments, showing that the pressure-drop increase during the fabric filtration of redispersed spray-dryer by-product (chiefly calcium salts and fly ash) is significantly reduced by electrostatic enhancement of the filtration. The pressure drop rise for a typical electrostatically augmented fabric filtration (ESFF) is only 25% or less of that of the rise for a conventional filtration cycle. The ESFF takes advantage of the electrical characteristics of the spray-dryer by-product, specifically the higher natural electrical charge, as compared to fly ash, and the relatively lower electrical resistivity of the spray dryer by-product at the high moisture and the low-temperature conditions of filtration of spray dryer by-product. The low resistivity of the spray-dryer by-product and certain fly ashes allows application of high corona voltages in the new center-wire ESFF to produce an even slower pressure-drop increase over the filtration cycle. Center-wire ESFF proved to be operable under conditions of high gas velocities and grain loadings that were beyond the range for successful conventional reverse-air fabric filtration. Results of tests on the center-wire ESFF are presented and compared with conventional fabric filtration.

  18. Mineral composition of fruit by-products evaluated by neutron activation analysis

    International Nuclear Information System (INIS)

    Brazil is one of the largest producers of fruits cropping 40 million tons per year. In agro-food processing, approximately 50 % of raw material is discarded generating large amounts of by-products. The lack of information on the nutritional quality of agroindustrial by-products precludes their potential use in the manufacture of food products accessible to all. In this context, the objective of this work was to investigate the nutritional quality of by-products of the industrial processing of fruits. Samples of bagasse, peel and seeds of several fruits (banana, camu camu, coconut, cupuacu, guava, jackfruit, mango, orange, papaya, pineapple, and soursop) were analysed by neutron activation analysis for the determination of Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sc and Zn. In general, higher levels of minerals were found in the by-products rather than in the pulps of fruits. This indicates that the use of the by-products should be encouraged, thereby reducing the economic and environmental impact of waste generated by agroindustrial processing. (author)

  19. Chemical stabilization of cadmium in acidic soil using alkaline agronomic and industrial by-products.

    Science.gov (United States)

    Chang, Yao-Tsung; Hsi, Hsing-Cheng; Hseu, Zeng-Yei; Jheng, Shao-Liang

    2013-01-01

    In situ immobilization of heavy metals using reactive or stabilizing materials is a promising solution for soil remediation. Therefore, four agronomic and industrial by-products [wood biochar (WB), crushed oyster shell (OS), blast furnace slag (BFS), and fluidized-bed crystallized calcium (FBCC)] and CaCO3 were added to acidic soil (Cd = 8.71 mg kg(-1)) at the rates of 1%, 2%, and 4% and incubated for 90 d. Chinese cabbage (Brassica chinensis L.) was then planted in the soil to test the Cd uptake. The elevation in soil pH caused by adding the by-products produced a negative charge on the soil surface, which enhanced Cd adsorption. Consequently, the diethylenetriamine pentaacetic acid (DTPA)-extractable Cd content decreased significantly (P < 0.05) in the incubated soil. These results from the sequential extraction procedure indicated that Cd converted from the exchangeable fraction to the carbonate or Fe-Mn oxide fraction. The long-term effectiveness of Cd immobilization caused by applying the 4 by-products was much greater than that caused by applying CaCO3. Plant shoot biomass clearly increased because of the by-product soil amendment. Cd concentration in the shoots was < 10.0 mg kg(-1) following by-product application, as compared to 24 mg kg(-1) for plants growing in unamended soil. PMID:23947715

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-10-01

    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.

  2. 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

    2014-06-01

    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.

  3. Agro biomass by-products to multifunctional ingredients, chemicals and fillers - AgroBio

    Energy Technology Data Exchange (ETDEWEB)

    Willfoer, S.; Manelius, R. (Aabo Akademi University, Turku (Finland), Lab. of Wood and Paper Chemistry), e-mail: swillfor@abo.fi, e-mail: rmanelius@abo.fi; Faulds, C; Sibakov, J. (VTT Technical Research Centre of Finland, Espoo (Finland)), e-mail: craig.faulds@vtt.fi, e-mail: juhani.sibakov@vtt.fi

    2011-11-15

    The AgroBio project started in August 2010 and now initial tests and analyses have been performed. At the moment, larger raw material amounts are collected so that proper materials tests can be done. The main objective of the project is to develop cost-effective and sustainable technologies to produce tailor- made filler particles from agricultural by-products. More specific scientific and technological goals of the project are to: Acquire by-products and to study the demand of their pre-processing (WP1), Develop the technology for agro by-product conversion and tailoring to desired filler particles by chemical and enzymatic means, and to characterize the produced filler particles (WP2 and WP3), Evaluate the behaviour of filler particles in selected industrial processes and their market potential (WP4), Estimate the economical and business feasibility of the concept and compare it with the currently used filler materials (WP 5). To date, the agro-industrial by-products have been mainly characterized and the first trials on particle size reduction and their food and paper applications have been tested. Additionally, a first round of feasibility interviews have been conducted with participating companies. (orig.)

  4. Olive oil enriched in lycopene from tomato by-product through a co-milling process.

    Science.gov (United States)

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

    2015-01-01

    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". PMID:26001089

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

    International Nuclear Information System (INIS)

    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

  6. 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: fatim@putra.upm.edu.my [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)

    2013-03-15

    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.

  7. 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

    2007-07-01

    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.

  8. Assessment of the use of industrial by-products for induced reduction of As, and Se potential leachability in an acid soil

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Jorda, M.P.; Garrido, F. [Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115-dup, 28006, Madrid (Spain); Garcia-Gonzalez, M.T., E-mail: mtgg@ccma.csic.es [Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115-dup, 28006, Madrid (Spain)

    2010-03-15

    Four industrial by-products (phosphogypsum, PG; red gypsum, RG; sugar foam, SF and ashes from the combustion of biomass, ACB) were evaluated as possible amendments for reducing the leachability and bioavailability of As and Se in a metalloid-spiked acidic soil. The treatments were applied as single, double and triple amendments and at two different rates. The effectiveness of the treatments was evaluated after a series of leaching experiments using a chelating agent (DTPA solution) or a weak acidification (acetic acid at pH 4.93). The most effective treatments (ACB and RG, both applied at high rate) were identified by means of Cluster Analysis using the leachability indexes. Different sorption mechanisms involved in the overall reduction of metalloid leachability were identified using scanning electron microscopy (SEM-BSE and SEM-EDS). In the ACB-treated samples, Se was found associated to organic matter aggregates and to Fe compounds. In the RG-treated samples, EDS analyses showed that As and Se were associated to Fe/Ti (hydr)oxides phases which are present not only in the by-product as maghemite and rutile, but also in the soil as hematite and goethite. In addition, the application of RG induced the formation of non-crystalline Al-hydroxy polymers with As and Se in their composition.

  9. Assessment of the use of industrial by-products for induced reduction of As, and Se potential leachability in an acid soil

    International Nuclear Information System (INIS)

    Four industrial by-products (phosphogypsum, PG; red gypsum, RG; sugar foam, SF and ashes from the combustion of biomass, ACB) were evaluated as possible amendments for reducing the leachability and bioavailability of As and Se in a metalloid-spiked acidic soil. The treatments were applied as single, double and triple amendments and at two different rates. The effectiveness of the treatments was evaluated after a series of leaching experiments using a chelating agent (DTPA solution) or a weak acidification (acetic acid at pH 4.93). The most effective treatments (ACB and RG, both applied at high rate) were identified by means of Cluster Analysis using the leachability indexes. Different sorption mechanisms involved in the overall reduction of metalloid leachability were identified using scanning electron microscopy (SEM-BSE and SEM-EDS). In the ACB-treated samples, Se was found associated to organic matter aggregates and to Fe compounds. In the RG-treated samples, EDS analyses showed that As and Se were associated to Fe/Ti (hydr)oxides phases which are present not only in the by-product as maghemite and rutile, but also in the soil as hematite and goethite. In addition, the application of RG induced the formation of non-crystalline Al-hydroxy polymers with As and Se in their composition.

  10. Enzymatic Hydrolysis of Salmon By-products: Effect of Process Conditions on ACE Inhibiting Activities of Fish Protein Hydrolysates

    OpenAIRE

    Five, Kathrine

    2013-01-01

    By-products from the salmon farming industry contain valuable components, such as proteins and lipids. By-products like frames, heads and viscera can be used as raw material for the production of fish protein hydrolysates with high nutritional value, but also bioactive properties. The hydrolysates are produced by enzymatic hydrolysis using endogenous and commercial enzymes, and the process conditions and raw material influence the properties of the hydrolysate. The first aim of this thesis wa...

  11. Trimethylamine and Organic Matter Additions Reverse Substrate Limitation Effects on the δ13C Values of Methane Produced in Hypersaline Microbial Mats

    OpenAIRE

    Kelley, Cheryl A.; Nicholson, Brooke E.; Beaudoin, Claire S.; Angela M Detweiler; Bebout, Brad M

    2014-01-01

    Methane production has been observed in a number of hypersaline environments, and it is generally thought that this methane is produced through the use of noncompetitive substrates, such as the methylamines, dimethylsulfide and methanol. Stable isotope measurements of the produced methane have also suggested that the methanogens are operating under conditions of substrate limitation. Here, substrate limitation in gypsum-hosted endoevaporite and soft-mat hypersaline environments was investigat...

  12. improving citric acid production from some carbohydrates by-products using irradiated aspergillus niger

    International Nuclear Information System (INIS)

    Twenty strains of A. niger were isolated from different sources, screened for their capacity to produce citric acid. All the isolated strains were able to produce citric acid in different quantities at different time intervals i.e. 4, 8 and 12 days on indicator medium. The best incubation period for production for all isolates was 12 days. The most potent strains for production were A1, A4 and A5, while A8, A16, A18 and A19 recorded weak production on that medium. Citric acid productivity were obtained by all strains when using different concentrations of four carbohydrate by-products (maize straw, potato peel wastes, sugar beet pulp and molasses) when each used alone without any additions after 12 days incubation and the production enhanced when the fermentation medium amended with the same concentrations of the mentioned substrates. Type and concentration of carbohydrate by-product affect the production of citric acid by A. niger strains under the study. Increasing substrate concentration led to increase in production, the best concentration for production was 25% for all carbohydrate by-products. As recorded with indicator medium, A1, A4 and A5 are also the most potent strains for production when growing on the four carbohydrate by-products supplemented to the basal medium, while A8, A6, A18 and A19 recorded the weak production with the carbohydrate by-products used.production of the parental isolates A1, A4 and A5 on indicator medium were: 0.96, 0.95 and 0.99 (mg/ml) respectively after 12 days incubation, while maximum production by the obtaining resulting isolates (Treated by UV irradiation) were: 1.78, 1.70 and 1.73 (mg/ml) from A4T2 (5 min.), A4T1 (10 min.) and A1T1 (5 min.), respectively.

  13. Malignant mesothelioma: clustering in a family producing asbestos cement in their home.

    OpenAIRE

    Otte, K.E.; Sigsgaard, T I; Kjaerulff, J

    1990-01-01

    In a family with a remarkable aggregation of malignant mesothelioma the father, mother, and a son all died of the condition, whereas two other sons and a daughter were unaffected. From 1944 to 1961 the family produced a material that was used to fix screws in drilled holes and consisted of amosite, gypsum, and sand. It was produced in the basement of their villa and was described as being a dusty job. The father died in 1984 aged 74, the son in 1985 aged 45, and the mother in 1987 aged 79. It...

  14. Utilization of by-products in ruminant diets in Cyprus

    International Nuclear Information System (INIS)

    Five experiments were carried out with the objective of studying the nutritive value of crop residues and agro-industrial by-products, either alone or in combination with non-protein nitrogen, and the use of these by-products in ruminant diets. The intake and nutritive value of poor quality roughages and other by-products (cereal straw, peanut hulls and waste paper) were improved considerably by supplements that provide nitrogen (soybean meal or urea) and energy (barley grain). Partial replacement of soybean meal in diets of fattening lambs by urea was possible and dry mature sheep could be maintained on cereal straw diets supplemented with small quantities of barley grain, urea, minerals and vitamins. Silage was made from citrus peels or grape marc and poultry litter. It replaced successfully part of the concentrate mixture in the diets of lactating cows and growing heifers. (author)

  15. Estimating indirect land use impacts from by-products utilization

    Energy Technology Data Exchange (ETDEWEB)

    Croezen, H.; Brouwer, F.

    2008-06-15

    Aim of this project part is providing an indication of the effects utilization of by-products from biofuels production can have on global land use and on land use changes. Potential influences on land use changes may also influence net GHG emissions, in case deforestation or other forms of changing natural habitats into crop land are avoided. In order to demonstrate the relevance we broadly translated avoided land use in potential GHG emission avoidance due to avoiding land use change. The analysis focuses on the utilization of by-products from so-called first generation biofuels production technologies as feed. This application avoids cultivation of primary feed crops such as soy, wheat and corn and thus reduces area requirement for cultivation of these crops and the GHG emissions related to crop cultivation and crop processing. Reduction in area requirement might also mean avoiding creation of extra agricultural area by transforming natural area's. This would avoid GHG emissions related to land use change. The by-products could alternatively be utilized as fuel or - in the future - as feedstock for second generation biofuels. By-products utilization as fuel will avoid fossil fuel consumption and related GHG emissions. The analysis is a follow up of the E4Tech scenario analysis. We used the amounts of crops applied as feedstocks in the E4Tech scenario's as starting point of our own analysis. In chapter 2 we estimate the amounts of by-products we have to consider. In chapter 3 we then estimate which amounts of primary feed crops are likely to be replaced by the considered amounts of by-products.

  16. Water-Extractable Carbon Pools and Microbial Biomass Carbon in Sodic Water-Irrigated Soils Amended with Gypsum and Organic Manures

    Institute of Scientific and Technical Information of China (English)

    O.P.CHOUDHARY; J.K.GILL; BIJAY-SINGH

    2013-01-01

    Microbial biomass carbon (MBC),a small fraction of soil organic matter,has a rapid turnover rate and is a reservoir of labile nutrients.The water-extractable carbon pools provide a fairly good estimate of labile C present in soil and can be easily quantified.Changes in soil MBC and water-extractable organic carbon pools were studied in a 14-year long-term experiment in plots of rice-wheat rotation irrigated with canal water (CW),sodic water (SW,10-12.5 mmolc L-1 residual sodium carbonate),and SW amended with gypsum with or without application of organic amendments including farmyard manure (FYM),green manure (GM),and wheat straw (WS).Irrigation with SW increased soil exchangeable sodium percentage by more than 13 times compared to irrigation with CW.Sodic water irrigation significantly decreased hot water-extractable organic carbon (HWOC) from 330 to 286 mg kg-1 soil and cold water-extractable organic carbon (CWOC) from 53 to 22 mg kg-1 soil in the top 0-7.5 cm soil layer.In the lower soil layer (7.5-15 cm),reduction in HWOC was not significant.Application of gypsum alone resulted in a decrease in HWOC in the SW plots,whereas an increase was recorded in the SW plots with application of both gypsum and organic amendments in both the soil layers.Nevertheless,application of gypsum and organic amendments increased the mean CWOC as compared with application of gypsum alone.CWOC was significantly correlated with MBC but did not truly reflect the changes in MBC in the treatments with gypsum and organic amendments applied.For the treatments without organic amendments,HWOC was negatively correlated with MBC (r =-0.57*)in the 0-7.5 cm soil layer,whereas for the treatments with organic amendments,both were positively correlated.Irrigation with SW significantly reduced the rice yield by 3 t ha-1 and the yield of rice and wheat by 5 t ha-1 as compared to irrigation with canal water.Application of amendments significantly increased rice and wheat yields.Both the rice yield and

  17. NATURAL ANTIOXIDANT INGREDIENT FROM BY-PRODUCTS OF FRUITS

    Directory of Open Access Journals (Sweden)

    G. S. El-Baroty

    2014-01-01

    Full Text Available The contents of total phenolics compounds and their phenolic constituents were quantified in organic and aqueous of four varieties (Zebdia, Sukkari, taimor and Hindi of mango (Mangifera indica L., seeds pulp and kernel, one varieties of pomegranate (Punica ranatum L., peel and peanut (Arachis hypogaea L., Giza 6, shell by-products. The antioxidant activities of all by products extracts were assessed by five antioxidant methods as well as by rancimate test. The total Phenolic content of aqueous and organic extracts of among all mango varieties, pomegranate and peanut shell showed the content values ranging from 71.06 to 124.18 mg/100g, 95.07 to 124.18 mg/100g and 41.64 to 71.06, respectively. Nineteen phenolic compounds were identified by High Performance Liquid Chromatography (HPLC among all mango varieties, of which vanillic acid, benzoic acid and mangiferin were occurred in high amounts. The major phenolic compounds were detected in pomegranate and peanut shell were chlorogenic and gallic and caffeic (24.42%, respectively. All fruits by products were exhibited remarkable antioxidant activity, with various degrees in all tested methods. However, among all by-products extracts, organic extract had higher antioxidant than that aqueous extracts toward all antioxidant tested. Mango kernel peel and pomegranates showed high radical scavenging activity, which could be compared with the synthetic antioxidants Butylated Hydroxyanisol (BHA. However, all by-products extracts exhibited high inhibit effect against the lipid peroxidation of sunflower oil (at 100°C as assessed by rancimat methods. However, this antioxidant activity was found to be strong significant correlation with phenolic contents (p<0.05 in by-product extracts. It can be thus concluded that varied varieties of mango, pomegranate and peanut by-products, although it constitutes the part of the fruits, it is valuable parts due to its antioxidant activities, it can be

  18. The next chapter in experimental petrology: Metamorphic dehydration of polycrystalline gypsum captured in 3D microtomographic time series datasets

    Science.gov (United States)

    Bedford, John; Fusseis, Florian; Leclere, Henry; Wheeler, John; Faulkner, Dan

    2016-04-01

    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

  19. Vanadium phosphate catalysts for biodiesel production from acid industrial by-products.

    Science.gov (United States)

    Domingues, Carina; Correia, M Joana Neiva; Carvalho, Renato; Henriques, Carlos; Bordado, João; Dias, Ana Paula Soares

    2013-04-10

    Biodiesel production from high acidity industrial by-products was studied using heterogeneous acid catalysts. These by-products contain 26-39% of free fatty acids, 45-66% of fatty acids methyl esters and 0.6-1.1% of water and are consequently inadequate for direct basic catalyzed transesterification. Macroporous vanadyl phosphate catalysts with V/P=1 (atomic ratio) prepared via sol-gel like technique was used as catalyst and it was possible to produce in one reaction batch a biodiesel contain 87% and 94% of FAME, depending on the by-product used as raw material. The initial FAME content in the by-products had a beneficial effect on the reactions because they act as a co-solvent, thus improving the miscibility of the reaction mixture components. The water formed during esterification process seems to hinder the esters formation, possibly due to competitive adsorption with methanol and to the promotion of the FAME hydrolysis reaction.The observed catalyst deactivation seems to be related to the reduction of vanadium species. However, spent catalysts can be regenerated, even partially, by reoxidation of the reduced vanadium species with air. PMID:22902409

  20. REDUCTION OF DISINFECTION BY-PRODUCT PERCURSORS BY NANOFILTRATION

    Science.gov (United States)

    The reduction of disinfection by-product (DBP) precursors by nanofiltration was investigated in Florida at both a groundwater site and a surface water site. eparate studies, involving pilot plant operations, were conducted for one year at each site. he principal research tasks at...

  1. Materials with Adsorptive Properties from Agricultural By-Products

    Science.gov (United States)

    This presentation will summarize the use of agricultural by-products (e.g., animal manure and plant waste) as starting materials to adsorb environmental contaminants such as mercury from air, ammonia from air, metal ions from water, and chlorinated organics from water. The results show that the mat...

  2. Leaching of Phase II Mercury Control Technology By-Products

    Energy Technology Data Exchange (ETDEWEB)

    Hesbach, P.A.; Kachur, E.K.

    2007-07-01

    The U.S. EPA has issued a final regulation for control of mercury from coal-fired power plants. An NETL research, development and demonstration program under DOE/Fossil Energy Innovations for Existing Plants is directed toward the improvement of the performance and economics of mercury control from coal-fired plants. The current Phase II of the RD&D program emphasizes the evaluation of performance and cost of control technologies through slip-stream and full scale field testing while continuing the development of novel concepts. One of the concerns of the NETL program is the fate of the captured flue gas mercury which is transferred to the condensed phase by-product stream. These adulterated by-products, both ashes and FGD material, represent the greatest challenge to the DOE goal of increased utilization of by-products. The degree of stability of capture by-products and their potential for release of mercury can have a large economic impact on material sales or the approach to disposal. One of the considerations for mercury control technology is the potential trade-off between effective but temporary mercury capture and less effective but more permanent sequestration. As part of a greater characterization effort of Phase II facility baseline and control technology sample pairs, NETL in-house laboratories have performed aqueous leaching procedures on a select subset of the available sample pairs. This report describes batch leaching results for mercury, arsenic, and selenium.

  3. Maximizing Utilization of Energy from Crop By-products

    Directory of Open Access Journals (Sweden)

    Budi Haryanto

    2014-03-01

    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.

  4. Nutritional Value of Irradiated Animal Feed By-Products

    International Nuclear Information System (INIS)

    Animal feed by-products, widely used in animal diets, are sources of disease organisms for animals and for human beings. Salmonella is the principal genus of concern.Radiation treatment (radicidation, radurization) is a promising method of decontamination of feed ingredients. Commercial samples of fish, meat, and blood meals were sealed by heat in polyethylene bags and irradiated at dose levels of 5.0, 10, 20 and 50 kGy. Their chemical analysis were carried out according to A. O. A.C [1] and the total protein efficiency (TPE) of the three animal feed by-products was determined according to Wood ham (2) by using one day old Dokki-4 chicks. Radiation induced an insignificant effect on the chemical constituent of meals. Also, the same trend was observed with TPE of both fish and meat meals. However, irradiation treatments improved TPE values of irradiated blood meal samples. From the results, it could be concluded that irradiation of animal feed by-products up to a dose level of 50 Gy has no adverse effects on the nutritional value of animal feed by-products

  5. Arctic Gypsum Endoliths: a biogeochemical characterization of a viable and active microbial community

    OpenAIRE

    L. A. Ziolkowski; Mykytczuk, N. C. S.; C. R. Omelon; Johnson, H; Whyte, L. G.; Slater, G. F.

    2013-01-01

    Extreme environmental conditions such as those found in the polar regions on Earth are thought to test the limits of life. Microorganisms living in these environments often seek protection from environmental stresses such as high UV exposure, desiccation and rapid temperature fluctuations, with one protective habitat found within rocks. Such endolithic microbial communities, which often consist of bacteria, fungi, algae and lichens, are small-scale ecosystems comprised of both producer...

  6. Experimental cancer studies of chlorinated by-products

    International Nuclear Information System (INIS)

    Chlorinated drinking water contains a number of different by-products formed during the chlorination process from organic matter. The carcinogenicity of only a fraction of them have been evaluated in experimental animals. The focus has been on compounds and groups of compounds that are most abundant in chlorinated drinking water or the in vitro toxicity data have suggested genotoxic potential. From trihalomethanes, chloroform causes liver tumors in mice and female rats and renal tumors in male mice and rats. Tumor formation by chloroform is strongly associated with cytotoxicity and regenerative cell proliferation in tissues and that has been considered to be one determinant of its carcinogenicity. From halogenic acetic acids, dichloroacetic acid (DCA) and trichlotoacetic acid (TCA) are hepatocarcinogenic in mice and DCA in male rats. Their genotoxicity is equivocal and nongenotoxic mechanisms, such as peroxisome proliferation and hypomethylation of DNA in the liver, likely contribute to tumor development. From chlorinated furanones (CHFs), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) is a multisite carcinogen in rats (e.g. in thyroid glands and liver) and it has caused DNA damage in vivo. MX may be a complete carcinogen because it also has promoter properties in vitro. Chlorinated drinking water may also contain brominated by-products providing the raw water contains bromide. At least some of them (bromodichloromethane, bromoform) have been shown to be carcinogenic in laboratory animals. Altogether, although several by-products have been shown to have carcinogenic potential in laboratory animals, it not yet possible to state which compounds or groups of by-products cause the cancer risk in chlorinated drinking water. The cellular mechanisms of their effects and these effects at low concentrations are still poorly understood. The few studies with mixtures of these by-products suggest that the mixture effects may be complex and unpredictable (inhibitory

  7. Pra Rancangan Pabrik Pembuatan Pupuk Amonium Sulfat Dari Gypsum Sintetik Hasil Pengolahan Unit Flue Gas Desulfurization PLTU Dengan Kapasitas 30.000 Ton/Tahun

    OpenAIRE

    Sianturi, Krisma Yessi

    2012-01-01

    Indonesia merupakan negara agraris sehingga tidak terlepas akan kebutuhan terhadap pupuk. Pupuk amonium sulfat, ZA (Zwuafel Amonium), dimanfaatkan sebagai pupuk nitrogen, terutama untuk tanaman industri dan perkebunan. Data impor amonium sulfat dari Badan Pusat Statistik Indonesia menunjukkan peningkatan 268.451.459 kg pada tahun 2010. Salah satu alternatif untuk kebutuhan amonium sulfat tersebut adalah memproduksi amonium sulfat dengan menggunakan gypsum hasil unit Flue Gas Desulfurization (...

  8. Populations of some molds in water-damaged homes may differ if the home was constructed with gypsum drywall compared to plaster.

    Science.gov (United States)

    Vesper, Stephen; Wymer, Larry; Cox, David; Dewalt, Gary

    2016-08-15

    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 from the 2006 Department of Housing and Urban Development's (HUD) American Health Homes Survey (AHHS) were the subject of this analysis. The concentrations of the 36 Environmental Relative Moldiness Index (ERMI) molds were compared in homes of different ages. The homes (n=301) were built between 1878 and 2005. Homes with ERMI values >5 (n=126) were defined as water-damaged. Homes with ERMI values >5 were divided in the years 1976 to 1977 into two groups, i.e., older (n=61) and newer (n=65). Newer water-damaged homes had significantly (p=0.002) higher mean ERMI values than older water-damaged homes, 11.18 and 8.86, respectively. The Group 1 molds Aspergillus flavus, Ammophilus fumigatus, Aspergillus ochraceus, Cladosporium sphaerospermum and Trichoderma viride were found in significantly higher concentrations in newer compared to older high-ERMI homes. Some mold populations in water-damaged homes may have changed after the introduction of gypsum drywall. PMID:27104493

  9. Short term influence of gypsum, farm manure and commercial humic acid on physical properties of salt affected soil in rice paddy system

    International Nuclear Information System (INIS)

    Addition of organic materials to soil has been one of the most common practices to improve soil properties. Combined application of organic and inorganic amendments has been known to play a significant role in improvement of soil properties. A field experiment was conducted to explore the role of gypsum (G), farm manure (FM) and commercial humic acid (HA) on the improvement of physical properties of saline sodic soil. Different dosages of G, FM and HA were applied to soil under cultivation of rice crop. Organic carbon (OC) and organic carbon pool (OC pool) were increased up to 73 % and 71 %, respectively, with 100 % soil gypsum requirement (SGR) combined with 20 ton FM ha/sup -1/. There was 15.8 % increase in water stable aggregates (WSA) by 100 % SGR combined with 20 ton FM ha-1. Application of gypsum particularly with farm manure decreased bulk density from 1.66 to 1.33 Mg m/sup -3/ and increased total porosity (TP) by 24 %. HA did not improve any soil property with considerable results in current study. There was positive significant (P<= 0.05) correlation between OC and OC pool, WSA and TP (r= 0.98, 0.91, 0.66, respectively; P<= 0.05), while bulk density had negative correlations with all soil properties examined in our study. (author)

  10. 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

    2011-01-01

    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.

  11. Preparation of Self-leveling Mortar with FGD Gypsum%脱硫石膏用于自流平砂浆的研究

    Institute of Scientific and Technical Information of China (English)

    彭明强; 叶蓓红

    2012-01-01

    Self-leveling floor material with flue gas desulfurization(FGD) gypsum was studied. A new kind of gypsum-based self-leveling mortar with fine fluidity, high strength, was developed with semi-hydrated gypsum by mixing quartz sand, water reducing agent, retarder, water retaining agent, antifoaming agent and ethylene-vinyl acetate(EVA) copolyment. The tests show that the main performance of this mortar reaches or exceeds the requirements specified in the standard of JC/T 1023-2007, such as fluidity, com-pressive strength,flexural strength and tensile strength.%利用脱硫石膏开展了地面自流平材料试验研究,结果表明,以α-半水石膏为基料,掺加石英砂以及减水剂、缓凝剂、消泡剂等外加剂可制备石膏基自流平砂浆,且该自流平砂浆流动度、抗折强度、抗压强度和拉伸黏结强度等主要技术性能指标均达到JC/T 1023-2007《石膏基自流平砂浆》标准要求.

  12. Sulfur by-product formation in the Stretford process. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Trofe, T.W.; DeBerry, D.W.

    1993-09-01

    Liquid redox sulfur recovery processes remove H2S from sour gas streams and produce elemental sulfur for sale or disposal. The Stretford Process is one of the oldest commercial liquid redox processes and it is based on a vanadium and anthraquinone redox system. Improvements in the operability and reliability of the Stretford process would be beneficial to the process user. The report presents results of research focused on developing an understanding of the process parameters and factors that impact sulfur by-product formation (e.g., sodium thiosulfate and sodium sulfate) in the Stretford process. The information in the report can help current Stretford plant process users better understand the operations of their plants, especially with regards to sulfur by-product formation and control strategies.

  13. Design, construction and performance testing of a solar dryer for agroindustrial by-products

    Energy Technology Data Exchange (ETDEWEB)

    Montero, I.; Miranda, T.; Rojas, S.; Celma, A.R. [University of Extremadura, Department of Chemical and Energetics Engineering, Industrial Engineering School, Av. Elvas s/n, 06071 Badajoz (Spain); Blanco, J. [PSA (CIEMAT), Department of Solar Chemistry, Ctra. Sens, P.O. Box 22, 04200 Tabernas (Almera) (Spain)

    2010-07-15

    Spain generates a big amount of agroindustrial by-products of high moisture that produce a high environmental impact. This fact motivates the aim of this paper, in which a solar dryer prototype is designed, constructed, and performance tested for the analysis of the drying kinetics of these by-products and their possible power valuation. The characteristics of the prototype are presented, together with the variations of the properties of temperature, relative humidity, air mass flow, and efficiency for indirect, mixed, passive, active, and hybrid operation modes. The most efficient operation mode will be the forced-hybrid one, followed by the passive and active modes. The analysis of the drying kinetics of the olive pomace shows the better performance of the hybrid and mixed modes, obtaining reductions of the drying time of a 50% in both cases. (author)

  14. STARCH/PULP-FIBER BASED PACKAGING FOAMS AND CAST FILMS CONTAINING ALASKAN FISH BY-PRODUCTS (WASTE

    Directory of Open Access Journals (Sweden)

    Syed H. Imam

    2008-08-01

    Full Text Available 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 highest flexural modulus (500-770 Mpa. Above 20% fiber content, the modulus dropped considerably in all foam samples. Foam panels with pollock frames had the highest flexural modulus, at about 15% fiber content (770 Mpa. Foams with salmon heads registered the lowest modulus, at 25% concentration. Attempts were also made to cast starch-glycerol-poly (vinyl alcohol films containing 25% fish by-product (salmon heads. These films showed a tensile strength of 15 Mpa and elongation at break of 78.2%. All foams containing fish by-product degraded well in compost at ambient temperature (24oC, loosing roughly between 75-80% of their weight within 7 weeks. The films degraded at a much higher rate initially. When left in water, foams prepared without fish by-product absorbed water much more quickly and deteriorated faster, whereas, water absorption in foams with fish by-product was initially delayed and/or slowed for about 24 h. After this period, water absorption was rapid.

  15. Characterization and Recovery of Rare Earths from Coal and By-Products

    Energy Technology Data Exchange (ETDEWEB)

    Granite, Evan J. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Roth, Elliot [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Alvin, Mary Anne [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-03-25

    Coal is a precious resource, both in the United States and around the world. The United States has a 250-year supply of coal, and generates between 30 - 40% of its electricity through coal combustion. Approximately 1 Gt of coal has been mined annually in the US, although the 2015 total will likely be closer to 900 Mt (http://www.eia.gov/coal/production/quarterly/). Most of the coal is burned for power generation, but substantial quantities are also employed in the manufacture of steel, chemicals, and activated carbons. Coal has a positive impact upon many industries, including mining, power, rail transportation, manufacturing, chemical, steel, activated carbon, and fuels. Everything that is in the earth’s crust is also present within coal to some extent, and the challenge is always to utilize abundant domestic coal in clean and environmentally friendly manners. In the case of the rare earths, these valuable and extraordinarily useful elements are present within the abundant coal and coal by-products produced domestically and world-wide. These materials include the coals, as well as the combustion by-products such as ashes, coal preparation wastes, gasification slags, and mining by-products. All of these materials can be viewed as potential sources of rare earth elements. Most of the common inorganic lanthanide compounds, such as the phosphates found in coal, have very high melting, boiling, and thermal decomposition temperatures, allowing them to concentrate in combustion and gasification by-products. Furthermore, rare earths have been found in interesting concentrations in the strata above and below certain coal seams. Much of the recent research on coal utilization in the United States has focused upon the capture of pollutants such as acid gases, particulates, and mercury, and the greenhouse gas carbon dioxide. The possible recovery of rare earth and other critical elements from abundant coal and by-products is an exciting new research area, representing a

  16. Richness, diversity and evenness of vegetation upon rehabilitation of gypsum mine spoiled lands in the Indian arid zone

    Science.gov (United States)

    Kumar, S.; Sharma, K.D.; Sharma, U.K.; Gough, L.P.

    1998-01-01

    Richness, diversity and evenness of vegetation, after rehabilitation of gypsum mine spoils at Barmer were investigated in plots protected and planted one year and four years ago. There were four water harvesting treatments, viz., half-moon terraces, micro-catchments with 5% slope, ridge and furrow and control, wherein, indigenous and exotic trees and shrubs were planted at 5 ?? 5 m spacing. Sampling of the planted and natural vegetation, using quadrats and transacts, revealed much less species richness in unplanted control as compared to all treatments and in all the years. The species richness that increased initially (within one year) gradually declined over time (during four year), though the extent varied in different treatments. The water harvesting treatment showing maximum initial increase in richness also showed maximum decline over time, though decline was more in annual species. Two perennial species increased in richness with time. This was further proved from the trends in diversity and evenness indices. It was concluded that natural successional process was accelerated by rehabilitation providing stability to the habitat.

  17. Adsorption of mercury in coal-fired power plants gypsum slurry on TiO2/chitosan composite material

    Science.gov (United States)

    Gao, P.; Gao, B. B.; Gao, J. Q.; Zhang, K.; Chen, Y. J.; Yang, Y. P.; Chen, H. W.

    2016-07-01

    In this study, a simple method was used to prepare a chitosan adsorbent to mix with KI and TiO2. Gravimetric analysis (TG), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the samples before and after adsorption of Hg2+. A mercury adsorption experiment was also conducted in the gypsum slurry. The results show that using hydrobromic acid as a solvent of adsorbent resulted in a better adsorption effect than using acetic acid alone. Also, the sample (CS-KI/TiO2-HBr) had a maximum mercury adsorption capacity when the pH=5 and the t=50°C. The characterization experiments showed that the thermal stability of composite materials declined and the TiO2 uniformly dispersed in the surface of the samples with a lamellar structure, generating a lot of cracks and recesses that increased the reactive sites. Furthermore, when the TiO2 reacted with CS, it resulted in Ti-C, Ti-O and Ti-N bonds. The Br- can prevent the growth of TiO2 crystal grains and strengthen the ability of I- to remove mercury. The adsorption isotherm and kinetic results indicated that the adsorption behaviour of CS-KI/TiO2-HBr as it removes Hg2+ is an inhomogeneous multilayer adsorption process. The surface adsorption and intraparticle diffusion effects are both important in the Hg2+ adsorption process.

  18. Recent developments in by-product plant processes

    Energy Technology Data Exchange (ETDEWEB)

    Herpers, E.T.; Barber, K.G.

    1985-01-01

    Energy saving and pollution control in by-product coke plant processes are considered. An example of a very cost-effective plant modification for energy saving is the retrofitting of heat exchangers to a benzole and naphthalene plant of the British Steel Corporation at Port Talbot. Energy savings are also possible in the carbonisation process, where there are sources of low grade heat which can be recovered. Recent developments in by-product plant pollution control include those in catalytic ammonia destruction for reduction of ammonia; the Sulfammon Process, high pressure gas treatment Sulfiban Process, and the Claus Process for reduction of H/sub 2/S; and the tower effluent treatment process for liquid effluents. Odorous emission control and noise abatement are also mentioned. 2 references.

  19. Utilization of biodiesel by-products for mosquito control.

    Science.gov (United States)

    Pant, Megha; Sharma, Satyawati; Dubey, Saurabh; Naik, Satya Narayan; Patanjali, Phool Kumar

    2016-03-01

    The current paper has elaborated the efficient utilization of non-edible oil seed cakes (NEOC), by-products of the bio-diesel extraction process to develop a herbal and novel mosquitocidal composition against the Aedes aegypti larvae. The composition consisted of botanical active ingredients, inerts, burning agents and preservatives; where the botanical active ingredients were karanja (Pongamia glabra) cake powder and jatropha (Jatropha curcas) cake powder, products left after the extraction of oil from karanja and jatropha seed. The percentage mortality value recorded for the combination with concentration, karanja cake powder (20%) and jatropha cake powder (20%), 1:1 was 96%. The coil formulations developed from these biodiesel by-products are of low cost, environmentally friendly and are less toxic than the synthetic active ingredients. PMID:26296531

  20. Agro-industrial by-products as ruminant feed

    International Nuclear Information System (INIS)

    A marked imbalance exists in many parts of the world between the number of ruminants and the availability of good quality fodder. The low feeding value of natural pastures, their seasonality of production, and the increasing cost of feed grain, have increased the dependence of ruminant animals on crop residues and by-products of agriculture for their nutrient requirements. Intensive animal production systems suitable for developed temperate regions have not been successful in the developing tropical countries, where appropriate farming systems for livestock production should have an integrated approach, combining both crop and livestock husbandry. Adoption of nutritional principles with a view to eliminating or reducing imbalances and optimizing rumen function have yielded excellent results, illustrating the future potential of fibrous residues and other agricultural by-products in ruminant feeding systems in developing countries. (author)

  1. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    Science.gov (United States)

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-03-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  2. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    Science.gov (United States)

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-06-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  3. Utilization of Biodiesel By-Products for Biogas Production

    OpenAIRE

    Nina Kolesárová; Miroslav Hutňan; Igor Bodík; Viera Špalková

    2011-01-01

    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 o...

  4. Chlorine dioxide and by-products in water distribution systems

    OpenAIRE

    Ferreira, Francisco Cardoso

    1991-01-01

    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...

  5. Health impact of disinfection by-products in swimming pools

    OpenAIRE

    Villanueva, Cristina M.; Laia Font-Ribera

    2012-01-01

    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 epidemio...

  6. Effect of Celebrity Endorsement in Advertising Activities by Product Type

    OpenAIRE

    Karasiewicz Grzegorz; Kowalczuk Martyna

    2014-01-01

    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 t...

  7. Soil surface properties affected by organic by-products

    OpenAIRE

    Pachepsky Ya.A.; Rawls W.J.; Fournier L.L.; Filgueira R.R.; Sikora L.J.

    2002-01-01

    The beneficial effects of amending soils with organic by-products include improvement of both chemical and physical factors. Very few studies have investigated changes in the soil specific surface area (SSA) after amendments with manures or composts. Soil samples were taken from plots before and after four years� application of manures, composts or nitrogen fertilizer. A corn-wheat-soybean rotation was grown. Soil samples were tested for changes in water retention at �15 bar, bu...

  8. By-products from Fish Processing: Focus on French Industry

    OpenAIRE

    Penven, Anais; Perez-galvez, Raul; Berge, Jean-pascal

    2013-01-01

    Biotechnology advances for marine by-products conversion into products of interest are numerous. In order to give maximum elements of understanding, it is essential to define the framework of this research to understand why and how bioconversion technologies are applicable. It is essential to look beyond the technical and technological advances on the subject and so to take into account the economic, social, political and environmental parameters, which govern all forms of approaches for fish...

  9. Sustainable bioethanol production using agro-industrial by-products

    OpenAIRE

    Pardão, J.; Diaz, I; Raposo, Sara; Manso, Teresa; Lima-Costa, Maria Emília

    2008-01-01

    This work aimed to evaluate a sustainable bioethanol production by a laboratorial isolate strain of Saccharomyces cerevisiae, along with the use of agro-industrial by-products as carbon source. The effect of several carbon sources and their concentrations was studied using carob pod extract (CPE) and beet molasses (BM) and compared with glucose and sucrose as conventional carbohydrates at different concentrations, 15, 20 and 30 g/l.No significant difference was found between m...

  10. Irradiated fuel by-product separation research in Canada

    International Nuclear Information System (INIS)

    Although no decision has been made to reprocess irradiated CANDU fuel, by-product separation research has recently been initiated in Canada because of its potential importance to Canadian research programs in advanced fuel cycles (especially U/Pu cycle development in the near term) and nuclear waste management. In addition, separated by-products could have a significant commercial potential. Demonstrated applications include: heat sources, gamma radiation sources, light sources, new materials for productions of other useful isotopes, etc. For illustrative purposes the calculated market value of by-products currently stored in irradiated CANDU fuel is approximately $210/kgU. Ontario Hydro has initiated a program to study the application of new separation technolgies, such as laser-based techniques and the plasma ion cyclotron resonance separation technique, to either augment and/or supplant the chemical extraction methods. The main goal is to develop new, more economical extraction methods in order to increase the magnitude of the advantages resulting from this approach to reprocessing. (author)

  11. Obtention of agricultural gypsum traced on 34 S (Ca34 SO4.2H2O), by chemical reaction between H234 SO4 and Ca(OH)2

    International Nuclear Information System (INIS)

    The gypsum (CaSO4.2H2O) has double function in the soil: as source of calcium and sulfur and reducing agent of aluminum saturation. The sulfur for the plants has acting in the vital functions and it is proven fact increase of the S deficiency in Brazilian soils. The isotope tracer 34 S can elucidate important aspects in the sulfur cycle. The Ca34 SO4.2H2O was obtained by chemical reaction between Ca(OH)2 and H234 SO4 solution. The acid was obtained by chromatography ionic change, using cationic resin Dowex 50WX8 and Na234 SO4 solution. The reaction was realized under slow agitation. After the reaction, the precipitate was separated and dried in ventilated stove at 60 deg C temperature. The Mass of the Ca34 SO4.2H2O produced was determined by method gravimetric. This way, a system contends resin 426 cm3, considering volume of 2.2 liters can be obtained a solution contends 44.2 g of H234 SO4, theoretically could be produced 78.0 g of Ca34 SO4.2H2O approximately. With results of the tests were verified that there was not total precipitation of the Ca34SO4.2H2O. Were produced 73.7± 0.6 g of Ca34 SO4.2H2O representing average income 94.6±0.8 %. The purity of the produced CaSO4.2H2O was 98%. (author)

  12. Coupled measurements of δ18O and δD of hydration water and salinity of fluid inclusions in gypsum from the Messinian Yesares Member, Sorbas Basin (SE Spain)

    Science.gov (United States)

    Evans, Nicholas P.; Turchyn, Alexandra V.; Gázquez, Fernando; Bontognali, Tomaso R. R.; Chapman, Hazel J.; Hodell, David A.

    2015-11-01

    We studied one cycle (Cycle 6) of gypsum-marl deposition from the Messinian Yesares Member in Sorbas Basin, Spain. The objective was to reconstruct the changing environment of deposition and its relation to astronomically-forced climate change. The δ18O and δD of gypsum hydration water (CaSO4 • 2H2O) and salinity of fluid inclusions were measured in the same samples to test if they record the composition of the mother fluid from which gypsum was precipitated. Water isotopes are highly correlated with fluid inclusion salinity suggesting the hydration water has not exchanged after formation. The relatively low water isotope values and fluid inclusion salinities indicate a significant influence of meteoric water, whereas δ34S, δ18OSO4 and 87Sr/86Sr support a dominant marine origin for the gypsum deposits. The discrepancy between water and elemental isotope signatures can be reconciled if meteoric water dissolved previously deposited marine sulfates supplying calcium and sulfate ions to the basin which maintained gypsum saturation. This recycling process accounts for the marine δ34S, δ18OSO4 and 87Sr/86Sr signatures, whereas the low δ18O and δD values of gypsum hydration water and fluid inclusion salinities reflect the influence of freshwater. The cyclic deposition of gypsum and marl in the Yesares Member has previously been interpreted to reflect changing climate related to Earth's precession cycle. We demonstrate that the δ18O, δD and salinity of the parent brine increased from low values at the base of the cycle to a maximum in the massive gypsum palisade, and decreased again to lower values in the supercones at the top of the cycle. This pattern, together with changes in mineralogy (calcite-dolomite-gypsum), is consistent with a precession-driven change in climate with wettest conditions (summer insolation maxima) associated with the base of the calcium carbonate marls and driest conditions (summer insolation minima) during formation of the gypsum

  13. Conversion of the biodiesel by-product glycerol by the non-conventional yeast Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying

    The focus on de veloping new renewable energy in the transportation sector by the EU has boosted the production of biodiesel from rapeseed and other vegetable oils in Europe. This has led to an immense increase in the production of glycerol, which is an inevitable byproduct from the biodiesel...... 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...

  14. Effects of industrial by-product amendments on As, Cd and Tl retention/release in an element-spiked acidic soil

    International Nuclear Information System (INIS)

    To asses the efficiency of two by-products (phosphogypsum (PG) and sugar foam (SF), rich in gypsum and calcium carbonate, respectively) in the immobilization of three toxic elements (As, Cd and Tl) in an acidic soil, batch-scale sorption and desorption experiments were conducted after 18 months of in situ amendment application. The Langmuir isotherms applied for sorption studies showed that the estimated maximum sorption capacity of the elements was highest in the SF-treated samples. The amount of element retained and the percentage of extraction after TCLP tests indicated that those samples amended with sugar foam (SF and PG + SF) had the potential to immobilize As, Cd and Tl in an acidic soil with low sorptive capacity. In addition to sorption and desorption experiments, scanning electron microscopy in back-scattered electron mode (SEM-BSE) showed the formation of Al-hydroxy polymers which provides the soil with additional sorption capacity. The three target elements were associated with the Al-hydroxy polymers, probably through direct coordination or the formation of ternary complexes. By means of statistical analysis it has been found that sorption processes of As, Cd and Tl in this soil mainly depend on the treatment, whereas desorption is an element-dependent process

  15. The production and utilization of by-product agricultural fertilizer from flue gases

    International Nuclear Information System (INIS)

    The electron-beam process is one of the most effective methods for removing SO2 and NOx from industrial flue gases and producing a usable by-product. This flue gas treatment consists of adding a small amount of ammonia to the flue gas and irradiating the gas by means of an electron beam. This causes reactions which convert SO2 and NOx to ammonium sulfate and ammonium nitrate. These salts are then collected from the flue gas by conventional collectors, such as a baghouse or electrostatic precipitator. This paper will describe the potential for production of the fertilizer and will analyze the market potential and consumption of the by-product. A principal focus of the work is an analysis and quantification of the major large-scale, growing and profitable markets for utility solid wastes that can be generated in the form of agricultural fertilizer. Cost study data is arranged to define the impact of commercial by-product field and revenue on the economics of full scale SO2 and NOx emission reduction activity

  16. Manufacturing of mortars and concretes non-traditionals, by Portland cement, metakaoline and gypsum (15.05%

    Directory of Open Access Journals (Sweden)

    Talero, R.

    1999-12-01

    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

  17. Utilization of Chicken By-Products to Form Collagen Films

    OpenAIRE

    Kumudini A. Munasinghe; Jurgen G. Schwarz; Matthew Whittiker

    2015-01-01

    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 fo...

  18. 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

    2015-05-01

    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 .

  19. Seismic testing of a three-hour fire-rated steel-framed gypsum drywall partition for nuclear plants

    International Nuclear Information System (INIS)

    The test specimen measured 1.22 by 3.05 m and consisted of three layers of 12.7 mm SHEETROCK Brand FIRECODE 'C' Gypsum Panels screw-attached to both sides of USG Steel 35SJ18 Studs 610 mm on centers. The specimen was first mounted in the earthquake simulator with the studs oriented horizontally and the runners vertically. Each runner was secured to a shaker support through which horizontal sinusoidal movement was induced normal to the surface of the wall. The damping ratio was found to be 9%. The average dynamic EI of the panel was 177000 GNxmm2. After the OBE scans, the specimen withstood the SSE scan for frequencies between 4 and 25 Hz. Resonance occured at 9 Hz. With a support acceleration of 3.0 gsub(e), the midspan acceleration reached 6.83 gsub(e). The same specimen was rotated 900 to a horizontal position with each runner attached to the corresponding shaker support which induced sinusoidal motion parallel to the runners. In the SSE shake at a frequency of 9 Hz and a support acceleration of 3.0 gsub(e), the midspan acceleration reached 4.66 gsub(e). To confirm the structural integrity of the specimen, it was then mounted in a vacuum chamber and tested in accordance with ASTM E 72. The rollers were spaced at 2.98 m. The panel yielded at a uniform load of 20.8 kN (equivalent to force at 8.8 gsub(e) acceleration) and failed at 26.3 kN (11.1 gsub(e)); both values greater than the 6.83 gsub(e) maximum dynamic midspan acceleration. The average static EI was 136000 GNxmm2 - close to the 177000 GNxmm2 dynamic EI. This transverse load test showed that the specimen was not structurally damaged by the shaker tests simulating earthquakes in nuclear plants. (orig./HP)

  20. Microbial characterization of microbial ecosystems associated to evaporites domes of gypsum in Salar de Llamara in Atacama desert.

    Science.gov (United States)

    Rasuk, Maria Cecilia; Kurth, Daniel; Flores, Maria Regina; Contreras, Manuel; Novoa, Fernando; Poire, Daniel; Farias, Maria Eugenia

    2014-10-01

    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

  1. Raman imaging in geomicrobiology: endolithic phototrophic microorganisms in gypsum from the extreme sun irradiation area in the Atacama Desert.

    Science.gov (United States)

    Vítek, Petr; Ascaso, Carmen; Artieda, Octavio; Wierzchos, Jacek

    2016-06-01

    The Raman imaging method was successfully applied for mapping the distribution of biomolecules (e.g., pigments) associated with cryptoendolithic and hypoendolithic microorganisms, as well as the inorganic host mineral matrix that forms the habitat for the biota. To the best of our knowledge, this is the first comprehensive study in the field of geomicrobiology based on this technique. The studied microbial ecosystem was located nearly 3000 m above sea level within the driest desert on Earth, the Atacama in Chile. Enhancement of carotenoid Raman signal intensity close to the surface was registered at different areas of endolithic colonization dominated by algae, with cyanobacteria present as well. This is interpreted as an adaptation mechanism to the excessive solar irradiation. On the other hand, cyanobacteria synthesize scytonemin as a passive UV-screening pigment (found at both the hypoendolithic and cryptoendolithic positions). The distribution of the scytonemin Raman signal was mapped simultaneously with the surrounding mineral matrix. Thus, mapping was done of the phototrophic microorganisms in their original microhabitat together with the host rock environment. Important information which was resolved from the Raman imaging dataset of the host rock is about the hydration state of Ca-sulfate, demonstrated on the presence of gypsum (CaSO4·2H2O) and the absence of both anhydrite (CaSO4) and bassanite (CaSO4·1/2H2O). Obtaining combined "in situ" simultaneous information from the geological matrix (inorganic) together with the microbial biomolecules (organic) is discussed and concluded as an important advantage of this technique. We discuss how selection of the laser wavelength (785 and 514.5-nm) influences the Raman imaging results. PMID:27055886

  2. Soil carbon sequestration in semi-arid soil through the addition of fuel gas desulfurization gypsum (FGDG)

    Science.gov (United States)

    Han, Young-Soo; Tokunaga, Tetsu; Oh, Chamteut

    2014-05-01

    This study investigated a new strategy for increasing carbon retention in slightly alkaline soils through addition of fuel gas desulfurization gypsum (FGDG, CaSO4•2H2O). FGDG is moderately soluble and thus the FGDG amendment may be effective to reduce microbial respiration, to accelerate calcite (CaCO3) precipitation, and to promote soil organic carbon (SOC) complexation on mineral surfaces, but rates of these processes need to be understood. The effects of FGDG addition were tested in laboratory soil columns with and without FGDG-amended layers, and in greenhouse soil columns planted with switchgrass, a biofuel crop. The results of laboratory column experiments demonstrated that additions of FGDG promote soil carbon sequestration through suppressing microbial respiration to the extent of ~200 g per m2 soil per m of supplied water, and promoting calcite precipitation at similar rates. The greenhouse experiments showed that the FGDG treatments did not adversely affect biomass yield (~600 g dry biomass/m2/harvest) at the higher irrigation rate (50 cm/year), but substantially reduced recoverable biomass under the more water-limited conditions (irrigation rate = 20 cm/year). The main achievements of this study are (1) the identification of conditions in which inorganic and organic carbon sequestration is practical in semi-arid and arid soils, (2) development of a method for measuring the total carbon balance in unsaturated soil columns, and (3) the quantification of different pathways for soil carbon sequestration in response to FGDG amendments. These findings provide information for evaluating land use practices for increased soil carbon sequestration under semi-arid region biofuel crop production.

  3. UN-ECE task force: 'by-product utilization from stationary installations'

    International Nuclear Information System (INIS)

    The task force has concluded as followed: Major sources of by-products considered in this report from stationary installations are large scale firing installations, waste incineration, upgrading processes and utilization in iron and steel, aluminium and copper industry, and the pulp and paper industry. The share of each sector source to the total amount of by-products generated differs significantly in the participating countries. State of the art processes as described in the report take account of the need for integrated pollution prevention and control. In particular the requirements set out in the Convention on Long Range Transboundary Air Pollution can still be satisfied when applying these state of the art processes. The report shows that a number of techniques for avoidance, reduction and/or utilization of by-products are in commercial operation in the branches discussed. They can therefore be considered to be best available. For some special by-products technical processes for the treatment are still in development and are not yet state-of-the-art. The implementation of the already proven techniques varies considerably in the different ECE-countries. This is mainly due to the following circumstances: differences in the design and stringency of legal regulations, availability of landfilling sites, costs of disposal, differences in industrial structure. Problems with by-product utilization originate mainly from: a) from a loss of international competitiveness of the respective industrial sector, if the reduction of the amount of by-products or their utilization leads to higher costs than conventional processes; b) from quality standards for materials which are inadequate for secondary raw materials thus creating acceptance problems of these materials. C) In some cases incineration and/or thermal recycling processes generate PCDD/F. quantities produces may be capable of reduction by means of process modification. If, however PCDD/F is released to the

  4. Properties and possibilities to use by-product from e-beam installations for partial recycling of ammonia

    International Nuclear Information System (INIS)

    Generated by-products from E-beam cleaning systems of industrial waste gases have been studied using different techniques like TG-DTA systems, Electron Microscopy, X-Ray diffraction and IR spectroscopy methods. On the base of the investigations it was found that the composition of the by-product varies depending on the content of pollutants in the waste gases and technological parameters during cleaning process. Size of particles and thermal stability of the by product were determined. Content of ammonium sulphate as a main component, ammonium nitrate and heavy metals content is also determined and discussed. During thermal treatment of the by-product at temperature range 543-663K half of the ammonia is released in the gas phase. Kinetic parameters of the thermal decomposition are determined and it is confirmed that for waste gases containing mainly SOx as a pollutants they are very close to the pure ammonium sulphate. By-product from demonstration E-beam installation at Maritsa-East -2 TPP is used to produce mixed fertilisers using milled Tunisia phosphorites or tribo-activated mixtures of the by-product, Tunisia phosphorite, potassium sulphate and aches from electrostatic precipitators of TPP. It was found that during thermo-tribochemical treatment of selected mixtures different type of fertilisers could be produced, where the soluble forms of Phosphorous may vary, depending on the conditions. During thermal treatment about half of ammonia is released in the gas phase opening a way for partial recycling of ammonia to the cleaning process. Agrochemical tests of the fertilisers on the base of by-product confirm their efficiency. (author)

  5. Utilization of biodiesel by-products for biogas production.

    Science.gov (United States)

    Kolesárová, Nina; Hutňan, Miroslav; Bodík, Igor; Spalková, Viera

    2011-01-01

    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. Hydrocarbon and by-product reserves in British Columbia, 2000

    International Nuclear Information System (INIS)

    Statistical data on oil, gas and by-product reserves in British Columbia as of 31 December 2000, as estimated by the Oil and Gas Commission was presented along with a summary of year-end remaining established reserves, estimates of the reserves of oil, gas and by-products, and detailed reserve and pool parameters. British Columbia set a record in 2000 with 753 wells drilled, of which 59 were classed as oil. Most of the oil drilling took place in the Hay River area. 449 gas wells were drilled in 2000, mostly in the Fort St. John area. An additional 120 wells were cased. Raw gas reserves in 2000 increased to 294.8 109m3, up slightly from the previous year. Remaining oil reserves at December 31, 2000 were 27,357 103m3, an increase of about 4 per cent over 1999. This report also included a historical review of oil and raw gas reserves by geological period and unconnected gas reserves by plant area. Established hydrocarbon reserves, summaries and a project/unit cross-reference listing was included. Oil pools under waterflood or gas injection were also highlighted. Four appendices were also included, one each for reserve and pool parameter listings for crude oil reserves, gas reserves, raw gas analysis, and remaining hydrocarbon products. tabs

  7. Utilization of Biodiesel By-Products for Biogas Production

    Directory of Open Access Journals (Sweden)

    Nina Kolesárová

    2011-01-01

    Full Text Available 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.

  8. Disposal of by-products in olive oil industry: waste-to-energy solutions

    International Nuclear Information System (INIS)

    Olive oil production industry is characterized by relevant amounts of liquid and solid by-products [olive mill wastewater (OMW) and olive husk (OH)], and by economical, technical and organizational constraints that make difficult the adoption of environmentally sustainable waste disposal approaches. In this context, waste treatment technologies aimed at energy recovery represent an interesting alternative. In the paper, a technical and economical analysis of thermal disposal plant solutions with energy recovery has been carried out. The considered plants enable the combined treatment of OMW and OH which, although penalizes the energy recovery, proves to be feasible and profitable in a future legislative scenario when stricter limitation on OMW disposal will force oil producers to bear high disposal costs. Results are compared by using economic performance measures, including revenues from produced energy and avoided disposal costs. A sensitivity and risk analysis is also performed in order to assess the economic profitability of the proposed solutions

  9. 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)

    2000-12-01

    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.

  10. Composition, characterization and atherogenic potential of oils, fats and other by products produced or marketed in Costa Rica

    International Nuclear Information System (INIS)

    Cardiovascular diseases are very common among Costa Rican people. They are related to diets high in lipids that cause arterial damage. The present study was undertaken to determine the quality of fats and oils consumed more frequently in our country. 15 different brands of butter and margarines (A, B, D1 to D11), 7 types of vegetable fat (E1 to E7) and 14 different brands of sunflower oil (EG1 to EG3), corn oil (EM1 to EM3), olive oil (EO1 to EO4), soy oil (ES1 to ES3) and palm oil (EV) were collected and identified. 67 percent of the products were made in Costa Rica, 33% were imported products. Using gas chromatography and nuclear magnetic resonance techniques, fatty acid composition, iodine and saponification number, average molecular weight, carbon-carbon double bond number, allyl and double aryl hydrogens were determined in the lipid fraction of the 36 different products. Two types of butter and one type of oil were found adulterated with triacylglycerols of different kind or source. Susceptibility of the products to lipid oxidation was determined only in terms of double bond number and allyl and double alryl hydrogens. Sunflower, corn and olive oils were the most susceptible products. Through polyunsaturated fatty acids / saturated fatty acids relation and atherogenic index the atherogenic potential of the products was evaluated. The findings were that 2 types of butter and 5 types of vegetable fat were the most injurious ones. (author)

  11. Identification and synthesis of by-products found in 4-methylthioamphetamine (4-MTA) produced by the Leuckart method.

    Science.gov (United States)

    Błachut, Dariusz; Wojtasiewicz, Krystyna; Krawczyk, Krzysztof; Maurin, Jan; Szawkało, Joanna; Czarnocki, Zbigniew

    2012-03-10

    The synthesis of the designer drug 4-methylthioamphetamine (4-MTA) has been carried out using the well-known Leuckart reaction in four versions. The treatment of 4-methylthiophenylacetone with formamide, mixture of formamide/formic acid, ammonium formate, and mixture of ammonium formate and formic acid followed by acid hydrolysis brought about the formation of 4-MTA contaminated with a number of impurities. The gas chromatography mass-spectrometry (GC-MS) analysis of the reaction mixtures allowed identification of the most prominent impurities, such as diasteromers of N,N-di-[β-(4-methylthiophenyl)isopropyl]amine, N,N-di-[β-(4-methylthiophenyl)isopropyl]methylamine, N,N-di-[β-(4-methylthiophenyl)isopropyl]formamide, the Schiff bases derived from 4-MTA and 4-methylbenzaldehyde (benzaldimine) and 4-methylthiophenylacetone (ketimine) as well as some heterocycles: 4-methyl-5-(4'-methylthiophenyl)pyrimidine, 4-(4'-methylthiobenzyl)pyrimidine, 2,6-dimethyl-3,5-di-(4'-methylthiophenyl)pyridine, 2,4-dimethyl-3,5-di-(4'-methylthiophenyl)pyridine. The correctness of identification was confirmed by independent synthesis of these compounds. Each synthesized reference compound was characterized by means of MS, (1)H and (13)C NMR, and IR methods. The stereochemistry of (RR/SS) diasteromer of N,N-di-[β-(4-methylthiophenyl)isopropyl]amine was confirmed by a crystallographic method. PMID:21982394

  12. Effects of Medium Temperature and Industrial By-Products on the Key Hardened Properties of High Performance Concrete

    OpenAIRE

    Md. Safiuddin; Sudharshan N. Raman; Muhammad Fauzi Mohd Zain

    2015-01-01

    The aim of the work reported in this article was to investigate the effects of medium temperature and industrial by-products on the key hardened properties of high performance concrete. Four concrete mixes were prepared based on a water-to-binder ratio of 0.35. Two industrial by-products, silica fume and Class F fly ash, were used separately and together with normal portland cement to produce three concrete mixes in addition to the control mix. The properties of both fresh and hardened concre...

  13. GLYCERINE: FROM A INCONVINIENT BIODIESEL BY-PRODUCT TO A POSSIBLE APPLICATION AS A FLOCCULANT IN WATER TREATMENT

    Directory of Open Access Journals (Sweden)

    GAUTO, Marcelo Antunes

    2010-01-01

    Full Text Available Glycerin is a by-product obtained during the biodiesel manufacture, through the transesterification reaction of vegetal oils. The prevision of excedent glycerine in the next few years, due to the increasing of the biodiesel production in Brazil, has been generating a discussion about new applications to this by-product. This article presents a theoretical study about the possible synthesis of a new flocculant agent, from semi-refined glycerine and p-nitrobenzoic acid to produce a quaternary ammonium salt, to be used in water treatment. The reactions which would occur during the synthesis of the flocculant agent and the necessary tests to the product validation are presented.

  14. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Science.gov (United States)

    Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

    2015-01-01

    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. Natural Bioactive Compounds from Winery By-Products as Health Promoters: A Review

    Directory of Open Access Journals (Sweden)

    Ana Teixeira

    2014-09-01

    Full Text Available The relevance of food composition for human health has increased consumers’ interest in the consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals. This fact has led to a growing attention of suppliers on reuse of agro-industrial wastes rich in healthy plant ingredients. On this matter, grape has been pointed out as a rich source of bioactive compounds. Currently, up to 210 million tons of grapes (Vitis vinifera L. are produced annually, being the 15% of the produced grapes addressed to the wine-making industry. This socio-economic activity generates a large amount of solid waste (up to 30%, w/w of the material used. Winery wastes include biodegradable solids namely stems, skins, and seeds. Bioactive compounds from winery by-products have disclosed interesting health promoting activities both in vitro and in vivo. This is a comprehensive review on the phytochemicals present in winery by-products, extraction techniques, industrial uses, and biological activities demonstrated by their bioactive compounds concerning potential for human health.

  16. Natural bioactive compounds from winery by-products as health promoters: a review.

    Science.gov (United States)

    Teixeira, Ana; Baenas, Nieves; Dominguez-Perles, Raul; Barros, Ana; Rosa, Eduardo; Moreno, Diego A; Garcia-Viguera, Cristina

    2014-01-01

    The relevance of food composition for human health has increased consumers' interest in the consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals. This fact has led to a growing attention of suppliers on reuse of agro-industrial wastes rich in healthy plant ingredients. On this matter, grape has been pointed out as a rich source of bioactive compounds. Currently, up to 210 million tons of grapes (Vitis vinifera L.) are produced annually, being the 15% of the produced grapes addressed to the wine-making industry. This socio-economic activity generates a large amount of solid waste (up to 30%, w/w of the material used). Winery wastes include biodegradable solids namely stems, skins, and seeds. Bioactive compounds from winery by-products have disclosed interesting health promoting activities both in vitro and in vivo. This is a comprehensive review on the phytochemicals present in winery by-products, extraction techniques, industrial uses, and biological activities demonstrated by their bioactive compounds concerning potential for human health. PMID:25192288

  17. Bacterial Cellulose Production from Industrial Waste and by-Product Streams

    Directory of Open Access Journals (Sweden)

    Erminda Tsouko

    2015-07-01

    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.

  18. Chlorine dioxine DBPs (disinfection by-products in drinking water

    Directory of Open Access Journals (Sweden)

    C. Lasagna

    2013-01-01

    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

    2014-12-01

    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. U-series dating of co-seismic gypsum and submarine paleoseismology of active faults in Northern Chile (23°S)

    Science.gov (United States)

    Vargas, Gabriel; Palacios, Carlos; Reich, Martin; Luo, Shangde; Shen, Chuan-Chou; González, Gabriel; Wu, Yi-Chen

    2011-01-01

    The convergence of the Nazca and South American plates along the subduction margin of the central Andes results in large subduction earthquakes and tectonic activity along major fault systems. Despite its relevance, the paleoseismic record of this region is scarce, hampering our understanding about the relationship between the Andes building and earthquake occurrence. In this study, we used the U-series disequilibrium method to obtain absolute ages of paleoearthquake events associated with normal displacements along the active Mejillones and Salar del Carmen faults in the Coastal Range of the Atacama Desert of northern Chile. The 230Th- 234U disequilibrium ages in co-seismic gypsum salts sampled along the fault traces together with marine evidences indicate that earthquakes occurred at ca. 29.7 ± 1.7 ka, 11 ± 4 ka and 2.4 ± 0.8 ka. When coupled with paleoseismic marine and radiocarbon ( 14C) records in the nearby Mejillones Bay evidencing large dislocations along the Mejillones Fault, the geochronological dataset presented here is consistent with the notion that gypsum salts formed during large earthquakes as a result of co-seismic dilatancy pumping of saline waters along the major faults. Based on maximum observed cumulative vertical offsets in the studied faults, this phenomena could have occurred episodically at a rate in the order of 1:40 to 1:50 with respect to the very large subduction earthquakes during the latest Pleistocene-Holocene period. The results presented here reveal that the U-series disequilibrium method can be successfully applied to date the gypsum salts deposited along faults during seismic events, and therefore directly constrain the age of large paleoearthquakes in hyperarid and seismically active zones.

  1. Oxidative stability during storage of fish oil from filleting by-products of rainbow trout (Oncorhynchus mykiss) is largely independent of the processing and production temperature

    DEFF Research Database (Denmark)

    Honold, Philipp; Nouard, Marie-Louise; Jacobsen, Charlotte

    2016-01-01

    used to produce high quality fish oil. In this study, the oxidative stability of fish oil produced from filleting by-products was evaluated. The oil was produced from conventional or organic fish (low and high omega-3 fatty acid content) at different temperatures (70 and 90°C). The oxidative stability......Rainbow trout (Oncorhynchus mykiss) is the main fish species produced in Danish fresh water farming. Large amounts of fileting by-products like heads, bones, tails (HBT), and intestines are produced when rainbow trout is processed to smoked rainbow trout filets. The filleting by-products can be...... of the oil was tested during storage at two different temperatures (20 and 40°C). Results showed that omega-3 content of the fish oil influenced the oxidative stability, whereas the processing temperature during oil production played a minor role....

  2. Human-induced hydrological changes and sinkholes in the gypsum karst of Lesina Marina area (Foggia Province, Italy)

    Science.gov (United States)

    Fidelibus, M. D.; Gutierrez, F.; Spilotro, G.

    2009-04-01

    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

  3. 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

    2016-05-01

    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.

  4. Phosphorus, nitrogen, and radionuclide retention and leaching from a Joel sand amended with red mud/gypsum

    International Nuclear Information System (INIS)

    The leaching of phosphorus (P), nitrogen (N), and radionuclides 232Th, 226Ra, 228Ra, and 40K from Joel sands amended with red mud/gypsum (RMG) at 9 rates (0, 2, 4, 8, 16, 32, 64, 128, and 256 t/ha) was measured using columns. Intense leaching conditions (34 mm/day for 12 days) and a high rate of applied P (320 kg/ha as superphosphate) and N (680 kg/ha as ammonium nitrate) were used to simulate extremes of irrigated vegetable production on the Swan Coastal Plain. Addition of the highest rate of RMG (256 t/ha) reduced leaching of fertiliser P and ammonium-nitrogen (NH4-N) by 85% and 50%, respectively, compared with 0 t/ha after 12 days. At 64 t RMG/ha P leaching was reduced 50% compared with 0 t/ha. Nitrate-nitrogen (NO3-N) leaching was not affected by addition of RMG. Reduced leaching of NH4-N was attributed to an increase in cation exchange capacity of the soil with the addition of RMG. Bicarbonate-extractable P in the soil increased with rate of RMG to >50 μg P/g soil at 256 t/ha. This indicates that soil testing of residual P could be used to reduce P inputs to vegetable crops after soils were amended with RMG. This would further reduce the impact of vegetable production on the water systems of the Swan Coastal Plain and extend the period of effectiveness of RMG amended soils. The increase in 232Th specific activity in Joel sand amended with RMG was well below statutory limits even at the highest rate. Neither 40K nor 226Ra were detectable in RMG amended sands up to 256 t RMG/ha. There was no evidence of leaching of 226Ra or 228Ra at any rate of RMG. These results suggest that the use of RMG amendment on commercial horticultural properties on the Swan Coastal Plain could be feasible. 30 refs., 7 figs., 2 tabs

  5. Speleogenesis in gypsum

    OpenAIRE

    Klimchouk A.

    1996-01-01

    Satisfactory explanation of the origin and development of caves (speleogenesis) is a core problem of karst studies. Karst evolves as a circulation system, organised and interconnected through a conduit structure. Such a system may include superficial inputs and outputs, expressed as or related to karst landforms. However, there may be no such components if the system is represented entirely by conduits as in the case with deep-seated intrastratal karst. The main differences between speleogene...

  6. Sampling from stochastic reservoir models constrained by production data

    Energy Technology Data Exchange (ETDEWEB)

    Hegstad, Bjoern Kaare

    1997-12-31

    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.

  7. Health impact of disinfection by-products in swimming pools.

    Science.gov (United States)

    Villanueva, Cristina M; Font-Ribera, Laia

    2012-01-01

    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. PMID:23247135

  8. Health impact of disinfection by-products in swimming pools

    Directory of Open Access Journals (Sweden)

    Cristina M. Villanueva

    2012-12-01

    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.

  9. Minimization of the formation of disinfection by-products.

    Science.gov (United States)

    Badawy, Mohamed I; Gad-Allah, Tarek A; Ali, Mohamed E M; Yoon, Yeoman

    2012-09-01

    The drinking water industry is required to minimize DBPs levels while ensuring adequate disinfection. In this study, efficient and appropriate treatment scheme for the reduction of disinfection by-product (DBPs) formation in drinking water containing natural organic matter has been established. This was carried out by the investigation of different treatment schemes consisting of enhanced coagulation, sedimentation, disinfection by using chlorine dioxide/ozone, filtration by sand filter, or granular activated carbon (GAC). Bench scale treatment schemes were applied on actual samples from different selected sites to identify the best conditions for the treatment of water. Samples were collected from effluent of each step in the treatment train in order to analyze pH, UV absorbance at 254 nm (UVA(254)), specific UV absorbance at 254 nm (SUVA(254)), dissolved organic carbon (DOC), haloacetic acids (HAAs) and trihalomethanes (THMs). The obtained results indicated that using pre-ozonation/enhanced coagulation/activated carbon filtration treatment train appears to be the most effective method for reducing DBPs precursors in drinking water treatment. PMID:22591848

  10. Effect of capacitive deionization on disinfection by-product precursors.

    Science.gov (United States)

    Liu, Danyang; Wang, Xiaomao; Xie, Yuefeng F; Tang, Hao L

    2016-10-15

    Formation of brominated disinfection by-products (DBPs) from bromide and natural organic matter upon chlorination imposes health risks to drinking water users. In this study, capacitive deionization (CDI) was evaluated as a potential process for DBP precursor removal. Synthetic humic acid and bromide containing saline water was used as model water prior to CDI treatment. Batch experiments were conducted at cell voltages of 0.6-, 0.9-, and 1.2V to study the influence of CDI on the ratio of bromide and dissolved organic carbon, bromine substitution factor, and DBP formation potential (FP). Results showed beneficial aspects of CDI on reducing the levels of these parameters. A maximum DBPFP removal from 1510 to 1160μg/L was observed at the cell voltage of 0.6V. For the removed DBPFP, electro-adsorption played a greater role than physical adsorption. However, it is also noted that there could be electrochemical oxidations that led to reduction of humic content and formation of new dichloroacetic acid precursors at high cell voltages. Because of the potential of CDI on reducing health risks from the formation of less brominated DBPs upon subsequent chlorination, it can be considered as a potential technology for DBP control in drinking water treatment. PMID:27285792

  11. Chemical separation and nuclear transmutation of by-product actinides

    International Nuclear Information System (INIS)

    The paper presents the most important results and conclusions of the assessment studies carried out by the Joint Research Centre-Ispra and by other organizations on the advanced waste disposal strategy based on chemical separation of By-product Actinides (BPA's) from high level liquid waste (HLLW) and their transmutation in nuclear reactors. The technological developments required for the implementation of this strategy have been identified: they concern mainly fuel reprocessing, BPA recovery from all important waste streams and fuel refabrication. After consideration of different strategies for BPA transmutation, the homogeneous recycling in FBR's appears to be most suitable due to its transmutation rate and the compatibility of BPA's with its fuel cycle. The fuel cycle with transmutation has been compared with an advanced reference fuel cycle on the basis of costs and risks. The large effort required for the development and implementation of this new fuel cycle, the increased costs operating the fuel cycle compared with the marginal benefits in the long-term risk of geological disposal, make this strategy not very attractive

  12. Generation of chlorine by-products in simulated wash water.

    Science.gov (United States)

    Shen, Cangliang; Norris, Pauline; Williams, Olivia; Hagan, Stephanie; Li, KaWang

    2016-01-01

    Free chlorine (FC) reacting with organic matter in wash water promotes the formation of chlorine by-products. This study aims to evaluate the dynamic impact of FC and organic load on the generation of haloacetic acids (HAAs) and trihalomethanes (THMs) in simulated wash water. Lettuce juice was sequentially added into FC solution with FC periodically replenished. Water samples were collected after each lettuce juice addition to measure water qualities and determine HAAs and THMs using US-Environmental-Protection-Agency (EPA) methods. Concentrations of 88-2103 μg/l of total HAAs and 20.79-859.47 μg/l of total THMs were detected during the study. Monobromoacetic, tribromoacetic, chlorodibromoacetic and trichloroacetic acid were the major HAAs components. Chloroform (trichloromethane) was the primary THMs present. A significant correlation of HAAs with chemical oxygen demand and THMs with FC was observed. Results indicated that optimizing wash water sanitizing systems to limit organic matters and maintain minimal effective FC concentration is critical. PMID:26212946

  13. The use of decorative furnishings from the FGD gypsum%脱硫石膏在装饰性陈设中运用的研究

    Institute of Scientific and Technical Information of China (English)

    张南

    2014-01-01

    脱硫半水石膏材料是工业废物再利用的环保材料,其烧制后为淡黄色粉末,具有石膏优良品质,用其制作装饰性陈设品,工艺简单,加适当的水即可成型,可塑性强,凝结时间快。成品不仅具有较好的装饰功能,而且还能用以仿制其他装饰材料的艺术效果,从而可取代其他高成本、不环保的装饰制品。%Desulfurization hemihydrate gypsum material is industrial waste re-use of environmental y friendly materials, as a pale yel ow powder after firing, with the gypsum of good quality, with the production of decorative furnishings, simple proces , plus the appropriate water to forming, plasticity,fast set ing time. The finished product not only has good decoration, but also for the artistic ef ect of imitation of other decorative materials, which can replace the other high-cost, non-environmental y friendly decorative products.

  14. Stable isotopic composition of soil calcite (O, C) and gypsum (S) overlying Cu deposits in the Atacama Desert, Chile: Implications for mineral exploration, salt sources, and paleoenvironmental reconstruction

    International Nuclear Information System (INIS)

    Highlights: ► We collected soils overlying two porphyry copper deposits and a pampa, Atacama Desert, Chile. ► δ18O for calcite over fracture zones at the Spence deposit suggests involvement of earthquake-induced groundwater. ► S isotopes in gypsum at Spence also indicates involvement of groundwater, consistent with elevated Cu, Se, I. ► At Gaby Sur and Tamarugal, S isotopes cannot distinguish sulfur of porphyry from redeposited sulfate from interior salars. ► The three sites studied have had different histories of salt accumulation and display variable influence of groundwater. - Abstract: Soils overlying two porphyry Cu deposits (Spence, Gaby Sur) and the Pampa del Tamarugal, Atacama Desert, Northern Chile were collected in order to investigate the extent to which saline groundwaters influence “soil” chemistry in regions with thick Miocene and younger sediment cover. Soil carbonate (calcite) was analyzed for C and O isotopes and pedogenic gypsum for S isotopes. Soil calcite is present in all soils at the Spence deposit, but increases volumetrically above two fracture zones that cut the Miocene gravels, including gravels that overlie the deposit. The C isotope composition of carbonate from the soils overlying fracture zones is indistinguishable from pedogenic carbonate elsewhere at the Spence deposit; all δ13CVPDB values fall within a narrow range (1.40–4.23‰), consistent with the carbonate having formed in equilibrium with atmospheric CO2. However, δ18OVPDB for carbonate over both fracture zones is statistically different from carbonate elsewhere (average δ18OVPDB = 0.82‰ vs. −2.23‰, respectively), suggesting involvement of groundwater in their formation. The composition of soils at the Tamarugal anomaly has been most strongly affected by earthquake-related surface flooding and evaporation of groundwater; δ13CVPDB values (−4.28‰ to −2.04‰) are interpreted to be a mixture of dissolved inorganic C (DIC) from groundwater and

  15. The effect of disinfectant soaking on dental gypsum model size%消毒液浸泡对牙科石膏模型尺寸的影响

    Institute of Scientific and Technical Information of China (English)

    朱操云; 徐蕴文; 徐侃

    2012-01-01

    PURPOSE: To study the influence of disinfectant soaking on the dimensional stability of three kinds of dental gypsum model. METHODS: Three commonly used gypsums ( type III , IV , V type) in clinic were used to make 24 specimens for 50 mm×l5 mm×l0 mm in size. One hour after release, the specimens were placed for 24 h. A digital caliper was used to measure the size of the gypsum model. Distilled water immersion was as used control, glutaraldehyde disinfectant and Metrix CaviCide disinfectant soaking were used for the experimental group. After soaking for 0.5h, the gypsum models were removed and placed for 0.5 h, 1 h, 2 h, 24 h. The size of the models was measured again using the same method. The data was analyzed with SPSS10.0 software package. RESULTS: The initial gypsum model length was (50.07±0.017) mm, (50.048±0.015) mm and (50.027±0.015) mm. After soaking for different times, the size of the model changed little, and the dimensions changed less than 0.01%. CONCLUSION: The results show that disinfectant soaking has no significant effect on dental model dimensions.%目的:探讨消毒液浸泡3种牙科石膏模型后对其尺寸稳定性的影响.方法:用临床常用的3种不同类型石膏(Ⅲ型、Ⅳ型、Ⅴ型)制作50 mm×15 mm×10 mm 3组共24个试件.1h后脱模,静置24 h后,用数显卡尺测量石膏模型尺寸.以蒸馏水浸泡作为对照,设戊二醛消毒剂、麦瑞斯消毒液浸泡为实验组,浸泡0.5 h取出,静置0.5、1、2、24 h后,用数显卡尺测量模型尺寸.采用SPSS10.0软件包对数据进行统计学分析.结果:浸泡前,3组石膏模型长度分别为(50.073±0.017) mm、(50.048±0.015) mm和(50.027±0.015)mm;浸泡后,各实验组、各时间点的模型尺寸基本无变化,石膏模型的尺寸变化小于0.01%.结论:消毒液浸泡对牙科石膏模型尺寸基本无影响.

  16. Current situation by product advertising on the czech market

    OpenAIRE

    Jitka Červencová

    1998-01-01

    Advertising represents for producers the least expensive admission to an ample market and it enables to consumers to orient at the market. All advertising means serve to intensifying of the product sale or image of firm. The article describes current situation in the area of exquisite instruments of advertising and next a firm's deciding if it hires an advertising agency or if carries out advertising on their own - what advantages and risks result from the cooperation of the firm and the agen...

  17. Biopolymers production from mixed cultures and pyrolysis by-products.

    Science.gov (United States)

    Moita, R; Lemos, P C

    2012-02-20

    Polyhydroxyalkanoates (PHAs) production from low value substrates and/or byproducts represents an economical and environmental promising alternative to established industrial manufacture methods. Bio-oil resulting from the fast-pyrolysis of chicken beds was used as substrate to select a mixed microbial culture (MMC) able to produce PHA under feast/famine conditions. In this study a maximum PHA content of 9.2% (g/g cell dry weight) was achieved in a sequencing batch reactor (SBR) operated for culture selection. The PHA obtained with bio-oil as a carbon source was a copolymer composed by 70% of hydroxybutyrate (HB) and 30% of hydroxyvalerate (HV) monomers. Similar results have been reported by other studies that use real complex substrates for culture selection indicating that bio-oil can be a promising feedstock to produce PHAs using MMC. To the best of our knowledge this is the first study that demonstrated the use of bio-oil resulting from fast pyrolysis as a possibly feedstock to produce short chain length polyhydroxyalkanoates. PMID:21983233

  18. Overview of Disinfection By-products and Associated Health Effects.

    Science.gov (United States)

    Villanueva, Cristina M; Cordier, Sylvaine; Font-Ribera, Laia; Salas, Lucas A; Levallois, Patrick

    2015-03-01

    The presence of chemical compounds formed as disinfection by-products (DBPs) is widespread in developed countries, and virtually whole populations are exposed to these chemicals through ingestion, inhalation, or dermal absorption from drinking water and swimming pools. Epidemiological evidence has shown a consistent association between long-term exposure to trihalomethanes and the risk of bladder cancer, although the causal nature of the association is not conclusive. Evidence concerning other cancer sites is insufficient or mixed. Numerous studies have evaluated reproductive implications, including sperm quality, time to pregnancy, menstrual cycle, and pregnancy outcomes such as fetal loss, fetal growth, preterm delivery, and congenital malformation. The body of evidence suggests only minor effects from high exposure during pregnancy on fetal growth indices such as small for gestational age (SGA) at birth. Populations highly exposed to swimming pools such as pool workers and professional swimmers show a higher prevalence of respiratory symptoms and asthma, respectively, although the direction of the association, and thus causality, is not clear among professional swimmers. The risk of asthma, wheezing, eczema, and other respiratory outcomes among children attending swimming pools has been the object of extensive research. Early studies suggested a positive association, while subsequent larger studies found no correlations or showed a protective association. Future research should develop methods to evaluate the effects of the DBP mixture and the interaction with personal characteristics (e.g., genetics, lifestyle), clarify the association between swimming pools and respiratory health, evaluate the occurrence of DBPs in low- and middle-income countries, and evaluate outcomes suggested by animal studies that have not been considered in epidemiological investigations. PMID:26231245

  19. Utilization of steam treated agricultural by -product as ruminant feed

    International Nuclear Information System (INIS)

    Shortage of animal food is a burning issue of the recent time, whereas the agricultural by -products are readily available to be used as ruminants feed. However, the low protein and digestibility are the hindrances in utilization of these low quality crop residues as a feed. In order to utilize rice straw as animal feed this study was conducted to investigate the influence of steam explosion treatment on its composition and in vitro degradability. The samples, I (untreated rice straw), II (rice straw exposed to 15.5 kgf/cm/ sub2/ steam pressure for 90 sec) and III (rice straw exposed to 15.5 kgf/cm/sup 2/steam pressure for 120 sec) were prepared. The results revealed that the crude protein (CP), ether extract (EE) and acid detergent lignin (ADL) contents of rice straw were improved after treatment with steam explosion in time dependent manner (P<0.05). The neutral detergent fiber (NDF), acid detergent fiber (ADF) and organic matter (OM) were higher, while dry matter (DM) and ash contents were lower (P<0.05) in II as compared to group I and III; however, after increasing the time at same pressure these parameters decreased. Furthermore, group III showed higher concentration of propionate, acetate, butyrate, and total VFA (P<0.05). While, group I exhibited higher concentration of iso-butyrate and iso-valerate (P<0.05). The concentration of valeric acid and acetate to propionate ratio were not affected by steam explosion treatment. Moreover, group III showed the higher in vitro DM degradability, OM degradability, DNDF and gas production (P<0.05); while, lower DADF and pH (P<0.05) compared with groups I and II. These findings suggest that the steam explosion treatment at 15.5 kgf/cm/sup 2/ pressure for 120 sec, may be used to enhance the nutritive value and digestibility of rice straw. (author)

  20. Pectic oligosaccharides from agricultural by-products: production, characterization and health benefits.

    Science.gov (United States)

    Babbar, Neha; Dejonghe, Winnie; Gatti, Monica; Sforza, Stefano; Elst, Kathy

    2016-08-01

    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. PMID:25641325

  1. The values of oil, natural gas and by-product reserves

    International Nuclear Information System (INIS)

    Selected evaluations of the most recent values of oil and gas reserves obtained from Sproule Associates Ltd.'s database were summarized. Each year Sproule Associates prepares independent evaluations of many oil and gas properties in Canada, the United States and around the world. The database includes information on more than 80 per cent of the wells drilled in Canada. Evaluations are prepared for all types of companies involved in producing oil, gas, and by-products. The factors which are considered when evaluating reserves include: (1) the difference in composition of crude oil, natural gas and associated by-products, (2) the variation in the capital and operating costs necessary to develop and maintain production, and (3) contrasting provincial and freehold royalties, compounded by federal and provincial income taxes. Data in this evaluation were grouped according to province, geological setting, type of reserve, cost of recovery, and operational procedure. The data is for use as supporting information for corporate reserve management, acquisition and divestment, equity financing, lending and borrowing, estate settlement, regulatory control and litigation.3 refs., 25 tabs

  2. Utilisation of biomass gasification by-products for onsite energy production.

    Science.gov (United States)

    Vakalis, S; Sotiropoulos, A; Moustakas, K; Malamis, D; Baratieri, M

    2016-06-01

    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. PMID:27118736

  3. By-product mutualism and the ambiguous effects of harsher environments - A game-theoretic model.

    Science.gov (United States)

    De Jaegher, Kris; Hoyer, Britta

    2016-03-21

    We construct two-player two-strategy game-theoretic models of by-product mutualism, where our focus lies on the way in which the probability of cooperation among players is affected by the degree of adversity facing the players. In our first model, cooperation consists of the production of a public good, and adversity is linked to the degree of complementarity of the players׳ efforts in producing the public good. In our second model, cooperation consists of the defense of a public, and/or a private good with by-product benefits, and adversity is measured by the number of random attacks (e.g., by a predator) facing the players. In both of these models, our analysis confirms the existence of the so-called boomerang effect, which states that in a harsh environment, the individual player has few incentives to unilaterally defect in a situation of joint cooperation. Focusing on such an effect in isolation leads to the "common-enemy" hypothesis that a larger degree of adversity increases the probability of cooperation. Yet, we also find that a sucker effect may simultaneously exist, which says that in a harsh environment, the individual player has few incentives to unilaterally cooperate in a situation of joint defection. Looked at in isolation, the sucker effect leads to the competing hypothesis that a larger degree of adversity decreases the probability of cooperation. Our analysis predicts circumstances in which the "common enemy" hypothesis prevails, and circumstances in which the competing hypothesis prevails. PMID:26780649

  4. Solar Grade Silicon from Agricultural By-products

    Energy Technology Data Exchange (ETDEWEB)

    Richard M. Laine

    2012-08-20

    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

  5. Fish peptone development using enzymatic hydrolysis of silver carp by-products as a nitrogen source in Staphylococcus aureus media

    OpenAIRE

    Fallah, Meysam; Bahram, Somayeh; Javadian, Seyed Roholla

    2015-01-01

    Fish peptone was produced using enzymatic hydrolysis of silver carp filleting by-products by alcalase and trypsin. Also, the efficiency of the hydrolysates as a nitrogen source in Staphylococcus aureus medium was compared with commercial TSB. The results indicated that the protein hydrolysate from alcalase and trypsin had high protein content (92.92%, 91.53 respectively), and degree of hydrolysis (4.94%, 4.6% respectively).The results showed that silver carp filleting waste can be an efficien...

  6. 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)

    2000-02-29

    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

  7. Anaerobic co-digestion of potato tuber and its industrial by-products with pig manure

    Energy Technology Data Exchange (ETDEWEB)

    Kaparaju, Prasad; Rintala, Jukka [Department of Biological and Environmental Science, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland)

    2005-01-01

    The possible use of potato tuber and its industrial by-products (potato stillage and potato peels) on farm-scale co-digestion with pig manure was evaluated in a laboratory study. The methane yields (m{sup 3}kg{sup -1} volatile solids (VS){sub addedwaste}) achieved on semi-continuous co-digestion at loading rate of 2kgVSm{sup -3}day{sup -1} in continuously stirred tank reactors at 35{sup o}C were 0.13-0.15 at 100:0 (VS% pig manure to VS% potato co-substrate), 0.21-0.24 at 85:15 and 0.30-0.33 at 80:20 feed ratio. Increasing the loading rate from 2 to 3kgVSm{sup -3}day{sup -1} at a feed VS ratio of 80:20 (pig manure to potato waste) produced methane yields of 0.28-0.30m{sup 3}kg{sup -1} VS{sub addedwaste}. Post-digestion (60 days) of the digested materials in batches produced 0.12-0.15m{sup 3}kg{sup -1} VS{sub addedwaste} of methane at 35{sup o}C. The results suggest that successful digester operation can be achieved with feed containing potato material up to 15-20% of the feed VS and that under similar feed VS, loading rate, retention time and feed VS ratio, the methane yields and process performance for potato tuber would be similar to that of its industrial residues. Thus, co-digestion of potatoes and/or its industrial by-products with manures on a farm-scale level would generate renewable energy and provide a means of waste treatment for industry.

  8. Organic amendments derived from a pharmaceutical by-product: benefits and risks

    Science.gov (United States)

    Gigliotti, Giovanni; Cucina, Mirko; Zadra, Claudia; Pezzolla, Daniela; Sordi, Simone; Carla Marcotullio, Maria; Curini, Massimo

    2015-04-01

    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

  9. Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production

    Energy Technology Data Exchange (ETDEWEB)

    Donal F. Day

    2009-03-31

    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

  10. Adhesives in Building--Lamination of Structural Timber Beams, Bonding of Cementitious Materials, Bonding of Gypsum Drywall Construction. Proceedings of a Conference of the Building Research Institute, Division of Engineering and Industrial Research (Spring 1960).

    Science.gov (United States)

    National Academy of Sciences - National Research Council, Washington, DC.

    The role of adhesives in building design is discussed. Three major areas are as follows--(1) lamination of structural timber beams, (2) bonding of cementitious materials, and (3) bonding of gypsum drywall construction. Topical coverage includes--(1) structural lamination today, (2) adhesives in use today, (3) new adhesives needed, (4) production…

  11. Strategy of Utilization of Locally Available Crop Residues and By-Products for Livestock Feeding in Tunisia

    Directory of Open Access Journals (Sweden)

    Moujahed-Raach, A.

    2001-01-01

    Full Text Available Important quantifies of crops residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country, but most of them are localised in the northern region. Some of the agricultural wastes are available in important quantifies but are of nutritionally poor or moderate qualifies (straw, olive wastes, poultry litter, etc, while others are produced in limited amounts but are of very interesting feeding values (sugar beet pulp, brewers grain, date residue, etc. The main applied strategies to valorise Tunisian agricultural by-products consist in ammoniation of cereal straws along with supplementation with multinutriment blocks and formulation of balanced diets based totally or partially on them. These alternatives are crucial in the improvement of feeding values of studied diets and animal performances essentially by improving microbial activity in the rumen. In Tunisia such solution could be applied both in extensive and moderate animal production systems.

  12. 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

    2009-12-01

    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.

  13. Roadmap for Interdisciplinary Research on Drinking Water Disinfection By-Products

    Science.gov (United States)

    Slide presentation on interdisciplinary research on drinking water disinfection by-products which summarized important issues with drinking water disinfection by-products and focused on emerging, unregulated DBPs.

  14. Chemical production from industrial by-product gases: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lyke, S.E.; Moore, R.H.

    1981-04-01

    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)

  15. Elucidation of the mechanism of reaction between S2O8(2-), Selenite and Mn2+ in aqueous solution and limestone-gypsum FGD liquor.

    Science.gov (United States)

    Akiho, Hiroyuki; Ito, Shigeo; Matsuda, Hiromitsu; Yoshioka, Toshiaki

    2013-10-01

    The mechanism of reaction between peroxodisulfate ion (S2O8(2-)), selenite (Se(IV)O3(2-)) and Mn(2+) as an inhibitor of selenite oxidation was studied using aqueous solutions composed of commercial reagents, as well as limestone-gypsum flue gas desulfurization (FGD) liquors sampled from coal fired power plants. The oxidation of selenite to selenate (Se(VI)O4(2-)) is promoted by the sulfate ion radical (SO4(-)) which results from decomposition of S2O8(2-). In the presence of Mn(2+), selenite oxidation was prevented due to the difference in rates of reaction with SO4(-). The ratio of the oxidation rate constants of selenite and Mn(2+) with SO4(-) was determined over a temperature range of 40-60 °C, and was found to be little influenced by the various coexisting components in FGD liquors. PMID:24015970

  16. 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

    2010-01-01

    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.

  17. Geochemical controls on leaching of lignite-fired combustion by-products from Greece

    International Nuclear Information System (INIS)

    Highlights: → The metal assemblage in ash fingerprints the geological setting of coal basins. → Free lime in ash influences the total and leachable contents of volatile elements. → The mode of occurrence of elements in lignite controls the fly ash leaching. → Oxyanionic-forming species are the main concern in terms of leaching of ashes. - Abstract: The mobility of inorganic pollutants is of key concern for a range of industrial and engineering applications of fly ash produced during the combustion of lignite in power generation. This paper investigates the role that the geochemical features of lignite, the ash composition and the partitioning of elements during combustion play in determining leaching properties of lignite fired by-products. The work is based on surveys on three lignite-fired power plants in Greece. Calcium-rich ashes show a high abatement potential for SO2 and other gaseous pollutants. For most elements, the concentrations in the parent lignite and the ashes follow the same trend. Relative enrichments in Cd, Co, Cr, Cu, Mo, Ni, Pb, U, V, W, Zn fingerprint the regional and local geological settings of the lignite basins. The total and leachable concentrations of highly volatile elements are strongly influenced by the interaction with ubiquitous free lime. A broad array of elements is highly insoluble in alkaline ash, while a few oxyanionic-forming elements display substantial mobility. Their mode of occurrence in the parent lignite plays a primary role in the leaching of combustion ashes. The outcomes of this study may assist in addressing the impact of co-firing high ash or high Ca alternative fuels on the leaching properties of combustion by-products.

  18. Methylene Blue Removal by Biochars from Food Industry By-Products

    Science.gov (United States)

    Orfanos, Alexis; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

    2016-04-01

    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.

  19. 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.

    1993-04-01

    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.

  20. 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.

    2015-01-01

    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. Th

  1. Biodegradation of Tributyltin (TBT) by Extremophile Bacteria from Atacama Desert and Speciation of Tin By-products.

    Science.gov (United States)

    Yáñez, Jorge; Riffo, Paula; Santander, Paola; Mansilla, Héctor D; Mondaca, María Angélica; Campos, Víctor; Amarasiriwardena, Dulasiri

    2015-07-01

    Biodegradation of tributyltin (TBT) by four tin resistant Gram negative bacteria isolated from extremely contaminated river sediments in the Atacama Desert in Chile was studied. Moraxella osloensis showed the greatest resistance and degradation capability of TBT, producing less toxic by-products, such as dibutyltin (DBT) and inorganic tin. In 7 days, approximately 80 % of TBT degradation was achieved, generating close to 20 % of DBT as degradation product. The degradation rate constant (k) was 0.022 [day(-1)] and TBT half-life (t1/2) in culture was 4.3 days. Debutylation is stated a probable mechanism of TBT degradation. PMID:25975619

  2. Evaluation of several microcrystalline celluloses obtained from agricultural by-products

    Directory of Open Access Journals (Sweden)

    John Rojas

    2011-01-01

    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.

  3. Fatty acids and algal lipids as precursors of chlorination by-products

    Institute of Scientific and Technical Information of China (English)

    Yan Liang; Yuen Shan Lui; Huachang Hong

    2012-01-01

    Six common algal fatty acids (FAs) with different numbers of double bonds,lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal cells were chlorinated to evaluate their potential in generating disinfection by-products (DBPs).The result showed that the more double bonds in the FAs,the higher the amounts of chloroform and dichloroacetic acid (DCAA) produced,but such a pattern was not observed for trichloroacetic acid (TCAA).Based on the previously reported composition of fatty acids in algal lipids,the DBP generation potentials of algal lipids were calculated.These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction,suggesting unknown lipophilic fraction(s) served as potent DBPs precursors.Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition,given quantified measured DBP production per unit algal lipid and proteins.The analysis showed that the observed DBP production was similar to that predicted (< 35% difference),suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform,DCAA and TCAA formation upon chlorinating algae.

  4. Impacts of drinking water pretreatments on the formation of nitrogenous disinfection by-products.

    Science.gov (United States)

    Chu, Wenhai; Gao, Naiyun; Deng, Yang; Templeton, Michael R; Yin, Daqiang

    2011-12-01

    The formation of disinfection by-products (DBPs), including both nitrogenous DBPs (N-DBPs) and carbonaceous DBPs (C-DBPs), was investigated by analyzing chlorinated water samples following the application of three pretreatment processes: (i) powdered activated carbon (PAC) adsorption; (ii) KMnO(4) oxidation and (iii) biological contact oxidation (BCO), coupled with conventional water treatment processes. PAC adsorption can remove effectively the precursors of chloroform (42.7%), dichloroacetonitrile (28.6%), dichloroacetamide (DCAcAm) (27.2%) and trichloronitromethane (35.7%), which were higher than that pretreated by KMnO(4) oxidation and/or BCO process. The removal efficiency of dissolved organic carbon by BCO process (76.5%)--was superior to that by PAC adsorption (69.9%) and KMnO(4) oxidation (61.4%). However, BCO increased the dissolved organic nitrogen (DON) concentration which caused more N-DBPs to be formed during subsequent chlorination. Soluble microbial products including numerous DON compounds were produced in the BCO process and were observed to play an essential role in the formation of DCAcAm in particular. PMID:22014706

  5. Ozone and hydrogen peroxide applications for disinfection by-products control in drinking water

    International Nuclear Information System (INIS)

    A great interest has been developed during the last years for ozone in drinking water treatments thanks to its strong oxidant and disinfectant power and for its efficiency in disinfection by-products (DBPs) precursors removal. However ozonization produces some specific DBPs, such as aldehydes and ketones; moreover, the presence of bromide in raw water engages ozone in a complex cycle in which both organic bromide and inorganic bromate are end products. In this paper the combination of hydrogen peroxide with ozone (known as peroxone process) and the ozone alone process were experimented on one surface water coming from the lake of Brugneto (Genova) in order to investigate bromate formation and trihalomethanes precursors removal during the oxidation process. The results show that the advanced peroxone process can be applied for bromate reduction (about 30-40%) with better results in comparison with the ozone alone process, while no advantages are shown for THMs precursors removal. The addition of in-line filtration step after pre-oxidation improves both bromate and THMs precursors removal, particularly with increasing hydrogen peroxide/ozone ratio in the oxidation step

  6. Production of bioethanol and associated by-products from potato starch residue stream by Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Mohamed [King Khalid University, Faculty of Science, Biological Science Department, P.O. Box 10255, Abha 61321 (Saudi Arabia); Darwish, Soumia M.I. [Department of Food Science and Technology, Faculty of Agriculture, Assiut University (Egypt)

    2010-07-15

    Potato starch residue stream produced during chips manufacturing was used as an economical source for biomass and bioethanol production by Saccharomyces cerevisiae. Results demonstrated that 1% H{sub 2}SO{sub 4} at 100 C for 1 h was enough to hydrolyze all starch contained in the residue stream. Two strains of S. cerevisiae (y-1646 and commercial one) were able to utilize and ferment the acid-treated residue stream under both aerobic and semi-anaerobic conditions. The maximum yield of ethanol (5.52 g L{sup -1}) was achieved at 35 C by S. cerevisiae y-1646 after 36 h when ZnCl{sub 2} (0.4 g L{sup -1}) was added. Addition of NH{sub 4}NO{sub 3} as a source of nitrogen did not significantly affect either growth or ethanol production by S. cerevisiae y-1646. Some secondary by-products including alcohol derivatives and medical active compound were found to be associated with the ethanol production process. (author)

  7. Evaluation of several microcrystalline celluloses obtained from agricultural by-products.

    Science.gov (United States)

    Rojas, John; Lopez, Alvin; Guisao, Santiago; Ortiz, Carlos

    2011-07-01

    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. PMID:22171310

  8. Thermal degradation and fire behaviour of thermal insulation materials based on food crop by-products

    OpenAIRE

    Lacasta Palacio, Ana María; Palumbo Fernández, Mariana; Formosa Mitjans, Joan

    2015-01-01

    Natural thermal insulation materials developed from renewable crop by-products and natural binders are analysed in terms of their thermal degradation and fire behaviour. A Pyrolysis Combustion Flow Calorimetre (PCFC) is used to characterise some kinds of crop by-products, including rice husk, corn pith and barley straw. This technique is complemented with a TG analysis. Six thermal insulation materials, formulated with such crop by-products and two kind of natural binders, corn st...

  9. Characterization of Chicken By-products by Mean of Proximate and Nutritional Compositions

    OpenAIRE

    Seong, Pil Nam; Cho, Soo Hyun; Park, Kuyng Mi; Kang, Geun Ho; Park, Beom Young; Moon, Sung Sil; Van Ba, Hoa

    2015-01-01

    Though a great amount of chicken by-products are consumed everyday in many countries worldwide, however, no attention has been paid to the investigation of nutritional composition of these by-products. In the present work, the basic information regarding the aspects of nutritional composition of chicken by-products such as; liver, gizzard, heart, lung, crop, small intestines, cecum and duodenum was studied. Our results revealed that the approximate composition range (minimum to maximum) of th...

  10. Pore formation during dehydration of polycrystalline gypsum observed and quantified in a time-series synchrotron radiation based X-ray micro-tomography experiment

    Directory of Open Access Journals (Sweden)

    F. Fusseis

    2011-10-01

    Full Text Available We conducted an in-situ X-ray micro-computed tomography heating experiment at the Advanced Photon Source (USA to dehydrate an unconfined 2.3 mm diameter cylinder of Volterra Gypsum. We used a purpose-built X-ray transparent furnace to heat the sample to 388 K for a total of 310 min to acquire a three-dimensional time-series tomography dataset comprising nine time steps. The voxel size of 2.2 μm3 proved sufficient to pinpoint reaction initiation and the organization of drainage architecture in space and time.

    We observed that dehydration commences across a narrow front, which propagates from the margins to the centre of the sample in more than four hours. The advance of this front can be fitted with a square-root function, implying that the initiation of the reaction in the sample can be described as a diffusion process.

    Novel parallelized computer codes allow quantifying the geometry of the porosity and the drainage architecture from the very large tomographic datasets (6.4 × 109 voxel each in unprecedented detail. We determined position, volume, shape and orientation of each resolvable pore and tracked these properties over the duration of the experiment. We found that the pore-size distribution follows a power law. Pores tend to be anisotropic but rarely crack-shaped and have a preferred orientation, likely controlled by a pre-existing fabric in the sample. With on-going dehydration, pores coalesce into a single interconnected pore cluster that is connected to the surface of the sample cylinder and provides an effective drainage pathway.

    Our observations can be summarized in a model in which gypsum is stabilized by thermal expansion stresses and locally increased pore fluid pressures until the dehydration front approaches to within about 100 μm. Then, the internal stresses are released and dehydration happens efficiently, resulting in new pore space. Pressure release, the production of pores

  11. Surface application of gypsum in low acidic Oxisol under no-till cropping system Aplicação superficial de gesso num Latossolo de baixa acidez sob sistema plantio direto

    Directory of Open Access Journals (Sweden)

    Eduardo Fávero Caires

    2011-04-01

    Full Text Available The conditions in which a favorable response to a gypsum application can be expected on crop yields are not clear. A 3-year field trial was carried out to evaluate the effects of gypsum application on soil chemical attributes and nutrition and yield of corn (Zea mays L. and soybean (Glycine max L. Merrill on a clayey Typic Hapludox of high fertility and low acidity under no-till in Guarapuava, Parana State, Brazil. Treatments were arranged in a randomized complete block design with four replications, and consisted of gypsum application on the soil surface at 4, 8, and 12 Mg ha-1. Gypsum application increased the P content in the soil most superficial layer (0.0 - 0.1 m and also the exchangeable Ca and S-SO4(2- contents and the Ca/Mg ratio in the soil profile (0.0 - 0.6 m. Gypsum also caused leaching of Mg and K exchangeable in the soil. An increase in Ca concentrations in the corn leaves, and in P and S concentrations in the corn and soybean leaves occurred following the gypsum application. A yield response of corn to initial application of gypsum was found, but subsequent soybean crops did not respond. Gypsum application proved to be an effective practice to maximize no-till corn grain yield.Não estão claras as condições em que se podem esperar efeitos favoráveis da aplicação de gesso na produção das culturas. Em um experimento de campo avaliaram-se, durante três anos, os efeitos da aplicação de gesso nos atributos químicos de um Latossolo Vermelho argiloso de alta fertilidade e baixa acidez sob plantio direto e na nutrição e produção de milho (Zea mays L. e soja (Glycine max L. Merrill, em Guarapuava (PR. Os tratamentos, dispostos em blocos completos ao acaso com quatro repetições, constaram da aplicação superficial de gesso nas doses 4, 8 e 12 Mg ha-1. A aplicação de gesso aumentou a concentração de P na camada mais superficial (0.0 - 0,1 m, bem como os teores de Ca trocável e de S-SO4(2- e a relação Ca/Mg no

  12. Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions%在非等温条件下石膏和硼石膏的加热脱水动力学研究

    Institute of Scientific and Technical Information of China (English)

    ī.Y.Elbeyli; S.Piskin

    2004-01-01

    Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

  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.

    Science.gov (United States)

    Dhada, Indramani; Sharma, Mukesh; Nagar, Pavan Kumar

    2016-10-01

    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. PMID:27208611

  14. Effect of poultry by-product meal on pulmonary hypertension, right ventricular failure and ascites in broiler chickens

    Science.gov (United States)

    Julian, Richard J.; Caston, Linda J.; Mirsalimi, S. Medhi; Leeson, Steve

    1992-01-01

    We tested the hypothesis that poultry by-product meal would produce a thermogenic response (an increased requirement for oxygen) resulting in an increased incidence of pulmonary hypertension with right ventricular failure and ascites in commercial broiler chickens. Four treatment groups, each with three replicates of 40 chicks, were fed a commercial broiler starter to day 21, grower to day 35, and the following experimental diets after day 35: group 1, commercial chicken broiler finisher; group 2, commercial chicken broiler finisher with poultry by-product meal added to replace part of the soyabean meal; group 3, commercial chicken broiler finisher with poultry fat added to replace the animal-vegetable (AV) fat; group 4, commercial chicken broiler finisher with both poultry by-product meal and poultry fat added to replace soyabean meal and AV fat. On day 35, pen temperature was reduced to 15°C, and on day 42 to 12°C. Mortality from ascites between days 35 and 56 was 11(9%) in group 2, 5(4%) in group 4 and 3(2.5%) in groups 1 and 3 The incidence of pulmonary hypertension, as measured by an increased right ventricle: total ventricle (RV:TV) ratio (RV:TV > 0.249) at processing on day 57, was higher in the groups receiving poultry by-product and poultry fat: 27(22.5%) in group 2, 26(21.7%) in group 3, and 20(16.7%) in group 4 compared to that of the controls 12(10%). PMID:17424018

  15. 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.

    2013-06-15

    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

  16. Boosting Farm Produce Supply

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the wake of escalating inflation,securing farm produce supply and stablizing grain prices could help to alleviate economic pressure The Chinese Government has pledged to secure a stable supply of farm produce.According to a document released after the annual Central Rural Work Conference held on December 22-23 in Beijing,preventing short supplies of farm produce and avoiding"ex-

  17. Fish peptone development using enzymatic hydrolysis of silver carp by-products as a nitrogen source in Staphylococcus aureus media.

    Science.gov (United States)

    Fallah, Meysam; Bahram, Somayeh; Javadian, Seyed Roholla

    2015-03-01

    Fish peptone was produced using enzymatic hydrolysis of silver carp filleting by-products by alcalase and trypsin. Also, the efficiency of the hydrolysates as a nitrogen source in Staphylococcus aureus medium was compared with commercial TSB. The results indicated that the protein hydrolysate from alcalase and trypsin had high protein content (92.92%, 91.53 respectively), and degree of hydrolysis (4.94%, 4.6% respectively).The results showed that silver carp filleting waste can be an efficient source for fish peptone production as a nitrogen source for S. aureus medium. However, the type of the used proteolytic enzyme considerably affected the performance of the resulting peptone despite the same DH. Fish peptone produced by alcalese performed significantly (P < 0.05) better than commercial TSB as a media for the bacteria while the performance of the trypsin peptone was not as good as the commercial medium. PMID:25838893

  18. Nutritional diversity of agricultural and agro-industrial by-products for ruminant feeding

    Directory of Open Access Journals (Sweden)

    J.A.G. Azevêdo

    2012-10-01

    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.

  19. 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.

    2013-01-01

    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 me

  20. Early age hydration of calcium sulfoaluminate (synthetic ye'elimite, C4A3S¯) in the presence of gypsum and varying amounts of calcium hydroxide

    International Nuclear Information System (INIS)

    Suspensions of synthetic ye'elimite (C4A3S¯) in a saturated gypsum (CS¯H2) 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 C4A3S¯, 15% CS¯H2, 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 (SO42−/OH−) AFm phases to form at early 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