The Australian national reactive phosphate rock project - Aims, experimental approach, and site characteristics

International Nuclear Information System (INIS)

McLaughlin, M.J.

2002-01-01

Field-based cutting trials were established across Australia in a range of environments to evaluate the agronomic effectiveness of 5 phosphate rocks, and 1 partially acidulated phosphate rock, relative to either single super-phosphate or triple superphosphate. The phosphate rocks differed in reactivity, as determined by the degree of carbonate substitution for phosphate in the apatite structure and solubility of phosphorus present in the fertilizers in 2% formic acid, 2% citric acid and neutral ammonium citrate. Sechura (Bayovar) and North Carolina phosphate rocks were highly reactive (>70% solubility in 2% formic acid), whilst Khouribja (Moroccan) and Hamrawein (Egypt) phosphate rock were moderately reactive. Duchess phosphate rock from Queensland was relatively unreactive ( 2 , from 4.0 to 5.1, and Colwell extractable phosphorus ranged from 3 to 47 μg/g prior to fertilizer application. Two core experiments were established at each site. The first measured the effects of phosphate rock reactivity on agronomic effectiveness, while the second core experiment measured the effects of the degree of water solubility of the phosphorus source on agronomic effectiveness. The National Reactive Phosphate Rock Project trials provided the opportunity to confirm the suitability of accepted procedures to model fertilizer response and to develop new approaches for comparing different fertilizer responses. The Project also provided the framework for subsidiary studies such as the effect of fertilizer source on soil phosphorus extractability; cadmium and fluorine concentrations in herbage; evaluation of soil phosphorus tests; and the influence of particle size on phosphate rock effectiveness. The National Reactive Phosphate Rock Project presents a valuable model for a large, Australia-wide, collaborative team approach to an important agricultural issue. The use of standard and consistent experimental methodologies at every site ensured that maximum benefit was obtained from data

Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

International Nuclear Information System (INIS)

El-Bahi, S.M.; Sroor, A.; Mohamed, Gehan Y.; El-Gendy, N.S.

2017-01-01

In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of "2"3"5U, "2"3"8U, "2"2"6Ra, "2"3"2Th and "4"0K was found as (45, 1031, 786, 85 and 765 Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819 Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870 Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897 Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population. - Highlights: • Level of radioactivity of phosphate rocks and by-products samples. • The radiological health hazard parameters. • Radiological risk to the health of the population. • The excess lifetime cancer risk factor.

Transfer of Some Major and Trace Elements From Phosphate Rock to Super-Phosphate Fertilizers

International Nuclear Information System (INIS)

El-Reefya, H.I.; Bin-Jaz, A.A.; Zaied, M.E.; Badran, H.M.; Badran, H.M.

2014-01-01

This study assesses the transfer of some major and trace elements from phosphate rock (PR) to single (SSP) and triple (TSP) superphosphate fertilizers. Samples from a fertilizer plant and local market were collected and analyzed using inductively coupled plasma spectrometer. Cluster analysis indicated that the inner-relationship among the concentration of the elements in PR, SSP, and TSP are different. Only one element (Mo) has concentration in SSP higher than phosphate rock. The production process of these two types of superphosphate leads to transfer higher portion of Mn, B, Cu, Mo, Sr, and V present in the phosphate rock to SSP than TSP. The potentially hazardous element Cd is also transmitted more to SSP than TSP, and Cr is equally transferred to both types. The mean elemental concentrations normalized to the percentage of P 2 O 5 demonstrate that for most elements they are the higher concentrations in SSP are linked to the phosphate contents

Microbial Leaching of Some Valuable Elements From Egyptian Phosphate Rock

International Nuclear Information System (INIS)

Kamal, H.M.; Hassanein, R.A.; Mahdy, H.M.A.; Mahmoud, K.F.; Abouzeid, M.A.

2012-01-01

Four phosphate rock samples representing different phosphate mineralization modes in Egypt were selected from Abu Tartar, Nile valley and Red sea areas. Factors affecting the phosphate rock solubilization and some of the contained valuable elements by Aspergillus niger, Penicillium sp. and Pseudomonas fluorescence, were studied with especial orientation towards the completion of phosphate rock samples solubilization especially die low grade one. Effect of nitrogen source type on leaching efficiency by Aspergillus niger when two nitrogen sources on the phosphate bioleaching efficiency, it is clear that the ammonium chloride is more favorable as nitrogen source than sodium nitrate in the bioleaching of phosphate rocks. When Aspergillus niger was applied under die following conditions: 50 g/1 of sucrose as a carbon source, 0.1 N of ammonium chloride as a nitrogen source, 10 days incubation period, 0.5% solid: liquid ratio for P 2 O 5 and 5% for U and REE and - 270 mesh of grain size. The optimum leaching of P 2 O 5 , U and REE from phosphate rock samples reached (23.27%, 17.4%, 11.4%, respectively), while at -60 mesh they reached to 16.58%, 28.9%, 30.2% respectively. The optimum conditions for the maximal leaching efficiencies of P 2 O 5 , U and REE when applying the Penicillium sp. from the phosphate rock samples were: 100 g/1 of sucrose as a carbon source for P 2 O 5 and U and 10 g/1 for REE, 7,15 and 10 days incubation period for P 2 O 5 , U and REE, respectively, 0.5% solid: liquid ratio for P 2 O 5 and 5% for U and REE. Finally, the application of phosphate rock samples grinded to -270 mesh of grain size for P 2 O 5 and (-60 to -140) for U and REE. The studied leaching efficiency of P 2 O 5 , U and REE gave at -270 mesh 33.66%, 24.3%, 15.9% respectively, while at -60 mesh they gave 33.76%, 26.7%, 17.8% and at -140 mesh gave 31.32%, 27.9%, 17.6%, respectively.The optimum conditions for the P 2 O 5 leaching efficiency when applying the Pseudomonas fluorescence were

Author Details

African Journals Online (AJOL)

Kamasho, JA. Vol 1, No 2 (1998) - Articles The influence of pyrite on the solubility of minjingu and panda phosphate rocks. Abstract PDF. ISSN: 0856 668X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of ...

Recovery of uranium from phosphatic rock and its derivatives

International Nuclear Information System (INIS)

Romero Guzman, E.T.

1992-01-01

The recovery of uranium present in the manufacture process of phosphoric acid and fertilizers has been one interesting field of study in chemistry. It is true that the recovery of uranium it is not very attractive from the commercial point of view, however the phosphatic fertilizers have an important amount of uranium which comes from the starting materials (phosphatic rock), therefore there must be many tons of uranium that are dispersed in the environmental together with the fertilizers used in agriculture every year. They are utilized for the enrichment of the nutrients which are exhausted in the soil. In this work, uranium was identified and quantified in the phosphatic rocks and in inorganic fertilizers using Gamma Spectroscopy, Neutron Activation Analysis, UV/Visible Spectrophotometry, Alpha Spectroscopy. On the other hand, it was done a correlation of the behaviour of uranium with inorganic elements present in the samples such as phosphorus, calcium and iron; which were determined by UV/Visible Spectrophotometry for phosphorus and Atomic Absorption Spectrometry for calcium and iron. The quantity of uranium found in the phosphatic rock, phosphoric acid and fertilizers was considerable (70-200 ppm). The adequate conditions for the recovery of 40% of total of uranium from the phosphatic rock with the addition of leaching solutions were stablished. (Author)

Recovery of uranium and the lanthanides from phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Habashi, F; Awadalla, F T; Zailaf, M

1986-06-01

A process is proposed for the treatment of phosphate rock for the recovery of uranium and lanthanides. The process assures the production of phosphatic fertilisers without polluting the environment with radioactive material.

Effect of heavy store dressing with rock phosphate on a fine sand soil

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Armi Kaila

1969-05-01

Full Text Available Results are reported of a long-term field trial on acid fine sand soil in which the effects of store dressing with rock phosphate in amounts of 0, 4000, 8000, or 12000 kg/ha was studied comparing them with an annual application of 200 kg/ha of superphosphate using the split plot technique. In the first four years, more thoroughly studied, the response to the store dressing with rock phosphate was distinct both in the dry matter yields and the phosphorus content of the cereal and the red clover-timothy hay. The differences between the various rates of rock phosphate treatments were not statistically significant, though there was some tendency to higher results with larger amounts of rock phosphate. The annual applications of superphosphate as surface dressing to the ley did not brought about any significant increase in the dry matter yield of the rock phosphate plots, and although they tended to increase the phosphorus content of hay, the increase was statistically significant only in a few cases. No effect was found on the phosphorus content of barley grain and straw in the ninth experimental year. No differences were found in the calcium, magnesium, or potassium content of the plant samples from the variously treated plots. Nitrogen content of clover and timothy was increased by both rock phosphate and superphosphate, particularly in the first year ley. In this soil, 4000 kg/ha of rock phosphate was effective enough to produce higher dry matter yields of hay, with equal phosphorus content, than the annual application of 200 kg/ha of superphosphate. Soil analyses indicated that this soil represented the extreme pattern of phosphorus retention in which applied phosphate is almost completely retained as aluminium bound forms of the fluoride soluble fraction supposed to be fairly available. It was suggested that in soils which retain the slowly dissolving rock phosphate phosphorus mainly as less available iron bound forms, heavy applications of

Standard characterization of phosphate rock samples from the FAO/IAEA phosphate project

International Nuclear Information System (INIS)

Binh, Truong; Zapata, F.

2002-01-01

Phosphate rocks (PR) are phosphate-bearing minerals that vary widely in their inherent characteristics and consequently their agronomic potential. In the framework of a FAO/IAEA networked research project, the evaluation of the agronomic effectiveness of natural and modified PR products under a variety of soil climate and crop management conditions was carried out. The characterization of phosphate rocks is the first and essential step in evaluating their suitability for direct application. If several PR sources are utilized, standardized methods should be used for comparison purposes to determine their agronomic potential. This paper describes the standard characterization of phosphate rock products utilized in the project, in particular the mineralogical and crystallographic analyses, physical analyses, chemical composition and solubility in conventional reagents. A total of 28 phosphate rock samples from 15 countries were collected and analyzed in specialized laboratories. The data on mineralogy, chemical composition and solubility in conventional reagents are closely interrelated. An arbitrary classification of the reactivity of the PR samples was made based on the solubility indices in conventional reagents. On another hand, the results of the crystallographic parameters, calculated indices of absolute solubility, specific surface and porosity reflect the variability of the physical state and the sample pre-conditioning treatment of the analyzed products. A proper characterization of phosphate rock samples should provide the maximum of basic information that can be obtained in a cost-effective manner in normal chemical laboratories. Based on the results of this characterization, the following determinations are recommended: a description of the sample, major elemental (total P, Ca, Mg) composition, solubility in conventional reagents (neutral ammonium citrate, citric and formic acid) and particle size analysis. The classification of PR samples for direct

Evaluating and quantifying the liming potential of phosphate rocks

International Nuclear Information System (INIS)

Sikora, F.J.

2002-01-01

The liming potential of phosphate rock was evaluated with theoretical calculations and quantified by laboratory titration and soil incubation. Three anions present in the carbonate apatite structure of phosphate rock that can consume protons and cause an increase in pH when dissolved from apatite are PO 4 3- , CO 3 2- , and F - . The pKa for HF is so low that F - has very little effect on increasing pH. The pKa for 2 protons on H 2 PO 4 - and H 2 CO 3 are sufficiently high enough to cause an increase in pH with PO 4 3- and CO 3 2- released into solution if the pH range is between 4 and 6. Because of the greater molar quantity of PO 4 3- compared toCO 3 2- , PO 4 3- exerts a greater affect on the liming potential of P rock. For a variety of phosphate rocks with a axes ranging from 9.322 to 9.374 A in the carbonate apatite structure, the theoretical % calcium carbonate equivalence (CCE) ranges from 59.5 to 62%. With the presence of gangue carbonate minerals from 2.5 to 10% on a weight basis in the phosphate rocks, the theoretical %CCE ranges from 59.5 to 63.1%. Use of AOAC method 955.01 for quantifying the %CCE of North Carolina phosphate rock (NCPR) and Idaho phosphate rock (IDPR) resulted in %CCE ranging from 39.9 to 53.7% which were less than the theoretical values. The lower values measured in the AOAC method was presumed to be due to formation of CaHPO 4 or CaHPO 4 ·2H 2 O precipitates which would result in less than 2 protons neutralized per mole of PO 4 3- released from carbonate apatite. The highly concentrated solution formed in the method was considered not indicative of a soil solution and thus determined %CCE values would be suspect. A soil incubation study was conducted to determine a more appropriate %CCE value in a soil environment using Copper Basin, Tennessee soil with a soil pH of 4.2. Agricultural limestone, NCPR, IDPR, and a granulated IDPR were added to 100 g of soil at rates of 0.1, 0.3, 1, 3, and 10 g/kg soil, incubated for 105 days at field

Recovery of uranium from wet process by the chloridic leaching of phosphate rocks

International Nuclear Information System (INIS)

Santana, A.O.; Paula, H.C.B.; Dantas, C.C.

1984-01-01

Uranium was recovered from chloridic leach liquor of phosphate rocks by solvent extraction on a laboratory scale. The extractor system is a mixture of di-(2-ethylhexyl) phosphoric acid (D 2 EHPA) and tributyl-phosphate (TBP) in a varsol diluent. The uranium concentration is 150 ppm in the rocks and 12 ppm in the leach liquor. The phosphate rocks are leached on a semi-industrial scale for dicalcium phosphate production. The recovery process comprises the following steps: extraction, reextraction, iron removal and uranium precipitation. (orig./EF)

Recovery of uranium from wet process by the chloridic leaching of phosphate rocks

Energy Technology Data Exchange (ETDEWEB)

Santana, A O; Paula, H C.B.; Dantas, C C

1984-03-01

Uranium was recovered from chloridic leach liquor of phosphate rocks by solvent extraction on a laboratory scale. The extractor system is a mixture of di-(2-ethylhexyl) phosphoric acid (D/sub 2/EHPA) and tributyl-phosphate (TBP) in a varsol diluent. The uranium concentration is 150 ppm in the rocks and 12 ppm in the leach liquor. The phosphate rocks are leached on a semi-industrial scale for dicalcium phosphate production. The recovery process comprises the following steps: extraction, reextraction, iron removal and uranium precipitation.

Phosphate-rich sedimentary rocks: significance for organic facies and petroleum exploration

Energy Technology Data Exchange (ETDEWEB)

Waples, D W

1982-03-01

Phosphorus-bearing rocks and sediments can be divided into two genetically distinct classes: phosphatic shales or limestones and phosphorites. Phosphatic shales are primary sediments in which phosphate nodules or micronodules have formed diagenetically by precipitation of calcium phosphates derived mainly from organic phosphorus. The nodules form in reducing environments at shallow depths within the sediments, where loss of phosphate by diffusion to the overlying water column is minimized. Highly biogenic sediments containing large amounts of organic matter and some fine clastic debris provide ideal environments for the formation of phosphate nodules. Phosphorites, in contrast, represent concentrated accumulations of reworked phosphate nodules which originated in phosphatic shales or limestones. Currents, wave action, recrystallization, and erosion and resedimentation are important mechanisms in the concentration process. Phosphatic shales and limestones may become excellent oil source rocks if thermal maturity is achieved. They are useful facies indicators for anoxic or nearly anoxic depositional environments, and are often associated with restricted basins, or, during certain geologic periods, with broad shelves developed during transgressions. Phosphorites, in contrast, are often correlated with sea-level regressions or uplifts. They are modest source rocks because of their low organic carbon contents and the fact that they were reworked under oxidizing conditions. Nevertheless, because phosphorites are derived from, and often grade into, phosphatic shales, they also are of potential utility in the search for oil source beds.

Analysis of some heavy metals in the rock phosphates

International Nuclear Information System (INIS)

Boujemaa, Chaker; Ayari, Taher

2005-01-01

The rock phosphates occupy an important place in the fields of the chemical industry. They are used for the manufacture of sevral products, mainly food manures, manures of the ground, the synthesis of certain acids and sevral other products of agricultural use. The quality of phosphates is related directly to the certain metals pose of the harmful problems for health and the environment. For the importance of these rock phosphates, the CNSTN proposed to carry out the proportioning of some toxic heavy metals by Atomic Absorption Spectrometry, within the framework of a project of end of studies, in order to evaluate the rate of toxicity by comparing it with the tolerable limits.(author). 3 refs

Manure derived biochar can successfully replace phosphate rock amendment in peatland restoration.

Science.gov (United States)

Pouliot, Rémy; Hugron, Sandrine; Rochefort, Line; Godbout, Stéphane; Palacios, Joahnn H; Groeneveld, Elisabeth; Jarry, Isabelle

2015-07-01

Phosphate rock fertilization is commonly used in peatland restoration to promote the growth of Polytrichum strictum, a nurse plant which aids the establishment of Sphagnum mosses. The present study tested whether 1) phosphorus fertilization facilitates the germination of P. strictum spores and 2) biochar derived from local pig manure can replace imported phosphate rock currently used in peatland restoration. Various doses of biochar were compared to phosphate rock to test its effect directly on P. strictum stem regeneration (in Petri dishes in a growth chamber) and in a simulation of peatland restoration with the moss layer transfer technique (in mesocoms in a greenhouse). Phosphorus fertilization promoted the germination of P. strictum spores as well as vegetative stem development. Biochar can effectively replace phosphate rock in peatland restoration giving a new waste management option for rural regions with phosphorus surpluses. As more available phosphorus was present in biochar, an addition of only 3-9 g m(-2) of pig manure biochar is recommended during the peatland restoration process, which is less than the standard dose of phosphate rock (15 g m(-2)). Copyright © 2015 Elsevier Ltd. All rights reserved.

Exploring plant factors for increasing phosphorus utilization from rock phosphates and native soil phosphates in acidic soils

International Nuclear Information System (INIS)

Feng Guanglin; Xiong Liming

2002-01-01

Six plant species with contrasting capacity in utilizing rock phosphates were compared with regard to their responses to phosphorus starvation in hydroponic cultures. Radish, buckwheat and oil rapeseed are known to have strong ability to use rock phosphates while ryegrass, wheat and sesbania are less efficient. Whereas other plants acidified their culture solution under P starvation (-P), radish plants make alkaline the solution. When neutralizing the pH of the solutions cultured with plants under either -P or + P conditions, solutions with P starved buckwheat, rapeseed, and radish had a higher ability to solubilize Al and Fe phosphates than did those cultured with sesbania, ryegrass and wheat. Characterization of organic ligands in the solutions identified that citrate and malate were the major organic anions exuded by rapeseed and radish. Besides citrate and malate, buckwheat exuded a large amount of tartrate under P starvation. In contrast, ryegrass, wheat and sesbania secreted only a limited amount of oxalic acid, regardless of P status. Changes in activities of phosphoenolpyruvate carboxylase, acid phosphatase, and nitrate reductase in these plants were also compared under P- sufficient or -deficient conditions. The results indicated that plant ability to use rock phosphates or soil phosphates is closely related to their responses toward P starvation. The diversity of P starvation responses was discussed in the context of co-evolution between plants and their environment. Approaches to use plant factors to enhance the effectiveness of rock phosphates were also discussed. (author)

The variable charge of andisols as affected by nanoparticles of rock phosphate and phosphate solubilizing bacteria

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Arifin, M.; Nurlaeny, N.; Devnita, R.; Fitriatin, B. N.; Sandrawati, A.; Supriatna, Y.

2018-02-01

Andisols has a great potential as agriculture land, however, it has a high phosphorus retention, variable charge characteristics and high value of zero net charge or pH0. The research is aimed to study the effects of nanoparticles of rock phosphate (NPRP) and biofertilizer (phosphate solubilizing bacteria/PSB) on soil pH, pHo (zero point of charge, ZPC) and organic-C in one subgroup of Andisols, namely Acrudoxic Durudands, Ciater Region West Java. The research was conducted from October 2016 to February 2017 in Soil Physics Laboratory and Laboratory of Soil Chemistry and Fertility, Soil Science Department, Faculty of Agriculture, Universitas Padjadjaran. This experiment used a completely randomized factorial design, consisting of two factors and three replications. The first factor was nanoparticles of rock phosphate consist of 4 doses 0; 25; 50 and 75 g/1 kg soil and the second factor was biofertilizer dose consist of g/1 kg soil and without biofertilizer. Total treatment combinations were 8 with 3 replications, so there were 24 experimental plots. The results showed that in general NPRR and biofertilizer will decrease the value of soil pH throughout the incubation periods. There is an interaction between nanoparticles of rock phosphate and biofertilizer in decreasing pHo in the first month of incubation, but after 4-month incubation period, NPRP increased. Interaction between 75 g nanoparticles of rock phosphate with 1 g biofertilizer/1 kg soil in fourth months of incubation decreased soil organic-C to 3.35%.

Mineralogical and textural characteristics of Kakul (Hazara) phosphate rock, NWFP, Pakistan

International Nuclear Information System (INIS)

Mehmood, R.; Bhatti, M.A.; Kazmi, K.R.; Mehmood, A.; Sheikh, S.T.; Aleem Shah, S.A.

2010-01-01

Various types of minerals, present in phosphate rock of Hazara area of Khyber Pukhtoonkhwa Province of Pakistan, were identified and their concentration was determined using a suitable method. The characteristics of the rock were defined by petrography, X-ray diffraction, and chemical analysis and the textural characteristics such as grain size, grain shape and their arrangement in the rock body were also investigated. The degree of liberation of phosphate-bearing mineral was studied by the particle-counting method. Mineralogical and textural observations indicated that fine-grained rock may be suitable for beneficiation by the froth flotation separation technique. (author)

Potency of Agroindustrial Wastewaters to Increase the Dissolution of Phosphate Rock Fertilizers

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Ainin Niswati

2014-06-01

Full Text Available The used of agroindustrial wastewaters are not maximum yet in Lampung Province, althought it can be used as an acid solvent because of its acidic properties. This study was aimed to explore the most potential agroindustrial wastewaters in dissolving phosphate rock through acidulation in the laboratory scale. The experiment was arranged in a factorial. The first factor was origined of phosphate rock (Sukabumi, west Java and Selagailingga, central Lampung and the second factor was solvent types (agroindustrial wastewaters which were pineapple, tapioca, tofu industry, and palm oil as well as conventional acid solvents which were HCl, H2SO4, and CH3COOH. The incubation processes were 0, 1, 2, and 3 months. The results showed that agroindustrial wastewaters that have the highest potency to solubize phosphate rock was industrial tofu wastewaters and followed by industrial wastewaters of tapioca, palm oil, and pineapple. Both the conventional acid and agroindustrial wastewaters solvent had a big potency to solubilize phosphate rock, however, its highest soluble P-value did not match with the ISO criteria for phosphate fertilizers Quality I (SNI because it did not reach the solubility of 80% of its total P2O5, but it has been qualified as a fertilizer both the quality phosphate A, B, and C (SNI.

Passive detection of Pb in water using rock phosphate agarose beads.

Science.gov (United States)

Edenborn, Harry M; Howard, Bret H; Sams, James I; Vesper, Dorothy J; Edenborn, Sherie L

2017-08-15

In this study, passive detectors for Pb were prepared by immobilizing powdered rock phosphate in agarose beads. Rock phosphate has been used to treat Pb-contaminated waters and soil by fixing the metal as an insoluble pyromorphite mineral. Under lab conditions, Pb was rapidly adsorbed from aqueous solution by the beads over time, consistent with the acidic dissolution of rock phosphate, the precipitation of pyromorphite within the pore space of the agarose gel matrix, and surface exchange reactions. Net accumulation of Pb occurred when beads were exposed to simulated periodic releases of Pb over time. Under field conditions, beads in mesh bags were effective at detecting dissolved Pb being transported as surface runoff from a site highly contaminated with Pb. Rates of Pb accumulation in beads under field conditions appeared to be correlated with the frequency of storm events and total rainfall. The rock phosphate agarose bead approach could be an inexpensive way to carry out source-tracking of Pb pollution, to verify the successful remediation of sites with Pb-contaminated soil, and to routinely monitor public water systems for potential Pb contamination. Published by Elsevier B.V.

Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

International Nuclear Information System (INIS)

Roos, Per; Jakobsen, Iver

2008-01-01

Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock

Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Roos, Per [Radiation Research Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Jakobsen, Iver [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark)], E-mail: iver.jakobsen@risoe.dk

2008-05-15

Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock.

The phosphorus status of andisols as influenced by nanoparticles of volcanic ash and rock phosphate

Science.gov (United States)

Devnita, Rina; Joy, Benny; Arifin, Mahfud; Setiawan, Ade; Rosniawaty, Santi; Meidina, Felia Shella

2018-02-01

Andisols need to be ameliorated to improve the phosphorus status. The objective of this research is to investigate the effect of nanoparticles of volcanic ash and rock phosphate as ameliorants in Andisols to P-retention, available P and potential P in Andisols. The research used a complete randomized experimental design in factorial with two factors. The first factor was nanoparticle of volcanic ash (a) and the second factor was rock phosphate (p). Both ameliorants consist of four doses on soil weight percentage (0%, 2.5%, 5.0% and 7.5%). The combined treatments were replicated three times. The soil and treatments were mixed and incubated for 4 months. Soil samples were taken after one month and four months of incubation to be analyzed the P-retention, available P and potential P. The results showed that there are interactions between the volcanic ash and rock phosphate on available P and potential P after one month of incubation. However, there were no interactions occurring between the volcanic ash and rock phosphate on P-retention after one and four months of incubation and no interactions on available P and potential P after four months. The best combined treatments in increasing available P and potential P after one month was obtained in 2.5% of volcanic ash and 5% of rock phosphate that increased available P to 405.75 ppm. The 2.5% of volcanic ash and 7.5% of rock phosphate increased potential P to 2190.26 mg/100 g. Independently, 7.5% of volcanic ash and rock phosphate decreased P-retention to 71.49% after one month and 89.74% after four months. Higher effect on the application of nanoparticle of volcanic ash and rock phosphate to the phosphorus status of Andisols recieved after one month of incubation is compared with four months of incubation.

Characterization and obtainment of phosphate rock concentrates of Turmequé, Boyacá

Science.gov (United States)

Zanguña, S. Quijano; Lozano Gómez, L. F.; Pineda Triana, Y.

2017-12-01

The work focuses on the use and exploitation of the mineral concentrates from phosphate rock (PR) coming from mines with a low percentage of phosphorus. The procedure was based on the collection of a source of phosphate rock from the department of Boyacá (municipality of Turmequé), using a randomized design with three replications. The samples were initially milled and sifted using meshes between 140 and 200 US standard, homogenizing them and improving the process of solubility of the phosphorus in the soil. We conduced Z-potential tests, which show that by performing a prior wash on the mineral and maintaining certain concentrations and pH defined, better results are achieved in terms of the buoyancy of the particles in the flotation process. The results obtained from the microflotation tests; both direct and inverse, and the results of chemical composition, with X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD), before and after the microflotation process, were carried out to obtain of commercial laws grade phosphate rock concentrate, confirm that the protocol used increases by 9% the value of total phosphorus in the collected sample. These concentrates from phosphate rock, could be used in the future for the attainment of simple superphosphate (SSP), with the help of sulphuric acid and ammonium thiosulphate mixtures.

Investigation of trace uranium content in rock phosphate ore samples from Kurun-Uro area, Nuba Mountains, Sudan

International Nuclear Information System (INIS)

Ali, Abdel Majid Abdel Galil Mohammed

1999-07-01

This investigation was carried out mainly to test the trace uranium level content in rock phosphate, which was used as a low cost fertilizer. Two types of rock phosphate were examined, namely, Kurun and Uro rocks from Nuba Mountains in the Southern Kurdufan province, Sudan.This area has a high background natural radioactivity. Moreover, it contains a rock phosphate zone lying between J. Kurun and Uro. The work included analytical methods carried out for thr rock phosphate samples using spectrophotometric and X-ray fluorescence techniques. The results obtained were compared with the data from literature and they showed a good agreement.The data was statistically analyzed to compare the results by the two techniques. The results of uranium content determined by the two analytical methods were significantly similar.The instrumental analysis revealed that different. Uranium content in the rocks phosphate samples of Uro type was found to be 1.6 times higher than Kurun type. (Author)

Precipitation and purification of uranium from rock phosphate

International Nuclear Information System (INIS)

AbowSlama, E.H.Y.; Sam, A.K.; Etemad Ebraheem

2014-01-01

This study was carried-out to leach uranium from rock phosphate using sulphuric acid in the presence of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia, magnesia and sodium hydroxide as precipitants, as well as purification of the products with TBP and matching its impurity levels with specifications of the commercial products. Alpha-particle spectrometry was used for determination of activity concentration of uranium isotopes in rock phosphate, resulting phosphoric acid, and in different forms of the yellow cake. Likewise, atomic absorption spectroscopy was used for determination of impurities. On the average, the equivalent mass concentration of uranium was 119.38 ± 79.66 ppm (rock phosphate) and 57.85 ± 20.46 ppm (phosphoric acid) with corresponding low percent of dissolution (48 %) which is considered low. The isotopic ratio ( 234 U: 238 U) in all stages of hydrometallurgical process was not much different from unity indicating lack of fractionation. Upon comparing the levels of impurities in different form of crude yellow cakes, it was found that the lowest levels were measured in hydrated trioxide (UO 3 ·xH 2 O). This implies that saturated magnesia is least aggressive relative to other precipitants and gives relatively pure crude cake. Therefore, it was used as an index to judge the relative purity of other forms of yellow cakes by taking the respective elemental ratios. The levels of impurities (Fe, Zn, Mn, Cu, Ni, Cd and Pb) in the purified yellow cake were found comparable with those specified for commercial products. (author)

Substoichiometric determination of uranium in phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Suzuki, N; Hanzawa, K; Imura, H

1986-01-01

The substoichiometric isotope dilution analysis for U(VI) in a synergic extraction system of an excess amount of a chelating agent hexafluoroacetylacetone (HHFA) and a substoichiometric amount of U(VI) can be precisely extracted, and U down to ppm levels can be accurately determined by the present method. This method was applied to the analysis of a phosphate rock.

Phosphatic Permian rocks of the Adobe Range, Nevada, and their environment of deposition

Science.gov (United States)

Ketner, Keith Brindley

1979-01-01

Permian sedimentary rocks in the Adobe range, northern Nevada, are phosphatic, and although the particles of phosphate are relatively more disseminated, they closely resemble the rocks of the Phosphoria Formation. In the northern Adobe Range, where the entire Permian sequence is approximately correlative with the Phosphoria Formation, it is 200 m thick and averages 1.7 percent P2O5 . In the southern Adobe Range, the Permian sequence is more than 1,700 m thick, and the upper half which is roughly correlative with the Phosphoria Formation averages more than 2 percent P2O5. Some thin beds in rocks of Permian age contain more than 20 percent P2O5. Phosphatic rocks of the Adobe Range were deposited in shallow water among islands in the western part of the epicontinental Phosphoria sea. The continental margin and the open ocean lay far to the west. At the same time, the Phosphoria Formation was being deposited in the eastern and central parts of the Phosphoria sea. Theories based on the work of Kasakov done in 1937 relating phosphate deposition directly to sites of upwelling oceanic waters are questioned. Nondeposition of diluent materials such as detritus and carbonate is probably of more importance in producing phosphate in economic concentrations than is geographic position with respect to upwelling waters.

Moroccan rock phosphate solubilization during a thermo-anaerobic ...

African Journals Online (AJOL)

In order to investigate the presence of thermo-tolerant rock phosphate (RP) solubilizing anaerobic microbes during the fermentation process, we used grassland as sole organic substrate to evaluate the RP solubilization process under anaerobic thermophilic conditions. The result shows a significant decrease of pH from ...

Economical and environmental impact of using of Nuba Mountain Rock Phosphate that contain uranium as a fertilizer without any treatment

International Nuclear Information System (INIS)

Hassan, Abdelrahman Khidir

1994-01-01

This study investigates the possible use of ground rock phosphate in Nuba Mountain for fertilization of arable land. Geological and chemical component of untreated ground rock phosphate has been compared with other ground rock phosphate from different geographical regions worldwide. The data show that economic exploitation of this rock phosphate as fertilizer is not feasible because of low solubility and low phosphorus content (12% on average). In addition, the high concentration of some elements in the rock phosphate could adversely affect the growth of the plant when it is applied on the soil by changing the chemical composition of the soil.As regards the environmental impact that could be result from the use of the rock phosphate as fertilizer is that it will unnecessarily increase the concentration of uranium which amount to 0.3% in the soil. The study recommends the use of this rock phosphate as a raw material for production of phosphoric acid and extraction of uranium and some elements as a bi-product of phosphate industry.(Author)

Availability of phosphorus from ground phosphate rocks for rape (Brassica napus L.)

International Nuclear Information System (INIS)

Zhu Yongyi; Yang Juncheng; Chen Jingjian; Liu Delin; Zhu Zhaomin; Wu Ming

1996-09-01

The availability of phosphorus from the ground phosphate rock, which is provided by Kaiyang mining plant, Guizhou Province of China, is investigated in pot experiment with acid red soil for rape (Brassica napus L. No. 13 Xingyou, Chinese Olive Group) by 32 P indirect labelling method. The results show that the yield increased significantly by applying ground phosphate rock (GPR) and the efficiency of GPR is equal to 17.1% of that from calcium superphosphate. It is calculated as that the fertilizer efficiency of 1 kg of calcium superphosphate is the same as that of 8.53 kg ground phosphate rock in Guizhou Province of China. The effect on the grain yield is evaluated by pot and field microplot experiments, and it is found that the main effect is to increase the pod number. The fertilizer efficiency in field experiment is the same as that in pot experiment. (9 refs., 1 fig., 7 tabs.)

The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilizers, in particular rock phosphate, in Venezuela: I. phosphorus uptake, utilization and agronomic effectiveness

International Nuclear Information System (INIS)

Casanova, E.; Salas, A.M.; Toro, M.

2002-01-01

Field experiments were conducted to evaluate the efficiency of natural and modified rock phosphate using conventional and isotopic techniques in an acid soil from El Pao, Cojedes state, Venezuela, using maize and sorghum with the application of different phosphate fertilizers to measure dry matter production, P accumulated in plant, efficiency parameters using isotopic techniques or yield. Finally, commercial plots were established with the application of soluble P fertilizers and rock phosphate products to validate the results obtained in the field experiments. The results showed highly significant differences between partially acidulated rock phosphate, natural rock phosphate, and the check plot in dry matter production, and P accumulation in plant and grain yield. When the efficiency parameters were evaluated in microplots with 32 P-TSP at 60 days of plant growth, it confirmed results obtained in semi commercial plots where the P in the plant derived from the fertilizer was 46% with partially acidulated rock phosphate (PAR) and 14% with natural Riecito rock phosphate (RR). Utilization coefficients of P by the plants were 34.2 and 8.8% for both treatments, respectively. The Substitution relation parameter showed that just 0.8 kg of P of PAR or 3.1 kg P of RR was required to produce the same yield as 1 kg P of TSP. These results were further validated in 5 ha commercial plots using corn and sorghum. (author)

P contribution derived from phosphate solubilizing microorganism activity, rock phosphate and SP-36 determination by isotope "3"2P technique

International Nuclear Information System (INIS)

Anggi Nico Flatian; Iswandi Anas; Atang Sutandi; Ishak

2016-01-01

The "3"2P isotope technique has been used to trace P nutrients in the soil and soil-plant systems. The use of the isotope "3"2P has made it possible to differentiate the P contribution derived from phosphate solubilizing microorganism activity and the fertilizer P in the soil. The aims of the study were to obtain the quantitative data of P contribution derived from phosphate-solubilizing microorganism activity (Aspergillus niger and Burkholderia cepacia), rock phosphate and SP-36 through P uptake by the plants using isotope "3"2P technique and also to study the effects on growth and production of corn plants. The results were showed that phosphate-solubilizing microorganism, rock phosphate and SP-36 was produced specific activity ("3"2P) lower than control. The results were indicated that all treatments could contribute P for the plants. The lower specific activity was caused by supply P from rock phosphate and SP-36, and also was caused by solubilized of unavailable "3"1P from PSM activity, which decreased specific activity on labeled soil. The combination of phosphate-solubilizing microorganism and SP-36 treatments produced the highest P contribution, significantly higher than control and SP-36 only. Phosphate derived from combination of microorganism and SP-36 treatments ranging from 56.06% - 68.54% after 50 days planting, after 35 days planting, 51.96% - 59.65% on stover, 46.33% - 47.70% on grain and 53.02% - 59.87% on corn cob. In addition, the treatments could significantly support the plant growth and yield. It is expressed by increased number of leave at 35 days after planting, dry weight of leave at 35 days after planting and dry weight of grain. (author)

Efficiency of Syrian and Indian rock phosphates for maize in two soils amended with sulphur

International Nuclear Information System (INIS)

Kanacri, S.

1995-01-01

A greenhouse pot experiment was conducted to evaluate the fertilizer use efficiency of three Syrian rock phosphates in comparison to Mussoorie rock phosphate from India for maize grown in a laterite (ultisol) and an alluvial (entisol) soil amended with sulphur, and using sup 3 sup 2 P-labelled triple superphosphate (TSP). Results showed that application of rock phosphates (RPs) to laterite soil significantly increased the dry matter yields of maize shoots, whereas, in alluvial soil, RPs were not found effective in increasing the yields. Data further indicated that all the three Syrian RPs were equally efficient in increasing dry matter yields in laterite soil and were superior to Mussoorie rock phosphate (MRP). Sulphur added in combination with RPs significantly enhanced the dry matter production as well as 'A' value of alluvial soil. Application of sulphur in conjunction with RPs significantly increased the 'A' value of laterite soil however, sulphur did not contribute to any significant increase in the yields. Syrian RPs were more reactive in soils than Mussoorie RP. (author). 7 refs., 6 tabs

Efficiency of Syrian and Indian rock phosphates for maize in two soils amended with sulphur

International Nuclear Information System (INIS)

Kanacri, Saloi; Bhujbal, B.M.

1993-01-01

A greenhouse pot experiment was conducted to evaluate the fertilizer use efficiency of three Syrian rock phosphates in comparison to Mussoorie rock phosphate from India for maize grown in a laterite (ultisol) and an alluvial (entisol) soil amended with sulphur, and using 32 P-labelled triple superphosphate (TSP). Results showed that application of rock phosphates (RPs) to laterite soil significantly increased the dry matter yields of maize shoots, whereas, in alluvial soil, RPs were not found effective in increasing the yields. Data further indicated that all the three Syrian RPs were equally efficient in increasing dry matter yields in laterite soil and were superior to Mussoorie rock phosphate (MRP). Sulphur added in combination with RPs significantly enhanced the dry matter production as well as 'A'value of alluvial soil. Application of sulphur in conjunction with RPs significantly increased the 'A' value of laterite soil, however, sulphur did not contribute to any significant increase in the yields. Syrian RPs were more reactive in soils than Mussoorie RP. (author). 7 refs., 6 tabs

Release of uranium decay-series nuclides from Florida phosphate rock

International Nuclear Information System (INIS)

Chin, P.A.; Deetae, S.; Burnett, W.C.

1985-01-01

Studies are being conducted on Florida phosphate rock to help understand the release of natural decay-series radionuclides into associated groundwaters. The authors have analyzed all isotopes with half-lives longer than a few days in samples of both weathered and unweathered phosphate rock previously separated into seven size classes. Samples which have been subjected to intense weathering display higher specific activities than relatively fresh materials with the highest activities in weathered samples occurring in the 210 Pb/ 226 Ra which is close to unity. Unweathered samples show exactly the reverse behavior. This is probably a result of 222 Rn diffusion and subsequent adsorption onto fine particles. Mass balance calculations of total activities by summation of the activities measured within each individual size class produce lower results compared to those actually measured in bulk samples of the phosphatic materials. This apparent loss may be due either to loss of very fine-grained, high-activity particles or actual solution of these radionuclides into the deionized water used during the wet seiving process

Radiological and chemical assessment of phosphate rocks in some countries

International Nuclear Information System (INIS)

Cevik, U.; Baltas, H.; Tabak, A.; Damla, N.

2010-01-01

In this study, the radiological, structural and chemical characterizations of Mardin-Mazidagi phosphate rock, which is an important phosphate fertilizer source in Turkey were investigated and compared to those of several different phosphate rocks of Tunisia, Egypt, Morocco, Algeria and Syria using gamma spectrometry, X-ray diffraction (XRD) and X-ray fluorescence (XRF) measurement techniques. Elemental analysis results of phosphate samples showed that they were mainly composed of CaO, P 2 O 5 , SiO 2 , Al 2 O 3 , SO 3 and Fe 2 O 3 . Elemental concentrations of U and Th were calculated using 226 Ra and 232 Th activity concentrations, respectively. As a result of XRD analysis, the main peaks of the samples were found to be Fluorapatite (Ca 5 (PO 4 ) 3 F). The radioactivity concentration levels for 226 Ra, 232 Th and 40 K in all phosphate samples ranged from 250 to 1029 Bq kg -1 with a mean of 535 Bq kg -1 , from 5 to 50 Bq kg -1 with a mean of 20 Bq kg -1 and from 117 to 186 Bq kg -1 with a mean of 148 Bq kg -1 , respectively. The computed values of annual effective doses ranged from 0.17 to 0.59 mSv, with a mean value of 0.33 mSv, which is lower than the recommended limit of 1 mSv y -1 by the International Commission on Radiological Protection.

TTPIXE analysis of phosphate rocks and phosphogypsum

International Nuclear Information System (INIS)

Martin, J.E.; Respaldiza, M.A.; Ontalba, M.A.; Garcia-Tenorio, R.; Bolivar, J.P.; Silva, M.F. da

1999-01-01

The TTPIXE technique was used for the determination of the concentrations of major, minor and trace elements in phosphate rock and phosphogypsum samples. All the samples came from a fertilizer industry site in Huelva (SW of Spain). The analyses were done using proton beams from the 3 MV Van de Graaff accelerator of the 'Instituto Tecnologico e Nuclear' (ITN), Sacavem (Portugal). The aim was to obtain data about the distribution of the different elements in the process of P 2 O 5 production in the factory. The information obtained allowed evaluation of the effectiveness of the chemical treatment employed, and gave a detailed information about the elemental composition of phosphogypsum, the main by-product of phosphate fertilizer production. These data can be useful to define the phosphogypsum management and to evaluate its environmental impact

Phosphate Rock Dissolution and Availability in Some Soils of Semi ...

African Journals Online (AJOL)

Fiifi Baidoo

crop production with less expensive indigenous phosphate rocks (PRs) merits the attention of ... spectrophoto-meter at 712 nm following the procedure of Murphy & Riley (1962). Laboratory analyses ..... L. M. and Goh K. M. (1989). Effects of ...

Measurement of radium - 226 in rock phosphate used as low cost fertilizer using gamma spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ahmed, M M.O.; Mohamed, O S [Atomic Energy Research Institute, Box 3001, Khartoum, (Sudan); Eltib, A E; Allasaad, I A.A. [faculty of Agriculture, University of Khartoum, (Sudan)

1995-10-01

This study was carried out to determine the concentration of radium - 226 in rock phosphate (used as low cost fertilizer), soil and plant. Two types of rock phosphates were examined, namely, Uro and kurun area in the Nuba mountains located in the western part of the sudan. The work included the determination of {sup 226} Ra levels in soil after applying different concentration of rock phosphate in pot experiments. The plant used was Abu sabien a sorghum which used for the animal feed. {sup 226} Ra in the soil using 20 g/pot (1000 kg/fed). of rock phosphate was found to be 88 and 104 Bq/kg for and 45 and 72 Bq/kg for kurun for season one and three respectively. As for the plant the concentration was found to be 1.2 and 1.4 Bq/kg for Uro and 0.4 and 0.6 Bq/kg for kurun for the first and third seasons respectively. The transfer factor of {sup 226} Ra from soil to plant was estimated to be (0.01). The concentration of {sup 226} Ra in the plant was found to be below the recommended values of contamination. 4 figs.

Measurement of radium - 226 in rock phosphate used as low cost fertilizer using gamma spectroscopy

International Nuclear Information System (INIS)

Ahmed, M.M.O.; Mohamed, O.S.; Eltib, A.E.; Allasaad, I.A.A.

1995-01-01

This study was carried out to determine the concentration of radium - 226 in rock phosphate (used as low cost fertilizer), soil and plant. Two types of rock phosphates were examined, namely, Uro and kurun area in the Nuba mountains located in the western part of the sudan. The work included the determination of 226 Ra levels in soil after applying different concentration of rock phosphate in pot experiments. The plant used was Abu sabien a sorghum which used for the animal feed. 226 Ra in the soil using 20 g/pot (1000 kg/fed). of rock phosphate was found to be 88 and 104 Bq/kg for and 45 and 72 Bq/kg for kurun for season one and three respectively. As for the plant the concentration was found to be 1.2 and 1.4 Bq/kg for Uro and 0.4 and 0.6 Bq/kg for kurun for the first and third seasons respectively. The transfer factor of 226 Ra from soil to plant was estimated to be (0.01). The concentration of 226 Ra in the plant was found to be below the recommended values of contamination. 4 figs

Recovering phosphorus and uranium values from phosphate rock

International Nuclear Information System (INIS)

Sze, M.C.Y.; Long, R.H.

1981-01-01

Phosphate rock is acidulated with aqueous nitric acid to produce an aqueous solution containing phosphate values, calcium and uranium values. The aqueous solution is contacted with an extraction solvent for the uranium values: the extraction solvent comprising a water immiscible organic diluent, a dialkyl phosphoric acid having at least 10 carbon atoms, and an organic phosphorus compound having the formula R 1 R 2 R 3 P = O where R 1 , R 2 and R 3 are each either alkyl or alkoxy, the organic phosphorus compound having at least 10 carbon atoms. The uranium values are then recovered from the extraction solvent. In an example the extraction solvent is HDEHP and TOPO in kerosene. (author)

Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

DEFF Research Database (Denmark)

Roos, Per; Jakobsen, Iver

2008-01-01

Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal......-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock. (c) 2007 Elsevier Ltd. All rights...

Phosphorus and uranium recovery process from phosphated rocks

Energy Technology Data Exchange (ETDEWEB)

Sze, M C.Y.; Long, R H

1981-01-30

Improvement of uranium recovery in phosphate rocks by treatment with nitric acid avoiding the formation of a precipitate including a part of the uranium. The separation of uranium from phosphoric acid is obtained by liquid-liquid extraction using dialkyl posphoric acid with at least 10 carbon atoms and a phosphoryl alkyl alkoxy compound with at least 10 carbon atoms and a non water miscible organic solvent.

Characterization of phosphorus leaching from phosphate waste rock in the Xiangxi River watershed, Three Gorges Reservoir, China.

Science.gov (United States)

Jiang, Li-Guo; Liang, Bing; Xue, Qiang; Yin, Cheng-Wei

2016-05-01

Phosphate mining waste rocks dumped in the Xiangxi River (XXR) bay, which is the largest backwater zone of the Three Gorges Reservoir (TGR), are treated as Type I industry solid wastes by the Chinese government. To evaluate the potential pollution risk of phosphorus leaching from phosphate waste rocks, the phosphorus leaching behaviors of six phosphate waste rock samples with different weathering degrees under both neutral and acidic conditions were investigated using a series of column leaching experiments, following the Method 1314 standard of the US EPA. The results indicate that the phosphorus release mechanism is solubility-controlled. Phosphorus release from waste rocks increases as pH decreases. The phosphorus leaching concentration and cumulative phosphorus released in acidic leaching conditions were found to be one order of magnitude greater than that in neutral leaching conditions. In addition, the phosphorus was released faster during the period when environmental pH turned from weak alkalinity to slight acidity, with this accelerated release period appearing when L/S was in the range of 0.5-2.0 mL/g. In both neutral and acidic conditions, the average values of Total Phosphorus (TP), including orthophosphates, polyphosphates and organic phosphate, leaching concentration exceed the availability by regulatory (0.5 mg/L) in the whole L/S range, suggesting that the phosphate waste rocks stacked within the XXR watershed should be considered as Type II industry solid wastes. Therefore, the phosphate waste rocks deposited within the study area should be considered as phosphorus point pollution sources, which could threaten the adjacent surface-water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recovering phosphorus and uranium values from phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Sze, M C.Y.; Long, R H

1981-02-11

Phosphate rock is acidulated with aqueous nitric acid to produce an aqueous solution containing phosphate values, calcium and uranium values. The aqueous solution is contacted with an extraction solvent for the uranium values: the extraction solvent comprising a water immiscible organic diluent, a dialkyl phosphoric acid having at least 10 carbon atoms, and an organic phosphorus compound having the formula R/sub 1/ R/sub 2/ R/sub 3/ P = O where R/sub 1/, R/sub 2/ and R/sub 3/ are each either alkyl or alkoxy, the organic phosphorus compound having at least 10 carbon atoms. The uranium values are then recovered from the extraction solvent. In an example the extraction solvent is HDEHP and TOPO in kerosene.

Recent revisions of phosphate rock reserves and resources: a critique

NARCIS (Netherlands)

Edixhoven, J.D.; Gupta, J.; Savenije, H.H.G.

2014-01-01

Phosphate rock (PR) is a finite mineral indispensable for fertilizer production, while P (phosphorus) is a major pollutant if applied or discharged in excess, causing widespread eutrophication (Carpenter and Bennet, 2011). High-grade PR is obtained from deposits which took millions of years to form

Recent revisions of phosphate rock reserves and resources : A critique

NARCIS (Netherlands)

Edixhoven, J.D.; Gupta, J.; Savenije, H.H.G.

2014-01-01

Phosphate rock (PR) is a finite mineral indispensable for fertilizer production, while P (phosphorus) is a major pollutant if applied or discharged in excess, causing widespread eutrophication (Carpenter and Bennet, 2011). High-grade PR is obtained from deposits which took millions of years to form

Characterisation of phosphate rocks at kurun mountain, Sudan

International Nuclear Information System (INIS)

Abdelgader, G. A. M.

2014-08-01

This main objective of this study was to characterise some Sudanese phosphate raw materials collected from Jebel Kurun, located in the eastern part of Nuba Mountain, Western Sudan. The study also aimed to investigate the association between uranium and phosphate and to determine the concentration of some essential elements and trace elements in the phosphate rock. A total of 30 samples were collected from Karun's eastran mountains, near Abujibiha City and have been analyzed for the selected elements using x-ray fluorescence. The obtained results showed that the average concentration of elements was Ca (11.3) and Fe (1.7) as a percentage, while it was Cu (1617.7), Ni (258.4), Pb (185.9), Ti (27.62), V (3779.9), U (160.9), Zn (152.8) and Mn (776.3) in ppm. The average total phosphorus content (analyzed as P O5 %) using UV-visible spectrometer was found to be 30.54%. This could be considered is acceptable percentage for phosphate to be 30.54%. This could be considered is acceptable percentage for phosphate to be used in industrial fertilizers and phosphoric acid production. The average total calcium carbonate was 15.7%. For the elements distribution, uranium found to be more concentrated in the summit of Jebel Kurun, and it displayed a correlation with lead. Furthermore, four groups of association have been noticed, based on elements concentrations.(Author)

Organic resources and earthworms affect phosphorus availability to sorghum after phosphate rock addition in semi-arid West Africa

NARCIS (Netherlands)

Ouédraogo, E.; Brussaard, L.; Mando, A.; Stroosnijder, L.

2005-01-01

A field experiment was laid out in Burkina Faso (West Africa) on an Eutric Cambisol to investigate the interaction of organic resource quality and phosphate rock on crop yield and to assess the contribution of earthworms (Millsonia inermis Michaelsen) to P availability after phosphate rock

Enhancement of the agronomic effectiveness of phosphate rock in a ferralsol from Cuba

International Nuclear Information System (INIS)

Rodriguez, R.; Herrera, J.A.; Garcia, A.; Nuviola, A.

2002-01-01

The Ferralsols from Ciego de Avila, Cuba, have a pH near neutrality and very low exchangeable acidity, thus, they are not suitable for direct application of phosphate rock. In laboratory and greenhouse experiments, different P fertilizers were tested in order to assess their agronomic effectiveness through the use of nuclear and conventional methods. The phosphate rocks (PRs) came from different deposits (Higuanojo, La Pimienta and Trinidad de Guedes from Cuba; Riecito, Baja California and North Carolina from other countries). Partial acidulation (PA) of some of these rocks was also evaluated. Trinidad de Guedes PAPRs were found to be highly effective compared to their natural PR when evaluated through dry matter production, P uptake and isotopic parameters. Further field experiments are needed to validate the greenhouse results to enhance the agronomic effectiveness of the local Trinidad de Guedes PR through partial acidulation. (author)

Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides in phosphate rocks and phosphate fertilizers

Energy Technology Data Exchange (ETDEWEB)

Komura, K; Yanagisawa, M; Sakurai, J; Sakanoue, M

1985-10-01

Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides have been studied for 2 phosphate rocks and 7 phosphate fertilizers. Uranium contents were found to be rather high (39-117 ppm) except for phosphate rock from Kola. The uranium series nuclides were found to be in various equilibration states, which can be grouped into following three categories. Almost in the equilibrium state, 238U approximately 230Th greater than 210Pb greater than 226Ra and 238U greater than 230Th greater than 210Pb greater than 226Ra. Thorium contents were found to be, in general, low and appreciable disequilibrium of the thorium series nuclides was not observed except one sample. Potassium contents were also very low (less than 0.3% K2O) except for complex fertilizers. Based on the present data, discussions were made for the radiation exposure due to phosphate fertilizers.

Field studies on two rock phosphate solubilizing actinomycete isolates as biofertilizer sources

Science.gov (United States)

Mba, Caroline C.

1994-03-01

Recently biotechnology is focusing attention on utilization of biological resources to solve a number of environmental problems such as soil fertility management. Results of microbial studies on earthworm compost in the University of Nigeria farm identified a number of rock phosphate solubilizing actinomycetes. Two of these, isclates 02 and 13, were found to be efficient rock phosphate (RP) solubilizers and fast-growing cellulolytic microbes producing extracellular hydrolase enzymes. In this preliminary field study the two microbial isolates were investigated with respect to their effects on the growth of soybean and egusi as well as their effect on the incidence of toxicity of poultry droppings. Application of these isolates in poultry manure-treated field plots, as microbial fertilizers, brought about yield increases of 43% and 17% with soybeans and 19% and 33% with egusi, respectively. Soil properties were also improved. With isolates 02 and 13, the soil available phosphorus increased at the five-leaf stage, while N-fixation in the soil increased by 45% or 11% relative to control. It was further observed that air-dried poultry manure after four days of incubation was still toxic to soybean. The toxic effect of the applied poultry manure was reduced or eliminated with microbial fertilizers 02 or 13, respectively. The beneficial effects of the microbial organic fertilizer are discussed. Justification for more intensive research on rock phosphate organic fertilizer is highlighted.

Phosphate rock utilization by soybean genotypes on a low-P ...

African Journals Online (AJOL)

Thirteen promiscuous soybean genotypes were evaluated in a low-P soil at Fashola in the derived savanna of Nigeria to compare their ability to acquire and utilize P from phosphate rock (PR) and single superphosphate (SSP). Changes in soil P fractions after a subsequent maize crop were also assessed. The treatments ...

Recovery of uranium from low-grade sandstone ores and phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R H [United States Atomic Energy Commission, Washington, D. C. (United States)

1967-06-15

This paper is concerned principally with commercial-scale experience in the United States in the recovery of uranium from low-grade sources. Most of these operations have been conducted by the operators of uranium mills as an alternative to processing normal-grade ores. The operations have been generally limited, therefore, to the treatment of low-grade materials generated in the course of mining normal-grade ores. In some circumstances such materials can be treated by simplified procedures as an attractive source of additional production. The experience gained in uranium recovery from phosphate rock will be treated in some detail. The land pebble phosphate rock of central Florida generally contains about 0.01 to 0.02% U{sub 3}O{sub 8}. While no uranium is being recovered from this source at the present time, it does represent a significant potential source of by-product uranium production because of the large tonnages being mined. (author)

Radiological, chemical and morphological characterizations of phosphate rock and phosphogypsum from phosphoric acid factories in SW Spain

Energy Technology Data Exchange (ETDEWEB)

Renteria-Villalobos, Marusia, E-mail: marusia@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Advanced Materials Research Center (CIMAV), Miguel de Cervantes 120, 31109 Chihuahua (Mexico); Vioque, Ignacio, E-mail: ivioque@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Mantero, Juan, E-mail: manter@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

2010-09-15

In this work, radiological, chemical, and also morphological characterization was performed in phosphate rock and phosphogypsum samples, in order to understand the behavior of toxic elements. Characterization was carried out using X-ray diffraction (XRD), X-ray fluorescence (XRF), gamma spectrometry and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Our results show that the phosphate rock was mainly composed of fluorapatite, calcite, perovskite, quartz, magnetite, pyrite and kaolinite, whereas phosphogypsum only exhibited dihydrated calcium sulfate. The activity concentration of U-series radioisotopes in phosphate rock was around 1640 Bq/kg. {sup 226}Ra and {sup 210}Pb tend to be distributed into phosphogypsum by up to 80%, whereas the fraction of U-isotopes is 10%. The most abundant trace elements in phosphate rock were Sr, Cr, V, Zn, Y, Ni and Ba. Some elements, such as Ba, Cd, Cu, La, Pb, Se, Sr, Th and Y, were enriched in the phosphogypsum. This enrichment may be attributed to an additional input associated to the sulfuric acid used for the phosphoric acid production. Furthermore, results from SEM-EDX demonstrated that toxic elements are not distributed homogeneously into phosphogypsum. Most of these elements are concentrated in particles <20 {mu}m of high porosity, and could be easily mobilized by leaching and/or erosion.

Radiological, chemical and morphological characterizations of phosphate rock and phosphogypsum from phosphoric acid factories in SW Spain

International Nuclear Information System (INIS)

Renteria-Villalobos, Marusia; Vioque, Ignacio; Mantero, Juan; Manjon, Guillermo

2010-01-01

In this work, radiological, chemical, and also morphological characterization was performed in phosphate rock and phosphogypsum samples, in order to understand the behavior of toxic elements. Characterization was carried out using X-ray diffraction (XRD), X-ray fluorescence (XRF), gamma spectrometry and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Our results show that the phosphate rock was mainly composed of fluorapatite, calcite, perovskite, quartz, magnetite, pyrite and kaolinite, whereas phosphogypsum only exhibited dihydrated calcium sulfate. The activity concentration of U-series radioisotopes in phosphate rock was around 1640 Bq/kg. 226 Ra and 210 Pb tend to be distributed into phosphogypsum by up to 80%, whereas the fraction of U-isotopes is 10%. The most abundant trace elements in phosphate rock were Sr, Cr, V, Zn, Y, Ni and Ba. Some elements, such as Ba, Cd, Cu, La, Pb, Se, Sr, Th and Y, were enriched in the phosphogypsum. This enrichment may be attributed to an additional input associated to the sulfuric acid used for the phosphoric acid production. Furthermore, results from SEM-EDX demonstrated that toxic elements are not distributed homogeneously into phosphogypsum. Most of these elements are concentrated in particles <20 μm of high porosity, and could be easily mobilized by leaching and/or erosion.

Neutron activation analysis of alternative phosphate rocks used in animal nutrition; Analise por ativacao neutronica por fontes alternativas de fosforo para a nutricao animal

Energy Technology Data Exchange (ETDEWEB)

Canella, Artur A.; Ferreira, Walter M. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Veterinaria]. E-mail: avelara@ufmg.br; Menezes, Maria Angela de B.C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: menezes@cdtn.br

2005-07-01

Since 1980's, Bovine Sponghiform Encephalophaty has insidiously created a fierce battleground between farmers, scientists, environmentalists and consumers. The use of meat and bone meals is currently prohibited in ruminant feeds throughout the world. Some inorganic sources offer the combination of high phosphorus content and acceptable animal digestibility make them options as supplemental phosphorus, for instance phosphate rocks, general term applied to minerals valued chiefly for their phosphorus content. However, phosphate rocks are long been known containing hazardous elements, make them sometimes unsuitable for animal nutrition. Neutron Activation Analysis has been supportive to the mineral evaluation of alternative phosphate rocks. This evaluation is subject of on-going doctoral thesis which has been carried-out by the main author. The NAA method has been very efficient due to its highly sensitive and multi-elemental nature. In this paper results of Vanadium content from three different phosphate rocks are presented. Their values have been pointed out that Brazilian phosphate rocks present hazardous elements at the same levels of phosphate rocks from some countries of Africa, North America and Middle East, data from our study (Brazilian data) and FAO - Food and Agriculture Organization (others countries). (author)

Biogeochemistry of uranium in plants associated to phosphatic rocks in the coastal region of Syria

International Nuclear Information System (INIS)

Jubeli, Y.; Al-Oudat, M.; Al-Rayes, A.; El-Sharabi, N.A.

2000-07-01

Investigation studies in general, demonstrate that background levels of U in plant ash are less than 2 ppm and plant materials which contain more in excess of this amount are indicative either of local uranium mineralization, or the presence of high background levels of uranium in the substrate. Uranium concentrations in different plant parts grown on decomposite phosphate rocks in the mountain coast region of Syria was investigated. Mean uranium concentrations in the soil ranged between 0.44 - 3.91 ppm in the reference area and 22 - 92 ppm in the area of outcrop in phosphate rocks. The results showed that low-order plant forms (Fuaria, Lycopodium, and Pteridium) readily accumulate uranium, whereas high-order forms accumulate uranium in certain parts only. The greatest amount of uranium in flowering parts is concentrated in the plant roots, followed by leaves, twigs and fruits. In addition, results showed that there is a good correlation between uranium in soil and uranium in plant roots. the study demonstrate that Galium Canum could be considered as a good uranium indicator plant for two reason: It was distributed on decomposite phosphate rocks only, and the high concentration of uranium in aerial part similar to the concentration in soil (89.9 ppm). Lagurus Ovatus may be considered as uranium indicator plant, because it was highly dense on the outcrop phosphate rocks, and has a high uranium concentration in its roots (up to 93 ppm) and aerial parts (up to 33 ppm) compared to concentrations in roots and aerial parts in the reference area (10.2 and 0.37 ppm) respectively. (Author)

The transport characteristics of {sup 238}U, {sup 232}Th, {sup 226}Ra, and {sup 40}K in the production cycle of phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-03-15

Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

Initial growth of maize in response to application of rock phosphate, vermicompost and endophytic bacteria

Directory of Open Access Journals (Sweden)

Lílian Estrela Borges Baldotto

2012-04-01

Full Text Available Due to the high energy requirement and demand for non-renewable resources for the production of chemical fertilizers, added also to the environmental impact caused by the use of such products, it is important to intensify research on bio-based agricultural inputs. The use of nitrogen-fixing endophytic and phosphate solubilizing bacteria can provide these nutrients to the plants from the air and poorly soluble phosphorus sources, such as phosphate rock. The objective of this study was to evaluate the nutrition and initial growth of maize (Zea mays L. in response to the inoculation of nitrogen-fixing and rock phosphate solubilizing endophytic bacteria, in single or mixed formulation, applied with vermicompost. The treatments containing bacteria, both diazotrophic and phosphate solubilizing, when compared to controls, showed higher levels of leaf nitrogen and phosphorus in maize, as well as higher growth characteristics. The application of vermicompost showed synergistic effect when combined with endophytic bacteria. Thus, the innovation of the combination of the studied factors may contribute to the early development of maize.

Sugarcane bagasse derivative-based superabsorbent containing phosphate rock with water-fertilizer integration.

Science.gov (United States)

Zhong, Kang; Zheng, Xi-Liang; Mao, Xiao-Yun; Lin, Zuan-Tao; Jiang, Gang-Biao

2012-10-01

To improve the water-fertilizer utilization ratio and mitigate the environmental contamination, an eco-friendly superabsorbent polymer (SPA), modified sugarcane bagasse/poly (acrylic acid) embedding phosphate rock (MSB/PAA/PHR), was prepared. Ammonia, phosphate rock (PHR) and KOH were admixed in the presence of acrylic acid to provide nitrogen (N), phosphorus (P) and potassium (K) nutrients, respectively. Impacts on water absorption capacity of the superabsorbent polymer (SAP) were investigated. The maximum swelling capacity in distilled water and 0.9 wt.% (weight percent) NaCl solution reached 414 gg(-1) and 55 gg(-1) (water/prepared SAP), respectively. The available NPK contents of the combination system were 15.13 mgg(-1), 6.93 mgg(-1) and 52.05 mgg(-1), respectively. Moreover, the release behaviors of NPK in the MSB/PAA/PHR were also studied. The results showed that the MSB/PAA/PHR has outstanding sustained-release plant nutrients property. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluation of available phosphorus and cadmium associated with phosphate rock for direct application

International Nuclear Information System (INIS)

Chien, S.H.

2002-01-01

Three greenhouse experiments were conducted to evaluate available P and Cd associated with the use of phosphate rock (PR) for direct application. These experiments were: (1) 'Estimation of Phosphorus Availability to Maize and Cowpea From Phosphate Rock as Enhanced by Water-Soluble Phosphorus'; (2) 'Modified Iron Oxide-Impregnated Paper Strip (Pi) Test for Soils Treated With Phosphate Fertilizers'; and (3) 'Effect of Acidulation of High Cadmium Containing Phosphate Rocks on Cadmium Uptake by Upland Rice'. In the first experiment, a medium-reactive Central Florida phosphate rock (PR) was used. The effectiveness of P sources in terms of increasing dry-matter yield and P uptake followed the order of TSP≥(PR+TSP)>PR for maize and TSP=(TSP+PR)>PR for cowpea. P uptake from PR in the presence of TSP was higher than P uptake from PR applied alone. With respect to P uptake from PR applied alone, the corresponding relative increase in P uptake from PR due to TSP influence was 165% for maize and 72% for cowpea. In the second experiment, a highly reactive North Carolina PR was used. Both Bray I and the Pi test (with CaCl 2 ) underestimated available P from PR with respect to TSP. Available P estimated by the Pi test with KCl was more closely related to P uptake with both PR and TSP. More P was extracted from PR by the Pi test with KCl than with CaCl 2 , whereas no effect was observed for TSP. In the third experiment, a low-reactive Togo PR and a highly reactive North Carolina PR were used. Both PRs were fully acidulated to SSP and Togo PR was also partially acidulated with H 2 SO 4 at 50% level to PAPR. Cd uptake by rice grain followed the order of NC-SSP > NC-PR and Togo-SSP > Togo PAPR > Togo PR. The results also showed that most of the Cd uptake was retained in rice root and straw. Total uptake of Cd, Ca, and P by the rice plant was higher from NC-PR than from Togo-PR. Cd concentration in rice grain showed no significant difference between NC-PR and Togo-PR, whereas Cd

Applications of isotope techniques for the assessment of soil phosphorus status and evaluation of rock phosphates as phosphorus sources for plants in subtropical China

International Nuclear Information System (INIS)

Xiong, L.M.; Zhou, Z.G.; Feng, G.L.; Lu, R.K.; Fardeau, J.C.

2002-01-01

In an attempt to assess current soil phosphorus status and evaluate the effectiveness of local rock phosphates in subtropical China, nearly 40 representative soil samples from this region were collected and characterized by using 32 P isotope and chemical extraction techniques. Pot experiments, incubation studies and field trials were conducted to investigate the interaction of rock phosphates and water-soluble phosphates as well as the effects of rock phosphate on soil chemical properties in selected soils. Results indicated that these soils were generally low in available phosphorus and high in P-fixing capacity. The soil characteristics dictated that the employed isotope kinetic model was less successful in predicting plant P uptake than the chemical procedures tested. A new chemical extraction method consisting of sodium bicarbonate and ammonium fluoride was proposed to evaluate available P in these Solis. Data on available P generated with the proposed method gave the best prediction of plant uptake amongst all methods compared. In a pot experiment, the combined application of soluble P fertilizer with local rock phosphate significantly enhanced plant growth and increased P uptake. This positive interaction was attributed to the improved soil chemical properties due to the application of low-grade rock phosphates, as demonstrated in incubation studies. These results suggest that rock phosphate-based fertilizers should be good alternative fertilizers for plants in similar acidic soils in southern China. (author)

Effectiveness of Direct Application of Phosphate Rock in Upland Acid Inceptisols Soils on Available-P and Maize Yield

Directory of Open Access Journals (Sweden)

Nurjaya

2013-03-01

Full Text Available Source of P fertilizer which is used by farmers in upland acid soils area is generally acidulated phosphate rock (PR,such as tripel super phosphate (TSP, super phosphate 36% P2O5 (SP-36, as well as partial acidulated phosphate rock (PAPR which contain 10-30% P2O5. Their effectiveness, however, varies and depends on the soil and planttypes. Phosphate rock fertilizers have a high prospects for acid soils because its effectiveness equals to the SP-36,cheaper, slow release, and its application can also leave the residual P in the soil that available for plants for next few seasons. Field experiment aimed to study the effectiveness of direct application of PR at upland acid soils and its effect on soil available-P as well as maize (Zea mays L. yield was conducted in Acid Inceptisols of Ciampea,Bogorin wet season years 2008/2009. The experiment was arranged by a Randomized Completely Block Design with 3 replications. Maize of P-12 variety was used as a plant indicator. The treatment consisted of 6 levels of phosphate rock: 0, 20, 30, 40, 50, and 60 kg P ha-1, as well as one level of SP-36 40 kg P ha-1 as standard fertilizer. In addition, urea of 300 kg ha-1 and KCl of 100 kg ha-1 were used as basal fertilization. The result showed that the application of PRin the amount ranging from 20 to 60 kg P ha-1 increased total-P and available-P, and pH, decreased exchangeable Al in the soils as well as increased maize straw and grain. Phosphate rock application at 40 kg P ha-1 level was equally effective as SP-36 in the tested soils. Critical level of soil P for maize grown in the soil was 675 and 5.00 mg P2O5 kg-1 extracted with HCl 25% and Bray I, respectively. The requirement of P for maize grown in the soil to achieve maximum profit was 38 kg P ha-1 and 17.5 kg P ha-1 or equivalent to PR of 583 and 268 kg ha-1 in low (soil P critical level soil P status, respectively.

Radiometric analysis of Hazara phosphate rock and fertilizers in Pakistan

International Nuclear Information System (INIS)

Khan, K.; Khan, H.M.; Tufail, M.; Khatibeh, A.J.A.H.; Ahmad, N.

1998-01-01

Natural radioactivity due to 40 K, 226 Ra and 232 Th has been measured in phosphate rock samples, collected from various localities of Hazara division of Pakistan, and in locally prepared and imported fertilizer. For data acquisition and analysis, a high-purity germanium (HPGe) detector and a PC-based MCA were used. The 226 Ra content was very high and was found to vary from 307.7 Bq kg -1 to 617.5 Bq kg -1 . This can result in a significant radiation exposure if the rock and fertilizer are handled in places with poor ventilation that could lead to radon accumulation. These data can be used to determine the radioactivity being spread along with fertilizer on agricultural lands. (author)

Radio phosphorus kinetics in the blood of sheep supplemented with dicalcium phosphate, mono ammonium phosphate, triple superphosphate and Tapira rock phosphate

International Nuclear Information System (INIS)

Abdalla, A.L.

1992-01-01

With the aim to study the kinetics of radio phosphorus ( 32 P) in the blood of animals supplemented with dicalcium phosphate (BIC), mono ammonium phosphate (MAP), triple superphosphate (SPT) and Tapira rock phosphate (TAP), 32 male sheep were kept in metabolic cages at the Animal Science Section / CENA - USP. Plasma was obtained by centrifugation and the specific activity, rate of disappearance and half life of 32 P in plasma were determined. In the red blood cells were determined the uptake rate of the radioisotope, the rate of disappearance and half life of 32 P up taken. It was observed a statistical significant difference (p 32 P in the plasma and erythrocytes. The specific activity and half life of 32 P in the plasma were statistically different (p<0,10) among sheep receiving the different phosphorus sources; the same was observed in respect to the red blood cells. It was concluded that the supplemented phosphorus source given in the diet of sheep may affect the kinetics of the radio phosphorus in the blood after been intravenously injected. (author)

Long term field evaluation of phosphate rock and superphosphate in acid soils of Hungary; Incubation and pot experiments

International Nuclear Information System (INIS)

Nemeth, T.; Osztoics, E.; Csatho, P.; Radimszky, L.; Baczo, G.Y.

2002-01-01

A series of experiments was conducted to compare the agronomic effectiveness of phosphate rock (from Algeria) and of single superphosphate (from Russia, Kola) on a moderately acidic pseudogley brown forest soil (Szentgyoergyvoelgy) and on a slightly acidic chernozem brown forest soil (Kompolt). Dynamics of water-soluble and ammonium lactate-soluble P-contents (AL-P) and soil pH-H 2 O changes were studied in a half-year long incubation experiment. A follow-up pot experiment with the same soils was carried out with winter rape as test plants. Both experiments were set up with similar P fertilizer sources and P rates (100, 200, and 400 mg mineral acid soluble P 2 O 5 per kg soil). At the beginning of incubation experiment, the water-soluble P content of the pseudogley brown forest soil was influenced by both the sources of P and the experimental conditions. The water-soluble P content decreased with time. After the 15 th to 20 th day of incubation, when the fast binding process of the water-soluble P ended, the effects of the P forms decreased. In this stage, the effects of environmental conditions depended on the form of the P fertilizer. The water-soluble P content of the phosphate rock-treated samples was affected to a great extent by soil water content, while the incubation temperature had a greater effect in soils treated with superphosphate. The AL-P content of soils was increased similarly by addition of equal rates of phosphate rock and super-phosphate at the beginning of incubation. The AL-P content of phosphate rock-treated soils was higher throughout the incubation period than of the superphosphate-treated soils -treated. Temperature had a greater effect on the AL-P content of soils than soil water content. As the AL-extraction may dissolve a substantial amount of the undecomposed phosphate rock, this method is not applicable to soil testing of available P forms from phosphate rock-treated soils. Initial soil pH decreased on average by 0.5 units in the

Determination of the uranium content of phosphate rocks

International Nuclear Information System (INIS)

Levin, R.; Ronen, S.

1977-03-01

A method is described for the spectrophotometric determination of uranium (VI) in the presence of various elements by extraction with 0.1M trioctylphosphine oxide (TOPO) dissolved in cyclohexane from 1.5M nitric acid. The colour is developed directly in the organic phase using Arsenazo I. The optical absorbance is measured at a wavelength of 600 nm. Possible interferences of accompanying elements can be eliminated by reduction with ascorbic acid and by screening with sodium fluoride. This method allows the determination of any uranium content, in the 20 to 200 μg range, of phosphate rocks containing up to 1 g (PO 4 ) 3-

Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

Directory of Open Access Journals (Sweden)

Qurban Ali Panhwar

2013-01-01

Full Text Available A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB and organic acids (oxalic & malic on phosphate (P solubilization from phosphate rock (PR and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM, and PSB strain (Bacillus sp. were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1, plant P uptake (0.78 P pot−1, and plant biomass (33.26 mg. Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1 compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

Application of hydrocyclone in no sliming of Itataia (CE) phosphatic rock

International Nuclear Information System (INIS)

Figueira, M.E.M.; Pereira, E.F.S.

1984-01-01

No sliming of Itataia-Ceara phosphatic rock was studied in hydrocyclone of 40mm diameter, in two atmospheres and with 5% of solids entire of the feed. Different openings of underflow and overflow of hydrocyclone were used. The best condition of no sliming was established in separation of 9,0 μm size, 80% of efficience and 48% of solids in the underflow. (M.A.C.) [pt

Phosphate rock formation and marine phosphorus geochemistry: the deep time perspective.

Science.gov (United States)

Filippelli, Gabriel M

2011-08-01

The role that phosphorite formation, the ultimate source rock for fertilizer phosphate reserves, plays in the marine phosphorus (P) cycle has long been debated. A shift has occurred from early models that evoked strikingly different oceanic P cycling during times of widespread phosphorite deposition to current thinking that phosphorite deposits may be lucky survivors of a series of inter-related tectonic, geochemical, sedimentological, and oceanic conditions. This paradigm shift has been facilitated by an awareness of the widespread nature of phosphogenesis-the formation of authigenic P-bearing minerals in marine sediments that contributes to phosphorite formation. This process occurs not just in continental margin sediments, but in deep sea oozes as well, and helps to clarify the driving forces behind phosphorite formation and links to marine P geochemistry. Two processes come into play to make phosphorite deposits: chemical dynamism and physical dynamism. Chemical dynamism involves the diagenetic release and subsequent concentration of P-bearing minerals particularly in horizons, controlled by a number of sedimentological and biogeochemical factors. Physical dynamism involves the reworking and sedimentary capping of P-rich sediments, which can either concentrate the relatively heavy and insoluble disseminated P-bearing minerals or provide an episodic change in sedimentology to concentrate chemically mobilized P. Both processes can result from along-margin current dynamics and/or sea level variations. Interestingly, net P accumulation rates are highest (i.e., the P removal pump is most efficient) when phosphorites are not forming. Both physical and chemical pathways involve processes not dominant in deep sea environments and in fact not often coincide in space and time even on continental margins, contributing to the rarity of high-quality phosphorite deposits and the limitation of phosphate rock reserves. This limitation is becoming critical, as the human demand

Comparative efficiency of high (trip super phosphate) and low (rock phosphate) grade p nutrition source enriched with organic amendment in maize crop

International Nuclear Information System (INIS)

Sabah, N.U.; Sarwar, G.; Tahir, M.A.

2016-01-01

Pakistan falls under arid to semi-arid climate and therefore, Pakistani soils are sufferer of phosphorus deficiency. Costly phosphatic commercial fertilizers and their unavailability at the time of crop demand is the burning issue in Pakistan. Under such circumstances, use of locally available rock phosphate (RP) grasps the interest of researchers now a day. Pakistan has blessed with considerable quantity of cheaper low grade RP in Abbottabad and Hazara districts of KPK province. Due to this scenario, a pot experiment was carried out to evaluate growth efficiency of maize crop by adding organic manure fortified with RP in comparison with TSP in normal soil (pHs= 8.15, ECe= 1.28 dSm-1, SAR = 4.77 mmol L-1, saturation percentage = 29% and sandy clay loam texture). The study was comprised of 7 treatments replicated three times including: T1 = Control (0 P); T2 = Recommended NK + organic material; T3 = Recommended NK + RRP; T4 = Recommended NK + RRP + OM; T5 = Recommended NK + TSP; T6 = Recommended NK + TSP + OM and T7 = N + K + TSP + 0.5 Organic manure. It was concluded that integrated use of organic amendment with RP (Local Hazara Red Rock Phosphate) and TSP proved superior as compared to their sole use on maize crop growth. A significant increase in available P concentration of the growth medium was observed due to addition of organic material along with TSP as a source of P. Addition of organic material also enhanced the soil carbon level as compared to control. It can be concluded that rock phosphate (RP) could be an effective and economic substitution for TSP when it is integrated with suitable organic amendment with specific size. (author)

Use of phosphate rocks for sustainable agriculture

International Nuclear Information System (INIS)

Zapata, F.; Roy, R.N.

2004-01-01

This publication deals with the direct application of phosphate rock (PR) sources to agriculture. Phosphorus (P) is an essential plant nutrient and its deficiency restricts crop yields severely. Tropical and subtropical soils are predominantly acidic, and often extremely P deficient with high P-sorption (fixation) capacities. Therefore, substantial P inputs are required for optimum plant growth and adequate food and fibre production. Manufactured water-soluble P fertilizers such as superphosphates are commonly recommended to correct P deficiencies, but most developing countries import these fertilizers, which are often in limited supply and represent a major outlay for resource-poor farmers. In addition, intensification of agricultural production in these countries necessitates the addition of P not only to increase crop production but also to improve soil P status in order to avoid further soil degradation. Hence, it is imperative to explore alternative P sources. Under certain soil and climate conditions, the direct application of PR, especially where available locally, has proved to be an agronomically and economically sound alternative to the more expensive superphosphates. PR deposits occur worldwide, but few are mined (for use mainly as raw materials to manufacture water-soluble P fertilizers). The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture initiated a Coordinated Research Project called 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilizers, in particular rock phosphates'. This was implemented by institutes of developing and industrialized countries from 1993 to 1998. The results obtained yielded new information on: chemistry of soil P; tests for available soil P; phosphate nutrition of crops; agronomic effectiveness of PR products; and P fertilizer recommendations with particular emphasis on PR use. Within the framework of the integrated plant nutrition systems promoted by

Evaluation of raw rock phosphate as substitute for bone meal in diet ...

African Journals Online (AJOL)

Experiment was conducted to determine the optimal replacement level of Raw Rock Phosphate (RRP) for bone meal in layers diet. A total of 144, 55 week-old shavers X Hubbard cross-strain laying hens were used for the study. Triplicate groups of 12 hens per replicate were placed on four test diets containing 0, 1, 1.5 and ...

Evaluation of natural radioactivity and heavy metals content in Sudanese phosphate rocks used as low cost fertilizer

International Nuclear Information System (INIS)

Elkhangi, F.A.; Aamhed, M.M.O.; Abdalla, I.A.

1997-01-01

This study was carried out to determine the level of natural radioactivity and heavy metals content of Sudanese rock phosphate used as low cost fertilizer. Thirty samples collected from two types of local phosphate rocks from the Nuba mountains (Uro and Kurun) were used in this study and the activity concentrations of natural radioactivity determined using gamma spectroscopy were compared to those found in samples of imported phosphorous fertilizers Single Super phosphate (SSP) and Triple Super phosphate (TSP). The results showed that the ' Ra activity concentration was 0.6 - 0.8 Bq/g for Uro and 0.3 - 0.5 Bq/g for Kurun. As for the most commonly used imported fertilizer TSP, the result was found to be greater than that of Uro (around 1.0 Bq/g). The heavy metals content of Uro and Kurun rocks measured using X-ray Fluorescence Technique showed their levels were below the toxic levels reported by Christina (1991). It is evident that the environmental hazard is comparable in the local and imported fertilizers and is acceptable in both cases by international standards. The determine factor therefore in optioning for the use of a local or an imported brand should then be the fertilizing efficiency of the brand used against other economic consideration rather than the fertilizers environmental impact

The transport characteristics of "2"3"8U, "2"3"2Th, "2"2"6Ra, and "4"0K in the production cycle of phosphate rock

International Nuclear Information System (INIS)

Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja

2017-01-01

Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing

Direct use of phosphate rock to improve crop production in Indonesia

International Nuclear Information System (INIS)

Sisworo, E.L.; Rasjid, H.; Sisworo, W.H.; Haryanto; Idris, K.

2002-01-01

In Indonesia most of the areas left for producing crops have soils such as Ultisols and Oxisols that are highly weathered, acid and of low fertility. One of the main constraints is their low available P to support food crop production. P inputs such as inorganic fertilizers, organic matter, and phosphate rock (PR) must be applied. Phosphate rock is one of the options for farmers to use as a P-source for food crops. In the frame of the coordinated research program three pot and five field experiments were conducted to determine the agronomic effectiveness of PR for food crops using 32 P isotopic techniques. Crops used in the pot experiments were lowland rice, soybean, and mungbean. One of the pot experiments was a crop rotation simulation where upland rice, soybean, and mungbean were grown in sequence. Two of the field experiments were a crop rotation of upland rice, soybean, and mungbean. In the field experiments, 32 P was used to determine the agronomic effectiveness, whenever possible. In general, the direct application of PR was able to increase plant growth in the pot experiments and crop production in the field experiments. Use of 32 P was a good tool to determine the agronomic effectiveness of PR in the pot and field experiments. (author)

Final report of the FAO/IAEA co-ordinated research project on the use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilisers, in particular rock phosphates

International Nuclear Information System (INIS)

Zapata, F.

1999-02-01

Soils in developing countries are often deficient in available P, and therefore require inputs of P fertiliser for optimum plant growth and production of food and fibre. Due to economic considerations, the cost of applying imported or locally produced water-soluble P fertilisers is often more expensive than utilising indigenous phosphate rock. Phosphate rocks show large differences in their suitability for direct application and several factors influence their capability to supply phosphorus to crops. Therefore, quantifying the P availability of soils amended with phosphate rocks in a variety of crop management and environmental conditions in developing countries is imperative for making recommendations on the best type and rate of P fertiliser sources for maximum agronomic and economic benefits. P-32 isotope techniques are very useful for such studies. The background situation of phosphate research and the topics to be investigated using isotope techniques were critically examined in a Consultants Meeting held at the IAEA Headquarters, Vienna, Austria, from 10 to 12 May 1993. For detailed information please refer to IAEA Report CT-1112. Based on the recommendations of this Consultants' Meeting, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the generous support of the French Government decided to implement the Co-ordinated Research Project (CRP) on 'The Use of Nuclear and Related Techniques for Evaluating the Agronomic Effectiveness of Phosphate Fertilisers, in particular Rock Phosphates'. This final report describes the Fourth and Final RCM of the CRP which was held in Vienna, 16-20 November 1998. It also contains a full description of the project and the conclusions and recommendations of the CRP. The programme of the meeting, list of participants, summaries submitted by the participants and list of publications are included as annexes

Final report of the FAO/IAEA co-ordinated research project on the use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphate fertilisers, in particular rock phosphates

Energy Technology Data Exchange (ETDEWEB)

Zapata, F

1999-02-01

Soils in developing countries are often deficient in available P, and therefore require inputs of P fertiliser for optimum plant growth and production of food and fibre. Due to economic considerations, the cost of applying imported or locally produced water-soluble P fertilisers is often more expensive than utilising indigenous phosphate rock. Phosphate rocks show large differences in their suitability for direct application and several factors influence their capability to supply phosphorus to crops. Therefore, quantifying the P availability of soils amended with phosphate rocks in a variety of crop management and environmental conditions in developing countries is imperative for making recommendations on the best type and rate of P fertiliser sources for maximum agronomic and economic benefits. P-32 isotope techniques are very useful for such studies. The background situation of phosphate research and the topics to be investigated using isotope techniques were critically examined in a Consultants Meeting held at the IAEA Headquarters, Vienna, Austria, from 10 to 12 May 1993. For detailed information please refer to IAEA Report CT-1112. Based on the recommendations of this Consultants' Meeting, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the generous support of the French Government decided to implement the Co-ordinated Research Project (CRP) on 'The Use of Nuclear and Related Techniques for Evaluating the Agronomic Effectiveness of Phosphate Fertilisers, in particular Rock Phosphates'. This final report describes the Fourth and Final RCM of the CRP which was held in Vienna, 16-20 November 1998. It also contains a full description of the project and the conclusions and recommendations of the CRP. The programme of the meeting, list of participants, summaries submitted by the participants and list of publications are included as annexes.

The Use of Ameliorant Fe3+ and Rock Phosphates in Peat Soil at Several Water Condition on the P Content of Plants Rice and Carbon Emission

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Nelvia

2009-09-01

Full Text Available The addition of ameliorant Fe3+ and rock phosphates containing high Fe cation can reduce effect of toxic organic acids, increase peat stability through formation of complex compounds and reduce carbon emission. The research was conducted in the laboratory and green house of the Departement of Soil Science, Faculty of Agriculture, Bogor Agriculture University. Peat samples with hemic degree of decomposition were taken from Riau. Rock phosphates were taken from the rock phosphates of PT. Petrokimia Gresik, Christmas Island phosphates, and Huinan China and FeCl3.6H2O was used as the other Fe3+ source. The aims of the research were to study (a the effect of the applications of ameliorant Fe3+ and rock phosphates on the P content of plants dan (b the effect of the application ameliorant Fe3+ and the contribution of Fe cation in rock phosphates in the decrease of carbon emission. The results showed that the P content of plants rice increased 58 – 286% with the applications of ameliorant Fe3+ and rock phosphates. The estimation of carbon loss through CO2 and CH4 emissions from peats if planted continuously with rice was around 2.5, 2.2 and 2.6 Mg of C ha-1 year-1 respectively in field capacity condition, two times of field capacity condition, and 5 cm of saturated condition. The application of ameliorant Fe3+ and rock phosphates containing high Fe cation increased the stability of peats and reduced the carbon loss around 1.7 Mg of C ha-1 year-1 (64% in 5 cm of saturated condition, 1.3 Mg of C ha-1 year-1 (58% in two times of field capacity condition, and 1.0 Mg of C ha-1 year-1 (41% in field capacity condition.

DETERMINATION OF RADIOACTIVITY IN MAIZE AND MUNG ...

African Journals Online (AJOL)

nb

The total annual effective dose for consumption of 226Ra and 228Th by adults ... through ore dust resulting from mining process. Therefore ... water. Agriculture, pastoralism and phosphate mining are the land uses development in Minjingu.

Effect of Azolla Based - Organic Fertilizer, Rock Phosphate and Rice Hull Ash on Rice Yield and Chemical Properties of Alfisols

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Sudadi

2014-07-01

Full Text Available The application of chemical fertilizer for long time may adverse soil environment. Organic agriculture, for example combination use of azolla based-organic fertilizer, phosphate rock and rice hull ash, was one of ways that able to recover it. Research was conducted in Sukosari, Jumantono, Karanganyar while soi chemical properties analysis was analysed in Soil Chemistry and Fertility Laboratory, Fac. of Agriculture, Sebelas Maret University April to November 2013. Research design used was RAKL with 5 treatments, each repeated 5 times. The treatments applied were P0 (control, P1 ( azola inoculum dosage 250 g/m2 + phosphate rock + rice hull ash equal to 150 kg/ha KCl, P2 (azola inoculum dosage 500 g/m2 + phosphate rock equal to 150kg/ha, SP-36 + rice hull ash equal to 100 kg/ha KCl, P3 (manure dosage of 5 ton/ha,P4 (Urea 250 kg/ha + SP-36 150 kg/ha + KCl 100 kg/ha. Data analysed statistically by F test (Fisher test with level of confident 95% followed by DMRT (Duncan Multiple Range Test if any significant differences. The result showed that the treatment combination of azolla, phosphate rock and rice hull ash increase soil organic matter content, cation exchange capacity, available-P and exchangeable-K as well as rice yield ( (at harvest-dry grain weight and milled-dry grain weight.

Application of nanoparticle of rock phosphate and biofertilizer in increasing some soil chemical characteristics of variable charge soil

Science.gov (United States)

Devnita, Rina; Joy, Benny; Arifin, Mahfud; Hudaya, Ridha; Oktaviani, Nurul

2018-02-01

Soils in Indonesia are dominated by variable charge soils where the technology like fertilization did not give the same result as the soils with permanent charge. The objectives of this research is to increase some chemical characteristic of variable charge soils by using the high negative charge ameliorations like rock phosphate in nanoparticle combined with biofertilizer. The research used a complete randomized experimental design in factorial with two factors. The first factor was nanoparticle of rock phosphate consists of four doses on soil weight percentage (0%, 2.5%, 5.0% and 7.5%). The second factor was biofertilizer consisted of two doses (without biofertilizer and 1 g.kg-1 soil biofertilizer). The combination treatments replicated three times. Variable charge soil used was Andisol. Andisol and the treatments were incubated for 4 months. Soil samples were taken after one and four months during incubation period to be analyzed for P-retention, available P and potential P. The result showed that all combinations of rock phosphate and biofertilizer decreased the P-retention to 75-77% after one month. Independently, application of 7.5% of rock phosphate decreased P-retention to 87.22% after four months, increased available P (245.37 and 19.12 mg.kg-1) and potential P (1354.78 and 3000.99 mg/100) after one and four months. Independently, biofertilizer increased the P-retention to 91.66% after four months, decreased available P to 121.55 mg.kg-1 after one month but increased to 12.55 mg.kg-1 after four months, decreased potential P to 635.30 after one month but increased to 1810.40 mg.100 g-1 after four months.

Direct use of phosphate rock to improve crop production in Indonesia

Energy Technology Data Exchange (ETDEWEB)

Sisworo, E L; Rasjid, H; Sisworo, W H; Haryanto, [Batan, Center for the application of isotopes and radiation, Jakarta (Indonesia); Idris, K [Bogor Agriculture Institute, Bogor (Indonesia)

2002-02-01

In Indonesia most of the areas left for producing crops have soils such as Ultisols and Oxisols that are highly weathered, acid and of low fertility. One of the main constraints is their low available P to support food crop production. P inputs such as inorganic fertilizers, organic matter, and phosphate rock (PR) must be applied. Phosphate rock is one of the options for farmers to use as a P-source for food crops. In the frame of the coordinated research program three pot and five field experiments were conducted to determine the agronomic effectiveness of PR for food crops using {sup 32}P isotopic techniques. Crops used in the pot experiments were lowland rice, soybean, and mungbean. One of the pot experiments was a crop rotation simulation where upland rice, soybean, and mungbean were grown in sequence. Two of the field experiments were a crop rotation of upland rice, soybean, and mungbean. In the field experiments, {sup 32}P was used to determine the agronomic effectiveness, whenever possible. In general, the direct application of PR was able to increase plant growth in the pot experiments and crop production in the field experiments. Use of {sup 32}P was a good tool to determine the agronomic effectiveness of PR in the pot and field experiments. (author)

Tanzania Journal of Science - Vol 40, No 1 (2014)

African Journals Online (AJOL)

Determination of radioactivity in maize and mung beans grown in the neighborhood of Minjingu phosphate mine, Tanzania · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Leonid L Nkuba, Najat K Mohammed, 51-59 ...

Plant- and microbial-based mechanisms to improve the agronomic effectiveness of phosphate rock: a review

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Melissa M. Arcand

2006-12-01

Full Text Available Deficiency in plant-available phosphorus is considered to be a major limiting factor to food production in many agricultural soils. Mineral resources are necessary to restore soil phosphorus content. In regions where conventional fertilizers are not used due to cost limitations or to mitigate adverse environmental effects, local sources of phosphate rock are being increasingly recognized for potential use as alternative phosphorus fertilizers. The main obstacle associated with using directly applied ground phosphate rock is that the phosphate released is often unable to supply sufficient plant-available phosphorus for crop uptake. Plantand microbial-based mechanisms are low-cost, appropriate technologies to enhance the solubilization and increase the agronomic effectiveness of phosphate rock. Common mechanisms of phosphate rock dissolution including proton and organic acid production will be reviewed for both plants and microorganisms. This review will also address possibilities for future research directions and applications to agriculture, as well as highlight ongoing research at the University of Guelph, Guelph, Canada.A deficiência de fósforo disponível nas plantas é considerada o maior fator de limitação na produção de alimentos em diversos solos agrícolas. São necessários recursos minerais para restaurar o conteúdo de fósforo no solo. Em regiões onde fertilizantes convencionais nãosão utilizados devido às limitações de custo ou de seus efeitos ambientais adversos, fontes locais de rocha fosfática estão sendo crescentemente reconhecidas por seu uso potencial como alternativa aos fertilizantes solúveis de fósforo. O principal obstáculo associado ao uso daaplicação direta da rocha fosfática no solo é que o fósforo liberado é, muitas vezes, incapaz de suprir as necessidades das plantas de forma a aumentar a produção. Mecanismos baseados no uso de plantas e micro-organismos são consideradas tecnologias

A study of accumulation of trace metals in coffee plants grown on ultisols fertilized with rock phosphates by energy dispersive x-ray fluorescence (EDXRF) technique

International Nuclear Information System (INIS)

Joseph, Daisy; Lal, Madan; D'Souza, T.J.

1995-01-01

Trace elements in soil and leaves of coffee plants have been analysed by a non-destructive Energy Dispersive X-ray Fluorescence (EDXRF) technique to study their accumulation due to repeated rock phosphate fertilization. Analysis of standard reference materials of soil and leaves through EDXRF yielded values within 5% error of the certified values. This method was therefore used to determine the trace metals (Fe, Cu, Zn, Rb, Sr, Nb, Zr and Y) concentrations of soils, rock phosphates and leaves of coffee grown in experimental ultisols. Results indicate that rock phosphate fertilization over a period of 10 years did not contribute significantly to high trace metal concentration in plants. (author). 6 refs., 5 tabs., 5 figs

Availability of rock phosphate with low P content in some Albanian soil: use of 32PO4

International Nuclear Information System (INIS)

Fardeau, J.C.; Migadel, F.; Gjermani, A.; Malja, S.

1983-10-01

The availability of a calcareous low P content rock phosphate (4,3% P) was measured. This Albanian ore was used, in pot experiments, on various local soils whose the pH is situated between 4,9 to 7,5. This phosphate was labelled with 32 P and 45 Ca in a reactor. The residual effect of this fertilizer was deduced from the results of isotopic dilution kinetic of phosphate ions realized in soil-solution systemes. The main results can be summarized as follow: 1. When the soil-water pH was higher than 6,1, the utilization coefficient of phosphorus was minus than 1%, even with 5,5 mounths. 2. The ratio of P and Ca derived from fertilizer and taken up by the crop is most generally different of those measured in the fertilizer. It depends of the soil constitution. 3. The analysis of isotopic dilution kinetic of phosphate ions shows that in the major part of these soils, whose the fixing capacity is very high, the rock phosphate and also superphosphate at 230 kg P 2 O 5 .ha -1 rate does not increase available soil phosphorus; it is only with rates over 800 kg P 2 O 5 .ha -1 that this objective can be reached. These results explain again that the fixing capacity of soil for phosphorus is a characteristic more useful for fertilization technique than the available phosphorus quantity [fr

Direct determination of 52 impurities content of phosphate rocks by spectroscopic method

International Nuclear Information System (INIS)

Harel, A.

1977-01-01

A direct method for the determination of 52 impurities content of phosphate rocks by dc-arc with the exposure of the cathode region only (0.5 and 0.8 mm below the upper electrode of the arc) instead of the entire arc is described. This method was applied to 31 elements in the 0.5 mm region and to Sc, Y, U, Th, and the rare earths in the 0.8 mm region. Great efforts were made at selecting the proper standard. The physico-chemical identity between the sample and the standard proved conditional on certain factors. Calcium meta phosphate with 20% graphite constituted a standard composition that was identical to the mineral material after suitable treatment. The identity between the standard and the sample was inferred from the temperature, electron density, evaporation rate and line intensity parameters

Weathering Profiles in Phosphorus-Rich Rocks at Gusev Crater, Mars, Suggest Dissolution of Phosphate Minerals into Potentially Habitable Near-Neutral Waters.

Science.gov (United States)

Adcock, Christopher T; Hausrath, Elisabeth M

2015-12-01

Abundant evidence indicates that significant surface and near-surface liquid water has existed on Mars in the past. Evaluating the potential for habitable environments on Mars requires an understanding of the chemical and physical conditions that prevailed in such aqueous environments. Among the geological features that may hold evidence of past environmental conditions on Mars are weathering profiles, such as those in the phosphorus-rich Wishstone-class rocks in Gusev Crater. The weathering profiles in these rocks indicate that a Ca-phosphate mineral has been lost during past aqueous interactions. The high phosphorus content of these rocks and potential release of phosphorus during aqueous interactions also make them of astrobiological interest, as phosphorus is among the elements required for all known life. In this work, we used Mars mission data, laboratory-derived kinetic and thermodynamic data, and data from terrestrial analogues, including phosphorus-rich basalts from Idaho, to model a conceptualized Wishstone-class rock using the reactive transport code CrunchFlow. Modeling results most consistent with the weathering profiles in Wishstone-class rocks suggest a combination of chemical and physical erosion and past aqueous interactions with near-neutral waters. The modeling results also indicate that multiple Ca-phosphate minerals are likely in Wishstone-class rocks, consistent with observations of martian meteorites. These findings suggest that Gusev Crater experienced a near-neutral phosphate-bearing aqueous environment that may have been conducive to life on Mars in the past. Mars-Gusev Crater-Wishstone-Reactive transport modeling-CrunchFlow-Aqueous interactions-Neutral pH-Habitability.

Physico-chemical characterization of Ogun and Sokoto phosphate ...

African Journals Online (AJOL)

Gypsum, calcite and lime were associated with both rock phosphates indicating their liming potential in the soil. ORP was more soluble in water, probably because it ... fertilizers and direct application in crop production. Keywords: Phosphorus, apatite, crop production, fertilizer, Ogun rock phosphate, Sokoto rock phosphate ...

Spectroscopic techniques for assessing the possible use of phosphate rock by-products for the removal of trace elements in soils.

Science.gov (United States)

Martinez-Sanchez, M. J.; Perez-Sirvent, C.; Garcia-Lorenzo, M. L.; Bech, J.; Hernandez-Cordoba, M.

2012-04-01

The production of fertilizers from apatite results in the obtention of considerable amounts of phosphate rock byproducts, representing a serious environmental problem. In addition, soil contamination with heavy metals due to mining or metallurgical activities is a severe environmental problem, increased when soil use is changed to agricultural or urban uses. The aim of this work was to study the possibility of using phosphate rock byproducts for the in situ treatment of soils polluted by heavy metals, allowing to revalorise phosphate rock residues and at the same time, providing a low-cost solution for the contaminated soil. The following methodologies were applied in order to characterise minerals phases present in phosphate rock residues: Wavelength Dispersive X-Ray Spectrometry (WDXRF), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectrometry (EDS), thermogravimetry (TG) and Fourier Transform Infrared Spectroscopy (FTIR). The results obtained showed that the samples studied had a fine texture, showing average contents of 71%, 24% of sand and 5% for silt, sand and clay, respectivaly. In addition, these materials showed basic-neutral pH values (7.5-9) and a cationic interchange capacity of 20.4 meq/100g. Studied samples showed a 22% of carbonates and a 13% of apatite in their composition and all of them showed 4 bands at 1.100, 1.044, 674 y 576 cm-1, corresponding to P-O vibrations in PO4 groups. OH band vibrations appeared at 3.700-3.550 cm-1, and detected band at 3.400 cm-1 and 633 cm-1 could correspond to occluded water. On the other hand, detected bands at 1.460-1.430, 874 cm-1 suggested the presence of CaCO3 and carbonates in the apatite. After sample characterization, the performance of these residues to adsorb trace element ions (Cd+2 and Pb+2) from acidic aqueous solutions (simulating acidic mine drainage) was studied. The use of spectroscopic techniques after mixing soils and phosphate rock products demonstrate that these residues could be

Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

International Nuclear Information System (INIS)

Zapata, F.

2000-01-01

An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and 32 P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The 32 P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The 32 P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations for PR

Application of multivariate statistical analyses in the interpretation of geochemical behaviour of uranium in phosphatic rocks in the Red Sea, Nile Valley and Western Desert, Egypt

International Nuclear Information System (INIS)

El-Arabi, A.M.Abd El-Gabar M.; Khalifa, Ibrahim H.

2002-01-01

Factor and cluster analyses as well as the Pearson correlation coefficient have been applied to geochemical data obtained from phosphorite and phosphatic rocks of Duwi Formation exposed at the Red Sea coast, Nile Valley and Western Desert. Sixty-six samples from a total of 71 collected samples were analysed for SiO 2 , TiO 2 , Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O, K 2 O, P 2 O 5 , Sr, U and Pb by XRF and their mineral constituents were determined by the use of XRD techniques. In addition, the natural radioactivity of the phosphatic samples due to their uranium, thorium and potassium contents was measured by gamma-spectrometry.The uranium content in the phosphate rocks with P 2 O 5 >15% (average of 106.6 ppm) is higher than in rocks with P 2 O 5 2 O 5 and CaO, whereas it is not related to changes in SiO 2 , TiO 2 , Al 2 O 3 , Fe 2 O 3 , MgO, Na 2 O and K 2 O concentrations.Factor analysis and the Pearson correlation coefficient revealed that uranium behaves geochemically in different ways in the phosphatic sediments and phosphorites in the Red Sea, Nile Valley and Western Desert. In the Red Sea and Western Desert phosphorites, uranium occurs mainly in oxidized U 6+ state where it seems to be fixed by the phosphate ion, forming secondary uranium phosphate minerals such as phosphuranylite.In the Nile Valley phosphorites, ionic substitution of Ca 2+ by U 4+ is the main controlling factor in the concentration of uranium in phosphate rocks. Moreover, fixation of U 6+ by phosphate ion and adsorption of uranium on phosphate minerals play subordinate roles

Mineral phosphate solubilizing bacterial community in agro-ecosystem

African Journals Online (AJOL)

STORAGESEVER

2009-12-15

Dec 15, 2009 ... patterns. Four insoluble phosphate sources; purulia rock phosphate (PRP), mussourie rock phosphate. (MRP) ... community composition analysis (Garland, 1996a) and ..... the threshold level that enabled only a few species to.

Looming Scarcity of Phosphate Rock and Intensification of Soil Phosphorus Research

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Philippe C. Baveye

2015-06-01

Full Text Available In recent years, many researchers have claimed that world reserves of rock phosphate were getting depleted at an alarming rate, putting us on the path to scarcity of that essential resource within the next few decades. Others have claimed that such alarmist forecasts were frequent in the past and have always been proven unfounded, making it likely that the same will be true in the future. Both viewpoints are directly relevant to the level of funding devoted to research on the use of phosphate fertilizers. In this short essay, it is argued that information about future reserves of P or any other resource are impossible to predict, and therefore that the threat of a possible depletion of P reserves should not be used as a key motivation for an intensification of research on soil P. However, there are other, more compelling reasons, both geopolitical and environmental, to urgently step up our collective efforts to devise agricultural practices that make better use of P than is the case at the moment.

Solubilização dos fosfatos naturais Patos de Minas e Arad em dois solos alagados Solubilization of Patos de Minas and Arad rock phosphate in two flooded soils

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Gustavo Krüger Gonçalves

2008-10-01

Full Text Available Na cultura do arroz irrigado, não foram observadas diferenças significativas no rendimento de grãos em experimentos de campo que confrontaram fontes solúveis e fosfatos naturais como fontes de P. No entanto, as alterações químicas que ocorrem durante o alagamento, principalmente aumento do pH e dos teores de P e Ca na solução do solo, provavelmente dificultam a dissolução de fosfatos naturais. O objetivo deste trabalho foi avaliar a solubilização dos fosfatos naturais de Patos de Minas e de Arad em dois solos alagados. Foram realizados dois experimentos, delineados em blocos ao acaso, com quatro repetições, em tipos de solos diferentes (Planossolo e Cambissolo. Foram testadas fontes de P: (a testemunha, sem P; (b superfosfato triplo; (c fosfato de Patos de Minas; e (d fosfato de Arad. Na solução do solo, foram avaliados os valores de pH e os teores de Fe, Mn, Ca, e P durante 88 dias de alagamento. O pH e os teores de Fe e Mn na solução do Planossolo e do Cambissolo não foram influenciados pela adição de superfosfato triplo e pelos fosfatos naturais de Arad e de Patos. Os teores de P na solução dos solos foram maiores com superfosfato triplo do que com os fosfatos naturais, indicando maior solubilização do primeiro durante o alagamento. Entre os fosfatos naturais, o de Arad apresentou maior solubilização do que o de Patos apenas no Planossolo.Differences in grain yield were not observed in experiments with paddy rice when comparing soluble phosphates and rock phosphate as phosphorus sources. However, chemical changes in flooded soils such as increases in pH and phosphorus and calcium levels in the soil solution probably decrease the dissolution of rock phosphates in flooded soils. The current work was therefore carried out with the objective of studying the solubilization of phosphate rocks in flooded soils. Two experiments, conducted in a random block design with four replications, were set up in two soil types

Release of radium and other decay-series isotopes from Florida phosphate rock. Final report

International Nuclear Information System (INIS)

Burnett, W.C.; Chin, P.; Deetae, S.; Panik, P.

1988-01-01

The purpose of this research was to determine the conditions under which uranium decay-series isotopes are released from phosphate rock into the environment. Particular attention was given to the behavior of radium, radon, and polonium. The emphasis was justified because of several documented cases citing elevated concentrations of these radioelements occurring in Florida ground waters. When it became clear that polonium was occasionally present at exceedingly high concentrations in shallow ground waters, the scope of the project was expanded to include a study of the distribution of Po-210 in the surficial aquifer of west central Florida. Studies of a series of phosphate rock samples representing various degrees of chemical weathering show that almost all uranium-series radionuclides display higher activities in weathered samples compared to fresh material. Most samples display a Pb-210/Ra-226 activity ratio less than secular equilibrium because of Rn-222 leakage. An unexpected result was the deficiency of Po-210, relative to Pb-210 in several samples. This implies that polonium, under certain conditions, may be more mobile than lead. Many wells in central Florida contain high concentrations of Po-210. Characteristics which high-polonium groundwaters have in common include low pH, presence of sulfide, and at least moderately high radon

Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil

International Nuclear Information System (INIS)

Chen, G.C.; He, Z.L.; Stoffella, P.J.; Yang, X.E.; Yu, S.; Calvert, D.

2006-01-01

There is increasing concern over P leaching from sandy soils applied with water-soluble P fertilizers. Laboratory column leaching experiments were conducted to evaluate P leaching from a typical acidic sandy soil in Florida amended with DPR fertilizers developed from dolomite phosphate rock (DPR) and N-Viro soil. Ten leaching events were carried out at an interval of 7 days, with a total leaching volume of 1183 mm equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachates were collected and analyzed for total P and inorganic P. Phosphorus in the leachate was dominantly reactive, accounting for 67.7-99.9% of total P leached. Phosphorus leaching loss mainly occurred in the first three leaching events, accounting for 62.0-98.8% of the total P leached over the whole period. The percentage of P leached (in the total P added) from the soil amended with water-soluble P fertilizer was higher than those receiving the DPR fertilizers. The former was up to 96.6%, whereas the latter ranged from 0.3% to 3.8%. These results indicate that the use of N-Viro-based DPR fertilizers can reduce P leaching from sandy soils. - Fertilizers developed from dolomite phosphate rock (DPR) reduce phosphorus leaching from sandy soil

Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

Energy Technology Data Exchange (ETDEWEB)

Zapata, F [International Atomic Energy Agency, Vienna (Austria)

2000-06-01

An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and {sup 32}P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The {sup 32}P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The {sup 32}P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations

Availability of rock phosphate with low P content in some Albanian soil: use of /sup 32/PO/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Fardeau, J C; Migadel, F; Gjermani, A; Malja, S

1983-10-01

The availability of a calcareous low P content rock phosphate (4,3% P) was measured. This Albanian ore was used, in pot experiments, on various local soils whose pH is situated between 4,9 to 7,5. This phosphate was labelled with /sup 32/P and /sup 45/Ca in a reactor. The residual effect of this fertilizer was deduced from the results of isotopic dilution kinetics of phosphate ions realized in soil-solution systems. The main results can be summarized as follows: 1. When the soil-water pH was higher than 6,1, the utilization coefficient of phosphorus was minus than 1%, even with 5,5 months. 2. The ratio of P and Ca derived from fertilizer and taken up by the crop is most generally different of those measured in the fertilizer. It depends on the soil constitution. 3. The analysis of isotopic dilution kinetics of phosphate ions shows that in the major part of these soils, whose fixing capacity is very high, the rock phosphate and also superphosphate at 230 kg P/sub 2/O/sub 5/.ha/sup -1/ rate does not increase available soil phosphorus; it is only with rates over 800 kg P/sub 2/O/sub 5/.ha/sup -1/ that this objective can be reached. These results explain again that the fixing capacity of soil for phosphorus is a characteristic more useful for fertilization technique than the available phosphorus quantity.

Analyses of uranium in some phosphate commercial products

International Nuclear Information System (INIS)

Kamel, N.H.M.; Sohsah, M.; Mohammad, H.M.; Sadek, M.

2005-01-01

The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public

Uranium in phosphate rocks and future nuclear power fleets

International Nuclear Information System (INIS)

Gabriel, S.; Baschwitz, A.; Mathonniere, G.

2014-01-01

phosphoric acid. Uranium recovery as a by-product of phosphate rocks could be competitive for the moment, but limited at the most to 10 kt U per year, i.e. less than 20% of current world demand. The only way to lift the constraint of capacity production is to produce uranium as a primary product of phosphates. Unfortunately, this solution is very unlikely due to its high unit cost. In line with these considerations, the correspondence between the estimated resources and the forecast energy scenarios is examined, first with the current type of light water reactors which burn uranium, and secondly with a mixed fleet with both light water reactors and fast reactors which use plutonium. (author)

Prevention of radioactive contamination in the manufacture of phosphate fertilizers

International Nuclear Information System (INIS)

Romero G, E.T.

1995-01-01

In this work was studied the separation of uranium from the phosphate rock to decrease the level of radioactivity in the phosphate fertilizers, this prevents the redistribution of uranium in the environment. The uranium leaching conditions from phosphate rock were estimated using alkaline solutions. The changes in the natural phosphate rock after leaching were studied. The amenability to separate the uranium from phosphate rock with ammonium carbonate / bicarbonate solution was determined. The uranium extraction was approximately 40%. The leaching conditions showed high selectivity for uranium without changes in the ore structure. The bulk ore was not dissolved. (Author)

In vitro DISSOLUTION OF ACIDULATED ROCK PHOSPHATE BY PHOSPHATE SOLUBILIZING MICROORGANISMS

Directory of Open Access Journals (Sweden)

Ángela Patricia Moreno Quevedo

2015-05-01

Full Text Available The low availability of phosphorus (P in the soil and the high cost of P fertilization are factors that limit agricultural productivity. A biotechnological alternative for to handle this problem is to use soil microorganisms capable of dissolving rock phosphate (RP, thus improving its effectiveness as a P fertilizer. This study was carried out with the objective of determining the effectiveness of Aspergillus niger –As-, Penicillium sp. –Pn-, Bacillus sp –B-. and an unidentified actinomycete –At- in the in vitro dissolution of two partially acidulated rock phosphates. The treatments consisted of 2x16 factorial arrangement [2 levels of RP: either Boyaca RP or Norte de Santander RP; 16 levels of inoculum: an uninoculated control, individual inoculations (with As, Pn, B, At, dual inoculations (AsPn, AsB, AsAt, PnB, PnAt, BAt, triple inoculations (AsPnB, AsPnAt, AsBAt, PnBAt, and quadruple inoculation (AsPnBAt]. Each treatment was replicated three times. Each treatment was replicated three times. It was found that the microbial effectiveness in the in vitro dissolution of RP depended on the type of RP, the composition of the inoculum used and the interaction of both factors. The best results were obtained with the Norte de Santander RP and A. niger used alone. When this fungus combined with the other microorganisms, its capacity to dissolve RP was significantly reduced. RESUMEN La baja disponibilidad de fósforo (P en el suelo y el costo de la fertilización fosfórica son limitantes para la productividad agrícola. Una alternativa biotecnológica para manejar este problema es mediante el uso de microorganismos del suelo capaces de disolver rocas fosfóricas (RP y así mejorar su efectividad como fertilizante fosfórico. Con este fin se realizó un ensayo para determinar la efectividad microbial en la disolución in vitro de dos RP (Norte de Santander y Boyacá parcialmente aciduladas. Los tratamientos consistieron en un arreglo factorial 2x

Determination of radioactivity in maize and mung beans grown in ...

African Journals Online (AJOL)

Two staple foods (maize and mung beans) which were cultivated in Minjingu village, where there is phosphate deposit in Tanzania, were collected directly from the farms. The activity concentrations of 226Ra, 228Th and 40K were determined in the maize and mung beans samples using γ ray spectrometry employing HPGe ...

Studies in the preparation of /sup 32/P labelled compounds from high grade rock phosphate with high fluorine content. [Water soluble P/sub 2/O/sub 5/, acidulation, curing

Energy Technology Data Exchange (ETDEWEB)

Murthy, T S; Cherian, S; Shivarudrappa, V; Subramanian, T K; Achari, P S [Bhabha Atomic Research Centre, Bombay (India). Primary Isotopes Section

1981-01-01

The labelled phosphate to be used for crop evaluation studies should have characteristics exactly similar to the industrial product employed in agriculture. For the preparation of /sup 32/P labelled compound from rock phosphate with high fluorine content, a number of parameters have been studied like particle size of the rock, temperature and amount of acid required, the curing time, etc. Because of the high reaction temperature, the curing time is reduced to experimental limits compared to the commercial product. This paper describes a method for the preparation of such a labelled phosphate and this yields a product with about 95% of the phosphate in the water soluble form.

[Effects of Phosphate Rock and Decomposed Rice Straw Application on Lead Immobilization in a Contaminated Soil].

Science.gov (United States)

Tang, Fan; Hu, Hong-qing; Su, Xiao-juan; Fu, Qing-ling; Zhu, Jun

2015-08-01

The soils treated with phosphate rock (PR) and oxalic acid activated phosphate rock (APR) mixed with decomposed rice straw were incubated in different moisture conditions for 60 days to study the effect on the basic property of the soil and on the speciation variation of Pb. The results showed that all these three types of immobilizing materials increased the pH, the Olsen-P, the exchangeable Ca and the soil cation exchange capacity, and APR showed more obvious effect; the pH and the exchangeable Ca of soil in the flooding treatment were higher than those in normal water treatment (70%), but the Olsen-P of soil in normal water treatment was a little bit more. These materials reduced exchangeable Ph fraction, and converted it into unavailable fraction. But the APR was better than raw PR in immobilizing lead, and the exchangeable Pb fraction was reduced by 40.3% and 24.2%, compared with the control, respectively, and the immobilization effect was positively correlated with the dosage. Decomposed rice straw could transform the exchangeable Ph fraction in soil into organic-bound fraction, while the flooding treatment changed it into the Fe-Mn oxide-bound and residue fractions.

effect of two rock phosphates and inoculation with VA mycorrhizae and phosphate solubilizing bacteria on the chickpea-rhizobium symbiosis

International Nuclear Information System (INIS)

Soliman, S.M.; Galal, Y.G.M.; El-Ghandour, I.A.

2004-01-01

A pot experiment was conducted tracing the effect of two types of phosphorus applied at different rates on the release of nitrogen from fertilizer and its impact on biological nitrogen fixation . chickpea (Cicer Arietinum c v. Cicer 36-ICARDA) was inoculated with peat-based inoculum of phosphorin (Bacillus Megatherium phosphate solubilizing bacteria), Mycorrhizae (VAM) and a mixture of phosphorin and VAM. three types of P fertilizer, i.e.superphosphate, rock P 1 (Safaga) and rock P2 (Abou-Trtour) were applied at rate of 25 and 50 mg Pkg -1 soil in the presence or absence of inoculum. labelled ammonium sulfate with 15 N 10% atom excess was applied at rates of 15 and 30 mg N kg -1 soil for chickpea and barley (reference crop) respectively . Addition of phosphorus fertilizers, especially at the high rates, positively affected the growth and dry weight as compared to the unfertilized control. infections with VAM mixed with phosphorin under low level of rock P (Abou-tarour) gave the highest values of dry weight and N and P uptake when compared with both superphosphate-P source and control. biological N 2 fixed was higher in dual inoculation treatments (i.e.phosphorin +VAM) than those receiving a single inoculum. the percentages of N 2 -fixed ranged from 24 to 53 according to inoculation treatments, P sources and levels

Detailed effects of particle size and surface area on 222Rn emanation of a phosphate rock.

Science.gov (United States)

Haquin, Gustavo; Yungrais, Zohar; Ilzycer, Danielle; Zafrir, Hovav; Weisbrod, Noam

2017-12-01

The dependency of radon emanation on soil texture was investigated using the closed chamber method. Ground phosphate rock with a large specific surface area was analyzed, and the presence of inner pores, as well as a high degree of roughness and heterogeneity in the phosphate particles, was found. The average radon emanation of the dry phosphate was 0.145 ± 0.016. The emanation coefficient was highest (0.169 ± 0.019) for the smallest particles (210 μm). The reduction rate followed an inverse power law. As expected, a linear dependence between the emanation coefficient and the specific surface area was found, being lower than predicted for the large specific surface area. This was most likely due to an increase in the embedding effect of radon atoms in adjacent grains separated by micropores. Results indicate that knowledge of grain radium distribution is crucial to making accurate emanation predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trace elements in rock phosphates and P containing mineral and organo-mineral fertilizers sold in Germany

Energy Technology Data Exchange (ETDEWEB)

Kratz, Sylvia, E-mail: sylvia.kratz@jki.bund.de; Schick, Judith; Schnug, Ewald

2016-01-15

68 rock phosphates and 162 P containing (organo-)mineral fertilizers sold in Germany were evaluated with regard to trace element contents. While Al, As, B, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, U, and Zn were higher in sedimentary than in igneous rock phosphates, the opposite was true for Co, Cu, Sn, Mn, Ti, Fe, and Sr. Comparing element concentrations to the currently valid legal limit values defined by the German Fertilizer Ordinance, it was found that some PK and many straight P fertilizers (superphosphate, triple superphosphate, partly acidulated rock phosphates) exceeded the limit of 50 mg Cd/kg P{sub 2}O{sub 5}. Mean values for As, Ni, Pb, and Tl remained below legal limits in almost all cases. While no legal limit has been defined for U in Germany yet, the limit of 50 mg U/kg P{sub 2}O{sub 5} for P containing fertilizers proposed by the German Commission for the Protection of Soils was clearly exceeded by mean values for all fertilizer types analyzed. A large share of the samples evaluated in this work contained essential trace elements at high concentrations, with many of them not being declared as such. Furthermore, trace elements supplied with these fertilizers at a fertilization rate leveling P uptake would exceed trace element uptake by crops. This may become most relevant for B and Fe, since many crops are sensitive to an oversupply of B, and Fe loads exceeding plant uptake may immobilize P supplies for the crops by forming Fe phosphate salts. The sample set included two products made from thermochemically treated sewage sludge ash. The products displayed very high concentrations of Fe and Mn and exceeded the legal limit for Ni, emphasizing the necessity to continue research on heavy metal removal from recycled raw materials and the development of environmentally friendly and agriculturally efficient fertilizer products. - Highlights: • Mineral fertilizers (MF) sold in Germany often exceed legal limits for Cd • MF sold in Germany contain high

Field evaluation of partially acidulated phosphate rocks in a Ferralsol from Cuba

International Nuclear Information System (INIS)

Rodriguez, R.; Herrera, J.

2002-01-01

Phosphorus (P) is needed in large areas of developing countries to improve soil fertility for crop production. The use of phosphate rock (PR) is an alternative to costly soluble P fertilizers, but it is ineffective usually in non-acid soils unless it is modified i.e. partially acidulated (PAPR). A laboratory incubation study using the isotopic exchange kinetic method of 32 P and field experiments were undertaken on a neutral Ferralsol of Cuba to evaluate the effectiveness of PAPRs as fertilizers for common bean (Phaseolus vulgaris, L.). Sulfuric-acid based PAPR using 40%, 50% and 60% of the acid required to produce single superphosphate were studied. In the laboratory experiment Trinidad de Guedes PAPR was effective in providing P to the soil, through increases in isotopically exchangeable P and the percentage of P derived from fertilizer (% Pdff). In the three field experiments carried out to compare the P sources, yields of common bean were increased by PAPR, though the response was less than with triple superphosphate (TSP). The relative agronomic effectiveness (RAE) of PAPR was greater than that of unacidulated PR. Taking into account the RAE values and the current cost of the P sources, the choice of Trinidad de Guedes PAPR instead of TSP could be economic, although the RAE value for PAPR was lower than that of TSP. This result indicates that PAPR could be used in the soil understudy to obtain the best economic return. DM yield, P uptake and grain yield of common bean were significantly increased by applying P as 50% PAPR. Low cost improvement of the agronomic value of PR can be achieved by partial acidulation, so this modification of the phosphate rock show promise for utilization of PR reserves indigenous to developing countries. (author)

Field evaluation of partially acidulated phosphate rocks in a Ferralsol from Cuba

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, R.; Herrera, J. [Ciego de Avila University, Ciego de Avila (Cuba)]. E-mail: herrera@uctr.unica.cu

2002-05-15

Phosphorus (P) is needed in large areas of developing countries to improve soil fertility for crop production. The use of phosphate rock (PR) is an alternative to costly soluble P fertilizers, but it is ineffective usually in non-acid soils unless it is modified i.e. partially acidulated (PAPR). A laboratory incubation study using the isotopic exchange kinetic method of {sup 32}P and field experiments were undertaken on a neutral Ferralsol of Cuba to evaluate the effectiveness of PAPRs as fertilizers for common bean (Phaseolus vulgaris, L.). Sulfuric-acid based PAPR using 40%, 50% and 60% of the acid required to produce single superphosphate were studied. In the laboratory experiment Trinidad de Guedes PAPR was effective in providing P to the soil, through increases in isotopically exchangeable P and the percentage of P derived from fertilizer (% Pdff). In the three field experiments carried out to compare the P sources, yields of common bean were increased by PAPR, though the response was less than with triple superphosphate (TSP). The relative agronomic effectiveness (RAE) of PAPR was greater than that of unacidulated PR. Taking into account the RAE values and the current cost of the P sources, the choice of Trinidad de Guedes PAPR instead of TSP could be economic, although the RAE value for PAPR was lower than that of TSP. This result indicates that PAPR could be used in the soil understudy to obtain the best economic return. DM yield, P uptake and grain yield of common bean were significantly increased by applying P as 50% PAPR. Low cost improvement of the agronomic value of PR can be achieved by partial acidulation, so this modification of the phosphate rock show promise for utilization of PR reserves indigenous to developing countries. (author)

Research and engineering assessment of biological solubilization of phosphate

Energy Technology Data Exchange (ETDEWEB)

Rogers, R.D.; McIlwain, M.E.; Losinski, S.J.; Taylor, D.D.

1993-03-01

This research and engineering assessment examined a microbial phosphate solubilization process as a method of recovering phosphate from phosphorus containing ore compared to the existing wet acid and electric arc methods. A total of 860 microbial isolates, collected from a range of natural environments were tested for their ability to solubilize phosphate from rock phosphate. A bacterium (Pseudomonas cepacia) was selected for extensive characterization and evaluation of the mechanism of phosphate solubilization and of process engineering parameters necessary to recover phosphate from rock phosphate. These studies found that concentration of hydrogen ion and production of organic acids arising from oxidation of the carbon source facilitated microbial solubilization of both pure chemical insoluble phosphate compounds and phosphate rock. Genetic studies found that phosphate solubilization was linked to an enzyme system (glucose dehydrogenase). Process-related studies found that a critical solids density of 1% by weight (ore to liquid) was necessary for optimal solubilization. An engineering analysis evaluated the cost and energy requirements for a 2 million ton per year sized plant, whose size was selected to be comparable to existing wet acid plants.

Revegetation of Acid Rock Drainage (ARD) Producing Slope Surface Using Phosphate Microencapsulation and Artificial Soil

Science.gov (United States)

Kim, Jae Gon

2017-04-01

Oxidation of sulfides produces acid rock drainage (ARD) upon their exposure to oxidation environment by construction and mining activities. The ARD causes the acidification and metal contamination of soil, surface water and groundwater, the damage of plant, the deterioration of landscape and the reduction of slope stability. The revegetation of slope surface is one of commonly adopted strategies to reduce erosion and to increase slope stability. However, the revegetation of the ARD producing slope surface is frequently failed due to its high acidity and toxic metal content. We developed a revegetation method consisting of microencapsualtion and artificial soil in the laboratory. The revegetation method was applied on the ARD producing slope on which the revegetation using soil coverage and seeding was failed and monitored the plant growth for one year. The phosphate solution was applied on sulfide containing rock to form stable Fe-phosphate mineral on the surface of sulfide, which worked as a physical barrier to prevent contacting oxidants such as oxygen and Fe3+ ion to the sulfide surface. After the microencapsulation, two artificial soil layers were constructed. The first layer containing organic matter, dolomite powder and soil was constructed at 2 cm thickness to neutralize the rising acidic capillary water from the subsurface and to remove the dissolved oxygen from the percolating rain water. Finally, the second layer containing seeds, organic matter, nutrients and soil was constructed at 3 cm thickness on the top. After application of the method, the pH of the soil below the artificial soil layer increased and the ARD production from the rock fragments reduced. The plant growth showed an ordinary state while the plant died two month after germination for the previous revegetation trial. No soil erosion occurred from the slope during the one year field test.

Phosphate solubilization and multiple plant growth promoting ...

African Journals Online (AJOL)

Phosphate solubilizing efficiencies of the strains were analyzed using different insoluble phosphorus sources and the results show that most isolates released a substantial amount of soluble phosphate from tricalcium phosphate, rock phosphate and bone meal. Screening for multiple plant growth promoting attributes ...

Integrated assessment of the phosphate industry

International Nuclear Information System (INIS)

Ryan, M.T.; Cotter, S.J.

1980-05-01

The phosphate industry in the United States includes three major activities, namely, mining and milling of phosphate rock, phosphate product manufacture, and phosphate product use. Phosphatic materials contain uranium, thorium, and their decay products in greater than background amounts. This assessment of the radiological impacts associated with the redistribution of radioactive components of phosphate materials may provide insight into the effects of uranium extraction from phosphate materials for use in the nuclear fuel cycle

Phosphorus availability in an acid tropical soil amended with phosphate rocks

International Nuclear Information System (INIS)

Zaharah, A.R.; Sharifuddin, H.A.H.

2002-01-01

The fate of P from phosphate rocks applied to Malaysian soils has not been studied in detail. Since the plantation sector is the major consumer of phosphate rock (PR) in Malaysia, studies on the dissolution and agronomic effectiveness of PR are of great interest to the country. Thus a series of greenhouse and laboratory experiments involving conventional chemical extractants and 32 P isotopic techniques was carried out to evaluate the agronomic effectiveness of PR sources of different reactivity. Phosphorus and other chemical properties of the soil and PRs studied were determined. The P solubility tests by 2% formic acid, 2% citric acid and neutral ammonium citrate gave positive correlation with P uptake by one-year old oil palm seedlings. Neutral ammonium citrate proved to be a better indicator of PR solubility and its correlation coefficient with P uptake improved by expressing citrate solubility as a percentage of the rock rather than as a percentage of total P 2 0 5 content. The agronomic effectiveness of TSP and 6 PR sources was evaluated in glasshouse conditions with oil palm seedlings for one year-period. The percentage of PR dissolution varied greatly among PR sources. The PR dissolution was assessed by 0.5 M NaOH, Pi strip, L-value and 1 M ammonium citrate-dissolved Ca. Irrespective of the methods used, the more reactive PR such as North Carolina and Tunisia dissolved more P than the lower reactive sources such as Christmas Island and China PR. All the four methods used gave positive correlation with plant P uptake, with 0.5M NaOH being the best indirect method for determining PR dissolution. Less than 30% of the applied P was dissolved during the one-year period, with only about 15 to 40% of the dissolved P being taken up by the oil palm seedlings. A laboratory 32 P isotopic exchange method was also carried out in this acid soil to assess the soil P status parameters. A low water soluble P concentration (Cp) was found for all PRs used. The ratio of the

Natural radionuclides in phosphatic fertilizer and their behaviour of absoption and accumulation in soils and crops

International Nuclear Information System (INIS)

Chen Jingjian; Zhu Yongyi; Yang Juncheng; Gu Baming

1990-06-01

The systematic data on the radioactivity of U, Th, Ra and 40 K in phosphate rocks, phosphatic fertilizers and soil are given. The radioactive composition and radioactivity in phosphatic fertilizers vary with different kinds of phosphatic fertilizers. The radioactive compositions in the phosphatic fertilizers made from phosphate rock are the same as that in the original phosphate rock, but the radioactivity is only 50∼60% of the original. The natural uranium in the compound fertilizer made from phosphoric acid is several times higher than that in the phosphate rock, and the other radionuclides were separated during the process of forming phosphoric acid. In soil, the radioactivity varies with the soil types. The U content is slightly higher in the south region with red earth and the 40 K is higher in the north region with black earth, but all are in normal level. Usually, the radioactivity of phosphate rock and phosphatic fertilizer is between the natural background of soil and the limitation of radioactive protection, but the radioactivity of 226 Ra in some phosphate rocks and phosphatic fertilizers in Guizhou and Hunan is higher than the permitted limitation set by the government

Phosphate Rocks: Sustainable Secondary Source for Uranium and their Agricultural Impact

International Nuclear Information System (INIS)

LeMone, D.V.; Goodell, P.C.; Harris, A.H.; Winston, J.W.

2009-01-01

-water systems. The potential resultant impact of this on plant life systems is and will continue to be subject to continuing research. In view of the environmental consequences of continued reliance on fossil fuels, the shift to the extensive development of nuclear power seems inevitable. Given the current national and international conditions, it's necessary to carefully examine the political and economic ramifications of such a shift. Competing alternatives of wind (cost and reliability), solar (cost and size), and hydro (at near capacity) will not even begin to substitute for the current fossil fuel usage (oil, coal, gas, tar sands, etc.). The only realistic source of utilizable energy, now and in the future, will have to be nuclear. The secondary extraction of uranium has long been a tantalizing prospect for developing a sustainable source of the metal. A number of phosphate rich nations have reassessed the prospect of such a development in Asia (e.g., China) North Africa, (e.g., Egypt) and the Middle East (Syria, Jordan). The development of a secondary industry involving extraction of uranium from phosphorite ores has a history of prior development in the United States with eight production plants in Florida and Louisiana. However as a result of a drop in the price of uranium (yellow cake), these plants were forced to close. If the sustainability of a uranium fuel supply is found to be a significant factor, the secondary recovery of uranium from phosphate processing provides a potential continuing source of the metal. The waste streams that result from the processes adapted for the secondary extraction of uranium from phosphate fertilizers also will require evaluation. This does not erase the potential and threatening political consequences involved in the potential illegal accumulation of available metal for clandestine and/or rogue military purposes. The primary sulfuric acid extraction process of phosphate rocks results in the accumulation of phosphogypsum. For every

Rock phosphate solubilization by the ectomycorrhizal fungus ...

African Journals Online (AJOL)

SAM

2014-06-18

Jun 18, 2014 ... To evaluate phosphate solubilization of ... and MHB had the potential to solubilize these phosphates by decreasing the pH and confirmed that ... Minerals like N, P, K, Ca, S, Zn, Cu and Sr are ... sterile distilled water, chopped, homogenized in 10 ml sterile .... The role of carbon source is important in mineral.

Phosphorus fertility recapitalization of nutrient-depleted tropical acid soils with reactive phosphate rock: An assessment using the isotopic exchange technique

International Nuclear Information System (INIS)

Fardeau, J.-C.; Zapata, F.

2002-01-01

A 'soil P fertility recapitalization' initiative utilizing large rates of phosphate rocks (PRs) was proposed to improve the soil P status and increase the sustainable food production in acid and P-deficient tropical soils. Two series of experiments were carried out using five tropical acid soils treated with heavy applications of Gafsa phosphate rock (GPR). In the first series, the soils were mixed with GPR at the following application rates: 0, 500, 1000 and 2000 mg P·kg -1 , and incubated for one month in moist conditions. In another series, 1000 mg P kg -1 applied as GPR was added to three soils and incubated for 1.5 month; thereafter 50 mg P kg -1 as triple superphosphate (TSP) were added. The 32 P isotopic exchange method was utilized to assess the contribution of GPR to the available soil P. Changes in amounts, E, of P transferred with time as phosphate ions from the soil particles to the soil solution as well as changes in pH, calcium and phosphate concentrations in soil suspensions were determined. It was found that: (i) the contribution of P from GPR to recapitalization of soil P fertility was mainly assessed by E pool size, pH, calcium and phosphate concentrations; other variables were not significant at the 0.1 level; (ii) heavy applications of GPR did not saturate all the P sorption sites, P freshly applied as water-soluble P was still sorbed; (iii) recapitalization of soil P fertility using GPR was partly obtained in some acid tropical soils; (iv) Upon dissolution, GPR provided calcium ions to crops and to soils, thus reducing Al toxicity, but its liming effect was limited. To explain these effects with heavy application rates of GPR, it was postulated that a coating of Al and Fe compounds is formed around PR particles with time, thus reducing further dissolution. (author)

Uranium production from phosphates

International Nuclear Information System (INIS)

Ketzinel, Z.; Folkman, Y.

1979-05-01

According to estimates of the world's uranium consumption, exploitation of most rich sources is expected by the 1980's. Forecasts show that the rate of uranium consumption will increase towards the end of the century. It is therefore desirable to exploit poor sources not yet in use. In the near future, the most reasonable source for developing uranium is phosphate rock. Uranium reserves in phosphates are estimated at a few million tons. Production of uranium from phosphates is as a by-product of phosphate rock processing and phosphoric acid production; it will then be possible to save the costs incurred in crushing and dissolving the rock when calculating uranium production costs. Estimates show that the U.S. wastes about 3,000 tons of uranium per annum in phosphoric acid based fertilisers. Studies have also been carried out in France, Yugoslavia and India. In Israel, during the 1950's, a small plant was operated in Haifa by 'Chemical and Phosphates'. Uranium processes have also been developed by linking with the extraction processes at Arad. Currently there is almost no activity on this subject because there are no large phosphoric acid plants which would enable production to take place on a reasonable scale. Discussions are taking place about the installation of a plant for phosphoric acid production utilising the 'wet process', producing 200 to 250,000 tons P 2 O 5 per annum. It is necessary to combine these facilities with uranium production plant. (author)

Availability of a P from phosphate rock, thermophosphate and trip superphosphate after different incubation periods

International Nuclear Information System (INIS)

Muraoka, T.; Boaretto, A.E.; Scivittaro, W.B.; Brasil, E.C.

2002-01-01

Patos phosphate rock, Yoorin thermophosphate and triple phosphate were mixed with a tropical acid soil (Haplic Ferralsol) and incubated for different periods (short term experiment 1: 0, 1 and 30 days, and long term experiment 2: 0, 1, 30, 60, 150 and 300 days). The experiments were started with the longest period in order to have all the periods ending at the same time when rice was sown. Soil samples were taken for available P determination through Bray 1 method. There was clear decrease in extractable P with increasing period of incubation, probably due to reversion reactions to form less soluble forms of P. In addition, the reversion reactions seemed to be a more intensive process than the dissolution process. The Yoorin thermophosphate, probably due to its alkaline nature and Si content, proved to be a superior agronomic P source by maintaining the same extractable P content during the whole incubation period. (author)

Influence of substrate rocks on Fe-Mn crust composition

Science.gov (United States)

Hein, J.R.; Morgan, C.L.

1999-01-01

Principal Component and other statistical analyses of chemical and mineralogical data of Fe-Mn oxyhydroxide crusts and their underlying rock substrates in the central Pacific indicate that substrate rocks do not influence crust composition. Two ridges near Johnston Atoll were dredged repetitively and up to seven substrate rock types were recovered from small areas of similar water depths. Crusts were analyzed mineralogically and chemically for 24 elements, and substrates were analyzed mineralogically and chemically for the 10 major oxides. Compositions of crusts on phosphatized substrates are distinctly different from crusts on substrates containing no phosphorite. However, that relationship only indicates that the episodes of phosphatization that mineralized the substrate rocks also mineralized the crusts that grew on them. A two-fold increase in copper contents in crusts that grew on phosphatized clastic substrate rocks, relative to crusts on other substrate rock types, is also associated with phosphatization and must have resulted from chemical reorganization during diagenesis. Phosphatized crusts show increases in Sr, Zn, Ca, Ba, Cu, Ce, V, and Mo contents and decreases in Fe, Si, and As contents relative to non-phosphatized crusts. Our statistical results support previous studies which show that crust compositions reflect predominantly direct precipitation from seawater (hydrogenetic), and to lesser extents reflect detrital input and diagenetic replacement of parts of the older crust generation by carbonate fluorapatite.

Dissolution of rock phosphate in animal manure soil amendment and lettuce growth

Directory of Open Access Journals (Sweden)

Kofi Agyarko

2016-04-01

Full Text Available A study was conducted in pots on the field to assess the effect of different quantities of poultry manure (PM, cattle manure (CM and pig manure (PG on the release of available phosphorus from Togo rock phosphate (RP and lettuce growth. There were eleven (11 treatments which were: Control (soil only; 2.5g RP; 2.5g CM; 2.5gRP + 2.5g CM; 2.5gRP + 5gCM; 2.5gPM; 2.5gRP + 2.5gPM; 2.5gRP + 5gPM; 2.5gPG; 2.5gRP + 2.5gPG; 2.5gRP + 5gPG, applied per kg soil, using the Completely Randomized Design (CRD with three replications. Available phosphorus and other parameters were assessed using standard methods. Results were statistically analyzed using the the GenStat (11th Edition statistical software package. The amount and type of animal manure in the amendment affected the amount of the available P released. The addition of 2.5g manure to 2.5g RP in a kg of soil significantly (P<0.05 increased available P by 4 to 7 times over the sole 2.5g RP/kg soil treatment. Doubling the amount of manure in the amendment (5g manure + 2.5g RP almost doubled the amount of P released, with the poultry manure combinations being more significant. The amount of available P in the soil positively related to the plant height (R2=63, leaf area (R2=0.55, dry weight (R2=0.73 and the percentage P in the leaf (R2=0.88 of lettuce. The PM at 2.5gRP + 5gPM recorded the highest significant (P<0.05 values. The study has provided further basis for manure selection and quantities to be used in enhancing the release of P from rock phosphate. However, investigations need to be continued using nuclear techniques.

[Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

Science.gov (United States)

Wang, Dan; Zhan, Jing; Sun, Qing-Ye

2014-07-01

The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

Evaluation of the availability of phosphorus from decalcium phosphate and rock phosphates from Patos de Minas, Tapira and Finos de Tapira for sheep, by the isotope dilution technique

International Nuclear Information System (INIS)

Vitti, D.M.S.S.

1989-01-01

'In vitro' and 'in vivo' assays were carried out to determine the phosphorus availability from dicalcium phosphate and rock phosphates from Patos de Minas, Tapira and Finos de Tapira. Twenty four male sheep, with 40 kg live weight, were assigned to three groups of eight animals each. The animals were housed individually in metabolism cages and received a diet containing cassava meal, urea, molasses, soybean meal and mineral mixture. Phosphate sources were added to give 4 g of phosphorus per animal per day. After two weeks on the experimental diet each sheep was injected intravenously with 200 μCi of 32 P (Na 2 HPO 4 ). Blood samples were collected from the jugular vein at 24 hs intervals for 8 days. The daily fecal outputs were collected for 8 days and sampled. The specific activities of plasma and feces were determined and the fecal endogenous loss and true phosphorus absorption were calculated. For 'in vitro' assay, rumen samples were collected from a fistulated steer and aliquots were incubated with 0.1 μCi 32 P (Na 2 HPO 4 ) in a medium containing the phosphorus sources. After centrifugation microorganisms were separated and phosphorus incorporation determined. The true absorption values were 58.92; 50.85; 47.99 and 42.72% for dicalcium phosphate, Finos de Tapira, Tapira and Patos, respectively. Dicalcium phosphate showed higher availability (P [pt

Using of natural radioactivity for determination of phosphorus content in phosphate rocks, apatites and superphosphates

Energy Technology Data Exchange (ETDEWEB)

Magas, S; Kasprzak, K S; Gorski, Z [Politechnika Poznanska (Poland). Inst. Chemii Podstawowej

1980-01-01

A quick radiometric method of determination of phosphorus content in natural phosphate rocks, apatites and phosphorus fertilizers, obtained from them has been developed on the basis of uranium and the products of its radioactive decay contained in these materials. The uranium content in these materials amounts to 0.01/0.02%, and is for a given deposit proportional to the phosphorus content. The method is well fitted for laboratory quick determination of phosphorus content in raw-materials and products in factories producing phosphorus fertilizers and makes possible the automation of process and proportioning of sulphuric acid in production of superphosphates.

Comment on: "Recent revisions of phosphate rock reserves and resources: a critique" by Edixhoven et al. (2014) - Phosphate reserves and resources: what conceptions and data do stakeholders need for sustainable action?

Science.gov (United States)

Scholz, R. W.; Wellmer, F.-W.

2015-01-01

Several recent papers predict a scarcity of phosphate reserves in the near future. The paper by Edixhoven et al. (2014), for instance, expresses the doubts about whether the upward estimate of reserves by the IFDC (2010) and the USGS (2010) provide an accurate, reliable, and comparable picture, as they are based on reports that do not clearly differentiate between phosphate ore and phosphate products (i.e., marketable phosphate rock concentrate). Further the indistinct use of the terms reserves and resources is criticized. Edixhoven et al. ask for a differentiated inventory of world phosphate reserves including "guidelines which determine the appropriate drill hole distances." The claim that humanity is on the safe side with respect to future phosphate is supply is doubted as the validity of the IFDC's upgrading of the Moroccan data to 50 Gt phosphate is questioned. The present paper identifies and discusses basic conceptual errors of the paper by Edixhoven et al. and related papers that predict a short or mid-term phosphorus scarcity. These include the non-acknowledgment of the dynamic nature of reserves (which depends on price, technology, and innovation for exploiting low-grade deposits, etc.), the mixing of finiteness and staticness of the ultimate recoverable resources (i.e., phosphorus that may be mined economically in the long-term future), the improper use of the Hubbert analysis (which, e.g., simply uses the USGS estimates of reserves as a substitute of an estimate of ultimate recoverable resources) and the geostatistical naive/unprofessional demand for fixed drilling plans to assess reserves. We reconstruct the IFDC and USGS estimates and conclude that there is no evidence for considering the 50 Gt phosphate concentrate as an unreasonable estimate for Moroccan reserves. However, the partial mixing of different units (e.g., phosphate ore and phosphate concentrate or marketable product) in the USGS data may be avoided by improving the data base and using

Chemical and physical characteristics of phosphate rock materials of varying reactivity

International Nuclear Information System (INIS)

Syers, J.K.; Currie, L.D.

1986-01-01

Several chemical and physical properties of 10 phosphate rock (PR) materials of varying reactivity were evaluated. The highest concentrations of As and Cd were noted. Because Cd and U can accumulate in biological systems, it may be necessary to direct more attention towards the likely implications of Cd and U concentrations when evaluating a PR for direct application. Three sequential extractions with 2% citric acid may be more useful for comparing the chemical solubility of PR materials, particularly for those containing appreciable CaC0 3 . The poor relationship obtained between surface area and the solubility of the PR materials suggests that surface area plays a secondary role to chemical reactivity in controlling the solubility of a PR in a chemical extractant. A Promesh plot provided an effective method for describing the particle-size characteristics of those PR materials which occurred as sands. Fundamental characteristics, such as mean particle size and uniformity, can readily be determined from a Promesh plot. (author)

Uranium recovery from phosphate rocks concentrated

International Nuclear Information System (INIS)

Azevedo, M.F. de.

1986-01-01

The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

Effects of phosphate-solubilizing bacteria, native microorganisms, and rock dust on Jatropha curcas L. growth.

Science.gov (United States)

Santana, E B; Marques, E L S; Dias, J C T

2016-10-05

Microorganisms with the ability to release nutrients to the soil from insoluble sources may be useful for plant cultivation. We evaluated the growth-promoting effect on Jatropha curcas L. of phosphate-solubilizing bacteria (PSB) and the native microbiota in soil with or without rock dust. J. curcas L. is important for biodiesel production. The experiments were performed in a greenhouse under a random-statistical design with 14 replicates. The soil received increasing dosages of rock dust. The presence of resident microorganisms and PSB inoculum was correlated with plant height, biomass production, and phosphorus content in plants for 120 days. Native soil microorganisms were detected and identified using denaturing gradient gel electrophoresis and DNA sequence analysis. Several bacterial populations belonged to the genus Bacillus. Populations associated with the phyla Chytridiomycota and Ascomycota were detected among the fungi. The best results for the variable plant height were correlated with the presence of resident microbiota and rock dust until the end of the experiment. The largest biomass production and the highest content of phosphorus occurred in the presence of soil-resident microbiota only up to 120 days. No significant effects were observed for biomass production with the use of PSB combined with rock dust. J. curcas L. under the influence of only resident microbiota showed the best plant growth results. Future research will focus on the specificity of resident microbiota activity in plant growth promotion and the isolation of these microorganisms to produce a new inoculum to be tested in various plants.

Phosphate recycling in the phosphorus industry

NARCIS (Netherlands)

Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

2004-01-01

The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the

Dry-column chromatography of uranium. Application to chemical analysis of monazite and phosphate rock for uranium

Energy Technology Data Exchange (ETDEWEB)

Oguma, K; Kuroda, R [Chiba Univ. (Japan). Faculty of Engineering

1981-08-01

A dry-column chromatographic technique has been applied to the separation of uranium from complicated matrices. It has been demonstrated that operating parameters of thin-layer chromatography on silanized silica gel in isopropyl ether - tetrahydrofuran - nitric acid (65:20:3) can be transferred to this technique. Chromatograms are thus easily developed on dry packed column with the solvent system of the type used in the TLC. Uranium is eluted off the column and determined with Arsenazo III spectrophotometrically. The technique is successfully applied to the determination of uranium in monazite and phosphate rock samples with good precision and accuracy.

Rock phosphate solubilizing and cellulolytic actinomycete isolates of earthworm casts

Science.gov (United States)

Mba, Caroline C.

1994-03-01

Four microbial isolates, OP2, OP3, OP6, and OP7, of earthworm casts of Pontoscolex corethrurus were found to be acid tolerant actinomycetes and efficient rock phosphate (RP) solubilizers that could grow fast on NH4Cl-enriched or N-free carboxymethyl cellulose or glucose as sole carbon source. CMC (carboxymethyl cellulose) induced production of extracellular cellulase enzyme and the production of reducing sugar in all the isolates. RP solubilizing power was observed to be inversely related to glucose consumption. The most efficient RP solubilizer was found to consume the least glucose. Growth was faster on cellulose than on glucose media. N-free CMC induced greater glucose production than NH4Cl-enriched CMC medium. Both CMC and glucose media were acidified by all the isolates, however, RP solubilizing power decreased with acidification. Solubilization power was greatest with isolate OP7, which also produced the greatest amount of reducing sugar per gram CMC. Both RP solubilizing power and the cellulolytic efficiency varied among isolates. A minimum of 631 µg P/0.1 g RP and a maximum of 951.4 µg P/0.1 g RP was recorded.

Inhalation dose assessment inside various storage godowns of a phosphatic fertiliser plant

International Nuclear Information System (INIS)

Shukla, V.K.; Eapen, C.D.; Mishra, U.C.

1995-01-01

The paper presents the assessment of inhalation dose from 222 Rn daughters received by the persons working inside various godowns, meant for storing rock phosphate and different types of phosphatic fertilisers produced by a plant at Bombay. The dose assessment was made by measuring the respirable airborne concentrations of 222 Rn daughters inside the godowns. Rock phosphate is the base material for the production of phosphatic fertilisers and it contains significant quantities of 226 Ra. 226 Ra activity in rock phosphate from different places is ranging between 5 (Udaipur, India) to 1480 Bq/kg (Florida, USA) and its range in NP: 20-20-0 and NPK: 15-15-15 type fertilisers is 254 to 272 Bq/kg and 127 to 208 Bq/kg respectively. 226 Ra is the source of emanation of 222 Rn inside the godowns. It was observed that though the specific activity of 218 Po, 214 Pb and 214 Bi in the total airborne particulate matter was higher inside the rock phosphate godown but the specific activity of the aforementioned radionuclides in the respirable fractions inside the phosphatic fertilisers' godown were more. The reasons for these observations are discussed in the paper. (author). 7 refs., 2 tabs

Determination of terbium in phosphate rock by Tb{sup 3+}-selective fluorimetric optode based on dansyl derivative as a neutral fluorogenic ionophore

Energy Technology Data Exchange (ETDEWEB)

Hosseini, Morteza, E-mail: smhosseini@khayam.ut.ac.ir [Department of Chemistry, Islamic Azad University, Savadkooh Branch, Savadkooh (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Veismohammadi, Bahareh [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Abkenar, Shiva Dehghan [Department of Chemistry, Islamic Azad University, Savadkooh Branch, Savadkooh (Iran, Islamic Republic of); Norouzi, Parviz [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

2010-04-07

For the first time a highly sensitive and selective fluorimetric optode membrane was prepared for determination of trace amounts of Tb(III) ions in phosphate rock samples. The Tb(III) sensing system was constructed by incorporating 5-(dimethylamino)-N'-(2-hydroxy-1-naphthoyl) naphthalene-1-sulfonohydrazine (L) as a neutral Tb(III)-selective fluoroionophore, in the plasticized PVC membrane containing sodium tetraphenyl borate as a liphophilic anionic additive. The response of the optode is based on the strong fluorescence quenching of L by Tb{sup 3+} ions. At a pH value of 5.0, the optode displays a wide concentration range of 1.0 x 10{sup -7} to 1.0 x 10{sup -2} M, with a relatively fast response time of less than 45 s. In addition, to high stability and reproducibility, the sensor shows a unique selectivity towards Tb{sup 3+} ion with respect to common cations. The optode was applied successfully to the trace determination of terbium ion in binary mixture and water samples and the determination of Tb{sup 3+} in phosphate rock samples.

Determination of terbium in phosphate rock by Tb3+-selective fluorimetric optode based on dansyl derivative as a neutral fluorogenic ionophore.

Science.gov (United States)

Hosseini, Morteza; Ganjali, Mohammad Reza; Veismohammadi, Bahareh; Faridbod, Farnoush; Abkenar, Shiva Dehghan; Norouzi, Parviz

2010-04-07

For the first time a highly sensitive and selective fluorimetric optode membrane was prepared for determination of trace amounts of Tb(III) ions in phosphate rock samples. The Tb(III) sensing system was constructed by incorporating 5-(dimethylamino)-N'-(2-hydroxy-1-naphthoyl) naphthalene-1-sulfonohydrazine (L) as a neutral Tb(III)-selective fluoroionophore, in the plasticized PVC membrane containing sodium tetraphenyl borate as a liphophilic anionic additive. The response of the optode is based on the strong fluorescence quenching of L by Tb(3+) ions. At a pH value of 5.0, the optode displays a wide concentration range of 1.0 x 10(-7) to 1.0 x 10(-2)M, with a relatively fast response time of less than 45 s. In addition, to high stability and reproducibility, the sensor shows a unique selectivity towards Tb(3+) ion with respect to common cations. The optode was applied successfully to the trace determination of terbium ion in binary mixture and water samples and the determination of Tb(3+) in phosphate rock samples. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

Effect of the temperature and the porosity of the gettering process on the removal of heavy metals from Tunisian phosphate rock

Directory of Open Access Journals (Sweden)

R. Daik

Full Text Available Gettering is a process by which unwanted impurities are removed by providing an alternative location, this method used by many researchers for the purification of silicon wafers or powder. In this work, this method is used for the first time to remove the impurities from Tunisian phosphate rock (TPR. This method consists in two steps: the rapid thermal processing by infrared furnace followed by a rapid chemical etching. In order to enhance the efficiency of this process, a porous layer on the surface of grains was grown. By this method, we have demonstrated in this present work that the majority of impurities were well extracted from TPR. UV–visible absorption spectra show that the highest intensity of absorbance (∼1 appears for the porous sample treated at 900 °C (P900 °C, which due to the presence of large quantities of impurities in the extracted solution. These results were well confirmed by AAS and ICP-AES which show that the majority of the impurities have been almost removed for the P900 °C sample. Keywords: Gettering process, Porous phosphate rock, Temperature, Impurities

Radiological impact of use of phosphate fertilizers

International Nuclear Information System (INIS)

Shukla, V.K.; Chinnaesakki, S.; Sartandel, S.J.; Shanbhag, A.A.; Puranik, V.D.

2003-01-01

The paper describes the results of gamma spectrometric measurements of 238 U, 233 Th, 226 Ra and 40 K in rock phosphates and various types of phosphate fertilizers and by-products. The increase in soil natural radioactivity has been assessed for major Indian crops. No significant increase in soil natural radioactivity is expected due to the application of phosphate fertilizers for agricultural productions. (author)

[Combination of phosphorus solubilizing and mobilizing fungi with phosphate rocks and volcanic materials to promote plant growth of lettuce (Lactuca sativa L.)].

Science.gov (United States)

Velázquez, María S; Cabello, Marta N; Elíades, Lorena A; Russo, María L; Allegrucci, Natalia; Schalamuk, Santiago

Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote solubilization of insoluble phosphates complexes, favoring plant nutrition. Another alternative to maintaining crop productivity is to combine minerals and rocks that provide nutrients and other desirable properties. The aim of this work was to combine AMF and S with pyroclastic materials (ashes and pumices) from Puyehue volcano and phosphate rocks (PR) from Rio Chico Group (Chubut) - to formulate a substrate for the production of potted Lactuca sativa. A mixture of Terrafertil®:ashes was used as substrate. Penicillium thomii was the solubilizing fungus and Rhizophagus intraradices spores (AMF) was the P mobilizer (AEGIS® Irriga). The treatments were: 1) Substrate; 2) Substrate+AMF; 3) Substrate+S; 4) Substrate+AMF+S; 5) Substrate: PR; 6) Substrate: PR+AMF; 7) Substrate: PR+S and 8) Substrate: PR+AMF+S. Three replicates were performed per treatment. All parameters evaluated (total and assimilable P content in substrate, P in plant tissue and plant dry biomass) were significantly higher in plants grown in substrate containing PR and inoculas with S and AMF. This work confirms that the combination of S/AMF with Puyehue volcanic ashes, PR from the Río Chico Group and a commercial substrate promote the growth of L. sativa, thus increasing the added value of national geomaterials. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Prevention of radioactive contamination in the manufacture of phosphate fertilizers; Prevencion de contaminacion radiactiva en la fabricacion de fertilizantes fosfatados

Energy Technology Data Exchange (ETDEWEB)

Romero G, E T

1996-12-31

In this work was studied the separation of uranium from the phosphate rock to decrease the level of radioactivity in the phosphate fertilizers, this prevents the redistribution of uranium in the environment. The uranium leaching conditions from phosphate rock were estimated using alkaline solutions. The changes in the natural phosphate rock after leaching were studied. The amenability to separate the uranium from phosphate rock with ammonium carbonate / bicarbonate solution was determined. The uranium extraction was approximately 40%. The leaching conditions showed high selectivity for uranium without changes in the ore structure. The bulk ore was not dissolved. (Author).

Evaluation methods used for phosphate-solubilizing bacteria ...

African Journals Online (AJOL)

This work aimed to evaluate the different selection methods and select inorganic phosphorus-solubilizing bacteria as potential plant-growth promoters. Bacterial isolates obtained from sugarcane roots and soil were tested using solid growth media containing bicalcium phosphate and Irecê Apatite ground rock phosphate as ...

Advances in process technology for eco-friendly phosphates by separation of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Singh, H; Mukherjee, T K [Uranium and Rare Earths Extraction Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Phosphates are used in the industry for fertilizers, industrial chemicals (detergents, water-treatment chemicals) and food-additives. The source of phosphates for the industry is rock-phosphate. Over 90% of phosphate rocks of the world are associated with uranium and its radioactive daughter products. Processing and use of phosphates is accompanied by radiation hazards. The concentration of radionuclides is low, but in view of large number of persons exposed to the hazards, the cumulative societal pollution load is high, and a matter of concern for international organisations. Chemical engineering techniques have been developed for the reduction of societal radiation hazard from the phosphates. In this paper, brief details of the process and developmental efforts in India are described. (author). 4 refs., 1 fig.

Rock phosphate solubilization by the ectomycorrhizal fungus ...

African Journals Online (AJOL)

SAM

2014-06-18

Jun 18, 2014 ... phosphate solubilization is accompanied by acid production. Thus, the evidence ..... of organic acids. (Khan et al., 2010) such as acetate, lactate, oxalate, ... (2014) also observed that oxalic acid was secreted by L. fraterna to ...

Geochemistry and mineralogy of Ogun phosphate rock

African Journals Online (AJOL)

user

m deep) within the same location. The pellets ... diffracted rays are collected by a detector and the information relayed to a ... Ogun phosphate deposits were formed in shallow marine ... process thus confirming the earlier work done by Jones.

Manufacture of phosphatic fertilisers and recovery of byproduct uranium - a review

International Nuclear Information System (INIS)

Ring, R.J.

1975-11-01

The processes used in the production of phosphatic fertilisers are reviewed and those in which uranium can be extracted as a byproduct are described in detail. The current status of the world and Australian phosphate rock and fertiliser industries is described and production figures and marketing information for these industries are also presented. Techniques for the recovery of byproduct uranium during the processing of phosphate rock to fertilisers are also examined in detail. Recovery from wet-process phosphoric acid by solvent extraction is the most promising approach. (author)

Isotopic assessment of soil phosphorus fertility and evaluation of rock phosphates as phosphorus sources for plants in subtropical China

International Nuclear Information System (INIS)

Xiong, L.M.; Zhou, Z.G.; Feng, G.L.; Lu, R.K.; Fardeau, J.C.

2002-01-01

Soil phosphorus (P) deficiency is a major factor limiting crop productivity in many tropical and subtropical soils. Due to the acidic nature of these soils, rock phosphate (RP)-based P fertilizers that are cheaper than manufactured water-soluble P fertilizers can be an attractive alternative under certain conditions. Assessment of the efficacy of these alternative P fertilizers and a rational management of local P resources for sustainable agricultural production require an understanding of the dynamics of P in the soil-plant system and the interactions of various P sources in soils and monitoring of soil available P levels. The present work was conducted to test the applicability of the 32 P isotopic kinetic method to assess the soil P fertility status and evaluate the agronomic effectiveness of local rock phosphates in subtropical China. A series of experiments was carried out in the laboratory, greenhouse and field conditions with the following specific objectives: (a) to evaluate the suitability of this isotopic kinetic method in evaluating soil P fertility in 32 soil samples collected across southern China, (b) to test and further develop chemical extraction methods for routine soil P testing, (c) to monitor the dissolution kinetics of local low to medium grade rock phosphate sources and their effect on soil properties and (d) to evaluate their agronomic effectiveness in greenhouse and field experiments. Since most of the studied soils had very low concentrations of soluble P and high P-fixing capacities, the isotopic kinetic method was found unsuitable for evaluating soil P fertility and to predict plant P uptake. In contrast, the proposed chemical extraction method (NaHCO 3 -NH 4 F) predicted very well plant P uptake, suggesting that this extraction method can be routinely used to evaluate soil bioavailable P in similar soils in subtropical China. From the incubation study, it was found that although the local low to medium grade RPs were inferior to the

Predicting the bioavailability of phosphorus in soil amended with phosphate rocks using isotopic exchange kinetics

International Nuclear Information System (INIS)

Mohammad Edwin Syah Lubis; Zaharah Abd Rahman; Sharifuddin Abd Hamid

1997-01-01

Investigations on plant responses to applications of various forms and rates of P fertilizers usually involve glasshouse and/or field experiments. This traditional procedure assumes that whatever the soil-fertilizer-plant system, increase in total P uptake by plant between no P treatment (control) and fertilizer treatment equals the plant P uptake from fertilizer. This study uses the isotopic exchange techniques in the laboratory to predict bioavailability of P fertilizers without the need to conduct glasshouse or field experiments. Serdang series soil (Typic Paleudult) was incubated with 7 sources of P fertilizers comprising of triple superhosphate (TSP) and phosphate rocks from North Carolina (NCPR), Algeria (APR), Tunisia (TPR), Jordan (JPR), Christmas Island (CIPR) and China (CPR) at the rates of 0, 2, 4, 6 and 8g Kg-' soil with 20% moisture content at room temperature in three replications. The soils were sampled at 1, 3, 6 and 9 months after incubation and isotopically exchangeable p determined by the method of Fardeau and Jappe (1976). Intensity, quantity and capacity factors of soil P were calculated and the residual availability of these fertilizers were predicted. Phosphorus in solution was highest in TSP treated soil for all treatments. Among the phosphate rocks, NCPR at rate 8g kg-' soil gave the highest value while, CPR at rate 2 gave the lowest value. Thus showing that these PRs have different reactivities in this soil, where NCPR, APR, TPR and JPR were the reactive PR, while CIPR and CPR were the unreactive ones. The isotopically exchangeable P at one minute (1) in the soil sampled 9 months after incubation was found to correlate very well with plant P uptake by oil palm seedlings grown under the same conditions. Calculations made on the percentage of P derived from these fertilizers up to a period of more than one year after application showed that the reactive PRs to have more residual P made available to plants than the unreactive PR

Investigation of uranium 238 level in phosphate rock samples from kurun mountain Eastern Nuba Mountains in the State of Kordfan (western Sudan)

International Nuclear Information System (INIS)

Yagoub, N. H. M.

2014-06-01

The natural radionuclide content of 20 samples collected from Kurun Mountain, western Sudan, has been determined using gamma spectrometry. The data showed that ''2''3 8 U and its decay products were the principal contributors of radioactivity in phosphate deposits. The range of the activity concentration was measured in apatite phosphate rock samples was 378.03-1332.58 Bq/Kg with a mean value of 815.46 Bq/Kg and the data showed that most of samples concentrated in medial comparable with top and bottom of mountain. The distribution of samples indicated that the weathering effect and the rainfall may be the main reasons to enhance the mobility and solubility of uranium from top to bottom of mountain.(Author)

The Influence of Pyrite on the Solubility of Minjingu and Panda ...

African Journals Online (AJOL)

28.5 million tons of sulphur. This study was ... bining PRs with elemental S, FYM ot 'and pyrite rock rere used.in this compost (Chien et al., ... Some of the possibility of using locally available the chemical properties of the rocks materials in ...

Uranium determination in phosphatized materials by drop electrode polarography

International Nuclear Information System (INIS)

Sequeira, F.M.C. de; Abrao, A.

1987-01-01

An uranium determination procedure in phosphate rocks and crude phosphoric acid is outlined polarography is used. Uranium is previously separedted by extraction with tri-n-byte phosphate 10%-petroleum ether using aluminium nitrate as salting out agent. (M.L.J.) [pt

Comparative study on precipitation methods of yellow-cake from acid leachate of rock phosphate and Its purification

International Nuclear Information System (INIS)

Abow Slama, E. H. Y.

2009-05-01

This study was carried-out to leach uranium from rock phosphate using sulphuric acid in presences of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia ((NH 4 ) 2 U 2 O 7 ), magnesia (UO 3 .xH 2 O) and sodium hydroxide (Na 2 U 2 O 7 ) as precipitants, as well as purification of the products with TBP extraction and matching its impurity levels with specification of the commercial products. Alpha-particle spectrometry was for used for determination of activity concentration of uranium isotopes (''2''3''4U and ''2''3''8U) in rock phosphate, resulting green phosphoric acid solution, and in different forms of the yellow cake from which the equivalent mass concentration of uranium was deduced. Likewise, AAS was used for determination of impurities (Pb, Ni, Cd, Fe, Zn, Mn, and Cu). On the average, the activity concentration of uranium in the rock phosphate was 1468±979 Bq/Kg (119.38±79.66 ppm), and 711±252 Bq/L (57.85±20.46 ppm) in the resulting green solution with corresponding percent of dissolution amounting to 48% which is considered low indicating that the experimental conditions (i.e. dissolution container, temperature, PH, retention time) were not optimal. However, the isotopic ratio (''2''3''4U, ''2''3''8U) in all stages of hydrometallurgical process was not much different from unity indicating lack of fractionation. Crude yellow cakes (hydrate uranium trioxide, ammonium diuranate and sodium diuranate) were precipitated from the green solutions prior to separation of iron and once after iron separation. Although, iron was tested using bipyridine and SCN, it was found in all types of crude samples analyzed this might be attributed to either the quality of the reagent used or inhibition of Fe present in the solution by stronger complexing agent. Uranium mass concentration in crude yellow cakes precipitated before iron separation was found following the order: UO 3 .xH 2 O

Specific activity of uranium and thorium in marketable rock phosphate as a function of particle size

Energy Technology Data Exchange (ETDEWEB)

Metzger, R; McKlveen, J W [Arizona State Univ., Tempe (USA); Jenkins, R [Phillip Morris Research Center, Richmond, VA (USA); McDowell, W J [Oak Ridge National Lab., TN (USA)

1980-07-01

Marketable rock phosphate fertilizer from Florida was classified into seven particle size fractions ranging from 149 ..mu..m to less than 0.5 ..mu..m using a Bahco Microparticle Classifier and air elutriation. The resulting size fractions were assayed for U and /sup 230/Th by solvent extraction and liquid scintillation ..cap alpha..-spectroscopy. Results indicated that the specific activity of U and /sup 230/Th increased with decreasing particle size. Maximum activities of 110 pCi/g U and 50 pCi/g /sup 230/Th were found in particles less than 1.0 ..mu..m in aerodynamic diameter. Qualitative emission spectrographic analysis of the fractions revealed that the concentrations of Al, Cu, Mg, Na, Ti and Zn also increased with decreasing particle size.

Effect of the addition of phosphate rocks in the biogas and biofertilizer production from the cattle wastes of bovine and buffaloes; Efeito da adicao de rochas fosfatadas na producao de biogas e biofertilizante a partir de dejetos de bovinos e bubalinos

Energy Technology Data Exchange (ETDEWEB)

Mello Alves, S de; Melo, C F.M. de [Empresa Brasileira de Pesquisa Agropecuaria, Belem, PA (Brazil). Centro de Pesquisa Agropecuaria do Tropico Umido; Prakasan, K

1985-12-31

This work shows the effect of the addition rock phosphates (phosphate of Olinda and phosphate of Jandia) in the biogas production and increasing the quality of biofertilizer. The addition of 1% and 2% of phosphate of Olinda increased the production of gas in the initial 30 days of incubation, but higher concentration (4% and 8%) inhibited the production. 5 refs., 1 fig., 8 tabs.

Effect of the addition of phosphate rocks in the biogas and biofertilizer production from the cattle wastes of bovine and buffaloes; Efeito da adicao de rochas fosfatadas na producao de biogas e biofertilizante a partir de dejetos de bovinos e bubalinos

Energy Technology Data Exchange (ETDEWEB)

Mello Alves, S. de; Melo, C.F.M. de [Empresa Brasileira de Pesquisa Agropecuaria, Belem, PA (Brazil). Centro de Pesquisa Agropecuaria do Tropico Umido; Prakasan, K.

1984-12-31

This work shows the effect of the addition rock phosphates (phosphate of Olinda and phosphate of Jandia) in the biogas production and increasing the quality of biofertilizer. The addition of 1% and 2% of phosphate of Olinda increased the production of gas in the initial 30 days of incubation, but higher concentration (4% and 8%) inhibited the production. 5 refs., 1 fig., 8 tabs.

Development of phosphate rock integrated with iron amendment for simultaneous immobilization of Zn and Cr(VI) in an electroplating contaminated soil.

Science.gov (United States)

Zhao, Ling; Ding, Zhenliang; Sima, Jingke; Xu, Xiaoyun; Cao, Xinde

2017-09-01

This study aims to develop an amendment for simultaneous immobilization of Zn and Cr(VI) in an abandoned electroplating contaminated soil. Nature phosphate rock was first activated with oxalic acid (O-PR) and then combined with FeSO 4 or zero-valent iron (ZVI) for immobilization of Zn and Cr(VI) from aqueous solutions. Finally, the optimized approach showing the highest immobilization ability in solution was applied in an electroplating contaminated soil. The O-PR combined with FeSO 4 was more effective in simultaneously removing Zn and Cr(VI) than the O-PR integrated with ZVI within the tested solution pH range of 5.5-8.5. Both O-PR with FeSO 4 and with ZVI removed over 95% of Zn from the solution; however, only 42-46% of Cr(VI) was immobilized by O-PR with ZVI, while O-PR with FeSO 4 almost precipitated all Cr(VI). Moreover, there were 75-95% Zn and 95-100% Cr(VI) remaining in the exhausted O-PR with FeSO 4 solid after toxicity characteristic leaching test (TCLP) while the exhausted O-PR with ZVI solid only retained 44-83% Zn and 32-72% Cr(VI). Zinc was immobilized mainly via formation of insoluble Fe-Zn phosphate co-precipitates, while iron-induced reduction of Cr(VI) into stable Cr(OH) 3 or Cr x Fe (1-x) (OH) 3 was responsible for Cr(VI) immobilization. Application of the O-PR integrated with FeSO 4 in the electroplating contaminated soil rapidly reduced the TCLP extractable Zn and Cr(VI) to below the standard limits, with decrease by 50% and 94%, respectively. This study revealed that combination of oxalic acid activated phosphate rock with FeSO 4 could be an effective amendment for remediation of Zn and Cr(VI) contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of dissolution of nonconventional phosphate fertilizers in ...

African Journals Online (AJOL)

Dissolution of phosphate rock (PR) depends on inherent chemical and physical properties of the rock and on external factors such as soils and plants. The objective of this study was to investigate, with a soil incubation experiment, the relationship between selected soil factors and extractable phosphorus (P) in order to ...

Enzymatic studies on phosphorus availability from phosphate compounds by microbial activities using nuclear techniques

International Nuclear Information System (INIS)

Abou Seer, A.M.M.

2002-01-01

the present study aimed to evaluate to evaluate the of phosphate solubilizing bacteria (PSB) and vesicular arbuscular mycorrhizae(VAM) as microbiological mean to convert the sparingly soluble P into available from utilized by plant through excretion of acid and alkaline phosphatase. rock phosphate as natural and a cheap source of P- fertilizer was applied in the present study. To trace the effect of microbial activity and phosphatase enzymes on phosphate availability from its compounds , set of experiments were conducted either in the lab. or green house. The obtained results could be summarized as following:- 1- phosphate solubilizing bacteria(PSB) w isolated from samples of fertile soil, 16 colonies showed positive reaction were chosen .2- bacteria , which exhibited high phosphate clearing zone (PCZ) selected to detect their efficiencies for dissolving rock phospate and select the effective one (most potent) on the basis of highest production of phosphatase and phosphorus solubilization.3- identification of the most potent (pseudomonas aeruginosa) 4- effective environmental and nutritional factors on phosphatase production by pseudomonas aeruginosa were discussed.green-house experiment: inoculation of wheat (triticum aestivum cv.sakha 8) with either PSB and /or VAM with or without rock-P fertilization was under taken. dual inoculation with psb (pseudomonas aeruginosa) and VAM improved the dry matter yield and N and P uptake by wheat as compared to other treatments. application of psb as well as VAM increased the availability of rock phosphate to be utilized by wheat

Some aspects of radiological impact in phosphate fertilizer industry. A case study of Itataia, Ceara State, Brazil

International Nuclear Information System (INIS)

Saad, Samir.

1995-10-01

The present study presents severalk aspects related to the phosphate industry from the origin of the raw materials to the final products. Emphasis is given in the approach of problems associated with the radiological impact and inherent risks when non monitorated products are used. Considerations are made on geological, geochemical and radiometrical characteristics of the main world deposits of phosphatic rocks. The critical patways of U-238 and Th-232 radionuclides are analysed from its origin to the final products. World-wide statistical data on several industrial phosphate branches are presented, and suggestions are made to draw attention to governmental organizations on the need for establishing specific technological development programs for the extraction of radionuclides from phosphate industrial products. The Itataia's project of industrial mining and milling, located in the state of Ceara, is focused here in great detail considering that is represents one of the biggest world concentrations of uranium associated with phosphatic rocks. Results from field studies performed in Itataia's mine are presented and analytical results from laboratory studies in samples from Itataia's (CE) and Barreiro's (MG) phosphatic rocks and Guaramicim's (PE) phospholite are also discussed. Finally, the study proposes a series of necessary actions to implement a national environmental monitoring plan i order to minimize the risks due to the radioactivity arising from phosphatic rocks and from derived fertilizers industry. (author). 37 refs., 31 figs., 37 tabs

Comparative evaluation of the effect of rock phosphate and monoammonium phosphate on plant P: Nutrition in Sod-podzolic and peat soils

International Nuclear Information System (INIS)

Bogdevitch, I.; Tarasiuk, S.; Putyatin, Yu.; Seraya, T.

2002-01-01

The direct application of finely ground rock phosphate (RP) imported from Russia has been suggested as an alternative to the almost twice more expensive water-soluble monoammonium phosphate (MAP) on acid (moderately limed) Sod-podzolic and peat soils. A pot experiment was conducted in 1997-1998 for a comparative evaluation of P availability from RP and MAP using the 32 P isotope dilution technique. The lupine was grown on Sod-podzolic silty clay loam soil with pH 6.0 and a medium level of available P. Ryegrass plants were grown on peat soil with pH 4.9 and a low level of native soil P fertility. Application of RP and MAP at a rate of 40 mg P/kg soil supplied similar moderate mount of P to lupine plants. The Pdff values, i.e. the fractions of P in the plants derived from the applied RP and MAP, were 7.4 and 8.4%, respectively. The application of the same P fertilizers to the peat soil had different effects on P nutrition of ryegrass plants. The Pdff values were 14.9% for RP and 22.1% for MAP. It may be concluded that for most annual crops water-soluble P forms such as MAP should be preferred. Direct application of RP is recommended for plants with an adequate rhizosphere ability to utilize P, such as lupine on acid Sod-podzolic silty clay loam soils (pH 137 Cs on contaminated, moderately limed Sod-podzolic silty clay loam and peat soils. These soils are widely spread in the radioactive contaminated area of Belarus after the Chernobyl accident. Direct application of RP may be one of the effective countermeasures for the decrease of 137 Cs transfer from the contaminated acid soils to crop production. (author)

Uranium recovery in a pilot plant as by product of the phosphate fertilizers

International Nuclear Information System (INIS)

Dantas, C.C.; Santos, F.S.M. dos; Paula, H.C.B.; Santana, A.O. de

1984-01-01

A process was developed and a piloto plant was installed to recovery uranium from chloridric leach liquor of phosphate rocks. The extractor system is a mixture of di(2-ethylhexyl) phosphoric acid (DEHPA) and tributyl-phosphate (TBP) in a kerosene diluent. The phosphate rocks are leached for dicalcium phosphate (CaHPO 4 ) production, by the reactions: Ca 3 (PO 4 ) 2 + 4 HCl → Ca(H 2 PO 4 ) 2 + CaCl 2 and Ca(H 2 PO 4 ) 2 + Ca(OH) 2 → CaHPO 4 + 2 H 2 O. The uranium recovery process comprises the following steps:extraction, scrubbing, reextraction, iron removal and uranium precipitation. The uranium is precipited as ADU with 80% of U 3 O 8 .(Author) [pt

The role of airborne radiometric survey in defining the distribution of phosphate rocks in the Syrian desert and the Northern Palmyrides

International Nuclear Information System (INIS)

Jubeli, Y.M.

2000-01-01

Gamma-ray spectrometry, an effective tool in geological mapping, was used to define boundaries between various lithological formations in three adjacent areas of Central Syria, namely, the Syrian Desert, Ar Rassafeh Badiayat and the Northern Palmyrides mountains. This paper describes the role of an airborne gamma spectrometric survey which was originally undertaken to assist uranium exploration. Interpretation of the total count data obtained through the survey has led to significant modifications and corrections to the previously published distribution map of the Palaeogene phosphate rocks. Another important result to the survey is the discovery of four previously unknown phosphorite horizons in the Rasm Al-Aawabed area of the Northern Palmyrides. In addition, previously unknown phosphatic horizons are outlined in the other study areas. The importance of this technique as an effective prospecting method, not only for U but also for exploring for the economically important phosphorite formations in Syria, is emphasized. Furthermore, its role in geological mapping is stressed, especially in areas that lack sufficient geological data. (author)

Elemental and radionuclides distribution in the production and use of phosphate fertilizers in Brazil

International Nuclear Information System (INIS)

Saueia, Catia Heloisa Rosignoli

2006-01-01

Fertilizer is considered an essential component for agriculture, because its use increases the natural soil nutrients, which are lost slow waste or erosion. The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dihydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The phosphate rock used as raw material presents in its composition, radionuclides of the U and Th natural series in. During the chemical attack of the phosphate rock, this equilibrium is disrupted and the radionuclides and the elements migrate to intermediate, final products and byproducts, according to their solubility and chemical properties. While the fertilizers are commercialized, the phosphogypsum is disposed in stack piles and can cause an impact in the environment. In order to evaluate the radionuclides and the elements distribution in the industrial process of phosphate fertilizer production, samples of concentrated rock, fertilizers (SSP, TSP, MAP and DAP) and phosphogypsum from three national industries (A, B and C), were analyzed. The characterization of the elements Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn and Zr, and the rare earths La, Ce, Nd, Sm, Eu, Tb, Yb and Lu, were performed by instrumental neutron activation analysis. The results obtained showed that, in general, the rare earth elements are distributed uniformly in the fertilizers and phosphogypsum, except for Lu. The elemental concentration present in the fertilizers SSP and TSP are of the same order of magnitude of the source rock. The same behavior was observed in the fertilizers MAP and DAP, except for the elements Co, Sc and U. The radionuclides of the U series ( 238 U, 234 U, 230 Th, 226 Ra, 210 Pb) and of the Th series ( 232 Th, 228 Ra, 228 Th

Natural Radioactivity in Abu-Tartor Phosphate Deposits and the Surrounding Region, New Valley, Egypt

International Nuclear Information System (INIS)

Khater, A.E.; Higgy, R.H.; Pimpl, M.

1999-01-01

Abu-Tartor phosphate mine. New Valley district, is one of the biggest phosphate mines in Egypt which will start full production soon. The planned ore rocks (24.8%P 2 O 5 ) annual production is 4 million tons. The aim of this study is to estimate the natural radioactivity levels in Abu-Tartor phosphate deposits and the surrounding region. The environmental radioactivity levels in the surrounding region will be considered as pre-operational levels which are essential to determine the radiological impacts of phosphate mining later on. Phosphate samples (ore rocks, wet rocks and beneficiation wastes) and environmental samples (soil, water and plant)were collected. The specific activities of Ra-226 (U-238) series, Th-232 series and K-40 were measured using gamma-ray spectrometry based on Hyper pure Germanium detectors. The specific activities of uranium isotopes (U-238, U-235 and U-234) were measured using alpha spectrometry based on surface barrier detectors after radiochemical separation. The specific activity of Pb-210 was measured using low background proportional gas counting system after radiochemical separation . The results were discussed and compared with national and international values

Radionuclide fluxes at a plant manufacturing dicalcium phosphate for domestic animals

International Nuclear Information System (INIS)

Gaefvert, T.; Holm, E.

2002-01-01

The objectives of this study is to map out the fluxes of radionuclides from the 238 U decay series as well as estimate doses to workers at a dicalcium phosphate plant. At the studied plant phosphate rock is used for the production of dicalcium phosphate, which is a source of calcium and phosphorous for domestic animals. A by-product in the manufacturing process is calcium chloride which is used in the oil industry, food industry and as road salt. In the phosphate rock, the radionuclides were found in secular radioactive equilibrium with an average activity concentration of 830 Bq·kg -1 . Separation and concentration processes was observed. Most of the 226 Ra was found in the calcium chloride while the major part of 238 U was found in the dicalcium phosphate, about 950 Bq·kg -1 . The annual occupational effective dose to workers was found to be below the 1 mSv limit. The study shows a good example of an important non-nuclear industry with a high input of natural radionuclides and several conceivable pathways to man. (author)

The application of isotopic (32P and 15N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

International Nuclear Information System (INIS)

Barea, J.M.; Toro, M.; Azcon, R.; Orozco, M.O.; Campos, E.; Azcon, R.

2002-01-01

A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of 15 N and 32 P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the 15 N/ 14 N ratio in plant shoots indicate an enhancement of the N 2 fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ( 32 P/ 31 P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the test soil that was Ca deficient at neutral

Enhanced stabilization of Pb, Zn, and Cd in contaminated soils using oxalic acid-activated phosphate rocks.

Science.gov (United States)

Zhang, Zhuo; Guo, Guanlin; Wang, Mei; Zhang, Jia; Wang, Zhixin; Li, Fasheng; Chen, Honghan

2018-01-01

Phosphate amendments, especially phosphate rock (PR), are one of the most commonly used materials to stabilize heavy metals in contaminated soils. However, most of PR reserve consists of low-grade ore, which limits the efficiency of PR for stabilizing heavy metals. This study was to enhance the stabilization of heavy metals through improving the available phosphorous (P) release of PR by oxalic acid activation. Raw PR and activated PR (APR) were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analysis, and laser diffraction to determine the changes of structure and composition of APR. The stabilization effectiveness of lead (Pb), zinc (Zn), and cadmium (Cd) in soils by APR was investigated through toxicity leaching test and speciation analysis. The results indicated that after treatment by oxalic acid, (1) the crystallinity of the fluorapatite phase of PR transformed into the weddellite phase; (2) the surface area of PR increased by 37%; (3) the particle size of PR became homogenized (20-70 μm); and (4) the available P content in PR increased by 22 times. These changes of physicochemical characteristics of PR induced that APR was more effective to transform soil heavy metals from the non-residual fraction to the residual fraction and enhance the stabilization efficiency of Pb, Zn, and Cd than PR. These results are significant for the future use of low-grade PR to stabilize heavy metals.

Calcium phosphate granulation in anaerobic treatment of black water: a new approach to phosphorus recovery

NARCIS (Netherlands)

Tervahauta, T.H.; Weijden, van der R.D.; Flemming, R.L.; Hernández, L.; Zeeman, G.; Buisman, C.J.N.

2014-01-01

Recovery of phosphorus from wastewater as calcium phosphate could diminish the need for mining of scarce phosphate rock resources. This study introduces a novel approach to phosphorus recovery by precipitation of calcium phosphate granules in anaerobic treatment of black water. The granules formed

Geology, mineralogy, geochemistry and origin of phosphates from Jandia, Cansa Perna, Itacupim (Para) and Pirocaua and Trauira (Maranhao)

International Nuclear Information System (INIS)

Costa, M. L. da.

1980-01-01

The phosphate occurrences of Northeastern Para and Northwestern Maranhao were formed by strong lateritic weathering of phosphorus-rich Precambrian rocks. The rock formation affected by those processes were phyllites and schists of the Gurupi Group in Cansa Perna and Pirocaua, a complex of felsic to mafic and ultramafic rocks metamorphosed in the greenschist facies in Itacupim and Trauira and probably phosphoritic sandstone in Jandia. The geology, the mineralogy of phosphates, oxides, hydroxides and silicates, the geochemistry of element distribution (aluminium, silicon, iron, calcium, etc) and trace elements distribution (strontium, rubidium, barium, rare earths, zirconium, niobium uranium, thorium, etc) and the phosphates origin are studied. (C.G.C.)

Isolation and identification of a phosphate solubilising fungus from soil of a phosphate mine in Chaluse, Iran

Directory of Open Access Journals (Sweden)

Raheleh Jamshidi

2016-07-01

Full Text Available Microbial solubilisation of phosphorus from insoluble phosphates is an environmental friendly and cost effective approach in sustainable soil management. Introducing the indigenous microorganisms to soil requires shorter adaptation period and causes fewer ecological distortions than exogenous microorganisms. This study was conducted to isolate and identify the indigenous fungi for phosphate solubilisation in Mazandaran, Iran. A potent phosphate solubilising fungus was isolated from an Iranian phosphate mine and selected for solubilisation of rock phosphate (RP. The identified fungus was characterised by calmodulin-based polymerase chain reaction method as Aspergillus tubingensis SANRU (Sari Agricultural Sciences and Natural Resources University. The phosphate solubilisation ability of the fungal strain was carried out in shake-flask leaching experiments containing various concentrations of RP (1%, 2%, 4%, or 8% w/v. The maximum P solubilisation rate of 347 mg/l was achieved at 1% of RP concentration on day 9. The regression analysis indicated that the P solubilised mainly through acidification. This study shows the possibility of using A. tubingensis SANRU for application in the management of P fertilisation.

short communication agronomic effectiveness of novel phosphate

African Journals Online (AJOL)

igneous Dorowa (Zimbabwe) phosphate rock was investigated in a greenhouse ... are higher than the levels considered desirable for acidulation was selected based on proportions ... The analysis for dry matter yield of and P uptake by maize ...

Recent revisions of phosphate rock reserves and resources: reassuring or misleading? An in-depth literature review of global estimates of phosphate rock reserves and resources

Science.gov (United States)

Edixhoven, J. D.; Gupta, J.; Savenije, H. H. G.

2013-09-01

Phosphate rock (PR) is a finite mineral indispensible for fertilizer production and a major pollutant. High grade PR is obtained from deposits which took millions of years to form and are gradually being depleted. Over the past three years, global PR reserves as reported by US Geological Survey (USGS) have seen a massive increase, from 16 000 Mt PR in 2010 to 65 000 Mt PR in 2011. The bulk of this four-fold increase is based on a 2010 report by International Fertilizer Development Center (IFDC), which increased Moroccan reserves from 5700 Mt PR as reported by USGS, to 51 000 Mt PR, reported as upgraded ("beneficiated") concentrate. IFDC used a starkly simplified classification compared to the classification used by USGS and proposed that agreement should be reached on PR resource terminology which should be as simple as possible. The report has profoundly influenced the PR scarcity debate, shifting the emphasis from depletion to the pollution angle of the phosphate problem. Various analysts adopted the findings of IFDC and USGS, and argued that that following depletion of reserves, uneconomic deposits (resources and occurrences) will remain available which will extend the lifetime of available deposits to thousands of years. Given the near total dependence of food production on PR, data on PR deposits must be transparent, comparable, reliable and credible. Based on an in-depth literature review, we analyze (i) how IFDC's simplified terminology compares to international best practice in resource classification and whether it is likely to yield data that meets the abovementioned requirements; (ii) whether the difference between ore reserves and reserves as concentrate is sufficiently noted in the literature, and (iii) whether the IFDC report and its estimate of PR reserves and resources is reliable. We conclude that, while there is a global development toward common criteria in resource reporting, IFDC's definitions contravene this development and - due to their

Radioactivity distribution in phosphate products, by-products, effluents, and wastes

International Nuclear Information System (INIS)

Guimond, R.J.; Windham, S.T.

1975-08-01

Phosphate rock throughout the world contains uranium in concentrations ranging from a few ppM to a few hundred ppM. In the United States, phosphate rock normally contains between 100 to 150 ppM uranium. Mining and processing of these ores redistributes much of the uranium daughters among the various products, by-products, and wastes. These materials are then widely dispersed throughout the environment. This redistribution may lead to increased exposure of the public to these naturally-occurring radionuclides. In determining the magnitude of the population exposure caused by this redistribution and in developing environmental standards and controls to prevent contamination of the biosphere from these naturally-occurring radionuclides it is necessary to determine the concentrations and total quantities of these radionuclides in the products, by-products, effluents and wastes of phosphate mining and manufacturing. Samples of phosphate ores, products, by-products, effluents, and wastes were obtained and analyzed for their radioactivity content. Quantities of radioactivity entering the environment through various products, by-products, effluents, and wastes were estimated

Phosphate fertilizers with varying water-solubilities applied to Amazonian soils: I. agronomic efficiency of P sources

International Nuclear Information System (INIS)

Brasil, E.C.; Muraoka, T.; Boaretto, A.E.; Scivittaro, W.B.

2002-01-01

The relative agronomic efficiency of four phosphate sources (triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin thermophosphate and North Carolina phosphate rock) were evaluated, in a pot experiment carried out under greenhouse conditions, using five soils (medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic) from Para State, Brazil. The soils received three rates of phosphorus (40, 80 and 120 mg P/kg of soil) plus the control (0P) treatment. A randomized block design with three replicates was used. Two consecutive crops (cowpea and rice) were used as test plants. The results showed that the best dry matter yield and P uptake for cowpea were obtained in soils fertilized with triple superphosphate. The agronomic efficiency index of ordinary Yoorin was superior to the coarse Yoorin and North Carolina phosphate rock for the cowpea grown as first crop. The indices were similar for all phosphate sources for the subsequent rice crop. The best residual effect was obtained with North Carolina phosphate rock and coarse Yoorin. The larger particle size of coarse thermophosphate resulted in a decreased P efficiency. (author)

Issues of natural radioactivity in phosphates

International Nuclear Information System (INIS)

Schnug, E.; Haneklaus, S.; Schnier, C.; Scholten, L.C.

1996-01-01

The fertilization of phosphorus (P) fertilizers is essential in agricultural production, but phosphates contain in dependence on their origin different amounts of trace elements. The problem of cadmium (Cd) loads and other heavy metals is well known. However, only a limited number of investigations examined the contamination of phosphates with the two heaviest metals, uranium (U) and thorium (Th), which are radioactive. Also potassium (K) is lightly radioactive. Measurements are done n the radioactivity content of phosphates, P fertilizers and soils. The radiation doses to workers and public as well as possible contamination of soils from phosphate rock or fertilizer caused by these elements or their daughter products is of interest with regard to radiation protection. The use of P fertilizers is necessary for a sustainable agriculture, but it involves radioactive contamination of soils. The consequences of the use of P fertilizers is discussed, also with regard to existing and proposed legislation. 11 refs., 2 figs., 7 tabs

PRINCIPAL COMPONENT ANALYSIS OF FACTORS DETERMINING PHOSPHATE ROCK DISSOLUTION ON ACID SOILS

Directory of Open Access Journals (Sweden)

Yusdar Hilman

2016-10-01

Full Text Available Many of the agricultural soils in Indonesia are acidic and low in both total and available phosphorus which severely limits their potential for crops production. These problems can be corrected by application of chemical fertilizers. However, these fertilizers are expensive, and cheaper alternatives such as phosphate rock (PR have been considered. Several soil factors may influence the dissolution of PR in soils, including both chemical and physical properties. The study aimed to identify PR dissolution factors and evaluate their relative magnitude. The experiment was conducted in Soil Chemical Laboratory, Universiti Putra Malaysia and Indonesian Center for Agricultural Land Resources Research and Development from January to April 2002. The principal component analysis (PCA was used to characterize acid soils in an incubation system into a number of factors that may affect PR dissolution. Three major factors selected were soil texture, soil acidity, and fertilization. Using the scores of individual factors as independent variables, stepwise regression analysis was performed to derive a PR dissolution function. The factors influencing PR dissolution in order of importance were soil texture, soil acidity, then fertilization. Soil texture factors including clay content and organic C, and soil acidity factor such as P retention capacity interacted positively with P dissolution and promoted PR dissolution effectively. Soil texture factors, such as sand and silt content, soil acidity factors such as pH, and exchangeable Ca decreased PR dissolution.

Environmental prospects of uranium from mineral phosphates

International Nuclear Information System (INIS)

Schnug, Ewald; Haneklaus, Nils

2012-01-01

Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10 6 average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO 2 depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

Environmental prospects of uranium from mineral phosphates

Energy Technology Data Exchange (ETDEWEB)

Schnug, Ewald [Technische Univ. Braunschweig (Germany). Faculty 2 - Life Sciences; Haneklaus, Nils [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme

2012-12-15

Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10{sup 6} average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO{sub 2} depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

Comment on: "Recent revisions of phosphate rock reserves and resources: a critique" by Edixhoven et al. (2014) - clarifying comments and thoughts on key conceptions, conclusions and interpretation to allow for sustainable action

Science.gov (United States)

Scholz, R. W.; Wellmer, F.-W.

2016-02-01

Several recent papers deal with concerns about the longevity of the supply of the mineral phosphorus. The paper by Edixhoven et al. (2014), for instance, expresses doubts about whether the upward estimate of reserves by the IFDC (2006, 2010) and the USGS (2010) provides an accurate, reliable, and comparable picture, as it is based on reports that do not clearly differentiate between phosphate ore and phosphate products (i.e., marketable phosphate rock concentrate). Further, the indistinct use of the terms reserves and resources is criticized. Edixhoven et al. (2014) call for a differentiated inventory of world phosphate reserves including "guidelines which determine the appropriate drill hole distances and a detailed granularity". The claim that "humanity is on the safe side" with respect to future phosphate supply is doubted, as the validity of the IFDC's upgrading of the Moroccan data to 50 Gt phosphate is questioned. The main achievement of Edixhoven et al. (2014) is to elaborate that in the literature frequently used data on phosphate rock ore and phosphate concentrate are not properly distinguished, resulting in incorrect summary figures. In addition, it is commendable to raise the question how transparency concerning reserve and resources data and information on the geopotential of phosphate can be achieved because phosphorus is a special element. As fertilizer, it cannot be substituted and there are no unlimited resources as for the other main nutrients potassium in sea water and nitrogen in the air. However, the paper by Edixhoven et al. (2014) contains in the opinion of the authors some incorrect statements. Our comment elaborates first that several statements, such as that the upgrading of the Moroccan data is "solely based" on one scientific paper, are incorrect. Secondly, the paper comments on and illuminates a set of, in our opinion, misleading statements. These include the fact that the dynamic nature of reserves (which depend on price, technology

Evaluation of phosphate rock as a p-source in the cropping system of upland rice - soybean - mungbean

International Nuclear Information System (INIS)

Rasyid, Havid; Sisworo, Elsye L.; Siswoyo, Wijang H.

1998-01-01

A seri of pot fertilizer experiments has ben carried out in the cropping system of upland rice - soybean - mungbean by using Red Yellow podsolic soil from Batumerta, South Sumatra. Three phosphate rock (PR) with 3 different sizes and 2 levels of tsp were used as a check and were applied in this study. The results showed that fertilization with PR could increase weight of day plant, % total-P, and total-P uptake . The contribution of P-derived from PR and TSP was determined using the dilution method 32 P isotope. the values for P-derived from PR or TSP raged from 26. % to 89.4 % efficiency of was from 0.15 % to 1.66%, and for TSP it ranged from 1.78 % to 20.0%. Increasing the levels of P-fertilizer either PR or TSP will decrease the P efficiency. Where the order for plants are : efficiency of P upland rice >soybean > mungbean. (author)

Correlation study of chemical elements in phosphate ores

International Nuclear Information System (INIS)

Braganca, Maura Julia Camara da Silva

1999-07-01

Geological phenomena, 1) endogenous (volcanism, magmatic flow, metasomatism); 2) metamorphic (resultant of action of high temperature and pressure) and; 3) exogenous (intemperism, contamination) can modify the chemical composition of rocks soils. Thus, chemical elements with little mobility can be used as indicators of the previous geological situation before the occurrence of these phenomena and can sign the chemical composition of the initial formation. The elements with great mobility can already be used as indicators of the characteristic and intensity of the changes, can point out the influence factors and its space and time conditions. In this work the results of the study of phosphated samples ores coming from two alkaline-carbonatitic chimneys (Araxa and Catalao) and from a meta sedimentary rock (Patos de Minas), located phosphate rock deposit, are presented. The results were obtained using the instrumental neutron activation analysis, inductively coupled plasma-mass spectrometry (ICP-MS) and ICP-AES techniques. A comparison of the three types of samples ores, using chemical, crystallographic and statistical methods, shows that the Araxa and Catalao present some geochemical similarities and they are distinguished of Patos de Minas, despite its geographic proximity. (author)

Effect of Combined Application of Phosphate Solubilizing Bacteria and Phosphrous Fertilizer on Growth and Yield of Sesame

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S. Nikmehr

2016-02-01

phosphorous fertilizer (0, 100, 200 and 400 kg ha-1 of triple superphosphate and 1200 kg ha-1 of rock phosphate and three bacterial levels (inoculation with two phosphate solubilizing fluorescent pseudomonad, isolates of P3 and P5 that known in this study as B1 and B2 and non-inoculated. It should be noted that rock phosphate used in this study has contained 4% of zinc oxide. The bacteria selected from microbial bank of Vali-E-Asr University were able to dissolve the insoluble phosphate and produce siderophore and IAA. Four months after planting, plants were cut at the soil surface, and shoot dry weight, stem height, number of Seeds in pot, seed dry weight and seed oil percentage were recorded. Also phosphorus and Zinc contents in shoot were determined. Results and Discussion: Results indicated that both bacteria (B1 and B2 significantly increased shoot dry weight and B1 increased seed dry weight. Also application of phosphorus fertilizer significantly increased shoot dry weight and plant height. 200 kg ha-1 of triple superphosphate had highest shoot dry weight and was similar with rock phosphate. Combined application of Phosphorous fertilizer and phosphate solubilizing bacteria increased shoot dry weight. Results also showed that seed oil was increased by application of Phosphate rock. Phosphorus concentration in seed was increased with Using B1 and B2 isolates. Application of B2 significantly increased phosphorus concentration in seed (11.5% and Phosphorous fertilizer levels increased concentration of P and Zn in seed. Application of 200 and 400 kg ha-1 triple superphosphate had the highest concentration of P and Zn in seed. Phosphorus fertilizer levels significantly enhanced uptake of P and Zn in shoot. Application of 200 and 400 kg ha-1 triple superphosphate led to increased uptake of phosphorous in shoot. Also rock phosphate significantly increased uptake of Zn in shoot. Combined application of Rock phosphate and bacteria of B1 and B2 had more significant effects on

"A Comparison of Several Methods in a Rock Slope Stability ...

African Journals Online (AJOL)

This researchuses the mentioned methods and principles in the stability analysis of some rock slopes in an open pit mine in Syria, that is Khneifees phosphate mine. The importance of this researchis that it shows the role of kinematical analysis in minimizing efforts when verifying the safety of rock slopes in site, and when ...

The effect of carbon dioxide during the desulfurization of flue gas with Mardin-Mazidagi phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Melike Sinirkaya; Hatice Bayrakceken; A. Kadir Ozer; M. Sahin Gulaboglu [Ataturk University, Erzurum (Turkey). Department of Chemical Engineering

2008-11-15

The effects of temperature, CO{sub 2} concentration and particle size on simultaneous calcination/sulfation of Mardin-Mazidagi phosphate rock in fluidized-bed reactor were investigated. For this, a raw sample was exposed to calcination and sulfation processes in a fluidized-bed reactor to determine the effects of parameters by using a model gas mixture similar to the flue gas composition. The calcination ratio increased with increasing temperature and decreasing particle size, but decreased with increasing CO{sub 2} concentration. In sulfation process, however, sulphate conversion ratio increased with increasing CO{sub 2} ratio and decreased with decreasing particle size. The sulfation reaction is well represented by the shrinking core model and can be divided into two regions with different rate controlling step. For low conversions, the controlling step was found to be chemical reaction at the interface, but the diffusion through the product layer for high conversion. The activation energies for the chemical reaction at the interface and diffusion through the product layer cases were calculated as 100 and 296 kJ mol{sup -1}, respectively. 23 refs., 13 figs., 1 tab.

Thermo-tolerant phosphate-solubilizing microbes for multi-functional biofertilizer preparation.

Science.gov (United States)

Chang, Cheng-Hsiung; Yang, Shang-Shyng

2009-02-01

In order to prepare the multi-functional biofertilizer, thermo-tolerant phosphate-solubilizing microbes including bacteria, actinomycetes, and fungi were isolated from different compost plants and biofertilizers. Except Streptomycesthermophilus J57 which lacked pectinase, all isolates possessed amylase, CMCase, chitinase, pectinase, protease, lipase, and nitrogenase activities. All isolates could solubilize calcium phosphate and Israel rock phosphate; various isolates could solubilize aluminum phosphate, iron phosphate, and hydroxyapatite. During composting, biofertilizers inoculated with the tested microbes had a significantly higher temperature, ash content, pH, total nitrogen, soluble phosphorus content, and germination rate than non-inoculated biofertilizer; total organic carbon and carbon-to-nitrogen ratio showed the opposite pattern. Adding these microbes can shorten the period of maturity, improve the quality, increase the soluble phosphorus content, and enhance the populations of phosphate-solubilizing and proteolytic microbes in biofertilizers. Therefore, inoculating thermo-tolerant phosphate-solubilizing microbes into agricultural and animal wastes represents a practical strategy for preparing multi-functional biofertilizer.

Field trials on the store dressing with rock phosphate

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Pentti Hänninen

1960-01-01

Full Text Available The possibility of improving the soil phosphorus status by a store dressing with rock phosphate has been studied in two field trials of five years standing. Hyperphosphate Reno was applied to the nurse crop of a red clover-timothy ley in amounts of 0, 1000 kg/ha, or 2000 kg/ha, respectively. The split-plot technique was used to study the response of the ley to an additional annual application of 200 kg/ha of superphosphate. The soil analyses distinctly proved that, in spite of a careful working in of the hyperphosphate with a spade harrow, the fertilizer had not penetrated deeper than to the layer from 1 to 3 inches, with a large part of it remaining in the top inch. The treatment with hyperphosphate had mostly increased the fraction of the calcium-bound phosphorus, and, to a very low degree, the aluminium-bound phosphorus. The effect of superphosphate could be detected only in the fractions of aluminium- and iron-bound phosphorus of the surface inch. Although the store dressing did not produce marked responses in the yields of either trial, the statistically significant negative interaction between the effect of it and of superphosphate may be taken to indicate that hyperphosphate was able to improve the phosphorus status of these soils to some degree. The analyses of the hay samples from one of the trials in the fifth experimental year showed that the store dressing, particularly with the higher amount of hyperphosphate was able to increase the phosphorus content of hay to a satisfactory level which was equal to that produced by the annual superphosphate dressing only. Their combined effect resulted in the production of hay dry matter containing more than 0.24 % of P. In one of the experiments the residual effect of the treatments on rye was studied. The response to superphosphate was highly significant, probably owing to the high demands of phosphorus by rye, connected with the overwintering conditions, and also to the fact that ploughing in

The application of isotopic ({sup 32}P and {sup 15}N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

Energy Technology Data Exchange (ETDEWEB)

Barea, J.M. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)]. E-mail: jmbarea@eez.csic.es; Toro, M.; Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain); Orozco, M.O. [Instituto de Sistematica y Ecologia, Academia Cubana de Ciencias, Habana (Cuba); Campos, E. [Departamento de Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin (CSIC), Granada (Spain); Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)

2002-05-15

A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of {sup 15}N and {sup 32}P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the {sup 15}N/{sup 14}N ratio in plant shoots indicate an enhancement of the N{sub 2} fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ({sup 32}P/{sup 31}P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the

Intercomparison of radon emanation in Moroccan and Tunisian phosphate rocks

International Nuclear Information System (INIS)

Khalil, A.; Membrey, F.; Klein, D.; Chambaudet, A.; Iraqui, R.

1992-01-01

We suggest a method for measuring the emanation of radon gas of phosphates mineral from different origins using solid state track nuclear detectors (CR39 and LR115) with the aim to determinate radioactivity effects on the human. (author)

Evaluation of factors that affect bioacidulation rock phosphate under in vitro conditions

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Laura Osorno Bedoya

2017-01-01

Full Text Available Phosphorus (P is an essential nutrient for plant development, unfortunately, its availability in many soils is low. Consequently, farmers apply high quantities of soluble P fertilizers, but this is an inefficient and costly practice. The direct use of rock phosphate (RP is a highly attractive option because its low cost, but this material has low solubility and low agronomic efficiency. In order to overcome this limitation, there is a growing interest in the use of soil microorganisms capable of dissolving RP and improving its value as a P fertilizer. The objective of this study was to evaluate the effect of some factors on the effectiveness of the fungus Mortierella sp. to dissolve RP under in vitro conditions. These factors included: (i incubation time, (ii type of RP, (iii initial concentration of soluble P, and (iv addition of vitamins and micronutrients. After the incubation period, P and pH were measured in solution. The results indicated that as a consequence of the biodissolution of RP, the highest concentration of soluble P in the medium was reached on the day 5th. The biodissolution of RP was reduced by the addition of vitamins and micronutrients and by the increase in the initial concentration of soluble P. Although microbial dissolution was more effective with North Carolina RP, RPs from Huila and Santander showed a good level of dissolution in a short period of time. Bioacidulation will improve the agronomic effectiveness of RP for its direct use or through a previous biotechnological process.

Effect of diazotrophic bacteria as phosphate solubilizing and indolic compound producers on maize plants

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Mónica Del Pilar López Ortega

2013-07-01

Full Text Available Phosphorus is limiting for growth of maize plants, and because of that use of fertilizers like Rock Phosphate has been proposed. However, direct use of Rock Phosphate is not recommended because of its low availability, so it is necessary to improve it. In this study, a group of diazotrophic bacteria were evaluated as phosphate-solubilizing bacteria, for their production of indolic compounds and for their effects on growth of maize plants. Strains of the genera Azosporillum, Azotobacter, Rhizobium and Klebsiella, were quantitatively evaluated for solubilization of Ca3(PO42 and rock phosphate as a single source of phosphorous in SRS culture media. Additionally, the phosphatase enzyme activity was quantified at pH 5.0, 7.0 and 8.0 using p-nitrophenyl phosphate, and production of indolic compound was determined by colorimetric quantification. The effect of inoculation of bacteria on maize was determined in a completely randomized greenhouse experiment where root and shoot dry weights and phosphorus content were assessed. Results showed that strain C50 produced 107.2 mg .L-1 of available-P after 12 days of fermentation, and AC10 strain had the highest phosphatase activity at pH 8 with 12.7 mg of p-nitrophenol mL .h-1. All strains synthetized indolic compounds, and strain AV5 strain produced the most at 63.03 µg .mL-1. These diazotrophic bacteria increased plant biomass up to 39 % and accumulation of phosphorus by 10%. Hence, use of diazotrphic phosphate-solubilizing bacteria may represent an alternative technology for fertilization systems in maize plants.

The mineralogical behavior of the phosphatic sedimentation in Pernambuco-Paraiba sedimentar coastal basin

International Nuclear Information System (INIS)

Albuquerque Menor, E. de; Amaral, A.J.R. do

1979-01-01

This work reports the execution of the ''Phosphate in the Sedimentary coastal zone of Pernambuco-Paraiba'' Project, resulting from the execution of 35 drilling holes distributed between Paulista City, State of Pernambuco and the Miriri river valley, State of Paraiba. The rocks were analysed by X-ray diffraction, and the results were used in the working up of mineralogical logs. The mineralogical logs interpretation makes possible to distinguish phosphorite and sandy phosphorite areas inside a mineralization zone, wich laterally passes to a phosphatic carbonatic rocks area situated far from cost line of that epoch. Differences of the mineral paragenesis are used under a regional sedimentar model conception and indicated as prospecting guides. The dominance of Kaolinite is related to continental sediments (Beberibe Formation). The dominance of montmorillonite, on the other hand, is more to marine facies than to particular conditions of the phosphatic mineralization. The analysis of these conditions shows that the continental areas resistant to the pre-Maestrichtrian transegressive oscillations coincide to the more favourable places to the phosphatic mineralization. (author) [pt

Uranium traps in the phosphate bearing sudr chalk, in northeastern sinai, Egypt

International Nuclear Information System (INIS)

Hussein, H.A.; El-Aassy, I.E.; Mahdy, M.A.; Dabbour, G.A.; Mansour, M.Gh.; Morsy, A.M.

1998-01-01

The maastrichtian sudr formation in northeastern sinai is composed of three members, the lower chalk, the middle phosphate and chart-bearing and the upper chalk members. Lemon yellow secondary uranium mineralization, distributed in the lower chalk member and in some phosphate beds from the middle phosphate member are observed. The XRD analyses of some samples from the uranium bearing chalk and the phosphate beds showed the presence of the secondary uranium minerals carnotite, bergenite and upalite. The mode of uranium occurrences could be interpreted as a result of the phosphatic beds decomposition and their subjection to later diagenetic processes. Uranium leaching circulation from phosphate rocks led to the liberation of uranium from the phosphates, and vanadium from the bituminous material and clay minerals. These migrated and were deposited locally and within the underlying chalk beds which acted as a lithologic trap

Phosphate ore beneficiation via determination of phosphorus-to-silica ratios by Laser Induced Breakdown Spectroscopy

International Nuclear Information System (INIS)

Asimellis, George; Giannoudakos, Aggelos; Kompitsas, Michael

2006-01-01

We report development and application of an in-situ applicable method to determine phosphate ore rock quality based on Laser-Induced Breakdown Spectroscopy (LIBS). This is an economically viable method for real-time evaluation of ore phosphate rocks in order to separate high-silica pebbles prior to deep beneficiation. This is achieved by monitoring relative emission line intensities from key probe elements via single laser ablation shots: the ratio of the phosphorous to silica line intensities (P/Si ratio) provides a simple and reliable indicator of ore rock quality. This is a unique LIBS application where no other current analytical spectroscopic method (ICP or XRF) can be applied. Method development is discussed, and results with actual ore samples are presented

Environmental considerations on uranium and radium from phosphate fertilizers

International Nuclear Information System (INIS)

Cioroianu, T.M.; Bunus, F.; Filip, D.; Filip, Gh.

2001-01-01

In the process of fertilizer production from natural phosphates of sedimentary origin, most of the existing radioactivity will be found in the final product. The phosphates exploited for fertilizer production at about 150 mill. tons/year are processed by two chemical methods: sulphuric and nitric acid attack. In the process of sulphuric acid attack of the phosphate rock, phosphoric acid and phosphogypsum are produced. The first product is used for fertilizer production, either as triplesuperphosphate (TSP) or diammonium phosphate (DAP). The phosphogypsum waste is deposited on stacks thus becoming a source of concern. In the case of nitric acid attack, the result is a phosphonitric (PN) solution, which is used to produce a complex fertilizer NPK. Uranium and 226Ra (usually in secular equilibrium) are dissolved and distributed between the intermediary products. Thus the average concentration of 100 mg/kg U in the phosphate rock is dissolved in 90-95 % in phosphoric acid while the 226Ra of initial 1000 / 2000 Bq/kg concentration is completely precipitated together with phosphogypsum. Therefore phosphogypsum waste has 1000-1500 Bq/kg 226Ra. The TSP fertilizer being produced by partial neutralization of phosphoric acid with phosphate rock with 100-150 mg/kg U, while 226Ra is only introduced in the neutralization process i.e. 500-800 Bq/kg. In the case of DAP, the uranium content is 140-170 mg/kg without the present of 226Ra. The complex fertilizer obtained through the process of nitric acid attack will have the whole uranium and radium of the phosphate rock (both are dissolved in nitric acid) with uranium and radium contents of 120-160 mg/kg, 1000-1500 Bq/kg respectively. The radioactivities of fertilizers produced may be a source of concern since both uranium and radium are exceeding the present accepted limits for their disposal in the environment. About 10,000-15,000 tons/yr. of uranium is spread every year on the agricultural lands worldwide by the use of phosphate

Evaluating the effectiveness of phosphate fertilizers in some Venezuelan soils

International Nuclear Information System (INIS)

Casanova, E.; Salas, A.M.; Toro, M.

2002-01-01

In Venezuela, 70% of the soils are acid with low natural fertility where phosphorus is the most limiting element together with nitrogen and potassium for plant growth. The efficiency of phosphate fertilization is low. Greenhouse and field experiments were conducted to evaluate the efficiency of natural and modified rock phosphate using conventional and isotopic techniques. An incubation experiment was done to measure changes in available P on application of different phosphate fertilizers at a constant rate of 100 mg P/kg in ten acid soils of agricultural importance in Venezuela. In the greenhouse, two experiments were conducted to relate P fixation to soil P availability and the response of an index plant (Agrostis sp.). A high variability in P fixing capacity of the soils (r1/Ro = 0.02-0.76) was observed with the same level of available P. This fixation index is defined as the proportion of the added radioactivity ( 32 P) remaining in the soil solution after 1 min of exchange and a low fixing capacity is indicated by the values close to 1. The proportion of the total soil P that can possibly enter the soil solution and therefore is potentially available for plant uptake was measured using the traditional method (Bray I) and the isotopic method (E value). The high variability was also apparent in available P extracted by Bray I showing a range of 10 to 88% of the total P removed by the extracting solution. The incubation studies showed that the effectiveness of the P source for available P in the soil solution was related to their reactivity and the soil P fixing properties. The increase in the fixing capacity of the soils used caused a significant reduction in the E value, independent of the source of P used. A high positive and significant correlation between Bray I extracted P and the E value (r = 0.95) obtained from the different treatments, showed the relationship of the extractant for some forms of available P in soils where rock phosphate was applied. In

Efficacité de la roche phosphatée de Matongo au travers d'un compostage sur une culture de pomme de terre sur un sol acide de Rabiro (Burundi

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Van den Berghe, C.

1993-01-01

Full Text Available Efficiency of phosphatic rock from Matongo applied in the composting process on potatoes on an acid soil of Rabiro. In the frame of the Cooperation between the CVHA (Cultures Vivrieres de Haute Altitute Project and the Program of Fertilisation of the Agro-systems on Altitude (FAVA of the Faculty of Agricultural Sciences in Burundi, the local phosphatic rock from Matongo has been compared to diammonium-phosphate when added in the composting process. The field trials with potatoes have shown that both phosphate sources have the same fertilizing value when the enriched compost was applied at the dose of 20 t/ha. It is very interesting from agricultural and economical viewpoint to use this phosphatic rock in combination with compost.

The use of 32P radioisotope techniques for evaluating the relative agronomic effectiveness of phosphate rock materials in a soybean-maize crop rotation in acid soils of Thailand

International Nuclear Information System (INIS)

Mahisarakul, J.; Pakkong, P.

2002-01-01

A series of greenhouse experiments was conducted over three years to evaluate the relative agronomic effectiveness (RAE) of phosphate rock materials in a soybean - maize crop sequence, using 32 P isotope dilution techniques. For the first two years, the crops were grown in a pot experiment in four acid soils of Thailand. In the first year, four increasing rates of TSP and one rate of four phosphate rocks (PRs) were used. The PRs used were Algerian PR, North Carolina PR, Petchaburi PR, and Ratchaburi PR. Soybean did not respond to P application from TSP, while there was good response in maize which was planted after soybean (1st residual effect). The percent P derived from TSP or PR fertilizer (%Pdff) had the following order: Warin soil > Mae Tang soil > Rangsit soil > Pakchong soil for soybean and Warin soil > Pakchong soil > Rangsit soil > Mae Tang soil for maize. In the second year, the soybean - maize rotation was replanted to study the residual effect of TSP and PRs, both applied at 180 mg P kg -1 . No significant response of soybean and maize to TSP was found in terms of dry matter yield. In terms of %Pdff and %RAE the soils ranked as follows: Rangsit soil > Pakchong soil Mae Tang soil > Warin soil for soybean and Warin soil > Rangsit soil > Mae Tang > Pakchong soil for maize. Both crops absorbed more P from TSP than from PRs. The %RAE in the 2nd year experiment was higher than %RAE in the 1st year In the third year, TSP and two PRs were applied at one P rate to Pakchong and Warin soils. The applied PRs were North Carolina PR (NCPR) and Lamphun phosphate rock (LPPR). PRs were applied either alone or in combination with TSP (50:50). Soybean was planted first, followed by maize. The P-response in terms of dry matter yield and %Pdff was highly significant in both soils. The RAE ranked as follows: TSP > NCPR + TSP > LPPR + TSP > NCPR > LPPR. Maize showed the same trend in RAE as soybean in both soils. The RAE for both crops was highest in Warin soil. (author)

Recent revisions of phosphate rock reserves and resources: a critique

Science.gov (United States)

Edixhoven, J. D.; Gupta, J.; Savenije, H. H. G.

2014-12-01

Phosphate rock (PR) is a finite mineral indispensable for fertilizer production, while P (phosphorus) is a major pollutant if applied or discharged in excess, causing widespread eutrophication (Carpenter and Bennet, 2011). High-grade PR is obtained from deposits which took millions of years to form and which are gradually being depleted. Recently, global PR reserves as reported by the US Geological Survey (USGS) have increased from 16 000 Mt PR in 2010 to 65 000 Mt PR in 2011 and further to 67 000 Mt PR in 2014. The majority of this 4-fold increase is based on a 2010 report by the International Fertilizer Development Center (IFDC), which increased Moroccan reserves from 5700 Mt PR as reported by USGS, to 51 000 Mt PR, reported as upgraded ("beneficiated") concentrate. The report also increased global resources from 163 000 Mt PR reported in the literature in 1989 to 290 000 Mt PR. IFDC used a simplified resource terminology which does not use the underlying thresholds for reserves and resources used in the USGS classification. IFDC proposed that agreement should be reached on PR resource terminology which should be as simple as possible. The report has profoundly influenced the PR scarcity debate, shifting the emphasis from resource scarcity to the pollution angle of the phosphate problem. In view of the high dependence of food production on PR and the importance of data on PR reserves and resources for scientific analysis and policy making, data on PR deposits should be transparent, comparable, reliable, and credible. We analyze (i) how IFDC's simplified terminology compares to international best practice in resource classification and whether it is likely to yield data that meet these requirements, (ii) whether the difference in volume between raw PR ore and upgraded PR concentrate is sufficiently noted in the literature, and (iii) whether the IFDC report presents an accurate picture of PR reserves and resources. We conclude that, while there is a global

Use of radioactive 32P technique to study phosphate rock dissolution in acid soils

International Nuclear Information System (INIS)

Mahisarakul, J.; Mullins, G.L.; Chien, S.H.

2002-01-01

A laboratory experiment was conducted to evaluate the dissolution of six sources of phosphate rock in two acid soils (Ultisols): a sandy soil and a red clay soil. Labile P was determined using the radioactive 32 P technique for Pi extractable P and resin extractable P. Incubations were conducted for 0, 1, 2, 3, 4 and 5 weeks for 32 P exchangeable technique, 0 and 5 weeks for Pi technique and 5 weeks for resin technique. Rates of PR were 0 and 400 mgP/ha. The results showed that labile P in the sandy soil decreased from 0-1 weeks for all the PRs except Hahotoe PR and Hazara PR's. Between 1 and 5 weeks labile P remained relatively constant. The ranking of labile P from PRs was: North Carolina = Kouribga > Matam > Hahotoe = Hazara> Patos de Minas. In the red soil, labile P from all PRs appeared to be relatively unchanged during the 0-5 week incubation. Pi extractable P in sandy soil showed no significant differences due to incubation time. In the red clay soil, there was a significant decrease in Pi-P extracted from soil mixtures with PRs after 5 weeks as compared to 0 weeks. Results of the Resin-extractable P in both sandy and red soils were in agreement with labile P as measured by 32 P exchange technique. (author)

Analysis of arab ore phosphate, for macro, micro and toxic elements using INAA method

International Nuclear Information System (INIS)

El-Ghawi, U.M.; Abugassa, I.O.; Alfakhri, S.M.

2003-01-01

Natural phosphates are used on large scale in the fertilizer industry and large quantities of phosphates are processed each year all over the world from fertilizer production. At present world usage of rock phosphates is approximately 90 million tons per annum. Because natural phosphates are a source of some valuable elements besides phosphorus used in fertilizers production, the objective of this paper is to check the level of radioactive elements of uranium and thorium, and the stable environmental pollutants like As and Cr in natural arab phosphate. In addition, rare earth elements (REEs) and other elements like (Fe, K, Mn, Na and Ti) were determined

The Response to P-Derived from Phosphate Rock and TSP by Crops Grown in a Simulated Crop Rotation System

International Nuclear Information System (INIS)

Sisworo, Elsye L; Sisworo, Widjang H; Havid-Rasjid; Syamsul-Rizal; Komarudin-Idris

2002-01-01

A green house experiment was carried out on a simulated crop rotation system of upland rice-soybean-mungbean to determine the effect of P-derived from different phosphate rock (PR) sources and TSP using 32 P. The data obtained reveal that all the P-sources has a significant effect on the growth of all the three crops, expressed in dry weight, % P-total and total P-uptake (mg P pot -1 ). For the P-source it was shown that % P-derived from PR/TSP and their uptake (mg P pot -1 ) was quite high, showing that the PR s applied were of good reactivity. The residue of the PR s has also still a good effect on plant growth than that of TSP. The efficiency of PR s was far below that of TSP. This apparently was due to the high rate of application, ten times the rate of TSP. (author)

Massilia phosphatilytica sp. nov., a phosphate solubilizing bacteria isolated from a long-term fertilized soil

DEFF Research Database (Denmark)

Zheng, Bang Xiao; Bi, Qing Fang; Hao, Xiuli

2017-01-01

A Gram-stain-negative and rod-shaped bacterial strain, 12-OD1T, with rock phosphate solubilizing ability was isolated from agricultural soil in Hailun, Heilongjiang, PR China. The isolate was affiliated to the genus Massilia, based on 16S rRNA gene sequence alignments, having the highest similari......A Gram-stain-negative and rod-shaped bacterial strain, 12-OD1T, with rock phosphate solubilizing ability was isolated from agricultural soil in Hailun, Heilongjiang, PR China. The isolate was affiliated to the genus Massilia, based on 16S rRNA gene sequence alignments, having the highest...

Influence of arbuscular mycorrhizal fungi, rhizobium inoculation and rock phosphate on growth and quality of lentil

International Nuclear Information System (INIS)

Yaseen, T.; Ali, K.

2016-01-01

Effective inoculation of legumes has the ability not only to ensure nutrients availability to plants particularly in N and P-limiting (due to improvement in nutrients fixation) environments but also can manipulate the environmental hazards associated with over inorganic fertilization. To support this view, the current experiment was conducted to study the influence of rock phosphorus fertilization, Arbuscular Mycorrhizae (AM) and Rhizobium inoculation on growth and yield parameters of Lens culinaris (NARC.2008-4). In addition, the current experiments aimed to evaluate the effect of different inoculation practices on crop quality in comparison with control (no inoculation).The experiment was laid out in randomized complete block design with four replications during winter (2010-11 and 2012-13) at the Department of Botany University of Peshawar Pakistan. Overall, inoculated plant performed superior in terms of plant growth and quality over control. All plants measured parameters (Leaf chlorophyll content, seed protein, fiber and ash content, plant height, number of seed pod-1, leaves plant-1, flowers plant-1, pods plant-1, pod length and thousand seed weight) were highest in plant samples inoculated with VAM and Rhizobium in combination as compared to sole application of VAM or Rhizobium. Combined inoculation of VAM and Rhizobium caused 10, 24, 17, 21 and 14% increase in seed protein content, leaf chlorophyll content, seed fiber content, seed ash content and number of seed pod-1 over sole application of VAM and Rhizobium when averaged over two years. Combined application of Rhizobium + VAM enhanced seed yield plant-1 by 45% over control and 24% and 28% over sole inoculation of VAM and Rhizobium respectively. It is therefore concluded that dual inoculation of VAM + Rhizobium and rock phosphate may be of only limited consequence in high input agricultural systems. (author)

Biosuper as a phosphate fertilizer in a calcareous soil with low ...

African Journals Online (AJOL)

SERVER

2007-06-04

Jun 4, 2007 ... Key words: Zea mays, phosphorus uptake, phosphorus fertilization, corn, Thiobacillus, rock phosphate. ... improve plant nutrients availability in calcareous soils and .... lus elicits the reaction of sulphur with water and oxygen, ...

Improving phosphorus availability from Patos phosphate rock for Eucalyptus: a study with 32P radiotracer

International Nuclear Information System (INIS)

Villanueva, Felipe Carlos Alvarez; Muraoka, Takashi; Trevizam, Anderson Ricardo

2006-01-01

Eucalyptus plantation in Brazil is generally set on low fertility soils, therefore phosphorus (P) fertilization is mandatory and increases the cost of plantation operation. Using species that more efficiently uptake phosphorus from less soluble sources is an interesting option. However, little is known about eucalyptus regarding its ability of using less soluble forms of phosphorus. The use of P by eucalyptus (E. urophylla, E. grandis, and E. urophylla E. grandis) was studied in greenhouse using a loamy-textured, hipodystrophic Typic Haplustox from the Cerrado region, and 32P isotopic method. The P sources tested were triple superphosphate (TSP), phosphate rock (PR) and the triple superphosphate mixed with PR (TSP+PR). The effectiveness of P sources in terms of increasing dry matter yield was TSP = (TSP + PR) > PR, and the P uptake followed the order (TSP + PR) > TSP > PR for both species plus the hybrid. The increase in P uptake from PR due to TSP influence was 217.3% for E. urophylla, 235.7% for E. grandis, and 28.7% for E. urophylla E. grandis, indicating an enhancement effect of TSP on the effectiveness of PR. The hybrid E. urophylla E. grandis was the most efficient genotype on P soil use and E. grandis most exigent in P fertilizer. (author)

BIOMETRIC PARAMETERS OF FIELD GROWN SESAME INFLUENCED BY ARBUSCULAR MYCORRHIZAL INOCULATION, ROCK PHOSPHATE FERTILIZATION AND IRRIGATION

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V.S. Harikumar

2017-08-01

Full Text Available The aim of the study was to assess the effect of inoculation with arbuscular mycorrhizal fungi (AMF and rock phosphate (RP fertilization on biometric parameters and mycorrhizal colonization of field grown sesame under rainfed and irrigated conditions. Inoculation of AMF Funneliformis dimorphicus improved the biometric parameters of the crop such as leaf area (LA, leaf area index (LAI, specific leaf weight (SLW, net assimilation rate (NAR, oil index (OI as well as mycorrhizal colonization (%F in roots. Mycorrhizal inoculation however, did not give any positive response on harvest index (HI. LA, LAI and OI and %F showed a general increment in treatments of no added P (P0, while the other parameters such as SLW and NAR were improved by the application of RP at half the recommended dose (P50. HI did not respond to RP fertilization. Most of the parameters (LA, LAI, NAR, %F showed higher values under rainfed condition than irrigated condition whereas, SLW, HI and OI improved significantly under irrigated condition. Results indicated that the inoculation of AMF to field grown sesame can compensate for 50% of the recommended P fertilizer under a need based irrigation schedule, without affecting the biometric parameters.

Phosphate fertilizers with varying water-solubility applied to Amazonian soils: II. Soil P extraction methods

International Nuclear Information System (INIS)

Muraoka, T.; Brasil, E.C.; Scivittaro, W.B.

2002-01-01

A pot experiment was carried out under greenhouse conditions at the Centro de Energia Nuclear na Agricultura, Piracicaba (SP, Brazil), to evaluate the phosphorus availability of different phosphate sources in five Amazonian soils. The soils utilized were: medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic. Four phosphate sources were applied: triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin termo-phosphate and North Carolina phosphate rock at P rates of 0, 40, 80 and 120 mg kg -1 soil. The dry matter yield and the amount of P taken up by cowpea and rice were correlated with the extractable P by anionic exchangeable resin, Mehlich-1, Mehlich-3 and Bray-I. The results showed that the extractable P by Mehlich-1 was higher in the soils amended with North Carolina rock phosphate. Irrespective of the phosphorus sources used, the Mehlich-3 extractant showed close correlation with plant response. The Mehlich-3 and Bray-I extractants were more sensitive to soil variations. The Mehlich-3 extractant was more suitable in predicting the P availability to plants in the different soils and phosphorus sources studied. (author)

Levels and behavior of natural radioactivity in the vicinity of phosphate fertilizer plants

International Nuclear Information System (INIS)

Garcia-Leon, M.; Martinez-Aguirre, A.; Perianez, R.; Garcia-Tenorio, R.; Bolivar, J.P.

1995-01-01

Phosphate rocks are used for phosphoric acid production, which is the basis of agricultural phosphate fertilizers. It is known that phosphate ores contain, due to geological reasons, important amounts of natural radioactivity, mainly U-isotopes and daughters. By studying a specific case in Southwestern Spain, it is shown that the operation of phosphate fertilizer factories clearly enhance the natural radiation levels of its close environment. Levels of U-, Th-isotopes, and other natural radionuclides are given for a wide set of different samples, which support such a conclusion. In addition, the study of isotopic ratios gives information on the environmental behavior of such radionuclides. (author). 17 refs., 3 figs., 4 tabs

PHOSPHATE CRYSTALLURIA IN VARIOUS FORMS OF UROLITHIASIS AND POSSIBILITIES OF ITS PROGNOSTICATION IN PATIENTS WITH PHOSPHATE STONES

Directory of Open Access Journals (Sweden)

O. V. Konstantinova

2017-01-01

Full Text Available Purpose. Definition of types of crystalluria in various forms of urolithiasis and biochemical signs of phosphate crystals in the urine, while phosphate urolithiasis (infectious origin.Patients and methods. The study involved 144 patients with recurrent urolithiasis — 75 women and 69 men. Of these, 46 — diagnosed calculi with uric acid, 44 — calcium oxalate or mixed with a prevalence of calcium oxalate, in 54 — phosphate rocks (carbonate-apatite and/or struvite. The age of patients ranged from 21 to 74 years. 93 people have been under long-term, within 2–15 years, outpatient observation. The examination included the collection of anamnesis, general and microbiological analysis of urine, biochemical blood serum and urine on 10 indicators, reflecting renal function, state of the protein, water and electrolyte metabolism, uric acid metabolism, the chemical composition of the stone analysis.Results. It was found that in patients with calcium oxalate stones phosphaturia has been diagnosed in 2% of cases. And, along with calcium phosphate crystals they had oxalate crystals. In patients with phosphate urolithiasis phosphaturia observed in 96% of patients, in two patients (4% they determined except phosphates also oxalate salt in urine sediment. Patients with phosphate urolithiasis at occurrence of phosphate crystalluria have metabolic state changes: increased serum uric acid concentration from 0.322 ± 0.009 to 0.367 ± 0.018 mmol/l daily renal excretion of inorganic phosphate 23.94 ± 2.93 mmol/day to 32.12 ± 4.39 mmol/day, and reduced total calcium content in urine 6.61 ± 0.94 mmol/day to 3.37 ± 0.89 mmol/day. The results led to the following conclusion.Conclusion. Biochemical signs of occurrence of phosphate crystalluria in patients with stones of infectious origin can be: the approaching level of excretion in the urine of inorganic phosphates to 32,12 ± 4,39 mmol/day, serum uric acid concentration to 0,367 ± 0,018 mmol/l, and the

Production of yellow cake from rock phosphate deposits and its characterization

International Nuclear Information System (INIS)

Zumrawi, N. S.

2002-05-01

This study was carried out mainly to produce uranium trioxide (UO 3 ), with the standard of commercial specifications from rock phosphate deposits in eastern part of Nuba mountains, south Kurdufan state. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. Elemental analysis has shown that the ore is rich in Ca and deficient in elements of potential interest such as Fe, Cu and Zn. Uranium content in ore, phosphoric acid and purified yellow cake (UO 3 ) obtained with different precipitants was analyzed using alpha-spectrometry. On the average, the activity concentration of uranium in ore corresponds to 82 ± 24 ppm (0.10%). From the data of pregnant liquor, it was observed that the addition of KCIO 3 as an oxidant improves the dissolution of uranium from the ore by almost 20%. Data has also indicated that the yellow cake purified by hydrogen peroxide has higher concentration of uranium by 44.5% over the one purified by TBP extraction. Undesirable impurities in yellow cake as dictated by the function to which it is intended for were analyzed and compared with international standard specifications set for commercial products. Uranium as U 3 O 8 was found to be 53% in yellow cake initially obtained as ammonium diuranate and purified by hydrogen peroxide and 38% in one, which is purified by TBP extraction. With the exception of Cr concentration, the values of the other critical impurities ( V, Mn, Co, Cu, Sr, Zr, Pb, Fe, Cl, Br, I) in UO 3 precipitated by hydrogen peroxide are either typical or lower than those internationally specified as standards for commercial products. Among the impurities considered Cd, Th and Mo were undetectable. The most salient point to be mentioned here regarding impurities is that Cd, which is most undesirable in yellow cake because of its high neutron absorption cross section, was undetectable in both types of yellow cakes ( i.e. purified by TBP extraction and by hydrogen peroxide). (Author)

Short- and long-term effects of sparingly soluble phosphates on crop ...

African Journals Online (AJOL)

availability and cultivated to various food and economic crops. The rock phosphates (particularly SRP) were more efficient than SSP in soil A but had less than 50% relative agronomic efficiency (RAE) in soil B, especially when tomato was the test crop.

Valence-associated uranium isotope fractionation of uranium enriched phosphate in a shallow aquifer, Lee County, Florida

International Nuclear Information System (INIS)

Weinberg, J.M.; Levine, B.R.; Cowart, J.B.

1993-01-01

The source of anomalously high concentrations of uranium, characterized by U-234/U-238 activity ratios significantly less than unity, in shallow groundwaters of Lee County, Florida, was investigated. Uranium in cores samples was separated into U(IV) and U(VI) oxidation state fractions, and uranium analyses were conducted by alpha spectrometry. Uranium mobility was also studied in selected leaching experiments. Results indicate that mobilization of unusually soluble uranium, present in uranium enriched phosphate of the Pliocene age Tamiami Formation at determined concentrations of up to 729 ppm, is the source for high uranium concentrations in groundwater. In leaching experiments, approximately one-third of the uranium present in the uranium enriched phosphate was mobilized into the aqueous phase. Results of previous investigations suggest that U-234, produced in rock by U-238 decay, is selectively oxidized to U(VI). The uranium enriched phosphate studied in this investigation is characterized by selective reduction of U-234, with a pattern of increasing isotopic fractionation with core depth. As a consequence, U-234/U-238 activity ratios greater than 1.0 in the U(IV) fraction, and less than 1.0 in the U(VI) fraction have developed in the rock phase. In leaching experiments, the U(VI) fraction from the rock was preferentially mobilized into the aqueous phase, suggesting that U-234/U-238 activity ratios of leaching groundwaters are strongly influenced by the isotopic characteristics of the U(VI) fraction of rock. It is suggested that preferential leaching of U(VI), present in selectivity reduced uranium enriched phosphate, is the source for low activity ratio groundwaters in Lee County

Interaction entre le fumier enrichi, le calcaire et les différentes sources de phosphore issues de la roche phosphatée de Matongo sur un ferralsol de la région du Bututsi (Burundi

Directory of Open Access Journals (Sweden)

Rwigema, JB.

1993-01-01

Full Text Available Interaction between enriched farmyard manure with fertilizers, lime and different phosphorus sources obtained from the phosphatic rock from Matongo on a ferralitic soil from the region of Bututsi (Burundi. This study on maize growing in pots shows that (i in combination with other inputs (farmyard manure and lime, the most soluble phosphorus sources (triple and simple superphosphate can be replaced by partially acidulated rock phosphate (50 % obtained by mixing simple superphosphate and rock phosphate both originating from the rock phosphate deposits in Matongo (Burundi, (ii the exchangeable Al can be reduced by both the addition of farmyard manure and lime, but the action of the different phosphorus 'source leave the most Bray-1 extractable phosphorus in the soil, the largest quantifies correspond to the highest doses of farmyard manure.

Uranium migration and retention during weathering of a granitic waste rock pile

International Nuclear Information System (INIS)

Boekhout, F.; Gérard, M.; Kanzari, A.; Michel, A.; Déjeant, A.; Galoisy, L.; Calas, G.; Descostes, M.

2015-01-01

Highlights: • We investigate the environmental impact of the granitic waste rock piles. • The majority of the waste rocks in the pile is barren- or overburden rock. • The main neo-formed U-bearing phases are (Ca) and (Cu) uranyl phosphates. • Under circum-neutral pH conditions they do not pose an environment threat. - Abstract: This study investigates the post-mining evolution of S-type granitic waste rocks around a former uranium mine, Vieilles Sagnes (Haute Vienne, NW Massif Central, France). This mine was operated between 1957 and 1965 in the La Crouzille former world-class uranium mining district and is representative of intra-granitic vein-type deposits. 50 years after mine closure and the construction and subsequent re-vegetation of the granitic waste rock pile, we evaluate the environmental evolution of the rock pile, including rock alteration, neo-formation of U-bearing phases during weathering, and U migration. Vertical trenches have been excavated through the rock pile down to an underlying paleo-soil, allowing the investigation of the vertical differentiation of the rock pile and its influence on water pathways, weathering processes and U migration and retention. Arenization dominantly drives liberation of U, by dissolution of uraninite inclusions in the most alterable granitic minerals (i.e. K-feldspar and biotite). Retention of U in the matrix at the base of the waste rock pile, and in the underlying paleo-soil most likely occurs by precipitation of (nano-) uranyl phosphates or a combination of co-precipitation and adsorption reactions of U onto Fe (oxy)hydroxides and/or clay minerals. Even though U-migration was observed, U is retained in stable secondary mineral phases, provided the current conditions will not be modified

Determination of uranium content in phosphate ores using different measurement techniques

Directory of Open Access Journals (Sweden)

Mohammad A. Al-Eshaikh

2016-01-01

Full Text Available The most important unconventional source of uranium is found in phosphate deposits; unfortunately, nowadays its exploitation is limited by economic constraints. The uranium concentrations in phosphate ores in the world vary regionally and most countries with large phosphate deposits have either plant in operation to extract uranium or are at the stage of pilot extraction plants. The aim of this investigation is to evaluate uranium content in the Saudi phosphate ores for, at least, two reasons: firstly, upgrading the phosphate quality by removing the uranium content in order to reduce the radioactivity in the fertilizer products. Secondly, getting benefit from the extracted uranium for its domestic use as a fuel in nuclear power and desalination plants. The results of this study show that the uranium concentration in Saudi phosphate rocks is relatively low (less than 100 ppm, which is not economically encouraging for its direct extraction. However, its extraction as a byproduct from the phosphoric acid, which will have higher concentration could be quite promising and worth exploiting.

The distribution pattern of main and trace elements in phosphatic laterites from Pirocaua Plateau (MA)

International Nuclear Information System (INIS)

Siqueira, N.V.M. de.

1982-01-01

The phosphate-laterite of Pirocaua (state of Maranhao) was studied with basis on several lines of evidence, namely, structure of the deposit, mineral distribution, variations in chemical composition and chemistry of ground waters in the region. The distribution of elements during the formation of the deposit is interpreted and the conditioning factors analysed. Air and water samples were studied respectively by X-ray diffraction and atomic absorption spectroscopy. The results show that fluctuations of the hydrostatic level were important during the formation of the phosphate horizon. When the deposit was formed there was also a decrease of the activity of the silicic acid and a parallel increase of acidity towards the top of the cross-section studied. In these conditions, Fe sup(2+) migrated towards the top of the deposit and was precipitated as Fe sup(3+) in the oxidizing zone. Migration of phosphate was in part due to its affinities to clay minerals, in which mechanism ground water played a major role. Mass balance calculations indicate that of the parent-rock is a phyllite, it is necessary an extreme enrichment in P and Sr to give the composition of the phosphate horizon. With basis on these observations we conclude that: 1) the parent-rock must have contents of P and Sr higher than the average for phyllites; or 2) the phosphate has some other source. (author)

Assessment of soil phosphorus status and management of phosphatic fertilisers to optimise crop production

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-02-01

Phosphorus (P) is an essential plant nutrient, and its deficiency in soils severely restricts crop yields. Tropical and subtropical soils are predominantly acidic and often extremely deficient in phosphorus. Moreover most of these soils possess a high phosphate sorption capacity. Strongly sorbed or fixed phosphate is unavailable for plant uptake. Therefore, substantial P inputs are required for optimum plant growth and adequate food and fiber production. Manufactured water-soluble P fertilizers, like superphosphates, are the commonest P inputs. However, in most developing countries these P fertilizers are not produced locally but are imported, and their supplies to resource-poor farmers in rural areas are limited. Many phosphate-bearing mineral deposits exist worldwide. Several developing countries with P-deficient tropical acid soils have important phosphate rock deposits, that is the raw material for the production of P fertilizers. Thus, under certain soil and climatic conditions, direct application of phosphate rocks (PRs) is an agronomically and economically sound alternative to the use of expensive superphosphates. In spite of extensive research on the application of PR to acid soils in temperate regions, there is scant information on the potential of local PR sources in tropical and subtropical regions. Phosphate rocks vary widely in their mineralogical, chemical and physical properties and consequently in their reactivity and agronomic potential. It is, therefore, necessary to assess the relative agronomic effectiveness of the indigenous and imported PRs using the commercially available superphosphate as a reference. Also, changes in the soil available P when amended with PR products and water-soluble P fertilizers need to be properly monitored with suitable soil P testing methods for the provision of adequate P fertilizer recommendations. During the 1980's, some local PR sources were evaluated in the FAO Fertilizer Programme. The idea of a project on PR

Assessment of soil phosphorus status and management of phosphatic fertilisers to optimise crop production

International Nuclear Information System (INIS)

2002-02-01

Phosphorus (P) is an essential plant nutrient, and its deficiency in soils severely restricts crop yields. Tropical and subtropical soils are predominantly acidic and often extremely deficient in phosphorus. Moreover most of these soils possess a high phosphate sorption capacity. Strongly sorbed or fixed phosphate is unavailable for plant uptake. Therefore, substantial P inputs are required for optimum plant growth and adequate food and fiber production. Manufactured water-soluble P fertilizers, like superphosphates, are the commonest P inputs. However, in most developing countries these P fertilizers are not produced locally but are imported, and their supplies to resource-poor farmers in rural areas are limited. Many phosphate-bearing mineral deposits exist worldwide. Several developing countries with P-deficient tropical acid soils have important phosphate rock deposits, that is the raw material for the production of P fertilizers. Thus, under certain soil and climatic conditions, direct application of phosphate rocks (PRs) is an agronomically and economically sound alternative to the use of expensive superphosphates. In spite of extensive research on the application of PR to acid soils in temperate regions, there is scant information on the potential of local PR sources in tropical and subtropical regions. Phosphate rocks vary widely in their mineralogical, chemical and physical properties and consequently in their reactivity and agronomic potential. It is, therefore, necessary to assess the relative agronomic effectiveness of the indigenous and imported PRs using the commercially available superphosphate as a reference. Also, changes in the soil available P when amended with PR products and water-soluble P fertilizers need to be properly monitored with suitable soil P testing methods for the provision of adequate P fertilizer recommendations. During the 1980's, some local PR sources were evaluated in the FAO Fertilizer Programme. The idea of a project on PR

Assessment of soil phosphorus status and management of phosphatic fertilizers to optimise crop production

International Nuclear Information System (INIS)

2002-03-01

Phosphorus (P) is an essential plant nutrient, and its deficiency in soils severely restricts crop yields. Tropical and subtropical soils are predominantly acidic and often extremely deficient in phosphorus. Moreover most of these soils possess a high phosphate sorption capacity. Strongly sorbed or fixed phosphate is unavailable for plant uptake. Therefore, substantial P inputs are required for optimum plant growth and adequate food and fiber production. Manufactured water-soluble P fertilizers, like superphosphates, are the commonest P inputs. However, in most developing countries these P fertilizers are not produced locally but are imported, and their supplies to resource-poor farmers in rural areas are limited. Many phosphate-bearing mineral deposits exist worldwide. Several developing countries with P-deficient tropical acid soils have important phosphate rock deposits, that is the raw material for the production of P fertilizers. Thus, under certain soil and climatic conditions, direct application of phosphate rocks (PRs) is an agronomically and economically sound alternative to the use of expensive superphosphates. In spite of extensive research on the application of PR to acid soils in temperate regions, there is scant information on the potential of local PR sources in tropical and subtropical regions. Phosphate rocks vary widely in their mineralogical, chemical and physical properties and consequently in their reactivity and agronomic potential. It is, therefore, necessary to assess the relative agronomic effectiveness of the indigenous and imported PRs using the commercially available superphosphate as a reference. Also, changes in the soil available P when amended with PR products and water-soluble P fertilizers need to be properly monitored with suitable soil P testing methods for the provision of adequate P fertilizer recommendations. During the 1980's, some local PR sources were evaluated in the FAO Fertilizer Programme. The idea of a project on PR

Radiation exposure due to agricultural uses of phosphate fertilizers

International Nuclear Information System (INIS)

Khater, Ashraf E.M.; AL-Sewaidan, H.A.

2008-01-01

Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. Over the last decades, the land reclamation and agriculture activities in Saudi Arabia and other countries have been widely expanded. Therefore, the usage of chemical fertilizers is increased. Selected phosphate fertilizers samples were collected and the specific activities of NORM were measured using a gamma ray spectrometer based on a hyper pure germanium detector and alpha spectrometer based on surface barrier detector. The obtained results show remarkable wide variations in the radioactivity contents of the different phosphate fertilizer samples. The mean (ranges) of specific activities for 226 Ra, 210 Po, 232 Th and 40 K, and radium equivalent activity are 75 (3-283), 25 (0.5-110), 23 (2-74), 2818 (9-6501) Bq/kg and 283 (7-589) Bq/kg, respectively. Based on dose calculations, the increment of the public radiation exposure due to the regular agricultural usage of phosphate fertilizers is negligible. Its average value 1 m above the ground is about 0.12 nGy/h where the world average value due to the NORM in soil is 51 nGy/h. Direct radiation exposures of the farmers due to phosphate fertilizers application was not considered in our study

Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

International Nuclear Information System (INIS)

Zapata, F.; Zaharah, A.R.

2002-01-01

Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg -1 soil). The 32 P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg -1 soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P uptake from the non

Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

Energy Technology Data Exchange (ETDEWEB)

Zapata, F. [Soil and Water Management and Crop Nutrition Section, International Atomic Energy Agency, Vienna (Austria)]. E-mail: F.Zapata@iaea.org; Zaharah, A.R. [Department of Land Management, Universiti Putra Malaysia, Serdang, Selangor (Malaysia)

2002-05-15

Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg{sup -1} soil). The {sup 32}P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg{sup -1} soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P

Field assessment of the relative agronomic effectiveness of phosphate rock materials in a soybean - Maize crop rotation using 32P isotope techniques

International Nuclear Information System (INIS)

Mahisarakul, J.; Siripaibool, C.; Claimon, J.; Pakkong, P.

2002-01-01

Field experiments were conducted at Phrabudhabart Field Crop Research Station, Lopbur Province during the period 1995-1997 to determine the relative agronomic effectiveness (RAE) in a soybean- maize crop rotation using 32 P isotope techniques. The soil of the experimental site was the Pakchong soil series (Oxic Paleustults). Four PRs were applied at 120 kg P ha -1 , namely Algerian PR (ARPR), North Carolina PR from USA (NCPR), Petchaburi PR from Thailand (PBPR) and Ratchaburi PR from Thailand (RBPR) and TSP was added at three rates (40, 60, 120 kg P ha -1 ). For the first year harvest, soybeans absorbed more P from TSP fertilizer (% FPU) applied at 40 kg P ha -1 than maize, but there was no yield response. Among four PRs, North Carolina phosphate rock (NCPR) gave the highest % Pdff as well as the highest RAE. Maize was planted after soybean to study the residual effect of TSP and PRs. The results were the same as in soybean. In the second year (1996) the grain yield of soybean was higher than in the first year (1995), and there was significant response to P from TSP. The RAE of NCPR was very high. Maize showed the opposite results. In this case Algerian PR (ARPR) had the highest RAE. In 1997, TSP and six PRs (same four used in 1995 and 1996, Morocco PR (MCPR), and Lumphun PR (LPPR)) were applied at 60 kg P ha -1 . Phosphate rocks were applied either alone or in combination with TSP (50:50). Application of TSP resulted in high yields of soybean. In terms of RAE the P sources ranked as follows: LPPR+TSP>ARPR>LPPR> MCPR>NCPR+TSP>NCPR. The residual effect of P on the following maize crop resulted in a high RAE for MCPR and LPPR. It was concluded that TSP should be applied to every crop. The reactivity of PRs in the first and the second year experiments were: ARPR>NCPR>RBPR>PBPR. Morocco PR and LPPR were also reactive PRs in the third experiment. The combination of PR and TSP resulted in better P uptake (%Pdff). (author)

Determination of phosphorus in silicate rocks by activation analysis

International Nuclear Information System (INIS)

Khalil, S.O.

1974-01-01

A neutron activation method for the determination of phosphorus from ammonium phosphomolibdate precipitate is applied to silicate rocks. Ammonium phosphate is added as carrier to the irradiated rock powder and the phosphorus is recovered as ammonium phosphomolibdate, which is precipitated several times in the presence of appropriate holdback carriers to ensure its radiochemical purity and then finally dissolved and reprecipitated as AgTlPO 4 for weighing and counting. The samples were irradiated for 3 1/2 days in a thermal flux of 2.10 10 n.s -1 .cm -2 and the β-activities were measured by an end-window Geiger-Mueller counter. The results for rock standards granite G-1 and diabase W-1 are given. (K.A.)

Pseudomonas fluorescens ATCC 13525 Containing an Artificial Oxalate Operon and Vitreoscilla Hemoglobin Secretes Oxalic Acid and Solubilizes Rock Phosphate in Acidic Alfisols

Science.gov (United States)

Archana, G.; Naresh Kumar, G.

2014-01-01

Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah), Fomitopsis plaustris oxalate transporter (FpOAR) and Vitreoscilla hemoglobin (vgb) in various combinations. Pf (pKCN2) transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the presence of an artificial oxalate operon containing oah and FpOAR genes in plasmid pKCN4, Pf (pKCN4) secreted 13.6 mM oxalate in the medium while 3.6 mM remained inside. This transformant solubilized 509 μM of phosphorus from rock phosphate in alfisol which is 4.5 fold higher than the Pf (pKCN2) transformant. Genomic integrants of P. fluorescens (Pf int1 and Pf int2) containing artificial oxalate operon (plac-FpOAR-oah) and artificial oxalate gene cluster (plac-FpOAR-oah, vgb, egfp) secreted 4.8 mM and 5.4 mM oxalic acid, released 329 μM and 351 μM P, respectively, in alfisol. The integrants showed enhanced root colonization, improved growth and increased P content of Vigna radiata plants. This study demonstrates oxalic acid secretion in P. fluorescens by incorporation of an artificial operon constituted of genes for oxalate synthesis and transport, which imparts mineral phosphate solubilizing ability to the organism leading to enhanced growth and P content of V. radiata in alfisol soil. PMID:24705024

Pseudomonas fluorescens ATCC 13525 containing an artificial oxalate operon and Vitreoscilla hemoglobin secretes oxalic acid and solubilizes rock phosphate in acidic alfisols.

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Kavita Yadav

Full Text Available Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah, Fomitopsis plaustris oxalate transporter (FpOAR and Vitreoscilla hemoglobin (vgb in various combinations. Pf (pKCN2 transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the presence of an artificial oxalate operon containing oah and FpOAR genes in plasmid pKCN4, Pf (pKCN4 secreted 13.6 mM oxalate in the medium while 3.6 mM remained inside. This transformant solubilized 509 μM of phosphorus from rock phosphate in alfisol which is 4.5 fold higher than the Pf (pKCN2 transformant. Genomic integrants of P. fluorescens (Pf int1 and Pf int2 containing artificial oxalate operon (plac-FpOAR-oah and artificial oxalate gene cluster (plac-FpOAR-oah, vgb, egfp secreted 4.8 mM and 5.4 mM oxalic acid, released 329 μM and 351 μM P, respectively, in alfisol. The integrants showed enhanced root colonization, improved growth and increased P content of Vigna radiata plants. This study demonstrates oxalic acid secretion in P. fluorescens by incorporation of an artificial operon constituted of genes for oxalate synthesis and transport, which imparts mineral phosphate solubilizing ability to the organism leading to enhanced growth and P content of V. radiata in alfisol soil.

Elemental and radionuclides distribution in the production and use of phosphate fertilizers in Brazil; Distribuicao elementar e de radionuclideos na producao e uso de fertilizantes fosfatados no Brasil

Energy Technology Data Exchange (ETDEWEB)

Saueia, Catia Heloisa Rosignoli

2006-07-01

Fertilizer is considered an essential component for agriculture, because its use increases the natural soil nutrients, which are lost slow waste or erosion. The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dihydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The phosphate rock used as raw material presents in its composition, radionuclides of the U and Th natural series in. During the chemical attack of the phosphate rock, this equilibrium is disrupted and the radionuclides and the elements migrate to intermediate, final products and byproducts, according to their solubility and chemical properties. While the fertilizers are commercialized, the phosphogypsum is disposed in stack piles and can cause an impact in the environment. In order to evaluate the radionuclides and the elements distribution in the industrial process of phosphate fertilizer production, samples of concentrated rock, fertilizers (SSP, TSP, MAP and DAP) and phosphogypsum from three national industries (A, B and C), were analyzed. The characterization of the elements Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn and Zr, and the rare earths La, Ce, Nd, Sm, Eu, Tb, Yb and Lu, were performed by instrumental neutron activation analysis. The results obtained showed that, in general, the rare earth elements are distributed uniformly in the fertilizers and phosphogypsum, except for Lu. The elemental concentration present in the fertilizers SSP and TSP are of the same order of magnitude of the source rock. The same behavior was observed in the fertilizers MAP and DAP, except for the elements Co, Sc and U. The radionuclides of the U series ({sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Pb) and of the Th series

The source of phosphate in the oxidation zone of ore deposits: Evidence from oxygen isotope compositions of pyromorphite

Science.gov (United States)

Burmann, Fabian; Keim, Maximilian F.; Oelmann, Yvonne; Teiber, Holger; Marks, Michael A. W.; Markl, Gregor

2013-12-01

Pyromorphite (Pb5[PO4]3Cl) is an abundant mineral in oxidized zones of lead-bearing ore deposits and due to its very low solubility product effectively binds Pb during supergene alteration of galena (PbS). The capacity of a soil or near-surface fluid to immobilize dissolved Pb depends critically on the availability of phosphate in this soil or fluid. Potential phosphorus sources in soil include (i) release during biological processes, i.e. leaching from litter/lysis of microbial cells (after intracellular enzyme activity) in soil and hydrolysis from soil organic matter by extracellular enzymes and (ii) inorganic phosphate from the dissolution of apatite in the adjacent basement rocks. Intracellular enzyme activity in plants/microorganisms associated with kinetic fractionation produces an oxygen isotope composition distinctly different from inorganic processes in soil. This study presents the first oxygen isotope data for phosphate (δ18OP) in pyromorphite and a comprehensive data set for apatite from crystalline rocks. We investigated 38 pyromorphites from 26 localities in the Schwarzwald (Southwest Germany) and five samples from localities outside the Schwarzwald in addition to 12 apatite separates from gneissic and granitic host rocks. Pyromorphites had δ18OP values between +10‰ and +19‰, comparable to literature data on δ18OP in the readily available P fraction in soil (resin-extractable P) from which minerals potentially precipitate in soils. δ18OP values below the range of equilibrium isotope fractionation can be attributed either to apatites that formed geochemically (δ18OP of apatites:+6‰ to +9‰) or less likely to biological processes (extracellular enzyme activity). However, for most of our samples isotopic equilibrium with ambient water was indicated, which suggests biological activity. Therefore, we conclude that the majority of pyromorphites in oxidized zones of ore bodies formed from biologically cycled phosphate. This study highlights that

Pollution control -- Recovery of uranium from phosphatic fertilizer industry

International Nuclear Information System (INIS)

Trivedi, R.N.; Pachaiyappan, V.

1979-01-01

Various uranium recovery processes, viz. Brazilian process (HCL leaching), selective extraction of U, Japanese process, ORNL process and the Indian methods, recently developed, pertaining to the fertilizer industry are reviewed and their relative merits are discussed. Special attention has been paid to the recovery of uranium from the Indian and imported phosphatic rocks, showing the advantages, both from the pollution control and nuclear energy aspects. (K.B.)

Kinetics of selenium release in mine waste from the Meade Peak Phosphatic Shale, Phosphoria Formation, Wooley Valley, Idaho, USA

Science.gov (United States)

Lisa L. Stillings; Michael C. Amacher

2010-01-01

Phosphorite from the Meade Peak Phosphatic Shale member of the Permian Phosphoria Formation has been mined in southeastern Idaho since 1906. Dumps of waste rock from mining operations contain high concentrations of Se which readily leach into nearby streams and wetlands. While the most common mineralogical residence of Se in the phosphatic shale is elemental Se, Se(0...

Changes in Soil Available Phosphorus, Leaf Phosphorus Content and Yield of Sword Bean (Canavalia Ensiformis (L.) DC.) by Application of SP-36 and Phosphate Rock on Acid Upland Soil of East Lampung

OpenAIRE

Achmad Arivin Rivaie

2015-01-01

A glasshouse trial was performed to determine changes in phosphorus (P) nutrition and the yield of sword bean (Canavalia ensiformis (L.) DC.) following the application of different rates and types of P fertilizer in an acid upland soil of East Lampung. Two different types of P fertilizer, namely SP-36 (total P = 36%) and Phosphate Rock (PR) (total P = 24.3%, particle size distribution = 75% <0.25 mm, 85% < 0.50 mm, 90% < 1.00 mm) were used in the trial. For the treatment, each P fert...

Investigation of Organic Matters and their Roles in Deposition and Phosphate Mineralization in the Kuh-e-Sefid Deposit, Ramhormoz

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Houshang Pourkaseb

2017-07-01

Full Text Available Introduction It has been recently stated that phosphorite deposits are in fact marine biogenic materials, due to bacterial activity producing bio-apatite. In addition, Phosphorites contain 15–20 wt.% P2O5 (Tzifas et al., 2014. In this deposit, phosphate mineralization has occurred as phosphorite lenses with Eocene age within the Pabdeh Formation, with thickness up to 1.5 meters and width of 15 meters and its hosted rock is black shale. According to the presence of indices of fossils such as Globorotalia, Hantkenina, its age can be attributed to the middle Eocene. The Pabdeh formation is a very rich organic matter in addition to the presence of phosphate (Damiri, 2011. The formation due to planktonic foraminifera rich in organic matter is like the hydrocarbon source rock (Daneshian et al., 2012. In marine basins where upwelling and productivity are limited, phosphates may develop outside of microbial cells and also within bacterial cellular structures, formed by slow bacterial assimilation of phosphorus from assaying organic matter in areas of restricted sedimentation (O’Brine et al., 1981. It is therefore suggested that the upwelling currents did that in the recycling of phosphorus from dead organisms such as fishes and other marine vertebrates. The aim of this study is investigation of organic matter’s species and their roles in deposition and phosphate mineralization in the Kuh-e-Sefid phosphate deposit using XRD, FTIR and Rock-Eval pyrolysis. Materials and methods In field observations, 12 samples were selected and they were taken from units of phosphate and shale host rock in the Kuh-e-Sefid phosphate ore deposit. Ten cross sections were studied by conventional microscopic methods. Rock-Eval analysis was used in order to determine the organic carbon in the geology Department of the Shahid Chamran University of Ahvaz. The Phosphorite samples were determined by XRD at the Kansaran Binaloud Company in the Science and Technology campus in

The recovery of uranium from phosphatic sources in relation to the E.E.C

International Nuclear Information System (INIS)

Derry, R.

1981-01-01

The recovery of uranium from phosphatic sources is reviewed in the context of the EEC. The potential and technology available for recovery from fertilizer products, furnace slag, beneficiated slimes, lached zone materials, leach residues and indigeneous phosphates is briefly assessed but the main emphasis is on the technology available for recovery from 30 per cent P 2 O 5 phosphoric acid produced from imported phosphate rock concentrate. In particular various solvent extraction processes now being used commercially at large scale phosphoric acid plants, mainly in North America, are discussed in detail together with research and development on solvent extraction and various other possible recovery processes. The available techniques are compared and a discussion of the economic aspects is given

ofMin° . ..... ,phoS 'hate Rock IUPR and Fann ard Manure" Effect ...

African Journals Online (AJOL)

tive interactions between phosphate rock organic air dried ground and sieved using a 2mm. sieve, .... combinations,A42. factorial comb'ination in a ran- ..... , . " - domized ..... A.L. Page. R.H. Miller and D.R.. ... Building up soil capital in sub-.

Radioactivity contents in dicalcium phosphate and the potential radiological risk to human populations

International Nuclear Information System (INIS)

Casacuberta, N.; Masque, P.; Garcia-Orellana, J.; Bruach, J.M.; Anguita, M.; Gasa, J.; Villa, M.; Hurtado, S.; Garcia-Tenorio, R.

2009-01-01

Potentially harmful phosphate-based products derived from the wet acid digestion of phosphate rock represent one of the most serious problems facing the phosphate industry. This is particularly true for dicalcium phosphate (DCP), a food additive produced from either sulphuric acid or hydrochloric acid digestion of raw rock material. This study determined the natural occurring radionuclide concentrations of 12 DCP samples and 4 tricalcium phosphate (TCP) samples used for animal and human consumption, respectively. Metal concentrations (Al, Fe, Zn, Cd, Cr, As, Hg, Pb and Mg) were also determined. Samples were grouped into three different clusters (A, B, C) based on their radionuclide content. Whereas group A is characterized by high activities of 238 U, 234 U (∼10 3 Bq kg -1 ), 210 Pb (2 x 10 3 Bq kg -1 ) and 210 Po (∼800 Bq kg -1 ); group B presents high activities of 238 U, 234 U and 230 Th (∼10 3 Bq kg -1 ). Group C was characterized by very low activities of all radionuclides ( -1 ). Differences between the two groups of DCP samples for animal consumption (groups A and B) were related to the wet acid digestion method used, with group A samples produced from hydrochloric acid digestion, and group B samples produced using sulphuric acid. Group C includes more purified samples required for human consumption. High radionuclide concentrations in some DCP samples (reaching 2 x 10 3 and 10 3 Bq kg -1 of 210 Pb and 210 Po, respectively) may be of concern due to direct or indirect radiological exposure via ingestion. Our experimental results based on 210 Pb and 210 Po within poultry consumed by humans, suggest that the maximum radiological doses are 11 ± 2 μSv y -1 . While these results suggest that human health risks are small, additional testing should be conducted.

Diversity and phosphate solubilization by bacteria isolated from Laki Island coastal ecosystem

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SRI WIDAWATI

2011-01-01

Full Text Available Widawati S (2011 Diversity and phosphate solubilization by bacteria isolated from Laki Island coastal ecosystem. Biodiversitas 12: 17-21. Soil, water, sand, and plant rhizosphere samples collected from coastal ecosystem of Laki Island-Jakarta were screened for phosphate solubilizing bacteria (PSB. While the population was dependent on the cultivation media and the sample type, the highest bacterial population was observed in the rhizosphere of Ipomea aquatica. The PSB strains isolated from the sample registered 18.59 g-1L-1, 18.31 g-1L-1, and 5.68 g-1L-1 of calcium phosphate (Ca-P, Al-P and rock phosphate solubilization after 7-days. Phosphate solubilizing capacity was the highest in the Ca-P medium. Two strains, 13 and 14, registered highest Phosphomonoesterase activities (2.01 µgNP.g-1.h-1 and 1.85NP µg.g-1.h-1 were identified as Serattia marcescens, and Pseudomonas fluorescense, respectively. Both strains were isolated from the crops of Amaranthus hybridus and I. aquatica, respectively, which are commonly observed in coastal ecosystems. The presence of phosphate solubilizing microorganisms and their ability to solubilize various types of phosphate species are indicative of the important role of both species of bacteria in the biogeochemical cycle of phosphorus and the plant growth in coastal ecosystems.

Changes in Soil Available Phosphorus, Leaf Phosphorus Content and Yield of Sword Bean (Canavalia ensiformis (L. DC. by Application of SP-36 and Phosphate Rock on Acid Upland Soil of East Lampung

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Achmad Arivin Rivaie

2015-01-01

Full Text Available A glasshouse trial was performed to determine changes in phosphorus (P nutrition and the yield of sword bean (Canavalia ensiformis (L. DC. following the application of different rates and types of P fertilizer in an acid upland soil of East Lampung. Two different types of P fertilizer, namely SP-36 (total P = 36% and Phosphate Rock (PR (total P = 24.3%, particle size distribution = 75% <0.25 mm, 85% < 0.50 mm, 90% < 1.00 mm were used in the trial. For the treatment, each P fertilizer type consisted of four rates (0, 50, 100 and 150 mg P2O5 kg-1 soil that were arranged in a Completely Randomized Design with four replications. The results showed that the application of P fertilizers had significant effects on soil pH, soil plant-available P, the potential-P (HCl 25%, leaf N and P concentrations, the yield of sword bean. Increased rates of both forms of P fertilizer increased the soil pH values. As the soil used had low pH and very high exchangeable Al, hence, this result is most probably related to the addition of Ca2+ to the soil solution that resulted from the P fertiliser applied (liming effect, either from SP-36 (monocalcium phosphate or PR (flour apatite. There was no difference in soil available P concentration due to the different in P fertilizer types, indicating that 4 months after the fertilizer application, the relatively insoluble Phosphate Rock had the same P solubility with SP-36. Increased rates of both forms of P fertilizer increased the sword bean yield. For the application of 0 kg P2O5 ha-1, although sword bean crops had pods, but, they did not give any seed. Whereas, at the addition of P fertilizer at the rate of 50, 100, and 150 kg P2O5 ha-1 for both P fertilizer types, the crops were able to give the seeds in the pods.

Effect of P nature phosphate dosage and embedding time of Azolla mycrophylla Kaulfuss on Yield of Rice (Oryza sativa L.

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Mahmudah Hamawi

2016-12-01

Full Text Available The effort of growing azolla in intercroping rice will be hoped to supply a green manure for rice plants. Additing P of the phosphat rock in the field can be expected to increase the result of rice yield.The research was conducted on December 2, 2006 to April 5, 2007 at Tegalgondo Karangploso of Malang. onsidering those problems, the researcher employs the factorial group randome desigh that compose two factor by controlling as comparison tool (inorganic treatment. The first factor is P in the phosphat rock contained 4 stages. As followed Po (without P, P1 (25 kg P ha-1, P2 (50 kg P ha-1, P3 (25 kg P ha-1. The second factor is time of incorporated Azolla microphylla Kaulfuss (W, which consist 4 stage. As followed W1 (incorporated 1 day before transplanting rice, W2 (50 % the azolla biomass in the field was incorporated during 14, 28, and 42 days after transplanting rice, W3 (50 % the azolla biomass in the field was incorporated during 21, and 49 days after transplanting rice, W4 (50 % the azolla biomass in the field was incorporated during 35 days after transplanting rice. The research was replicated 3 replications. The research finding showed that phosphat rock with 25 kg of P ha-1 doses combinationed with time of incorporating the azolla biomass at 14, 28 and 42 days after transplanting rice, the result of rice would be increasing in 31,4 % and R/C value resulted 1,47. Giving phosphat rock with 25 – 75 kg P ha-1 doses increased the azolla biomass at 146,4 % until 153 % and increased the yield of rice at 21,1% until 43,8 %.

Sphingosine-1-Phosphate and the S1P3 Receptor Initiate Neuronal Retraction via RhoA/ROCK Associated with CRMP2 Phosphorylation

Science.gov (United States)

Quarta, Serena; Camprubí-Robles, Maria; Schweigreiter, Rüdiger; Matusica, Dusan; Haberberger, Rainer V.; Proia, Richard L.; Bandtlow, Christine E.; Ferrer-Montiel, Antonio; Kress, Michaela

2017-01-01

The bioactive lipid sphingosine-1-phosphate (S1P) is an important regulator in the nervous system. Here, we explored the role of S1P and its receptors in vitro and in preclinical models of peripheral nerve regeneration. Adult sensory neurons and motor neuron-like cells were exposed to S1P in an in vitro assay, and virtually all neurons responded with a rapid retraction of neurites and growth cone collapse which were associated with RhoA and ROCK activation. The S1P1 receptor agonist SEW2871 neither activated RhoA or neurite retraction, nor was S1P-induced neurite retraction mitigated in S1P1-deficient neurons. Depletion of S1P3 receptors however resulted in a dramatic inhibition of S1P-induced neurite retraction and was on the contrary associated with a significant elongation of neuronal processes in response to S1P. Opposing responses to S1P could be observed in the same neuron population, where S1P could activate S1P1 receptors to stimulate elongation or S1P3 receptors and retraction. S1P was, for the first time in sensory neurons, linked to the phosphorylation of collapsin response-mediated protein-2 (CRMP2), which was inhibited by ROCK inhibition. The improved sensory recovery after crush injury further supported the relevance of a critical role for S1P and receptors in fine-tuning axonal outgrowth in peripheral neurons. PMID:29066950

Impact Of Low Grade Uranium Ores On The Echo System and the Workers of Phosphate Industry

International Nuclear Information System (INIS)

Anwar, S.M.

1999-01-01

The present study aims to investigate the influence of uranium present in phosphate rocks as an environmental factor in the ccho system and on the workers of Abu-Zaabal Phosphate Company subjected to the inhalation of big quantities of rock phosphate dust during the benefication of the ore and the production of the fertilizers. Besides. extra amount of uranium reach the workers also through two path ways.The first is direct through eating contaminated planted grown in the near by area.The second is indirect through eating animals fed with contaminated plants. The uranium content is estimated in the soil samples at different depths, water (irrigation and drainage), air samples and plant samples (shoot and root) in Berseem from the four directions, urine samples from twenty workers in charge of the processing of phosphate compared to twenty volunteers far from the contaminated area.The results showed an elevated values for phosphorus and uranium in the air, water. soil and plant (Berseem) around Abu Zaabal Factory and extending to about 2 km from all directions. Urine may be considered as a biological indicator medium for the uptake of uranium in uranium miners and the workers in charge of ore processing and can represent the major route of excretion for the absorbed metal. Significant differences were shown between the uranium level in the urine of workers group and the control group

Phosphorus availability of rock phosphates as compared with feed-grade phosphates for swine Disponibilidade de fósforo em fosfatos de rocha em comparação à de fosfatos bicálcicos para suínos

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Luiz Waldemar de Oliveira Souza

2009-01-01

Full Text Available One hundred ninety two swine were used in a trial to assess the relative bioavailability of phosphorus (RBP in six phosphate sources. Phosphates were three feed grade phosphates (FP, two made in Brasil, and one USA made, and three rock phosphate samples (RP originated from two mines sites in Brasil, and one mine site in Israel. Levels of calcium, phosphorus and fluorine in RP were 29, 12 and 1.7% (RP source 1, 33, 14 and 1.4% (RP source 2, and 30, 14 and 3.6% (RP source 3, respectively. Pigs were fed a corn-soybean meal basal diet (18% CP, 0.95% Lys, 0.75% Ca, 0.37% P or the basal diet with 0.15% P from a standard purified grade calcium phosphate (SP, or with 0.15% P from experimental FP or RP. Each diet was fed to six pen replicates of four pigs per pen for 35 days (14.4 to 39.9 kg. Weight gain (WG, feed/gain (FG, plasma P (PP, bone ash (BA, and breaking strength of metacarpals and metatarsals (BS-MM and femurs (BS-F were improved by phosphorus addition. However, performance and bone parameters were depressed by RP, as compared to FP dietary supplementation. WG, BA, BS-MM and BS-F were regressed to P added, and slope-ratios were calculated to assess RBP in the FP and RP sources. The average bioavailability of P in the FP and RP sources, relative to SP, were 89 and 49% (WG, 112 and 49% (BA, 78 and 28% (BS-MM, and 101 and 52% (BS-F, respectively. Low animal performance and bone strength related to toxicity should be expected if rock phosphates are used to feed pigs.Cento e noventa e dois leitões foram usados em um experimento para avaliar a biodisponibilidade relativa do fósforo (RBP em seis fontes fosfáticas. As fontes foram três fosfatos de uso em nutrição (FP, dois fabricados no Brasil e um nos Estados Unidos, e três amostras de fosfatos de rocha (RP, originados de duas minas brasileiras e uma mina situada em Israel. Os níveis de cálcio (Ca, fósforo (P e flúor (F nos fosfatos de rocha foram 29, 12 e 1,7% (fonte RP 1, 33, 14 e 1

Determinação de cádmio, cobre, cromo, níquel, chumbo e zinco em fosfatos de rocha Determination of cadmium, copper, chromium, nickel, lead and zinc in rock phosphates

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Mari Lucia Campos

2005-04-01

Full Text Available A preocupação com metais pesados provenientes de fertilizantes minerais deve-se à possibilidade de entrada desses elementos na cadeia alimentar. O objetivo deste trabalho foi determinar o teor de metais pesados e comparar três métodos de extração (Embrapa, USEPA 3051A e USEPA 3050B de Cd, Cr, Cu, Ni, Pb e Zn em fosfatos de rochas nacionais e importados. A quantificação dos teores desses elementos foi feita em espectrofotômetro de absorção atômica de chama ar-acetileno. Entre os fosfatos estudados, o termofosfato apresentou concentrações significativamente superiores de Cr, Cu, Ni e Zn e o fosfato natural 2, de Cu, Ni, Pb e Zn. O fosfato reativo 3 apresentou a maior quantidade de Cd (145±13 mg kg-1 e o fosfato natural 2, a maior quantidade de Pb (234±9 mg kg-1. Os métodos avaliados podem ser aplicados em estudos de teor de metais pesados em fertilizantes fosfatados.The possibility of food chain transfer is a matter of concern on studies related to heavy metals in mineral fertilizers. The objective of this paper was to determine the content of heavy methods and to compare three extraction procedures (Embrapa, 1999; USEPA 3051A and USEPA 3050B for Cd, Cr, Cu, Ni, Pb, and Zn in national and imported rock phosphates. The quantification of the trace elements content was performed by air-acetylene flame atomic absorption spectroscopy. Among the studied phosphates, the thermophosphate presented significantly greater concentrations of Cd, Cr, Cu, Ni, and Zn whereas Cu, Ni, Pb, and Zn were found in greater contents in the natural phosphate 2. The reactive phosphate 3 presented the greatest quantity of Cd (145±13 mg kg-1 and the natural phosphate 2, the highest quantity of Pb (234±9 mg kg-1. The tested methods can be applied in studies concerning heavy metals in phosphate fertilizers.

Assessment of soil phosphorus tests for situations in Australia where reactive phosphate rock and water-soluble fertilizers are used

International Nuclear Information System (INIS)

McLaughlin, M.J.

2002-01-01

A selection of commonly used soil P tests, which included anion and cation exchange resin membranes, were compared in a glasshouse experiment using subterranean clover, and evaluated in the field at 19 sites from the National Reactive Phosphate Rock Project in 1993 and at 6 sites in 1995. The ability of the soil P tests to predict plant response was used to evaluate the tests. In the glasshouse experiment, the resin test was less effective than the Bray and Colwell tests in its ability to assess the level of plant available P from the different fertilizer treatments. Seventy one percent of the variation in total P content of the subterranean clover tops was explained by resin extractable P values, whereas the Colwell procedure accounted for 81% and the Bray 1 procedure accounted for 78%. Water and CaCl 2 extracts were poor predictors of P content. In the field experiments, all tests evaluated performed poorly in describing the relationship between soil test P and the level of P applied and relative yield and soil test P over a wide range of soil types and environments. The best performing test was the Bray 1 test, though the relationship was poor. (author)

Investigation by gamma-ray spectrometry and INAA of radioactivity impact on phosphate fertilizer plant environment

International Nuclear Information System (INIS)

Pantelica, A.; Companis, I.; Georgescu, I. I.; Pincovshi, E.

2006-01-01

The radioactive polluting effect of a phosphate fertilizer plant on the environment was investigated by gamma-ray spectrometry and neutron activation analysis (INAA). The hazards could arise from industrial plants using raw phosphate materials to prepare fertilizers for agricultural purposes due to the phosphate rock which, depending on the type and geographical zone of provenance may contain rather large amounts of uranium. The fertilizer plant under study is situated about 4 km from the town of Turnu Magurele, on the left bank of the Danube River in Romania. The main by-products of the factory are: nitro phosphate type fertilizers (NP, NPK), Ammonia, Nitric acid, Ammonium nitrate, Urea, Sulfuric acid, Phosphoric acid, Sodium fluorosilicate and Aluminum sulfate. Gamma-ray spectrometry was used to determine activity concentrations of naturally occurring radionuclides ( 2 26Ra, 2 35U, 2 38U, 2 32Th, and 4 0K), as well as 1 37Cs man-made radionuclide in surface soils collected from semicircular areas within radii of 0.5 and 15 km of the plant; in addition, different NPK type fertilizers and phosphate rocks were investigated. The samples (mass of about 100-g each) were kept tightly closed for one month to permit 2 26Ra to establish radioactive equilibrium with its decay products. This method makes it possible to assess U, Th, and K contents in samples by measuring 2 38U and 2 32Th (in equilibrium with their radioactive daughters) and 4 0K radioactivity, taken into account that 1 g of U, Th and K yield 1 2358 Bq 2 38U, 569 Bq 2 35U, 4057.2 Bq 2 32Th and 33.11 Bq 4 0K, respectively. The spectrometrical chain was based on a HPGe (EG and G Ortec) detector of 30 % relative efficiency and 2.1 keV resolution at 1332 keV of 6 0Co. INAA technique (neutron irradiation at TRIGA reactor of SCN Pitesti) was used to determine macro, micro and trace elements in samples collected from both technological shops of the factory (air dust and drinking tap water) and its surroundings

Avaliação do fosfato de rocha com baixo teor de flúor na alimentação de eqüinos em crescimento Evaluation of rock phosphate with low fluorine level in diets for growing horses

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Mauro Dal Secco de Oliveira

1999-11-01

Full Text Available Utilizaram-se 18 potras com idade média de 11 meses e peso vivo médio de 250 kg, alimentadas com 3 dietas contendo fosfato bicálcico (FB; 50% de fosfato bicálcico mais 50% fosfato de rocha de Tapira (BT e fosfato de rocha de Tapira (FT, incorporados ao concentrado (1,5% do peso vivo/animal/dia e ao sal mineralizado (50 g/animal/dia. O nível médio de flúor nas dietas FB, BT e FT foi, respectivamente, de 53,0; 90,0 e 184,0 ppm. O consumo diferenciado de fluoreto nas diferentes dietas não acarretou efeitos sobre os parâmetros ganho de peso, perímetro torácico, perímetro do joelho e perímetro da canela. Os animais que receberam a dieta contendo exclusivamente fosfato de rocha apresentaram menor aumento de altura na cernelha (1,27cm quando comparados àqueles que receberam dietas contendo fosfato bicálcico (1,55 e 1,30cm.Eighteen fillies of Brasileiro de Hipismo breed with initial age between 9 and 12 months and 250kg of average weight were used in a complete block design, during a five-month trial to evaluate the use of three different inorganic phosphorus sources. The sources were dicalcium phosphate (FB, half and half dicalcium phosphate/Tapira rock phosphate mixture (BT and Tapira rock phosphate (FT. They were added to a basal concentrate, given at the rate of 1.5% of average body weight and to a mineralized salt, of which 50 g/animal was offered daily. The mean fluoride level (concentrate plus salt in diets FB, BT and FT was 53, 90 and 184 ppm respectively. The mean monthly withers height gain was 1.55 (FB, 1.30 (BT and 1.27cm (FT and there was a significant difference between FB and FT diets.

The Impact of Phosphate Loading Activities on Environment: The Egyptian Red Sea Coast

International Nuclear Information System (INIS)

El-Shabasy, A.M.; Diab, H.M.; Ataiw, S.E.H.

2013-01-01

The phosphate industry in Egypt includes three major activities, namely, mining and milling of phosphate rock, phosphate product manufacture, and phosphate product use. The production of fertilizers from natural phosphate ore can lead to the redistribution of uranium and other radionuclides in products, by-products and residues and hence, to severe environmental impacts and increased radiation exposures. In this study, the impact of loading cargoes of phosphate ore into ships at the Red Sea coast has been evaluated. The main objective was to assess the impact of phosphate loading activities near marine environment by determining the activity concentrations of '2 26 Ra ( 238 U) series, 232 Th series and 40 K in soil, sediment and seawater from El- Hamraween and Safaga Port where phosphate mine. The specific activities of 226 Ra ( 238 U) series, 232 Th series and 40 K (Bq/kg dry weight) were measured using gamma ray spectrometers based on hyper-pure germanium detectors. The specific activities showed high concentration level of 226 Ra. The concentration and distribution pattern of 226 Ra in sediment can be used to trace the radiological impact of the non-nuclear industries on the Red Sea coast. The absorbed dose (nGy/h) was also evaluated and can be used as a pre-operational baseline to estimate the possible radiological impacts due to mining, processing and future phosphate industrial activities. Because of the limited measures to control radiological hazards to individuals and the environment, normal occupational health and environmental protection measures were designed to protect against radiological hazards.

Interpretation of the phosphate showings found in Uruguay. Recommendations for a a working programme

International Nuclear Information System (INIS)

Slansky, M.

1983-01-01

The radioactive anomalies put in evidence during the investigation of uranium and the mining inventory carried out in Uruguay, are due to rocks more or less strongly phosp hated of the top proterozoic and of the paleozoic. These anomalies drive to interrogating ourselves on the possibilities of existence of deposits of phosphates exploitable

The radiological impact of the Belgian phosphate industry

Energy Technology Data Exchange (ETDEWEB)

Vanmarcke, H.; Paridaens, J. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, 2400 Mol (Belgium)

2006-07-01

The Belgian phosphate industry processes huge amounts of phosphate ore (1.5 to 2 Mton/year) for a wide range of applications, the most important being the production of phosphoric acid, fertilizers and cattle food. Marine phosphate ores show high specific activities of the natural uranium decay series (usually indicated by Ra-226) (e.g. 1200 to 1500 Bq/kg for Moroccan ore). Ores of magmatic origin generally contain less of the uranium and more of the thorium decay series (up to 500 Bq/kg). These radionuclides turn up in by-products, residues or product streams depending on the processing method and the acid used for the acidulation of the phosphate rock. Sulfuric acid is the most widely used, but also hydrochloric acid and nitric acid are applied in Belgium. For Flanders, the northern part of Belgium, we already have a clear idea of the production processes and waste streams. The five Flemish phosphate plants, from 1920 to 2000, handled 54 million ton of phosphate ore containing 65 TBq of radium-226 and 2.7 TBq of thorium- 232. The total surface area of the phosphogypsum and calcium fluoride sludge deposits amounts to almost 300 ha. There is also environmental contamination along two small rivers receiving the waste waters of the hydrochloric production process: the Winterbeek (> 200 ha) and the Grote Laak (12 ha). The data on the impact of the phosphate industry in the Walloon provinces in Belgium is less complete. A large plant produced in 2004 0.8 Mton of phosphogypsum, valorizing about 70 % of the gypsum in building materials (plaster, cement), in fertilizers, and in other products such as paper. The remainder was stored on a local disposal site. The radiological impact of the Belgian phosphate industry on the local population will be discussed. At present most contaminated areas are still recognizable as waste deposits and inaccessible to the population. However as gypsum deposits and other contaminated areas quickly blend in with the landscape, it is

Rust and schreibersite in Apollo 16 highland rocks - Manifestations of volatile-element mobility

Science.gov (United States)

Hunter, R. H.; Taylor, L. A.

Rust is a manifestation of halogen and volatile-metal mobility in the lunar environment. Schreibersite is stable as the primary phosphorus-bearing phase in the highland rocks, a consequence of the inherently low oxygen fugacity within impact-generated melts. Apatite and whitlockite are subordinate in these rocks. The partitioning of P into phosphide in impact-generated melts, and the failure of phosphate to crystallize, effects a decoupling of the halogens and phosphorus. Of the Apollo 16 rocks, 63% contain rust, 70% contain schreibersite, and 52% contain both phases, thereby establishing the pervasiveness of volatile-elements throughout the highland rocks. The major portion of these volatile-bearing phases occur in impact melt-rocks or in breccia matrices. Rhabdites of schreibersite in some of the FeNi grains indicate that there is a meteoritic contribution to the phosphorus in these rocks. Cl/P2O5 ratios in lunar highland rocks are a function of secondary effects, with any apparent Cl-P correlations being coincidential. The present observations preclude the validity of models based on such elemental ratios in these rocks. The presence of rust in the clast laden matrices of pristine rocks indicates fugitive element localization. Pristine clasts may have been contaminated. The basis for a pristine volatile chemistry is questioned.

Impact of phosphate-solubilizing bacteria inoculation methods on phosphorus transformation and long-term utilization in composting.

Science.gov (United States)

Wei, Yuquan; Zhao, Yue; Fan, Yuying; Lu, Qian; Li, Mingxiao; Wei, Qingbin; Zhao, Yi; Cao, Zhenyu; Wei, Zimin

2017-10-01

This study aimed to assess the effect of phosphate-solubilizing bacteria (PSB) application and inoculation methods on rock phosphate (RP) solubilization and bacterial community during composting. The results showed that PSB inoculation in different stages of composting, especially both in the beginning and cooling stages, not only improved the diversity and abundance of PSB and bacterial community, but also distinctly increased the content of potential available phosphorus. Redundancy analysis indicated that the combined inoculation of PSB in the initial stage with higher inoculation amount and in the cooling stage with lower inoculation amount was the best way to improve the inoculation effect and increase the solubilization and utilization of RP during composting. Besides, we suggested three methods to improve phosphorus transformation and long-term utilization efficiency in composts based on biological fixation of phosphates by humic substance and phosphate-accumulating organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

The use of 32P dilution techniques to evaluate the effect of mycorrhizal inoculation on plant uptake of P from products of fermentation mixtures including agrowastes, Aspergillus niger and rock phosphate

International Nuclear Information System (INIS)

Vassilev, N.; Vassileva, M.; Azcon, R.; Barea, J.-M.

2002-01-01

Some microorganisms, such as filamentous fungi, are capable of solubilizing rock phosphate products, which are a less costly alternative to conventional P fertilizers used so far in agriculture. However, metabolizable C compounds must be supplied to the microbes to solubilize rock phosphate (RP). On another hand, huge quantities of organic materials are produced by cultivated plants every year and their residues became agrowastes, which may often pose significant environmental problems. An attractive approach to solubilize RP would therefore, be the application of microorganisms possessing a high acid-producing activity in fermentation processes based on agrowastes. In this context, Aspergillus niger was successfully cultivated on sugar beet (SB) waste material supplemented with 3.0 g/l RP acidifying the medium by releasing citric acid and thus decreasing the pH to 3.0-3.5. At the end of the solid-state fermentation process, the product contained mineralized (69%) organic matter, RP solubilized to 224 μg/ml and fungal mycelium. A series of microcosms greenhouse experiments were then carried out aimed at evaluating the effectiveness of such product, added at a rate of 5% (v/v), to a neutral, calcareous, P-deficient soil. Clover (Trifolium repens) inoculated or not with an arbuscular mycorrhizal fungus, was the test plant. It was shown that the product improved plant growth and P acquisition. Mycorrhizal inoculation further enhanced the effectiveness of the fermentation product. The use of the isotopic 32 P dilution technique showed a lowering of the specific activity of the treated plants, thus indicating that plants benefited from P solublilized from RP by the microbial treatments applied in this experiment. The reported biotechnological approach offers a potential application for sustainability purposes. (author)

Effect of phosphate solubilizing bacteria on the development of coffee seedlings.

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Carlos Adolfo Cisneros-Rojas

2016-12-01

Full Text Available The aim of this study was to evaluate the effect of solubilizing phosphate bacterias (BSF, Kocuria sp. and Bacillus subtilis, on the development of coffee seedlings Castillo variety. The experiment was conducted in a greenhouse condition, in Palmira, Colombia during 2013-2014 years. The experimental design was completely random, with nine treatments and ten repetitions. The treatments were established under three types of substrates for the seedlings: natural soil (Typic Melanudand + decomposed coffee pulp (1:1 lacking or presenting BSF (treatments 1-4, natural soil + decomposed coffee pulp (1:1 + phosphate rock (RF with or without microorganisms (treatments 5-8, and natural soil without BSF subjected to fertilization with diammonium phosphate (DAP (treatment 9. The application of decomposed coffee pulp with and without RF and BSF favored the availability of phosphorus that helped to the development of coffee seedlings, the above was re ected in the chemical analysis of the substrate and the response of variables, root and total dry aerial weight. Length and volume root, foliar P and recovery phosphorus ef ciency (ERF, did not present signi cant differences.

Ratio and rate effects of 32P-triple superphosphate and phosphate rock mixtures on corn growth

International Nuclear Information System (INIS)

Franzini, Vinicius Ide; Mendes, Fernanda Latanze

2009-01-01

The availability of phosphorus (P) from 'Patos de Minas' phosphate rock (PR) can be improved if it is applied mixed with a water-soluble P source. The objective of this study was to evaluate 32 P as a tracer to quantify the effect of the ratio of mixtures of triple superphosphate (TSP) with PR and the rates of application on P availability from PR. Two experiments were conducted in a greenhouse utilizing corn (Zea mays L.) plants as test crop. In the first experiment, the P sources were applied at the rate of 90 mg P kg -1 soil either separately or as compacted mixtures in several TSP:PR ratios (100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 calculated on the basis of the total P content). In the second experiment, the TSP was applied alone or as 50:50 compacted mixtures with PR applied at four P rates (15, 30, 60 and 90 mg P kg -1 ) while the sole PR treatment was applied at the 90 mg kg -1 P rate . The mixture of PR with TSP improved the P recovery from PR in the corn plant and this effect increased proportionally to the TSP amounts in the mixture. When compared with the plant P recovery from TSP (10.52%), PR-P recovery (2.57%) was much lower even when mixed together in the ratio of 80% TSP: 20% PR. There was no difference in PR-P utilization by the corn plants with increasing P rates in the mixture (1:1 proportion). Therefore, PR-P availability is affected by the proportions of the mixtures with water soluble P, but not by P rates. (author)

Aplicação de fosfato natural e reciclagem de fósforo por milheto, braquiária, milho e soja Rock phosphate fertilization and phosphorus recycling by pearl millet, Brachiaria sp., corn and soybean

Directory of Open Access Journals (Sweden)

José Salvador Simoneti Foloni

2008-06-01

Full Text Available Este trabalho teve por objetivo avaliar, comparativamente, a capacidade extratora de P da soja (Glycine max, milho (Zea mays, braquiária brizantha (Brachiaria brizantha e milheto (Pennisetum glaucum, submetidos a diferentes doses do fertilizante fosfatado natural fosforita Alvorada, em condições controladas. Utilizou-se um Argissolo Vermelho distroférrico de textura média, corrigido e adubado com N, K e micronutrientes. As espécies foram cultivadas em vasos de 18 dm³ por 50 dias em casa de vegetação, com aplicação de 0, 100, 200 e 400 kg ha-1 de P2O5. As quantidades de fosfato natural foram calculadas com base na teor total de P2O5. O milho, ao contrário da soja, respondeu positivamente ao aumento da dose de P2O5 via fosforita Alvorada. A Brachiaria brizantha cv. Marandu, apesar da menor produção de matéria seca em relação ao milheto, apresentou alta eficiência na absorção de P, mesmo com o fornecido deste nutriente por meio de fonte pouco solúvel. O milheto apresentou-se como importante espécie de cobertura do solo, graças ao alto potencial para produção de fitomassa e reciclagem de P num intervalo de tempo relativamente curto (50 dias.The objective of this experiment was to compare the ability of soybean (Glycine max, corn (Zea mays, Brachiaria brizantha cv. Marandu and pearl millet (Pennisetum glaucum for P-uptake, at different levels of the Alvorada natural rock phosphate, under controlled conditions. The soil used was a dystrophic Hapludalf (180 g kg-1 clay, which was limed and fertilized with N, K and micronutrients. The crops were grown in 18 dm³ pots for 50 days in a greenhouse, at different P2O5 rates (0, 100, 200, and 400 kg ha-1. The amount of rock phosphate was calculated based on the total P2O5 content. Contrasting to soybean, there was a positive response of maize to higher P2O5 doses. The dry matter production by Brachiaria brizantha cv. Marandu was lower than that observed for pearl millet, but it still

Evaluation of phosphatic fertilizers of different solubility for common bean using isotopic methods

International Nuclear Information System (INIS)

Garcia Altunaga, Aurelio; Hernandez Barrueta, German; Nuviola Montoya, Antonio; Mendez Perez, Nancy; Herrero Echevarria, Grisel; Drevon, Jean Jacques

2005-01-01

Glass house experiments were carried out in the Experimental Station La Renee located in Habana province in the year 2003. The objective of this study was to evaluate the effectiveness of phosphorus (P) sources varying in solubility for common bean (Phaseolus vulgaris L.) nutrition using the isotopic dilution method with 32 P , growing under two soils: Acrisol and Rhodic Ferralsol. The P sources, evaluated in both soils were phosphate rock (PR) Trinidad de Guedes and PR partially solubilized at 50% with H 2 SO 4 , namely FPA 50, whereas single super phosphate (SS) and triple super phosphate (TSP) were used in the Acrisol and Rhodic Ferralsol Soils, respectively. The common bean genotypes were BAT 477, DOR 364, DOR 390 and Censa, and BAT 58, BAT 477, DOR 364 and CC-25-9(N) in the Acrisol and Rhodic Felrrasol soils, respectively. Dry matter production, P extraction, and the fraction and quantity of P in plants obtained from different P sources were evaluated, and P use efficiency of each P fertilizer were calculated. Single and tripe super phosphate and FPA 50 were effective P fertilizers in both soils whereas RF was not. (author) [es

Mineralization of soluble P fertilizers and insoluble rock phosphate in response to phosphate-solubilizing bacteria and poultry manure and their effect on the growth and P utilization efficiency of chilli (Capsicum annuum L.)

Science.gov (United States)

Abbasi, M. K.; Musa, N.; Manzoor, M.

2015-08-01

The ability of soil microorganisms and organic manure to convert insoluble phosphorus (P) to an accessible form offers a biological rescue system for improving P utilization efficiency in soil-plant systems. Our objective was to examine the P mineralization potential of two soluble P fertilizers (SPF), i.e., single superphosphate (SSP) and diammonium phosphate (DAP), and of insoluble rock phosphate (RP) with and without phosphate-solubilizing bacteria (PSB) and poultry manure (PM) and their subsequent effect on the growth, yield and P utilization efficiency (PUE) of chilli (Capsicum annuum L.). An incubation study was carried out on a loam (slightly alkaline) soil with 12 treatments: T0 - control; T1 - RP; T2 - SSP; T3 - DAP; T4 - PM; T5 - 1/2 RP+1/2 SSP; T6 - 1/2 RP+1/2 DAP; T7 - 1/2 RP+1/2 PM; T8 - RP+PSB; T9 - 1/2 RP+1/2 SSP+PSB; T10 - 1/2 RP+1/2 DAP+PSB; and T11 - 1/2 RP+1/2 PM+PSB. Phosphorus mineralization was measured by analyzing extractable P from the amended soil incubated under controlled conditions at 25 °C for periods of 0, 5, 15, 25, 35 and 60 days. A complementary greenhouse experiment was conducted in pots with chilli (Capsicum annuum L.) as a test crop. Growth, yield, P uptake and PUE of the chilli was determined during the study. Results indicated that P mineralization in soil amended with RP was 6.0-11.5 mg kg-1, while both soluble P fertilizers resulted in 68-73 mg P kg-1 at day 0, which decreased by 79-82 % at the end of incubation. The integrated use of PSB and PM with RP in T11 stimulated P mineralization by releasing a maximum of 25 mg P kg-1 that was maintained at high levels without any loss. Use of PSB decreased soil pH. In the greenhouse experiment, RP alone or RP+PSB did not have a significant impact on plant growth. However, the combined use of RP, PM and PSB in T11 resulted in similar growth, yield and P uptake of chilli as DAP. The PUE of applied P varied from 4 to 29 % and was higher in the treatments that included PSB. We conclude

Kinetics of phosphorus and potassium release from rock phosphate and waste mica enriched compost and their effect on yield and nutrient uptake by wheat (Triticum aestivum).

Science.gov (United States)

Nishanth, D; Biswas, D R

2008-06-01

An attempt was made to study the efficient use of rice straw and indigenous source of phosphorus and potassium in crop production through composting technology. Various enriched composts were prepared using rice straw, rock phosphate (RP), waste mica and bioinoculant (Aspergillus awamori) and kinetics of release of phosphorus and potassium from enriched composts and their effect on yield and nutrient uptake by wheat (Triticum aestivum) were carried out. Results showed sharp increases in release in water-soluble P and K from all the composts at 8th to 12th day of leaching, thereafter, it decreased gradually. Maximum release of water-soluble P and K were obtained in ordinary compost than enriched composts during the initial stages of leaching, but their differences narrowed down at latter stages. Data in pot experiments revealed that enriched composts performed poorly than diammonium phosphate during initial stages of crop growth, but they out yielded at the latter stages, particularly at maturity stage, as evident from their higher yield, uptake, nutrient recoveries and fertility status of P and K in soils. Moreover, enriched composts prepared with RP and waste mica along with A. awamori resulted in significantly higher biomass yield, uptake and recoveries of P and K as well as available P and K in soils than composts prepared without inoculant. Results indicated that enriched compost could be an alternate technology for the efficient management of rice straw, low-grade RP and waste mica in crop production, which could help to reduce the reliance on costly chemical fertilizers.

Uranium in early proterozoic phosphate-rich metasedimentary rocks of east-central Minnesota

International Nuclear Information System (INIS)

McSwiggen, P.L.; Morey, G.B.; Weiblen, P.W.

1986-01-01

Exploration for unconformity-type uranium deposits in the late 1970s in east-central Minnesota led to the discovery of several uranium-bearing phosphorite occurrences in rocks of early Proterozoic age. In this report the authors use the term phosphorite for a rock or specimen that contains substantial sedimentary apatite (Altschuler et al., 1958). The deposits in Minnesota are especially interesting because of their high uranium content but low metamorphic grade. These occurrences characteristically contain 0.025 to 0.085 percent U and locally as much as 0.157 percent U (Ullmer, 1981), whereas typical primary marine phosphorites have uranium contents of 0.005 to 0.02 percent U (Altschuler et al., 1958). The presence of uranium in a marine phosphorite generally is explained by either the replacement of calcium in the apatite crystal structure or the adsorption of uranium in admixed organic matter and cryptocrystalline apatite. In east-central Minnesota the uranium is closely associated with the finely crystalline apatite, but the uranium has also been involved in several episodes of remobilization and redeposition. Thus, even though the phosphorite deposits are an interesting geologic phenomenon in themselves, they also are important as a possible source for epigenetic uranium deposits that may occur in the area

Soil Chemical Properties and Nutrient Uptake of Cocoa as Affected by Application of Different Organic Matters and Phosphate Fertilizers

Directory of Open Access Journals (Sweden)

Sugiyanto Sugiyanto

2008-07-01

Full Text Available Effort repair of land quality better be done by simultan namely with application of organic matters and inorganic fertilization. The objective of this research is to study the effect of varied organic matters source and phosphate fertilizers on the chemicals soil characteristic and cocoa nutrient uptake. The experiment was laid experimentally in split-plot design and environmentally in randomized complete block design. The main plot was source of P consisted of, control, SP 36 and rock phosphate in dosage of 200 mg P2O5 per kg of air dry soil. Source of organic matter as sub-plot consisted of control (no organic matter, cow dung, cocoa pod husk compost and sugar cane filter cake, each in dosage of 2.5 and 5.0%. Result of this experiment showed application of cow dung, cocoa pod husk compost and sugar cane filter cake increased content of C, N, Ca exchangeable, Fe available, and pH in soil, and SP 36 increased availability of P in soil. Application of sugar cane filter cake increased N, K, Ca, Mg, and SO4 uptake but did not increase Cl uptake, application of cow dung in dosage 5% increased N, K, and Cl uptake and cocoa pod husk compost dosage 5% increased N and K uptake of cocoa. SP 36 increased Mg uptake of cocoa but rock phosphate did not increase it. They were not interaction between organic matters and phosphate fertilizers to nutrient uptake of cocoa. Nutrient soil content as affected by organic matters correlated with nutrient uptake of cocoa.Key words : soil chemical properties, nutrient uptake, cocoa, organic matter, phosphate fertlizers.

How changing root system architecture can help tackle a reduction in soil phosphate (P) levels for better plant P acquisition

KAUST Repository

HEPPELL, J.; TALBOYS, P.; PAYVANDI, S.; ZYGALAKIS, K. C.; FLIEGE, J.; WITHERS, P. J. A.; JONES, D. L.; ROOSE, T.

2014-01-01

© 2014 John Wiley & Sons Ltd. The readily available global rock phosphate (P) reserves may run out within the next 50-130 years, causing soils to have a reduced P concentration which will affect plant P uptake. Using a combination of mathematical

Development of a new biofertilizer with a high capacity for N2 fixation, phosphate and potassium solubilization and auxin production.

Science.gov (United States)

Leaungvutiviroj, Chaveevan; Ruangphisarn, Pimtida; Hansanimitkul, Pikul; Shinkawa, Hidenori; Sasaki, Ken

2010-01-01

Biofertilizers that possess a high capacity for N(2) fixation (Azotobacter tropicalis), and consist of phosphate solubilizing bacteria (Burkhoderia unamae), and potassium solubilizing bacteria (Bacillus subtilis) and produce auxin (KJB9/2 strain), have a high potential for growth and yield enhancement of corn and vegetables (Chinese kale). For vegetables, the addition of biofertilizer alone enhanced growth 4 times. Moreover, an enhancement of growth by 7 times was observed due to the addition of rock phosphate and K-feldspar, natural mineral fertilizers, in combination with the biofertilizer.

Phosphate dynamics on the application of rice straw compost-biochar and phosphate fertilization in rice fields

International Nuclear Information System (INIS)

Ania Citraresmini; Taufiq Bachtiar

2016-01-01

Soil productivity is determined by soil characteristics itself, which consist of physical, chemical and biological character. The linkage between these three properties can be represented by a single indicator, namely the carbon content in the soil. One of the effects of soil organic matter fulfillment is the availability of soil nutrients, especially to the nutrient that limits the lowland rice production. In this case, P (phosphorus) nutrient become a limiting factor because their numbers are often in abundance but in a form that can not be used by plants. Experiments were carried out with the aim of studying the impact of straw compost application that integrates with Biochar, to the availability of P in lowland soil. The interaction of straw compost + Biochar with PSB inoculation and P sources, become the treatment that being tested in the experiment. Randomized Block Design with factorial pattern is applied as design experiment. As the first factor is the application dose of straw compost + Biochar, consists of 5 levels of treatment : 0; 1; 2; 3; 4 t ha -1 . Second factor is several sources of P, consist of 5 levels of treatment : without P sources (p 0 ); 100 kg ha -1 SP-36 fertilizer (p1); rock phosphate at the dose of 163 kg ha -1 (p 2 ); PSB inoculation at the inoculation dose of 2 kg ha -1 (p 3 ); and rock phosphate inoculated with PSB (p 4 ). The experiment done in the green house of PAIR-BATAN experimental station, Jakarta, on March-July 2014. Phosphorus dynamic as a result of the tested treatments, determined by using radioisotope 32 P technology at the activity of 30 mCi and described clearly on the plant P uptake data of Sidenuk rice plant variety. The experiment result showed that the treatments applied is causing significantly different response on the soil C-organic, the number of PSB populations, 32 P plant counting and plant P uptake derived from several P sources in the plant. (author)

Ratio and rate effects of {sup 32}P-triple superphosphate and phosphate rock mixtures on corn growth

Energy Technology Data Exchange (ETDEWEB)

Franzini, Vinicius Ide; Mendes, Fernanda Latanze [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Programa de Pos-Graduacao em Solos e Nutricao de Plantas; Muraoka, Takashi [Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP (Brazil)]. E-mail: muraoka@cena.usp.br

2009-01-15

The availability of phosphorus (P) from 'Patos de Minas' phosphate rock (PR) can be improved if it is applied mixed with a water-soluble P source. The objective of this study was to evaluate {sup 32}P as a tracer to quantify the effect of the ratio of mixtures of triple superphosphate (TSP) with PR and the rates of application on P availability from PR. Two experiments were conducted in a greenhouse utilizing corn (Zea mays L.) plants as test crop. In the first experiment, the P sources were applied at the rate of 90 mg P kg{sup -1} soil either separately or as compacted mixtures in several TSP:PR ratios (100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 calculated on the basis of the total P content). In the second experiment, the TSP was applied alone or as 50:50 compacted mixtures with PR applied at four P rates (15, 30, 60 and 90 mg P kg{sup -1}) while the sole PR treatment was applied at the 90 mg kg{sup -1}P rate . The mixture of PR with TSP improved the P recovery from PR in the corn plant and this effect increased proportionally to the TSP amounts in the mixture. When compared with the plant P recovery from TSP (10.52%), PR-P recovery (2.57%) was much lower even when mixed together in the ratio of 80% TSP: 20% PR. There was no difference in PR-P utilization by the corn plants with increasing P rates in the mixture (1:1 proportion). Therefore, PR-P availability is affected by the proportions of the mixtures with water soluble P, but not by P rates. (author)

Optimization of Eisenia fetida stocking density for the bioconversion of rock phosphate enriched cow dung–waste paper mixtures

International Nuclear Information System (INIS)

Unuofin, F.O.; Mnkeni, P.N.S.

2014-01-01

Highlights: • Vermidegradation of RP-enriched waste mixtures is dependent on E. fetida stocking density. • A stocking density of 12.5 g-worms kg -1 resulted in highly humified vermicomposts. • P release from RP-enriched waste vermicomposts increases with E. fetida stocking density. • RP-enriched waste vermicomposts had no inhibitory effect on seed germination. - Abstract: Vermitechnology is gaining recognition as an environmental friendly waste management strategy. Its successful implementation requires that the key operational parameters like earthworm stocking density be established for each target waste/waste mixture. One target waste mixture in South Africa is waste paper mixed with cow dung and rock phosphate (RP) for P enrichment. This study sought to establish optimal Eisenia fetida stocking density for maximum P release and rapid bioconversion of RP enriched cow dung–paper waste mixtures. E. fetida stocking densities of 0, 7.5, 12.5, 17.5 and 22.5 g-worms kg −1 dry weight of cow dung–waste paper mixtures were evaluated. The stocking density of 12.5 g-worms kg −1 resulted in the highest earthworm growth rate and humification of the RP enriched waste mixture as reflected by a C:N ratio of <12 and a humic acid/fulvic acid ratio of >1.9 in final vermicomposts. A germination test revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg −1 feedstock suggesting that for maximum P release from RP enriched wastes a high stocking density should be considered

Optimization of Eisenia fetida stocking density for the bioconversion of rock phosphate enriched cow dung–waste paper mixtures

Energy Technology Data Exchange (ETDEWEB)

Unuofin, F.O., E-mail: funmifrank2009@gmail.com; Mnkeni, P.N.S., E-mail: pmnkeni@ufh.ac.za

2014-11-15

Highlights: • Vermidegradation of RP-enriched waste mixtures is dependent on E. fetida stocking density. • A stocking density of 12.5 g-worms kg{sup -1} resulted in highly humified vermicomposts. • P release from RP-enriched waste vermicomposts increases with E. fetida stocking density. • RP-enriched waste vermicomposts had no inhibitory effect on seed germination. - Abstract: Vermitechnology is gaining recognition as an environmental friendly waste management strategy. Its successful implementation requires that the key operational parameters like earthworm stocking density be established for each target waste/waste mixture. One target waste mixture in South Africa is waste paper mixed with cow dung and rock phosphate (RP) for P enrichment. This study sought to establish optimal Eisenia fetida stocking density for maximum P release and rapid bioconversion of RP enriched cow dung–paper waste mixtures. E. fetida stocking densities of 0, 7.5, 12.5, 17.5 and 22.5 g-worms kg{sup −1} dry weight of cow dung–waste paper mixtures were evaluated. The stocking density of 12.5 g-worms kg{sup −1} resulted in the highest earthworm growth rate and humification of the RP enriched waste mixture as reflected by a C:N ratio of <12 and a humic acid/fulvic acid ratio of >1.9 in final vermicomposts. A germination test revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg{sup −1} feedstock suggesting that for maximum P release from RP enriched wastes a high stocking density should be considered.

Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?

Science.gov (United States)

Emsbo, Poul; McLaughlin, Patrick I.; Breit, George N.; du Bray, Edward A.; Koenig, Alan E.

2015-01-01

The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.

Natural Radioactivity Measurements in Soil and Phosphate Samples from El-Sabaea, Aswan, Egypt

International Nuclear Information System (INIS)

Harb, S.; Abbady, A.; El-Kamel, A.H.; Abd El-Mageed, A.I.; Negm, H.H.

2009-01-01

The knowledge on radioactivity content of the various radionuclides in the soil and rocks play an important role in health physics. The main aim of this work is to estimate the concentrations of natural radionuclides 226 Ra, 228 Ra, 228 Th, 232 Th and 40 k in soil and phosphate samples and, impact of the El-Sabaea phosphate factory on the human health. This can be investigated via gamma-ray spectroscopy by 2 x 2 inch NaI(Tl) scintillation detector. The range of 226 Ra, 232 Th and 40k were from 59.7±6.7 to 638.3±31.0, from 9.4±1.4 to 40.6±6.3, from 213.1±9.5 to 798.9±30.6 in Bq/kg respectively

Gafsa rock phosphate and triple superphosphate for dry matter production and P uptake by corn Fosfato de Gafsa e superfosfato triplo na produção de matéria seca e absorção de fósforo pelo milho

Directory of Open Access Journals (Sweden)

Rossini Mattos Corrêa

2005-04-01

Full Text Available Crops in general make poor use of phosphorous fertilizer and, as a result, recommended rates and production costs are very high. Phosphorus can be made more readily available to plants by proper management of phosphate fertilization, selecting both, type of fertilizer and application method. This study was carried out to evaluate the efficiency of the natural Gafsa rock phosphate and the triple superphosphate on dry matter production and P uptake by corn plants cultivated in a greenhouse. Fertilizers were applied localized and broadcast/incorporated on to two soils with contrasting phosphorus capacity factors (PCF. Rock phosphate broadcast application was as efficient as triple superphosphate in increasing corn plant dry matter in the Tropudult, with lower PCF. This effect was not observed on the Haplustox, owing to the lower P solubility due to the higher Ca concentration in this soil. Triple superphosphate rates increased plant P uptake in both soils and for both application forms. Rock phosphate resulted in higher P-content in plants, but only for broadcast application on the Ultisol.Os fertilizantes fosfatados, de modo geral, apresentam baixa eficiência de utilização pelas culturas. Essa realidade faz com que as doses aplicadas sejam altas, elevando o custo de produção. O aumento da disponibilidade de fósforo para as plantas pode ser obtido mediante o manejo correto da adubação fosfatada, com ênfase na fonte utilizada e no modo de aplicação mais adequado para solos com diferentes capacidades de adsorção do elemento. Avaliou-se a eficiência do fosfato natural de Gafsa e do superfosfato triplo, em amostras de dois solos (Argissolo Amarelo e Latossolo Amarelo com diferentes fatores capacidade de fósforo (FCP, em diferentes doses aplicadas de forma incorporada e localizada, sobre a produção de matéria seca e absorção de fósforo por plantas de milho cultivadas em casa de vegetação. No Argissolo Amarelo (menor FCP o fosfato

Effect of the enriched filter pie with natural phosphate and microorganisms on soil and plant in a Vermelho-Distrófico Latossolo

Directory of Open Access Journals (Sweden)

Leónides Castellanos González

2016-03-01

Full Text Available The objective of the research was to evaluate the use of filter pie and phosphate rock enriched with biofertilizer microorganisms on the population of microorganisms and phosphorus tenor in the soil and on plants. The experiment was conducted in a vegetation house with corn plants with Latossolo Red-Distrófico, containing seven treatments disposed in an entirely randomized design, where the treatments were: soil samples and filter pie with additions of phosphate of Araxá rock enriched with microorganisms coming from Biopack (1, Embrafos (2 and Azotofos (3, and without enrichment with microorganisms (4, and three controls, soil just with filter pie (5, soil just with phosphate rock (6 and only soil (7, with three repetitions. Height, stem diameter and number of leaves for plants were evaluated at 14, 28 and 42 days. At the 45 days the dry matters of leafs and roots were evaluated, as the same as populations of the microorganisms and phosphorus tenor in the soil and in the aerial part of the plant. The tenor of soluble phosphorus in the soil and accumulated phosphorous in the aerial part of corn plan were increased by the treatments with filter pie but not higher with filter pie enriched with biofertilizers, so its use isn’t justified. The pie treatments increase the fungus, total and solubilizers bacterial populations in the soil, provoking an increase of the height, diameter, number of leaves and dry matter of corn plants in a Red-Distrófico Latossolo.

Spatial database of mining-related features in 2001 at selected phosphate mines, Bannock, Bear Lake, Bingham, and Caribou Counties, Idaho

Science.gov (United States)

Moyle, Phillip R.; Kayser, Helen Z.

2006-01-01

This report describes the spatial database, PHOSMINE01, and the processes used to delineate mining-related features (active and inactive/historical) in the core of the southeastern Idaho phosphate resource area. The spatial data have varying degrees of accuracy and attribution detail. Classification of areas by type of mining-related activity at active mines is generally detailed; however, for many of the closed or inactive mines the spatial coverage does not differentiate mining-related surface disturbance features. Nineteen phosphate mine sites are included in the study, three active phosphate mines - Enoch Valley (nearing closure), Rasmussen Ridge, and Smoky Canyon - and 16 inactive (or historical) phosphate mines - Ballard, Champ, Conda, Diamond Gulch, Dry Valley, Gay, Georgetown Canyon, Henry, Home Canyon, Lanes Creek, Maybe Canyon, Mountain Fuel, Trail Canyon, Rattlesnake, Waterloo, and Wooley Valley. Approximately 6,000 hc (15,000 ac), or 60 km2 (23 mi2) of phosphate mining-related surface disturbance are documented in the spatial coverage. Spatial data for the inactive mines is current because no major changes have occurred; however, the spatial data for active mines were derived from digital maps prepared in early 2001 and therefore recent activity is not included. The inactive Gay Mine has the largest total area of disturbance, 1,900 hc (4,700 ac) or about 19 km2 (7.4 mi2). It encompasses over three times the disturbance area of the next largest mine, the Conda Mine with 610 hc (1,500 ac), and it is nearly four times the area of the Smoky Canyon Mine, the largest of the active mines with about 550 hc (1,400 ac). The wide range of phosphate mining-related surface disturbance features (141) from various industry maps were reduced to 15 types or features based on a generic classification system used for this study: mine pit; backfilled mine pit; waste rock dump; adit and waste rock dump; ore stockpile; topsoil stockpile; tailings or tailings pond; sediment

Phosphorus release capacity of soluble P fertilizers and insoluble rock phosphate in response to phosphate solubilizing bacteria and poultry manure and their effect on plant growth promotion and P utilization efficiency of chilli (Capsicum annuum L.)

Science.gov (United States)

Abbasi, M. K.; Musa, N.; Manzoor, M.

2015-01-01

The ability of soil microorganisms and organic manures to convert insoluble phosphorus (P) to an accessible form offers a biological rescue system for improving P solubilization and utilization in soil-plant systems. Our objective was to examine the P supplying capacity of soluble P fertilizers (SPF) i.e. single super phosphate (SSP) and di-ammonium phosphate (DAP) and insoluble rock phosphate (RP) after adding phosphate solubilizing bacteria (PSB) and poultry manure (PM) and their subsequent effect on the growth, yield and P-utilization efficiency (PUE) of chill (Capsicum annuum L.). An incubation study was carried-out on a sandy loam neutral soil with twelve treatments including T0: control; T1: RP; T2: SSP; T3: DAP; T4: PM; T5: 1/2 RP + 1/2 SSP; T6: 1/2 RP + 1/2 DAP; T7: 1/2 RP + 1/2 PM; T8: RP + PSB; T9: 1/2 RP + 1/2 SSP + PSB; T10: 1/2 RP + 1/2 DAP + PSB; T11: 1/2 RP + 1/2 PM + PSB. Phosphorus release capacity of added amendments was measured by analyzing extractable P from the amended soil incubated under controlled condition at 25 °C for 0, 5, 15, 25, 35, 60 days period. To complement the incubation study, a greenhouse experiment was conducted in pots with chilli (Capsicum annuum L.) used as a test crop. Growth, yield, P-uptake and PUE of the chilli was determined during the study. Results indicated that P release capacity of soil amended with RP varied between 6.0 and 11.5 mg kg-1 while the soluble P fertilizers i.e. SSP and DAP displayed a maximum of 73 and 68 mg P kg-1 at the start of the experiment (day 0). However, the P released tendency from SSP and DAP declined during incubation and at the end 82 and 79% of P initially present had been lost from the mineral pool. Integrated use of PSB and PM with RP in 1/2 RP + 1/2 PM + PSB treatment stimulated P mineralization by releasing a maximum of 25 mg P kg-1 that was maintained at high levels without any loss. Application of PSB tended to decrease pH showing an acidifying effect on soil. In the greenhouse

Production and Purification of UO3 from rock phosphate deposits and its characterization

International Nuclear Information System (INIS)

Zumrawi, N. S.; Sam, A. K.

2005-01-01

This study was carried out mainly to produce uranium trioxide (UO 3 ), matching standard commercial specification from rock phosphate deposits in Uro and Kurun at eastern part of the Nuba Mountains. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. The powdered ore sample was leached with concentrated H 2 SO 4 acid with and without addition of KCIO 3 as an oxidant. The crude yellow cake was precipitated from the resulting green solution of phosphoric acid as Na 2 U 2 O 7 and (NH 4 ) 2 U 2 O 7 and subsequently purified by TBP extraction (tributylphosphate) and hydrogen peroxide as UO 4 .2H 2 O. TBP purified product was dried and calcined to UO 3 whereas UO 4 .2H-2O was dried and reduced to UO 3 by Na 2 S 2 O 3 . Prior to precipitation of crude yellow cake, Fe in the phosphoric acid solution was precipitated using magnesia. Elemental analysis has shown that the ore is rich in Ca and deficient in elements of potential interest such as Fe, Cu and Zn. Uranium content in ore, phosphoric acid and purified yellow cake (UO 3 ) obtained with different precipitants was analyzed using alpha-spectrometry. On the average, the activity concentration of uranium in ore corresponds to 82±42 ppm (0.01%). From the data of pregnant liquor, it was observed that the addition of KCIO 3 as an oxidant improves the dissolution of uranium from the ore by almost 20%. Data has also indicated that the yellow cake purified by hydrogen peroxide exhibit higher concentration of uranium by 45.5% over the one purified by TBP extraction. Undesirable impurities in yellow cake as dictated by the function to which it is intended for were analyzed and compared with international standard specifications set for commercial products. Uranium as U 3 O 3 was found to be 53% in yellow cake initially obtained as ammonium diuranate and purified by hydrogen peroxide and 38% in one which is purified by TBP extraction. With the exception of Cr, the values of the

Radiological aspects of storage and release of waste materials by the phosphate industry

International Nuclear Information System (INIS)

Eggink, G.J.

1995-03-01

The production of phosphate fertilizers from phosphate rock following the wet process leads to the generation of phosphogypsum containing large amounts of natural radionuclides. The removal of radionuclides from the gypsum occurs only on a limited scale. The majority is stockpiled on land or discharged into the surface water. Europe produced in 1991 in total over 4 Mton of P 2 O 5 , with an estimated 19 Mton of L phosphogypsum. Since 1987 the total European production of phosphate fertilizers decreased. For nine European countries detailed information on phosphogypsum production is obtained: Belgium, France, Germany, the Netherlands, Norway, Portugal, Spain, Sweden and Great Britain. In 1991 they generated together an estimated 11,8 Mton of phosphogypsum, which is about 63% of the total European production. 27% is discharged into rivers and seas (3.2 Mton) and 68% is stockpiled on land in special dumpsites (8 Mton). In Belgium the remaining 5% (0.6 Mton) is processed with the aid of a special installation into products suitable to be used in building materials, for road construction etc. 4 figs., 3 tabs., 3 appendices, 18 refs

Spectrophotometric determination of trace uranium in phosphate ore samples from kurum and uro areas, Nuba mountains, Sudan

International Nuclear Information System (INIS)

Mohamed, A. A.; Ali, A. H.; Altayeb, M. A. H.

2004-01-01

A method was proposed for the spectrophotometric determination of uranium content in phosphate ores. the method is based on the use of nitrogen (v) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 425 nm. The procedure was used for the determination of trace uranium content in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in Sudan. X-ray fluorescence technique was employed for the assessment of the method used. The spectrophotometric method results show a high similarity with those obtained by XRF technique. This agreement indicates that the procedure proposed here has been successfully applied for the determination of uranium in phosphate ores. (Author)

Phosphated minerals to be used as radioactive reference materials

International Nuclear Information System (INIS)

Braganca, M.J.C.S.; Tauhata, L.; Clain, A.F.; Moreira, I.

2003-01-01

The production and the supplying of certified reference materials, or deliberated contaminated materials containing natural radionuclides for laboratories which analyses environmental samples are fundamentals for the correct measurements of their radioactive levels. This analysis quality represents a important step for the safeguards of the population health, and quality control of the imported and exported products, such as minerals, agricultural and raw materials. The phosphate rocks, containing significant concentrations of thorium, and used as raw material and fertilizers justified a study for better characterization and distinction to be used cas certified reference radioactive materials. Therefore, samples from the two carboanalytical-alkaline chimneys (Araxa and Catalao), and one from metasedimentar origin (Patos de Minas), distant 100 km from each other, were collected and chemical and cholecystographic characterized by optical emission, X-ray diffraction and fluorescence. The element concentrations were determined by neutron activation analysis, ICP-MS and ICP-AES. The results, after multivariate statistical analysis and study of correlations among elements, have shown geochemical similarities of the phosphates from Araxa and Catalao, and differences from Patos de Minas, despite of the geographic proximity. The concentration of thorium between 200 and 500 (mg/g) allows to use such minerals as reference materials

Inoculation of arbuscular mycorrhizal fungi and phosphate solubilizing bacteria in the presence of rock phosphate improves phosphorus uptake and growth of maize

International Nuclear Information System (INIS)

Wahid, F.; Sharif, M.; Khan, M. A.; Khan, S. A.

2016-01-01

The beneficial microbes like arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) are known to play an important role in phosphorous (P) supply to plants in a sustainable manner in P deficient soils. In this scenario, a pot experiment was conducted under greenhouse condition to assess the synergistic effect of AMF and PSB strains (Coccus DIM7 Streptococcus PIM6 and Bacillus sp. PIS7) on P solubility from RP and their successive uptake by maize (Zea-mays L. Azam) crop at alkaline soil. The experiment was completely randomized design with three replications having calcareous silty clay loam soil, low in organic matter, nitrogen and phosphorus contents. RP was used as a crude phosphate alone and/or in combination with the native AMF and PSB inoculum. The Results indicated that the rhizosphere interactions between AMF and PSB significantly promote RP mineralization in soil and improved all growth parameters including shoot (56 percent), root yield (52 percent), height (41 percent), N (80 percent) and P (91 percent) uptake by the maize plants as compared to control and single inoculation. A remarkable increase in soil spore density, PSB population and percent root colonization in maize plants were also recorded by the combined inoculation of AMF and PSB with RP. From this study, it is concluded that the combined application of AMF and PSB with RP has the potential to improve maize growth and nutrients uptake. Moreover, AMF and PSB inoculants are recommended as useful biofertilizers for enhancing P solubility and bioavailability in P deficient agricultural soils. (author)

Water - rock interaction in different rock environments

International Nuclear Information System (INIS)

Lamminen, S.

1995-01-01

The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

Investigating Microbial Biofilm Formations on Crustal Rock Substrates

Science.gov (United States)

Weiser, M.; D'Angelo, T.; Carr, S. A.; Orcutt, B.

2017-12-01

Ocean crust hosts microbial life that, in some cases, alter the component rocks as a means of obtaining energy. Variations in crust lithology, included trace metal and mineral content, as well as the chemistry of the fluids circulating through them, provide substrates for some microbes to metabolize, leading to formation of biofilm community structures. Microbes have different parameters for the situations in which they will form biofilms, but they must have some source of energy in excess at the site of biofilm formation for them to become stationary and form the carbohydrate-rich structures connecting the cells to one another and the substrate. Generally, the requirements for microbes to form biofilms on crustal minerals are unclear. We designed two experiments to test (1) mineral preference and biofilm formation rates by natural seawater microbial communities, and (2) biofilm development as a function of phosphate availability for an organism isolated from subseafloor ocean crust. In Experiment 1, we observed that phyric basalt groundmass is preferentially colonized over aphyric basalt or metal sulfides in a shallow water and oxic seawater environment. In experiment 2, tests of the anaerobic heterotroph Thalassospira bacteria isolated from oceanic crustal fluids showed that they preferentially form biofilms, lose motility, and increase exponentially in number over time in higher-PO4 treatments (50 micromolar), including with phosphate-doped basalts, than in treatments with low phosphate concentrations (0.5 micromolar) often found in crustal fluids. These observations suggest phosphate as a main driver of biofilm formation in subsurface crust. Overall, these data suggest that the drivers of microbial biofilm formation on crustal substrates are selective to the substrate conditions, which has important implications for estimating the global biomass of life harbored in oceanic crust.

Availability of metals in samples of phosphogypsum and phosphate fertilizers used in agriculture

International Nuclear Information System (INIS)

Bourlegat, Fernanda Melo le

2010-01-01

The Brazilian phosphate fertilizer is obtained by wet reaction of the igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid, and dehydrated calcium sulphate (phosphogypsum) as by-product. Part of this phosphogypsum is stored in stacks at open air and part has been used in agriculture, as soil amendment. To assure a safe utilization of phosphogypsum it is important to determine the levels of impurities, particularly of metals, present in phosphogypsum. In this paper, the concentration of metals (As, Ba, Cd, Cr, Co, Cu, Hg, Ni, Pb, Se, Zn and rare earth elements) present in Brazilian phosphogypsum and also in single super phosphate (SSP), triple super phosphate (TSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP) were determined. The metals Cd, Cu, Ni, Pb and Zn were determined following the procedure 'EPA 3052'. The same elements, As and Se were also determined following the procedure 'EPA 3050B', recommended by Ministerio da Agricultura, Pecuaria e Abastecimento (MAPA). All these metals are controlled by environmental and agriculture regulation institutes in Brazil. The concentrations obtained for the metals analyzed by using the two procedures were different. Ba, Co, Cr and rare earth elements were determined by neutron activation analysis. In order to evaluate the availability of these metals As, Cd, Cr, Co, Cu, Ni, Pb, Se and Zn to the environment, the content of the same elements were determined following a procedure established by the EC (European Community), which includes an initial attack of the samples with EDTA-NH 4 0.05M, at pH 7.0. In all these cases, phosphogypsum presented metals concentration lower than the phosphate fertilizers, and the results are below the limits adopted by MAPA and Companhia Ambiental do Estado de Sao Paulo (CETESB). The results obtained using the methodology with mild attack show that the metals are not available to the environment, giving evidence that the application of

Removal of phosphate from solution by adsorption and precipitation of calcium phosphate onto monohydrocalcite.

Science.gov (United States)

Yagi, Shintaro; Fukushi, Keisuke

2012-10-15

The sorption behavior and mechanism of phosphate on monohydrocalcite (CaCO(3)·H(2)O: MHC) were examined using batch sorption experiments as a function of phosphate concentrations, ionic strengths, temperatures, and reaction times. The mode of PO(4) sorption is divisible into three processes depending on the phosphate loading. At low phosphate concentrations, phosphate is removed by coprecipitation of phosphate during the transformation of MHC to calcite. The sorption mode at the low-to-moderate phosphate concentrations is most likely an adsorption process because the sorption isotherm at the conditions can be fitted reasonably with the Langmuir equation. The rapid sorption kinetics at the conditions is also consistent with the adsorption reaction. The adsorption of phosphate on MHC depends strongly on ionic strength, but slightly on temperature. The maximum adsorption capacities of MHC obtained from the regression of the experimental data to the Langmuir equation are higher than those reported for stable calcium carbonate (calcite or aragonite) in any conditions. At high phosphate concentrations, the amount of sorption deviates from the Langmuir isotherm, which can fit the low-to-moderate phosphate concentrations. Speciation-saturation analyses of the reacted solutions at the conditions indicated that the solution compositions which deviate from the Langmuir equation are supersaturated with respect to a certain calcium phosphate. The obtained calcium phosphate is most likely amorphous calcium phosphate (Ca(3)(PO(4))(2)·xH(2)O). The formation of the calcium phosphate depends strongly on ionic strength, temperature, and reaction times. The solubility of MHC is higher than calcite and aragonite because of its metastability. Therefore, the higher solubility of MHC facilitates the formation of the calcium phosphates more than with calcite and aragonite. Copyright © 2012 Elsevier Inc. All rights reserved.

Phosphate dissolving fungi: Mechanism and application in alleviation of salt stress in wheat.

Science.gov (United States)

Gaind, Sunita

2016-12-01

The present investigation reveals the solubilization efficiency of tri-calcium phosphate (TCP), Udaipur rock phosphate (URP), aluminium phosphate (AP) and ferric phosphate (FP) by Aspergillus niger (ITCC 6719) and Trichoderma harzianum (ITCC 6721) as function of carbon concentrations. Increasing glucose concentration from 1 to 7% in the growth medium, though improved the phosphorus (P) solubilization significantly but each fungal strain preferred different optimum carbon concentrations for mediating solubilization of different P sources. The two fungi employed different mechanisms to reduce medium pH for release of P from TCP, AP and FP. However, URP was solubilized solely through fungal production of citric, succinic, propionic, malic and acetic acid. A linear increase in citric acid production with increasing carbon concentration was recorded during FP solubilization by T. harzianum. The cell free culture filtrate of A. niger detected high phytase and low acid phosphatase activity titre whereas results were vice versa for T. harzianum. Both the fungal strains possessed plant growth promoting attributes such as auxin and sidreophore production and could solubilize Zn. In hydroponic system (with 60mM of sodium chloride concentration), supplementation with culture filtrate from each fungal strain increased the shoot growth of wheat seedlings significantly compared to non culture filtrate control. Use of A.niger as bio-inoculant could be a sustainable approach to improve soil P availability, promote plant growth and alleviate adverse effect of salt stress. Copyright © 2016 Elsevier GmbH. All rights reserved.

Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils

International Nuclear Information System (INIS)

Thawornchaisit, Usarat; Polprasert, Chongrak

2009-01-01

The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO 4 fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO 4 /Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO 4 /Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively.

Artificial citrate operon and Vitreoscilla hemoglobin gene enhanced mineral phosphate solubilizing ability of Enterobacter hormaechei DHRSS.

Science.gov (United States)

Yadav, Kavita; Kumar, Chanchal; Archana, G; Kumar, G Naresh

2014-10-01

Mineral phosphate solubilization by bacteria is mediated through secretion of organic acids, among which citrate is one of the most effective. To overproduce citrate in bacterial systems, an artificial citrate operon comprising of genes encoding NADH-insensitive citrate synthase of E. coli and Salmonella typhimurium sodium-dependent citrate transporter was constructed. In order to improve its mineral phosphate solubilizing (MPS) ability, the citrate operon was incorporated into E. hormaechei DHRSS. The artificial citrate operon transformant secreted 7.2 mM citric acid whereas in the native strain, it was undetectable. The transformant released 0.82 mM phosphate in flask studies in buffered medium containing rock phosphate as sole P source. In fermenter studies, similar phenotype was observed under aerobic conditions. However, under microaerobic conditions, no citrate was detected and P release was not observed. Therefore, an artificial citrate gene cluster containing Vitreoscilla hemoglobin (vgb) gene under its native promoter, along with artificial citrate operon under constitutive tac promoter, was constructed and transformed into E. hormaechei DHRSS. This transformant secreted 9 mM citric acid under microaerobic conditions and released 1.0 mM P. Thus, incorporation of citrate operon along with vgb gene improves MPS ability of E. hormaechei DHRSS under buffered, microaerobic conditions mimicking rhizospheric environment.

Oxygen isotope variations in phosphate of biogenic apatites. Pt. 2. Phosphorite rocks

Energy Technology Data Exchange (ETDEWEB)

Kolodny, Y; Luz, B; Shemesh, A [Hebrew Univ., Jerusalem (Israel). Dept. of Geology

1983-09-01

Phosphorites from sedimentary sequences ranging in age from Archaen to Recent were analysed for delta/sup 18/O in both the PO/sub 4/ (delta/sup 18/Osub(p)) and CO/sub 3/ (delta/sup 18/Osub(c)) in the apatite lattice. The oxygen isotope record is considerably better preserved in phosphates than in either carbonates or cherts. The use of the Longinelli and Nuti temperature equation yields temperatures for Recent phosphorites that are in good agreement with those measured in the field. The delta/sup 18/Osub(p) values of ancient phosphorites decrease with increasing age. These changes with time are not likely to be due to post-depositional exchange. Changes in delta/sup 18/O values of seawater and variations of temperatures with time can account for the delta/sup 18/Osub(p) time trend, but the latter explanation is preferred. In Ancient phosphorites delta/sup 18/Osub(c) in structurally bound carbonate in apatite is not a reliable geochemical indicator.

Phosphate Recovery From Sewage Sludge Containing Iron Phosphate

NARCIS (Netherlands)

Wilfert, P.K.

2018-01-01

The scope of this thesis was to lay the basis for a phosphate recovery technology that can be applied on sewage sludge containing iron phosphate. Such a technology should come with minimal changes to the existing sludge treatment configuration while keeping the use of chemicals or energy as small as

Effects of Microbial and Phosphate Amendments on the Bioavailability of Lead (Pb) in Shooting Range Soil

Energy Technology Data Exchange (ETDEWEB)

Brigmon, Robin; Wilson, Christina; Knox, Anna; Seaman, John; Smith, Garriet

2005-06-16

, or U and contains about 27% total phosphate, most of which is available. FA and NCA are two types of rock phosphates that release small amounts of phosphate over time. Total phosphate is around 30% with only 1-2% phosphate available (Knox et al. 2005). In this study, we describe the influence of combining the two microbial and three phosphate amendments on reducing lead bioavailability in shooting range soil.

Phosphate-a poison for humans?

Science.gov (United States)

Komaba, Hirotaka; Fukagawa, Masafumi

2016-10-01

Maintenance of phosphate balance is essential for life, and mammals have developed a sophisticated system to regulate phosphate homeostasis over the course of evolution. However, due to the dependence of phosphate elimination on the kidney, humans with decreased kidney function are likely to be in a positive phosphate balance. Phosphate excess has been well recognized as a critical factor in the pathogenesis of mineral and bone disorders associated with chronic kidney disease, but recent investigations have also uncovered toxic effects of phosphate on the cardiovascular system and the aging process. Compelling evidence also suggests that increased fibroblastic growth factor 23 and parathyroid hormone levels in response to a positive phosphate balance contribute to adverse clinical outcomes. These insights support the current practice of managing serum phosphate in patients with advanced chronic kidney disease, although definitive evidence of these effects is lacking. Given the potential toxicity of excess phosphate, the general population may also be viewed as a target for phosphate management. However, the widespread implementation of dietary phosphate intervention in the general population may not be warranted due to the limited impact of increased phosphate intake on mineral metabolism and clinical outcomes. Nonetheless, the increasing incidence of kidney disease or injury in our aging society emphasizes the potential importance of this issue. Further work is needed to more completely characterize phosphate toxicity and to establish the optimal therapeutic strategy for managing phosphate in patients with chronic kidney disease and in the general population. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Mass balances by uranium-series disequilibria in natural phosphate deposits and mine products

International Nuclear Information System (INIS)

Osmond, J.K.; Cowart, J.B.

1985-01-01

In a closed system U-238 is in radioactive equilibrium with its longer lived daughters, U-234, Th-230, and Ra-226. In a system that is open on a time scale of 10 4 to 10 5 years, as in rock weathering, the various daughters and isotopes become separated. Nevertheless, equilibrium still pertains to the total system, so that material balances between weathering components and residual products can be calculated, based on parent-daughter radioactivity ratios. The authors have applied this balancing concept to the weathering of phosphatic ores in central Florida and to phosphate mining products. In the natural system studied in Florida, the leached zones are ten times more extensive than enriched zones, and have higher concentrations of Th-230 and Ra-226 relative to U-238 and U-234. Although there are significant movements of long-lived radio-elements locally, and occasional notable disequilibria of short-lived daughters, leaching by ground water is not a major factor in the regional budget. In the mining process, uranium follows the enriched phosphate and also the clay residues. Thorium and radium follow the clay residues and the gypsum by-product. Mine effluent waters, although somewhat higher in radioactivity than natural waters, do not remove appreciable amounts of the radio-elements

The Itataia phosphate-uranium deposit (Ceará, Brazil) new petrographic, geochemistry and isotope studies

Science.gov (United States)

Veríssimo, César Ulisses Vieira; Santos, Roberto Ventura; Parente, Clóvis Vaz; Oliveira, Claudinei Gouveia de; Cavalcanti, José Adilson Dias; Nogueira Neto, José de Araújo

2016-10-01

The Itataia phosphate-uranium deposit is located in Santa Quitéria, in central Ceará State, northeastern Brazil. Mineralization has occurred in different stages and involves quartz leaching (episyenitization), brecciation and microcrystalline phase formation of concretionary apatite. The last constitutes the main mineral of Itatiaia uranium ore, namely collophane. Collophanite ore occurs in massive bodies, lenses, breccia zones, veins or episyenite in marble layers, calc-silicate rocks and gneisses of the Itataia Group. There are two accepted theories on the origin of the earliest mineralization phase of Itataia ore: syngenetic (primary) - where the ore is derived from a continental source and then deposited in marine and coastal environments; and epigenetic (secondary) - whereby the fluids are of magmatic, metamorphic and meteoric origin. The characterization of pre- or post-deformational mineralization is controversial, since the features of the ore are interpreted as deformation. This investigation conducted isotopic studies and chemical analyses of minerals in marbles and calc-silicate rocks of the Alcantil and Barrigas Formations (Itataia Group), as well as petrographic and structural studies. Analysis of the thin sections shows at least three phosphate mineral phases associated with uranium mineralizaton: (1) A prismatic fluorapatite phase associated with chess-board albite, arfvedsonite and ferro-eckermannite; (2) a second fluorapatite phase with fibrous radial or colloform habits that replaces calcium carbonate in marble, especially along fractures, with minerals such as quartz, chlorite and zeolite also identified in calc-silicate rocks; and (3) an younger phosphate phase of botryoidal apatite (fluorapatite and hydroxyapatite) related with clay minerals and probably others calcium and aluminum phosphates. Detailed isotopic analysis carried out perpendicularly to the mineralized levels and veins in the marble revealed significant variation in isotopic

The Potential of Improved Fallows to Improve and Conserve the Fertility of Nutrients-Depleted Soils of Western Kenya

International Nuclear Information System (INIS)

Jama, B.; Amandou, I.; Niang; Amadalo, B.; Wolf, J.; Rao, M.R.; Buresh, R.J.

1999-01-01

Maize yields are low low and declining in the densely populated highlands of Western Kenya where soils are deficient mainly in nitrogen, phosphrous and, in some areas potassium. Over the last seven years, a team of scientists from several agricultural institutions, national and international has been developing and testing on-farm soil fertility improving technologies. Improved fallows of fast-growing leguminous species appear to be one such technology that could be a more productive alternative to the commonly practiced natural fallows. Sesbania session, Crotolaria grahamiana and Tephrosia vogelii are some the promising species. In six to eight months, fallows of these species can root to N rich subsoil (0.5-2 m) below the soil surface and recycle it to the surface soil through leaf and root litter. Within this period, N sufficient for the requirements of moderate maize yields (3-4 t ha -1 ) can be recycled particular y in sites not limited by available soil P. Such fallows can also recycle sufficient K in K deficient sites. Unfortunately soils in most areas of Western Kenya are P deficient and although improved fallows can enhance the availability of soil P less available to crops, they cannot increase its supply. Under these conditions, P inputs from external sources is necessary to improve crop yields meaningfully and economically. Agronomic evaluations of inorganic P sources for maize suggests Minjingu phosphates rock can be alternative to more expensive water-soluble P sources, e.g., triple superphosphate. The need for P input and the benefits of integrating it with improved fallows in order to overcome deficiencies of other nutrients, particularly N and K is highlighted in this paper

Triphenyl phosphate allergy from spectacle frames

DEFF Research Database (Denmark)

Carlsen, L; Andersen, K E; Egsgaard, Helge

1986-01-01

A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri......-m-cresyl phosphate, but no reaction to tri-p-cresyl phosphate. Gas chromatography of the tricresyl phosphate 5% pet. patch test material supplied from Trolab showed that it contained a mixture of a wide range of triaryl phosphates, including 0.08% triphenyl phosphate which is above the threshold for detecting...

Thermal Inertia of Rocks and Rock Populations

Science.gov (United States)

Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

2001-01-01

The effective thermal inertia of rock populations on Mars and Earth is derived from a model of effective inertia versus rock diameter. Results allow a parameterization of the effective rock inertia versus rock abundance and bulk and fine component inertia. Additional information is contained in the original extended abstract.

Composition of the Rex Chert and associated rocks of the Permian Phosphoria Formation: Soda Springs area, SE Idaho

Science.gov (United States)

Hein, James R.; McIntyre, Brandie; Perkins, Robert B.; Piper, David Z.; Evans, James

2002-01-01

This study, one in a series, reports bulk chemical and mineralogical compositions, as well as petrographic and outcrop descriptions of rocks collected from three measured outcrop sections of the Rex Chert member of the Phosphoria Formation in SE Idaho. The three measured sections were chosen from ten outcrops of Rex Chert that were described in the field. The Rex Chert overlies the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, the source of phosphate ore in the region. Rex Chert removed as overburden comprises part of the material disposed in waste-rock piles during phosphate mining. It has been proposed that the chert be used to cap and isolate waste piles, thereby inhibiting the leaching of potentially toxic elements into the environment. It is also used to surface roads in the mining district. The rock samples studied here constitute a set of individual chert beds that are representative of each stratigraphic section sampled. The informally named cherty shale member that overlies the Rex Chert in measured section 1 was also described and sampled. The upper Meade Peak and the transition zone to the Rex Chert were described and sampled in section 7. The cherts are predominantly spicularite composed of granular and mosaic quartz, and sponge spicules, with various but minor amounts of other fossils and detrital grains. The cherty shale member and transition rocks between the Meade Peak and Rex Chert are siliceous siltstones and argillaceous cherts with ghosts of sponge spicules and somewhat more detrital grains than the chert. The overwhelmingly dominant mineral is quartz, although carbonate beds are rare in each section and are composed predominantly of calcite and dolomite in addition to quartz. Feldspar, mica, clay minerals, calcite, dolomite, and carbonate fluorapatite are minor to trace minerals in the chert. The mean concentrations of oxides and elements in the Rex Chert and the cherty shale member are dominated by SiO2, which averages 94

Browse Title Index

African Journals Online (AJOL)

Items 51 - 100 of 127 ... Vol 26, No 1 (2009), Occurrence of foot and mouth disease serotypes in ... of Spirometra and other gastrointestinal helminths in dogs of Minjingu village, ... Vol 28, No 1 (2013), Rodents and Shrews as Vectors of Zoonotic ...

Artificial Citrate Operon Confers Mineral Phosphate Solubilization Ability to Diverse Fluorescent Pseudomonads

Science.gov (United States)

Adhikary, Hemanta; Sanghavi, Paulomi B.; Macwan, Silviya R.; Archana, Gattupalli; Naresh Kumar, G.

2014-01-01

Citric acid is a strong acid with good cation chelating ability and can be very efficient in solubilizing mineral phosphates. Only a few phosphate solubilizing bacteria and fungi are known to secrete citric acids. In this work, we incorporated artificial citrate operon containing NADH insensitive citrate synthase (gltA1) and citrate transporter (citC) genes into the genome of six-plant growth promoting P. fluorescens strains viz., PfO-1, Pf5, CHAO1, P109, ATCC13525 and Fp315 using MiniTn7 transposon gene delivery system. Comprehensive biochemical characterization of the genomic integrants and their comparison with plasmid transformants of the same operon in M9 minimal medium reveals the highest amount of ∼7.6±0.41 mM citric and 29.95±2.8 mM gluconic acid secretion along with ∼43.2±3.24 mM intracellular citrate without affecting the growth of these P. fluorescens strains. All genomic integrants showed enhanced citric and gluconic acid secretion on Tris-Cl rock phosphate (TRP) buffered medium, which was sufficient to release 200–1000 µM Pi in TRP medium. This study demonstrates that MPS ability could be achieved in natural fluorescent pseudomonads by incorporation of artificial citrate operon not only as plasmid but also by genomic integration. PMID:25259527

Metals concentration in phosphogypsum and phosphate fertilizers produced in Brazil using INAA

International Nuclear Information System (INIS)

Le Bourlegat, Fernanda M.; Saueia, Catia H.R.; Mazzilli, Barbara P.; Favaro, Deborah I.T.

2009-01-01

Phosphogypsum is obtained by wet reaction of the igneous phosphate rock with concentrated sulphuric acid, giving as final product phosphoric acid and dihydrated calcium sulphate (CaSO 4 .2H 2 O) as by-product. It may contain high quantities of P 2 O 5 , trace metals and radionuclides of U and Th series. Phosphogypsum worldwide production on 2006 was estimated in 170 million tons. All the countries that produce phosphate fertilizers by wet process are facing the same problem of finding solutions for the safe application of phosphogypsum, in order to minimize the impact caused by the disposal of large amounts of this by-product. Phosphogypsum can be used in agriculture as a soil amendment; however, for its safe application the concentration of the impurities present and their behaviour in the environment should be better understood. The radiological characterization has been extensively studied in the last decade, but there are few studies about the metals concentration in phosphogypsum. This work intends to determine the concentration of metals (Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn e Zr) and rare earth elements (REE) present in phosphogypsum produced in Brazil and to compare the results with those found in the phosphate fertilizers commonly commercialized. The technique used for the determination of the metals was instrumental neutron activation analysis (INAA). (author)

How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

Science.gov (United States)

Ezawa, Tatsuhiro; Saito, Katsuharu

2018-04-27

Contents Summary I. Introduction II. Foraging for phosphate III. Fine-tuning of phosphate homeostasis IV. The frontiers: phosphate translocation and export V. Conclusions and outlook Acknowledgements References SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Rock pushing and sampling under rocks on Mars

Science.gov (United States)

Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

1978-01-01

Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

Diferentes fontes de P no desenvolvimento do meloeiro e disponibilidade de fósforo no solo Use of biofertilizantes phosphated of the development of the melon and readiness of phosphorus

Directory of Open Access Journals (Sweden)

Michelangelo de Oliveira Silva

2011-06-01

Full Text Available Avaliou-se o desenvolvimento da cultura do melão, como também a disponibilidade de fósforo nos solos com o uso de biofertilizante fosfatado após três ciclos da cultura. Os tratamentos foram distribuídos em blocos casualizados com três repetições, arranjados num fatorial 2 x 3 x 7, correspondente a dois tipos de solos (Latossolo Amarelo e Neossolo Flúvico; três fontes de fósforo (superfosfato triplo, biofertilizante fosfatado e a rocha fosfatada; e sete níveis de fósforo (0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0 do recomendado para a cultura e para cada solo. Os fertilizantes superfosfato triplo, biofertilizante de rocha fosfatada e rocha fosfatada não apresentaram diferenças significativas na produção de matéria seca, porém o biofertilizante foi o que mais disponibilizou P nos dois solos estudados após três ciclos da mesma cultura.This work assessed the development of melon crops,and the availability of phosphorus in the soil with the use of biofertilizer phosphate after three cycles of culture. The treatments were distributed into randomized block design with three repetitions, arranged in a factorial 2 x 3 x 7, corresponding to two types of soils (Yellow Latossol and Fluvic Neosol; three sources of phosphorus (triple superphosphate, bio-fertilizer phosphate and rocks and seven levels of phosphorus (0; 0.5; 1.0; 1.5; 2.0; 2.5; 3.0 of recommended for the culture and for each soil. The triple superphosphate fertilizer, biofertilizer rock phosphate and rock phosphate showed no significant differences in dry matter production, but the biofertilizer was the most available P in both soils after three cycles of the same culture.

Role of Phosphate Transport System Component PstB1 in Phosphate Internalization by Nostoc punctiforme.

Science.gov (United States)

Hudek, L; Premachandra, D; Webster, W A J; Bräu, L

2016-11-01

In bacteria, limited phosphate availability promotes the synthesis of active uptake systems, such as the Pst phosphate transport system. To understand the mechanisms that facilitate phosphate accumulation in the cyanobacterium Nostoc punctiforme, phosphate transport systems were identified, revealing a redundancy of Pst phosphate uptake systems that exists across three distinct operons. Four separate PstB system components were identified. pstB1 was determined to be a suitable target for creating phenotypic mutations that could result in the accumulation of excessive levels of phosphate through its overexpression or in a reduction of the capacity to accumulate phosphate through its deletion. Using quantitative real-time PCR (qPCR), it was determined that pstB1 mRNA levels increased significantly over 64 h in cells cultured in 0 mM added phosphate and decreased significantly in cells exposed to high (12.8 mM) phosphate concentrations compared to the level in cells cultured under normal (0.8 mM) conditions. Possible compensation for the loss of PstB1 was observed when pstB2, pstB3, and pstB4 mRNA levels increased, particularly in cells starved of phosphate. The overexpression of pstB1 increased phosphate uptake by N. punctiforme and was shown to functionally complement the loss of PstB in E. coli PstB knockout (PstB - ) mutants. The knockout of pstB1 in N. punctiforme did not have a significant effect on cellular phosphate accumulation or growth for the most part, which is attributed to the compensation for the loss of PstB1 by alterations in the pstB2, pstB3, and pstB4 mRNA levels. This study provides novel in vivo evidence that PstB1 plays a functional role in phosphate uptake in N. punctiforme IMPORTANCE: Cyanobacteria have been evolving over 3.5 billion years and have become highly adept at growing under limiting nutrient levels. Phosphate is crucial for the survival and prosperity of all organisms. In bacteria, limited phosphate availability promotes the

Effects of low molecular weight organic acids on the immobilization of aqueous Pb(II) using phosphate rock and different crystallized hydroxyapatite.

Science.gov (United States)

Wei, Wei; Cui, Jing; Wei, Zhenggui

2014-06-01

Understanding the effects of low molecular weight organic acids (LMWOAs) on the transformation of Pb(II) to geochemically stable pyromorphite (PY) by apatite materials (AMs), has considerable benefits for risk assessment and remediation strategies for contaminated water and soil. In this study, we systematically investigated the immobilization of Pb(II) from aqueous solution by natural phosphate rock (PR) and different crystallized hydroxyapatite (HAp) in the absence and presence of LMWOAs (oxalic, malic and citric acids). The results indicated that the effectiveness of PR and HAp in immobilizing Pb(II) followed in descending order by HAp2 (the poorly crystallized HAp), HAp1 (the well crystallized HAp) and PR, regardlessof the presence of LMWOAs. The presence of malic and citric acids significantly decreased the immobilizationefficiency of Pb(II) by HAp1 and PR, clarifying the lower adsorption affinities of Pb(II)-organic acid complexes on HAp1 and PR rather than Pb(II) ion. On thecontrary, oxalic acid could markedly enhance the removal of Pb(II) from aqueous solution by HAp1 and PR through the formation of lead oxalate, which was confirmed by FT-IR and XRDanalysis. Results also showed that LMWOAs had little promoting or inhibiting effect on the immobilization of Pb(II) by HAp2. This study suggested that the ubiquity of LMWOAs in natural environments could retard the transformation efficiency of Pb(II) to PY by AMs, especiallyin thepresenceof oxalic acid, and the poorly crystallized HAp2 had great potential to remediate Pb(II)-contaminated water and soil due to its insusceptibility to LMWOAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial

Directory of Open Access Journals (Sweden)

Eunsoo Lim

2018-03-01

Full Text Available Background : For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods : We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48 or a control group (n = 22. We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results : The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0% patients achieved the primary goal, as compared with 16 (72.7% in the control group (P = 0.430. The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087, but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851. However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193. The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363 nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569. Conclusion : Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

Zinc phosphate conversion coatings

Science.gov (United States)

Sugama, Toshifumi

1997-01-01

Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Eltayeb, M. A. H.; Mohammed, A. A.

2003-01-01

In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Mohammed, A.A.; Eltayeb, M.A.H.

2003-01-01

In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas.

Science.gov (United States)

Becknell, Brian; Smoyer, William E; O'Brien, Nicole F

2014-11-01

This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity. This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas. Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity. Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

Phosphate transporter mediated lipid accumulation in Saccharomyces cerevisiae under phosphate starvation conditions.

Science.gov (United States)

James, Antoni W; Nachiappan, Vasanthi

2014-01-01

In the current study, when phosphate transporters pho88 and pho86 were knocked out they resulted in significant accumulation (84% and 43%) of triacylglycerol (TAG) during phosphate starvation. However in the presence of phosphate, TAG accumulation was only around 45% in both pho88 and pho86 mutant cells. These observations were confirmed by radio-labeling, fluorescent microscope and RT-PCR studies. The TAG synthesizing genes encoding for acyltransferases namely LRO1 and DGA1 were up regulated. This is the first report for accumulation of TAG in pho88Δ and pho86Δ cells under phosphate starvation conditions. Copyright © 2013. Published by Elsevier Ltd.

21 CFR 137.175 - Phosphated flour.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Phosphated flour. 137.175 Section 137.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and phosphated...

Estimating the Wet-Rock P-Wave Velocity from the Dry-Rock P-Wave Velocity for Pyroclastic Rocks

Science.gov (United States)

Kahraman, Sair; Fener, Mustafa; Kilic, Cumhur Ozcan

2017-07-01

Seismic methods are widely used for the geotechnical investigations in volcanic areas or for the determination of the engineering properties of pyroclastic rocks in laboratory. Therefore, developing a relation between the wet- and dry-rock P-wave velocities will be helpful for engineers when evaluating the formation characteristics of pyroclastic rocks. To investigate the predictability of the wet-rock P-wave velocity from the dry-rock P-wave velocity for pyroclastic rocks P-wave velocity measurements were conducted on 27 different pyroclastic rocks. In addition, dry-rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theories and it was seen that estimates for saturated P-wave velocity from the theories fit well measured data. For samples having values of less and greater than 20%, practical equations were derived for reliably estimating wet-rock P-wave velocity as function of dry-rock P-wave velocity.

Radiological impact during the extraction, processing and use of phosphate minerals in Cuba

International Nuclear Information System (INIS)

Zerquera, Juan T.; Prendes Alonso, Miguel; Ramos Biltres, Odalys

2008-01-01

The use of phosphates for the production of fertilisers is a practice broadly diffused in the world. Their wide use is associated to the contribution of this material to formulation of Nk fertilisers. It is known in turn that phosphates have in their composition appreciable quantities of radioactive elements of natural origin. For this reason the use of phosphates in the composition of fertilizers can cause a radiological impact to both workers and public during all the phases of extraction and processing of phosphates, as well as during the production and application of these fertilizers. Finally the transfer of radionuclides contained in the fertilizers to the products of human consumption (vegetables, milk, meat) can produce an additional radiological impact on population. In Cuba there exist six locations of phosphoric rocks, located in the counties of Pinar del Rio, Havana, Matanzas, Sancti-Spiritus and Holguin. From these deposits there were studied the two ones which are in exploitation: 'La Pimienta' deposit, located in the West part of the country and 'Trinidad de Guedes' deposit, located in the Centre-West of Cuba. Paper shows the results obtained by the Center for Radiation Protection and Hygiene (CPHR) in the determination of radionuclides concentrations in collected in the sites samples. Based on these results and taking into account both the features of routine works carried out in the sites and the later use of collected mineral as fertilizer, doses to mining workers and to members of the public were estimated. Estimated doses are in the range 0.3 - 2.70 mSv per year for workers and in the range 1.3 - 17 μSv per year. (author)

'Escher' Rock

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

Dust input in the formation of rock varnish from the Dry Valleys (Antarctica)

Science.gov (United States)

Zerboni, A.; Guglielmin, M.

2017-12-01

Rock varnish is a glossy, yellowish to dark brown coating that covers geomorphically stable, aerially exposed rock surfaces and landforms in warm and cold arid lands. In warm deserts, rock varnish consists of clay minerals, Mn-Fe oxides/hydroxides, and Si+alkalis dust; it occasionally containis sulphates, phosphates, and organic remains. In Antarctica, rock varnish developed on a variety of bedrocks and has been described being mostly formed of Si, Al, Fe, and sulphates, suggesting a double process in its formation, including biomineralization alternated to dust accretion. We investigated rock coatings developed on sandstones outcropping in the Dry Valleys of Antarctica and most of the samples highlithed an extremely complex varnish structure, alternating tihn layer of different chemical compostion. Optical microscope evidenced the occurrence of highly birefringent minerals, occasionally thinly laminated and consisitng of Si and Al-rich minerals (clays). These are interlayered by few micron-thick dark lenses and continous layers. The latter are well evident under the scanning electron microscope and chemical analysis confirmed that they consist of different kinds of sulphates; jarosite is the most represented species, but gypsum crystals were also found. Fe-rich hypocoatings and intergranula crusts were also detected, sometimes preserving the shape of the hyphae they have replaced. Moreover, small weathering pits on sandstone surface display the occurrence of an amorphous, dark Mn/Fe-rich rock varnish. The formation of rock varnish in the Dry Valleys is a complex process, which required the accretion of airborne dust of variable composition and subsequent recrystallization of some constituent, possibly promoted by microorganisms. In particualr, the formation of sulphates seems to preserve the memory of S-rich dust produced by volcanic eruptions. On the contrary, the formation of Mn-rich varnish should be in relation with the occurrence of higher environmental

Effectiveness of North Carolina phosphate rock and fertilizer tablets in reclaiming disturbed land in Copper Basin, Tennessee, USA

International Nuclear Information System (INIS)

Sikora, F.J.; Soileau, J.M.; Maddox, J.J.; Kelsoe, J.J.

2002-01-01

Open smelting of copper ore about 100 years ago resulted in approximately 9,300 ha of disturbed land with severely eroded acidic soils at Copper Basin, Tennessee, USA. A field study was initiated in 1992 to compare revegetation from surface application of North Carolina phosphate rock (PR) and triple superphosphate (TSP) at 20, 59, and 295 kg P ha -1 , and determine benefits of fertilizer tablets. Measurements included survival and growth of transplanted pine seedlings, ground cover from an aerially seeded grass/legume mixture, and soil acidity. Tree survival was greater than 87% with no difference among treatments. When fertilizer tablets were not used, tree height and diameter increased with increasing soil P rates with growth maximized at 59 kg P ha -1 . After 96 and 240 d, there was no difference between PR and TSP with respect to growth of loblolly pine. After 960 days, PR caused greater tree growth compared to TSP. Weeping love grass provided the most ground cover, and its growth was stimulated with fertilizer tablets and P application. Fescue, lespedeza, and black locust trees responded more to PR than to TSP. Soil pH increased, and 0.01-M SrCl 2 extractable Al decreased, with increasing rate of PR. The molar ratios of Ca:Al in 0.01-M SrCl 2 soil extracts were also greater with PR compared to TSP. Decreased soil acidity, increased growth of loblolly pines, and increased diversity of ground cover vegetation from PR application makes PR a suitable material for reclaiming extremely acidic soils. Fertilizer tablets had an effect of improving loblolly pine growth when no P was surface applied. However, with surface P application of 59 kg ha -1 as PR, fertilizer tablets did not add any additional benefit to loblolly pine growth. Some improvement in tree growth was observed using fertilizer tablets with P applied as TSP at 59 kg ha -1 . Fertilizer tablets did greatly improve ground coverage of weeping love grass. Use of fertilizer tablets in reclamation efforts in

Rock fragmentation

Energy Technology Data Exchange (ETDEWEB)

Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

1976-01-01

Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

International Nuclear Information System (INIS)

Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

2000-01-01

The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

Direct separation of uranium and thorium from Qatrani phosphatic raw ore by consecutive percolation leaching

Energy Technology Data Exchange (ETDEWEB)

Hussein El-Sayed, M

1984-07-01

Phosphatic sandstone of Qatrani area contains high concentrations of uranium and thorium (1450 and 870 ppm respectively). These elements were directly separated from a representative sample of the ore by percolation leaching. Separation made was carried out by using two different leaching reagents, citric and nitric acids for obtaining two separate concentrates of U and Th consecutively from the sample. Uranium was leached first by using citric acid where other rock ingredients were left intact. The effects of: (a) increasing acid input amounts and (b) increasing leaching solution volumes (dilution) on U leaching efficiency were studied. The results revealed that citric acid reaction upon phosphate is limited in spite of higher residual acidity reported in the leach liquors. Regarding uranium, its leaching efficiency increased by increasing acid amounts and/or leaching solution volumes while fixing the acid input amounts. The efficiency of U leaching is more pronounced in the second case than in the first. Increasing U leaching while phosphate dissolution is limited could be interpreted as that the relative complexing affinity of citrate anion for hexavalent uranium is by far much greater than with phosphate. Thorium was thereafter leached by using dilute solutions of nitric acid to avoid dissolution of nitric acid to avoid dissolution of impurities. Percolation leaching experiments were thus performed on the uranium-free samples in the columns used previously in uranium leaching. The effects of increasing acid amounts and increasing leach liquor recycles on Th (and P/sub 2/O/sub 5/) leaching efficiency were studied.

Phosphate application to firing range soils for Pb immobilization: The unclear role of phosphate

International Nuclear Information System (INIS)

Chrysochoou, Maria; Dermatas, Dimitris; Grubb, Dennis G.

2007-01-01

Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable

Calcium-phosphate biomineralization induced by alkaline phosphatase activity in Escherichia coli: localization, kinetics and potential signatures in the fossil record

Science.gov (United States)

Cosmidis, Julie; Benzerara, Karim; Guyot, François; Skouri-Panet, Fériel; Duprat, Elodie; Férard, Céline; Guigner, Jean-Michel; Babonneau, Florence; Coelho, Cristina

2015-12-01

Bacteria are thought to play an important role in the formation of calcium-phosphate minerals composing marine phosphorites, as supported by the common occurrence of fossil microbes in these rocks. Phosphatase enzymes may play a key role in this process. Indeed, they may increase the supersaturation with respect to Ca-phosphates by releasing orthophosphate ions following hydrolysis of organic phosphorus. However, several questions remain unanswered about the cellular-level mechanisms involved in this model, and its potential signatures in the mineral products. We studied Ca-phosphate precipitation by different strains of Escherichia coli which were genetically modified to differ in the abundance and cellular localization of the alkaline phosphatase (PHO A) produced. The mineral precipitated by either E. coli or purified PHO A was invariably identified as a carbonate-free non-stoichiometric hydroxyapatite. However, the bacterial precipitates could be discriminated from the ones formed by purified PHO A at the nano-scale. PHO A localization was shown to influence the pattern of Ca-phosphate nucleation and growth. Finally, the rate of calcification was proved to be consistent with the PHO A enzyme kinetics. Overall, this study provides mechanistic keys to better understand phosphogenesis in the environment, and experimental references to better interpret the microbial fossil record in phosphorites.

Rock mechanics for hard rock nuclear waste repositories

International Nuclear Information System (INIS)

Heuze, F.E.

1981-09-01

The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

Elastic Rock Heterogeneity Controls Brittle Rock Failure during Hydraulic Fracturing

Science.gov (United States)

Langenbruch, C.; Shapiro, S. A.

2014-12-01

For interpretation and inversion of microseismic data it is important to understand, which properties of the reservoir rock control the occurrence probability of brittle rock failure and associated seismicity during hydraulic stimulation. This is especially important, when inverting for key properties like permeability and fracture conductivity. Although it became accepted that seismic events are triggered by fluid flow and the resulting perturbation of the stress field in the reservoir rock, the magnitude of stress perturbations, capable of triggering failure in rocks, can be highly variable. The controlling physical mechanism of this variability is still under discussion. We compare the occurrence of microseismic events at the Cotton Valley gas field to elastic rock heterogeneity, obtained from measurements along the treatment wells. The heterogeneity is characterized by scale invariant fluctuations of elastic properties. We observe that the elastic heterogeneity of the rock formation controls the occurrence of brittle failure. In particular, we find that the density of events is increasing with the Brittleness Index (BI) of the rock, which is defined as a combination of Young's modulus and Poisson's ratio. We evaluate the physical meaning of the BI. By applying geomechanical investigations we characterize the influence of fluctuating elastic properties in rocks on the probability of brittle rock failure. Our analysis is based on the computation of stress fluctuations caused by elastic heterogeneity of rocks. We find that elastic rock heterogeneity causes stress fluctuations of significant magnitude. Moreover, the stress changes necessary to open and reactivate fractures in rocks are strongly related to fluctuations of elastic moduli. Our analysis gives a physical explanation to the observed relation between elastic heterogeneity of the rock formation and the occurrence of brittle failure during hydraulic reservoir stimulations. A crucial factor for understanding

Rock.XML - Towards a library of rock physics models

Science.gov (United States)

Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

2016-08-01

Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

Method of stripping plutonium from tributyl phosphate solution which contains dibutyl phosphate-plutonium stable complexes

International Nuclear Information System (INIS)

Ochsenfeld, W.; Schmieder, H.

1976-01-01

Fast breeder fuel elements which have been highly burnt-up are reprocessed by extracting uranium and plutonium into an organic solution containing tributyl phosphate. The tributyl phosphate degenerates at least partially into dibutyl phosphate and monobutyl phosphate, which form stable complexes with tetravalent plutonium in the organic solution. This tetravalent plutonium is released from its complexed state and stripped into aqueous phase by contacting the organic solution with an aqueous phase containing tetravalent uranium. 6 claims, 1 drawing figure

Phosphate control in dialysis

Directory of Open Access Journals (Sweden)

Cupisti A

2013-10-01

Full Text Available Adamasco Cupisti,1 Maurizio Gallieni,2 Maria Antonietta Rizzo,2 Stefania Caria,3 Mario Meola,4 Piergiorgio Bolasco31Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; 2Nephrology and Dialysis Unit, San Carlo Borromeo Hospital, Milan, Italy; 3Territorial Department of Nephrology and Dialysis, ASL Cagliari, Italy; 4Sant'Anna School of Advanced Studies, University of Pisa, Pisa, ItalyAbstract: Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source

Response of seedlings of Grevillea robusta A. Cunn to phosphorus fertilization in acid soils from Kenya

International Nuclear Information System (INIS)

Karanja, N.K.; Mwendwa, K.A.; Zapata, F.

2002-01-01

Three experiments were conducted to assess the response of G. robusta to phosphorus fertilization using acid low-P soils from Eastern (Andosols, Gituamba) and Western (Acrisols, Kakamega) Kenya. In the first experiment, P was applied as Minjingu Phosphate rock (MPR, 12.9% total P) at 0, 25.8 and 38.7 kg P/kg soil into pots containing five kg soil. In the second experiment, 2g VAM soil + roots inoculum/5 kg soil was included in addition to the same MPR rates but only to Acrisol, Kakamega. In the third experiment, MPR and TSP were added to 2 kg soil (Acrisols, Kakamega) at a rate of 25.8 mg P kg -1 soil and 32 P isotope dilution techniques were used to assess P uptake and divided into two destructive shoot harvests at 3 and 6 MAT (months after transplanting). Application of MPR in Andosols significantly (P <0.05) reduced height and root collar diameter of G. robusta as compared to the control whereas significant increases (P<0.05) in height and root collar diameter were recorded in the Acrisol in the P-fertilized treatments compared to control. Interaction soil with P fertilizer rates was highly significant (p<0.001) for both height and root collar diameter growth. The roots were not infected with VA-mycorrhizae after 12 months. At 3 MAT the percentage P derived from the MPR and TSP (%Pdff) was 3% and 6% respectively. P uptake decreased significantly (p<0.05) between 3 and 6 months. The results indicate that addition of P fertilizer and inoculation with VA-mycorrhizae to G. robusta in the two soils was probably required at the early stages of growth. Further research, especially extensive root studies (nursery and field) are required to explain the above observations. (author)

Growth response of Grevillea robusta A. Cunn. seedlings to phosphorus fertilization in acid soils from Kenya

Directory of Open Access Journals (Sweden)

Karanja N.K.

1999-01-01

Full Text Available Three experiments were conducted to assess the response of Grevillea robusta to phosphorus fertilization using acid soils showing low P levels from Eastern (Gituamba-Andosols and Western (Kakamega-Acrisols Kenya. In the first experiment P was applied as Minjingu phosphate rock (MPR- 13/P at 0, 52 and 77 kg P per ha into 5 kg of soil. In the second experiment 2 g vesicular arbuscular mycorrhizae (VAM soil + root inoculum per 5 kg soil was included in addition to the same MPR rates using Kakamega soil only. In the third experiment, MPR and triple superphosphate (TSP were added to 5 kg Kakamega soil at a rate of 25.8 mg P per kg soil, and 32P isotope dilution techniques were used to assess P uptake in the shoot harvested at 3 and 6 MAT (months after transplanting. Application of MPR to the Andosol reduced height and root collar diameter of G. robusta significantly (p < .05 as compared to the control. Significant increases (p < .05 in height and root collar diameter where P was added compared to control were recorded with the Acrisol. Soil interaction with P fertilizer rates was highly significant (p < .001 for both height and root collar diameter growth. The roots were not infected with VAM upon harvesting at 12 months. At 3 MAT the percentage P derived from the MPR and TSP was 3/ and 6/ respectively. P uptake decreased significantly (p < .05 between 3 and 6 months. The results indicated that addition of P fertilizer in the Acrisols was probably required at the early stages of G. robusta growth but further research and particularly root studies are required to ascertain the above observations.

Uranium-phosphate relationship in phosphated chalks of the Mons and Picardie Bassins

Energy Technology Data Exchange (ETDEWEB)

Quinif, Y; Charlet, J M; Dupuis, C; Robaszynski, F [Faculte Polytechnique de Mons (Belgium)

1981-11-30

The lithological and geochemical conditions relative to the ''Senonian'' phosphatic chalks are relatively simple in the Basins of Mons (Belgium) and of Picardy (France). Their characteristics permit us to study chiefly the uranium-phosphate relation. It appears a very good linear correlation between the phosphate and the uranium. The coefficient U/P/sub 2/O/sub 5/ remains a constant from the bottom to the top of the same section, but changes in space for synchronic formations (lateral variation of geochemical facies) and in time for two separated basins.

Uranium abundance in some sudanese phosphate ores

International Nuclear Information System (INIS)

Adam, A.A.; Eltayeb, M.A.H.

2009-01-01

This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

Uranium from phosphate ores

International Nuclear Information System (INIS)

Hurst, F.J.

1983-01-01

The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

Rock burst governance of working face under igneous rock

Science.gov (United States)

Chang, Zhenxing; Yu, Yue

2017-01-01

As a typical failure phenomenon, rock burst occurs in many mines. It can not only cause the working face to cease production, but also cause serious damage to production equipment, and even result in casualties. To explore how to govern rock burst of working face under igneous rock, the 10416 working face in some mine is taken as engineering background. The supports damaged extensively and rock burst took place when the working face advanced. This paper establishes the mechanical model and conducts theoretical analysis and calculation to predict the fracture and migration mechanism and energy release of the thick hard igneous rock above the working face, and to obtain the advancing distance of the working face when the igneous rock fractures and critical value of the energy when rock burst occurs. Based on the specific conditions of the mine, this paper put forward three kinds of governance measures, which are borehole pressure relief, coal seam water injection and blasting pressure relief.

Bioavailability of radionuclides 226Ra, 228Ra and 210Pb present in the brazilian phosphate fertilizers and phosphogypsum

International Nuclear Information System (INIS)

Russo, Ana Carolina

2013-01-01

Phosphogypsum, also called gypsum, by-product of the phosphate fertilizer industry, can be used as soil conditioner since it provides improvements in the soil-plant system. However, this by-product concentrates radionuclides of the U and Th series, present in the phosphate rock used as raw material, which can impact the environment. In order to study the bioavailability of radionuclides, samples of phosphogypsum and phosphate fertilizers (monoammonium phosphate and triple superphosphate) were analyzed. The concentration of 226 Ra, 228 Ra and 210 Pb were determined by gamma spectrometry. The samples were leached with a mild EDTA solution and the radionuclides present in the final solution were determined by total alpha and beta counting on a gas flow proportional counter. The percentage of extraction varied from 1.6% to 1.7% for 210 Pb, from 0.5% to 1.4% for 226 Ra and from 0.1% to 1.0% for the 228 Ra in phosphogypsum samples. The low percentage of extraction obtained for the radionuclides can be partly explained by the low solubility of phosphogypsum, which ranged from 7.7% to 16%. For the monoammonium phosphate samples the percentage of extraction were less than 26% for 226 Ra, less than 10% for '2 28 Ra and less than 10% for 210 Pb. In spite of the high solubility of 77% of monoammonium phosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. For the triple superphosphate samples, the percentage of extraction was 2.3% for 226 Ra, 1.2% for 228 Ra and 11.3% for 210 Pb. In spite of the high solubility of 66% of triple superphosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. (author)

Electrochemical Reduction of Zinc Phosphate

International Nuclear Information System (INIS)

Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

2010-01-01

We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

For Those About to Rock : Naislaulajat rock-genressä

OpenAIRE

Herranen, Linda

2015-01-01

For those about to rock – naislaulajat rock-genressä antaa lukijalleen kokonaisvaltaisen käsityksen naisista rock-genressä: rockin historiasta, sukupuolittuneisuudesta, seksismistä, suomalaisten naislaulajien menestyksestä. Työn aineisto on koottu aihepiirin kirjallisuudesta ja alalla toimiville naislaulajille teetettyjen kyselyiden tuloksista. Lisäksi avaan omia kokemuksiani ja ajatuksiani, jotta näkökulma naisista rock-genressä tulisi esille mahdollisimman monipuolisesti. Ajatus aihees...

Proceedings of the 3. Canada-US rock mechanics symposium and 20. Canadian rock mechanics symposium : rock engineering 2009 : rock engineering in difficult conditions

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

This conference provided a forum for geologists, mining operators and engineers to discuss the application of rock mechanics in engineering designs. Members of the scientific and engineering communities discussed challenges and interdisciplinary elements involved in rock engineering. New geological models and methods of characterizing rock masses and ground conditions in underground engineering projects were discussed along with excavation and mining methods. Papers presented at the conference discussed the role of rock mechanics in forensic engineering. Geophysics, geomechanics, and risk-based approaches to rock engineering designs were reviewed. Issues related to high pressure and high flow water conditions were discussed, and new rock physics models designed to enhance hydrocarbon recovery were presented. The conference featured 84 presentations, of which 9 have been catalogued separately for inclusion in this database. tabs., figs.

Art Rocks with Rock Art!

Science.gov (United States)

Bickett, Marianne

2011-01-01

This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

Calcium phosphates: what is the evidence?

Science.gov (United States)

Larsson, Sune

2010-03-01

A number of different calcium phosphate compounds such as calcium phosphate cements and solid beta-tricalcium phosphate products have been introduced during the last decade. The chemical composition mimics the mineral phase of bone and as a result of this likeness, the materials seem to be remodeled as for normal bone through a cell-mediated process that involves osteoclastic activity. This is a major difference when compared with, for instance, calcium sulphate compounds that after implantation dissolve irrespective of the new bone formation rate. Calcium phosphates are highly biocompatible and in addition, they act as synthetic osteoconductive scaffolds after implantation in bone. When placed adjacent to bone, osteoid is formed directly on the surface of the calcium phosphate with no soft tissue interposed. Remodeling is slow and incomplete, but by adding more and larger pores, like in ultraporous beta-tricalcium phosphate, complete or nearly complete resorption can be achieved. The indications explored so far include filling of metaphyseal fracture voids or bone cysts, a volume expander in conjunction with inductive products, and as a carrier for various growth factors and antibiotics. Calcium phosphate compounds such as calcium phosphate cement and beta-tricalcium phosphate will most certainly be part of the future armamentarium when dealing with fracture treatment. It is reasonable to believe that we have so far only seen the beginning when it comes to clinical applications.

Uranium leaching from phosphatic sandstone and shale of Qatrani using citrate as a new leaching reagent

International Nuclear Information System (INIS)

Hussein, E.M.

1997-01-01

Uranium is found in Qatrani area (Southwest of Cairo and North of lake Qarun) in various forms in sedimentary rocks. Two important ore materials have been chosen for studying the recovery of their uranium contents namely; the phosphatic sandstone and the carbonaceous shale. The main emphasis in this thesis is the choice of an acid that would selectively leach uranium from thesis ores while leaving calcium phosphate and carbonate minerals minerals almost completely intact. Citric acid was indeed found advantageous due primarily to its strong ability to form stable complexes with uranium over a wide range of PH values beside the possibility of controlling thr solubility of calcium-bearing compounds by adding calcium citrate. The latter is actually characterized by its ability to exist in an unionized or associated from in citric acid solutions. From the general leaching characteristics of both uranium and P 2 O 5 from Qatrani phosphatic sandstone by citric acid, it was found that uranium could be completely leached beside the possibility of realizing a differential leaching percent values vs P 2 O 5 which is generally of limited solubility. Such a low solubility of P 2 O 5 has even been completely inhibited by providing calcium citrate to the citric acid solutions in amounts sufficient to exist in an optimum ionized non-associated state. Such a provision would render the solution unable to carry any further calcium ions thus the breakdown of the phosphate mineral was hindered while uranium has completely been selectively

Interpretation of the phosphate showings found in Uruguay. Recommendations for a a working programme; Interpretacion de los indicios de fosfato encontrados en Uruguay: recomendaciones para un programa de trabajo

Energy Technology Data Exchange (ETDEWEB)

Slansky, M

1983-07-01

The radioactive anomalies put in evidence during the investigation of uranium and the mining inventory carried out in Uruguay, are due to rocks more or less strongly phosp hated of the top proterozoic and of the paleozoic. These anomalies drive to interrogating ourselves on the possibilities of existence of deposits of phosphates exploitable.

A mineralogical investigation of a uranium-bearing phosphatic siltstone from Tsongnapan, Northwestern Cape Province

International Nuclear Information System (INIS)

Brynard, H.J.

1980-02-01

A sample of uranium-bearing phosphatic siltstone from Tsongnapan in the Northwestern Cape Province was investigated mineralogically. The siltstone consists of cyclically alternating apatite- and calcite spherulite-rich layers. The calcite content of the rock is 11,4% and the apatite content is 42,1%. The groundmass shows the presence of the following elements: Si, Ca, P, Fe, Mg, K, Al, Cu and Zn. Detrital quartz, albite and magnetite are mainly confined to calcite spherulitic layers. The uranium content of the siltstone is 1 120 ppm U 3 O 8 and the thorium content 638 ppm ThO 2 . Both uranium and thorium occur mainly in the apatite-rich groundmass and to a minor extent in subsidiary monazite and zircon. Laboratory-scale metallurgical tests showed that the uranium is almost wholly leachable by hydrochloric acid while sulphuric and acetic acid dissolve only a small percentage of the uranium with concomitant formation of calcium sulphate. The rock probably formed in a low-energy regime in a marine environment where apatite and calcite spherulites crystallised from a possibly colloidal state [af

Estimation of the radiological impact in the use of phosphate fertilizer in citric plantations

International Nuclear Information System (INIS)

Zerquera, J.T.; Prendes A, M.; Alonso J, M.T.; Perez S, D.

1996-01-01

The use of fertilizers in the agriculture is a potential danger of environmental contamination, because the elements contained in them could suffer an important redistribution in the environment. This is the case of radioactive elements of natural origin, like K-40 and nuclides of U and Th series, present in the ores used in the production of industrial fertilizers. Phosphoric rocks used in fertilizers contain, generally, important concentrations of radioactive elements greater than other rocks of the earth core. In Cuba, preliminary determinations of Ra-226 concentrations in phosphoric rocks reveal results in the order of 2.7 Bq/kg. These values are greater than the mean of the rest of soils of the country. Due to this fact, a study on the radiological impact of this practice was developed. The study was carried out in citric plantations of the province of Pinar del Rio, where phosphate fertilizer is widely used. Samples of different parts of the plant were taken and analyzed by means of gamma spectrometric techniques. The paper presents values for Ra-226 that are in the range 27-40 Bq/kg. These results show that the use of fertilizers does not imply a significant radiological impact. Punctual valves of transfer coefficients of Ra-226 in soil -stem-leave-peel and - juice chains were estimated. (authors). 6 refs., 4 tabs

Phosphate additives in food--a health risk.

Science.gov (United States)

Ritz, Eberhard; Hahn, Kai; Ketteler, Markus; Kuhlmann, Martin K; Mann, Johannes

2012-01-01

Hyperphosphatemia has been identified in the past decade as a strong predictor of mortality in advanced chronic kidney disease (CKD). For example, a study of patients in stage CKD 5 (with an annual mortality of about 20%) revealed that 12% of all deaths in this group were attributable to an elevated serum phosphate concentration. Recently, a high-normal serum phosphate concentration has also been found to be an independent predictor of cardiovascular events and mortality in the general population. Therefore, phosphate additives in food are a matter of concern, and their potential impact on health may well have been underappreciated. We reviewed pertinent literature retrieved by a selective search of the PubMed and EU databases (www.zusatzstoffe-online.de, www.codexalimentarius.de), with the search terms "phosphate additives" and "hyperphosphatemia." There is no need to lower the content of natural phosphate, i.e. organic esters, in food, because this type of phosphate is incompletely absorbed; restricting its intake might even lead to protein malnutrition. On the other hand, inorganic phosphate in food additives is effectively absorbed and can measurably elevate the serum phosphate concentration in patients with advanced CKD. Foods with added phosphate tend to be eaten by persons at the lower end of the socioeconomic scale, who consume more processed and "fast" food. The main pathophysiological effect of phosphate is vascular damage, e.g. endothelial dysfunction and vascular calcification. Aside from the quality of phosphate in the diet (which also requires attention), the quantity of phosphate consumed by patients with advanced renal failure should not exceed 1000 mg per day, according to the guidelines. Prospective controlled trials are currently unavailable. In view of the high prevalence of CKD and the potential harm caused by phosphate additives to food, the public should be informed that added phosphate is damaging to health. Furthermore, calls for labeling

Response of Sorghum bicolor L. to Residual Phosphate on Two Contrasting Soils Previously Planted to Cowpea or Maize

Directory of Open Access Journals (Sweden)

Tola Omolayo Olasunkanmi

2016-01-01

Full Text Available Proper fertilizer nutrient management through adequate utilization of the residual value coupled with healthy crop rotation contributes significantly to sustainable crop production. This study was conducted to evaluate the direct and residual effects of two rock phosphate (RP materials on two contrasting soils previously planted with either the cereal crop or the leguminous crop. The effectiveness of the RP materials as substitute for the conventional P fertilizers was evaluated using single superphosphate as reference at the Department of Agronomy, University of Ibadan, Ibadan, Nigeria. The experiments were 2 × 2 × 4 factorial in completely randomized design. The test crops in the first cropping performed better on the slightly acidic loamy sand than on the strongly acidic sandy clay loam. Performance of each crop was improved by P supply in the first and second cropping. Single superphosphate proved to be more efficient than the RPs in the first cropping but not as effective as MRP in the second cropping. In the second cropping, sorghum performed better on the soil previously cropped to cowpea while Morocco RP had the highest residual effect among the P-fertilizer sources. It is evident that rock phosphates are better substitutes to the conventional phosphorus fertilizers due to their long term residual effect in soils. The positive effects of healthy rotation of crops as well as the negative effects of low soil pH are also quite obvious.

The Usability of Rock-Like Materials for Numerical Studies on Rocks

Science.gov (United States)

Zengin, Enes; Abiddin Erguler, Zeynal

2017-04-01

The approaches of synthetic rock material and mass are widely used by many researchers for understanding the failure behavior of different rocks. In order to model the failure behavior of rock material, researchers take advantageous of different techniques and software. But, the majority of all these instruments are based on distinct element method (DEM). For modeling the failure behavior of rocks, and so to create a fundamental synthetic rock material model, it is required to perform related laboratory experiments for providing strength parameters. In modelling studies, model calibration processes are performed by using parameters of intact rocks such as porosity, grain size, modulus of elasticity and Poisson ratio. In some cases, it can be difficult or even impossible to acquire representative rock samples for laboratory experiments from heavily jointed rock masses and vuggy rocks. Considering this limitation, in this study, it was aimed to investigate the applicability of rock-like material (e.g. concrete) to understand and model the failure behavior of rock materials having complex inherent structures. For this purpose, concrete samples having a mixture of %65 cement dust and %35 water were utilized. Accordingly, intact concrete samples representing rocks were prepared in laboratory conditions and their physical properties such as porosity, pore size and density etc. were determined. In addition, to acquire the mechanical parameters of concrete samples, uniaxial compressive strength (UCS) tests were also performed by simultaneously measuring strain during testing. The measured physical and mechanical properties of these extracted concrete samples were used to create synthetic material and then uniaxial compressive tests were modeled and performed by using two dimensional discontinuum program known as Particle Flow Code (PFC2D). After modeling studies in PFC2D, approximately similar failure mechanism and testing results were achieved from both experimental and

Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent - Method validation.

Science.gov (United States)

Wijnker, J J; Tjeerdsma-van Bokhoven, J L M; Veldhuizen, E J A

2009-01-01

Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent the spread of foot-and-mouth disease and classical swine fever via treated casings. The commercially available Quantichrom™ phosphate assay kit has been evaluated as to whether it can serve as a reliable and low-tech method for routine analysis of casings treated with phosphate. The outcome of this study indicates that this particular assay kit has sufficient sensitivity to qualitatively determine the presence of phosphate in treated casings without interference of naturally occurring phosphate in salt used for brines in which casings are preserved.

Characterization of a calcium phosphate cement based on alpha-tricalcium phosphate obtained by wet precipitation process

International Nuclear Information System (INIS)

Thurmer, M.B.; Diehl, C.E.; Vieira, R.S.; Coelho, W.T.G.; Santos, L.A.

2012-01-01

There are several systems of calcium phosphate cements being studied. Those based on alpha-tricalcium phosphate are of particular interest. After setting they produce calcium deficient hydroxyapatite similar to bone like hydroxyapatite. This work aims to obtain alpha-tricalcium phosphate powders by the wet precipitation process, using calcium nitrate and phosphoric acid as reagents. This powder was characterized by infrared spectroscopy, X-ray diffraction and particle size distribution. In order to prepare the calcium phosphate cement, the powder was mixed with an accelerator in an aqueous solution. The mechanical properties of the cement were assessed and it was evaluated by means of apparent density, X-ray diffraction and scanning electron microscopy. The described method produced crystalline alpha-tricalcium phosphate as the major phase. The calcium phosphate cement showed high values of compression strength (50 MPa). The soaking of the cement in a simulated body fluid (SBF) formed a layer of hydroxyapatite like crystals in the surface of the samples. (author)

U-Pb, Pb-Pb, and K-Ar isotopic study and petrography of uraniferous phosphate-bearing rocks in the Thelon Formation, Dubawnt Group, Northwest Territories, Canada

International Nuclear Information System (INIS)

Miller, A.R.; Cumming, G.L.; Krstic, D.

1989-01-01

The Thelon Formation, uppermost unit of the Dubawnt Group, overlies a regionally extensive paleoweathered zone developed on a wide range of lithochronological units including formations in the lower Dubawnt Group. Authigenic uraniferous phosphate minerals, fluorapatite and goyazite, cementing Thelon conglomerate - sandstone and filling fractures in the underlying paleoweathered zone, were dated in an attempt to better constrain the age of Thelon sedimentation and diagenesis. The oldest age, 1720 ± 6 Ma, derived from phosphate-cemented sediments, is interpreted as a minimum age for diagenesis and therefore brackets initial Thelon sedimentation between emplacement of fluorite-bearing granites at 1753 Ma and authigenic phosphate cementation at 1720 Ma. Additional ages of 1685 ± 4 and 1647 Ma are interpreted as remobilization or subsequent cementation events. K-Ar ages on illite, 1386 ± 37 and 1266 ± 31 Ma, from the paleoweathered zone and basal conglomerate, respectively, are significantly younger than ages derived from coexisting phosphate. These K-Ar ages recorded hydrothermal events that may be related to processes associated with unconformity-type uranium mineralization at approximately 1400-1300 Ma. Ages from the Thelon Basin permit geochronologic correlations with the Athabasca and Hornby basins, long correlated on the basis of similarities in sedimentation, stratigraphy, and tectonic setting

Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

Directory of Open Access Journals (Sweden)

Stef Robijn

Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

Uranium, yttrium, and rare earth elements accumulation during the Cretaceous anoxic events in carbonaceous rocks in the Pacific Ocean

Science.gov (United States)

Savelyeva, Olga; Philosofova, Tatyana; Bergal-Kuvikas, Olga; Savelyeva, Svetlana

2017-04-01

We have studied the carbonate-siliceous section of paleooceanic Albian-Cenomanian deposits on the Kamchatsky Mys peninsula (Eastern Kamchatka, Russia) [1].The section is represented by a rhythmic alternation of planktonic limestones and jaspers, accumulated in the open ocean environment. The rhythmicity can be attributed to climate variations that reflect a fluctuation of astronomical parameters (Milankovitch cycles) [2, 3].The section contains two beds enriched in organic carbon, corresponding to the two oceanic anoxic events - MCE and OAE2 [3]. The maximum content of organic matter in those beds reaches 68%. Our geochemical studies revealed an enrichment of the carbonaceous rocks in some major and trace elements including PGE, in comparison with the surrounding limestone and jasper [4].The accumulation of the ore elements in carbonaceous beds is caused by euxinic conditions during sedimentation.The content of uranium, yttrium, and rare earth elements in carbonaceous rocks is up to 60, 142 and 312 ppm respectively. Phosphate grains (bone detritus) with microinclusions of yttrium and uranium minerals were revealed in the carbonaceous rocks using the scanning electron microscope. These data prove the hypothesis of the sorbtion of U and Y by phosphate detritus from seawater. Microprobe analysis also showed an increased content of Cu, Zn, V in some pyrite framboids, which indicates that these elements are fixed in rocks by Fe-sulphide phase or organic matter under euxinic conditions. Our research may bring us closer to understanding the mechanism of syngenetic accumulation of metals in the black shales. This work was supported by the RFBR (No. 16-05-00546). [1] Palechek, T.N., Savelyev, D.P., Savelyeva, O.L. (2010) Stratigraphy and Geological Correlation 18, (1) 63-82. [2] Savelyeva, O.L. (2010). Vestnik Kraunts. Nauki o zemle 1 (15), 45-55 (in Russian). [3] Savelyev, D.P., Savelyeva, O.L., Palechek, T.N., Pokrovsky, B.G. (2012) Geophysical Research Abstracts, 14, EGU

Phosphate and phosphate fertilizer sector: structure and future prospects. [Uranium recovery

Energy Technology Data Exchange (ETDEWEB)

Zenaidi, B

1981-12-01

A statement of the past evolution of this sector's structure is given. Various prospective studies which have been made are reviewed and lead to the precision of the phosphate requirement in the year 2000 which is between 200 and 250 Mt. Only a small section p. 696-697 is devoted to recovery of uranium contained in phosphate and prospects in this field are given.

Effect of fertilizer type on cadmium and fluorine concentrations in clover herbage

International Nuclear Information System (INIS)

McLaughlin, M.J.

2002-01-01

This study investigated whether changing phosphatic fertilizer type affects the accumulation of cadmium (Cd) and fluorine (F) in pasture herbage. North Carolina phosphate rock and partially acidulated fertilizers derived from this rock generally have higher Cd and F concentrations compared to single superphosphate currently manufactured in Australia. Clover herbage from sites of the National Reactive Phosphate Rock (RPR) trial was collected and analysed for concentrations of Cd (11 sites) and F (4 sites). A comparison was made between pastures fertilized with 4 rates of single superphosphate, North Carolina phosphate rock, and partially acidulated phosphate rock having Cd concentrations of 283, 481, and 420 mg Cd/kg P respectively, and 170, 271, and 274 g F/kg P respectively. One site used Hemrawein (Egypt) phosphate rock (HRP) having a Cd and F concentration of 78 mg Cd/kg P and 256 g F/kg P respectively. To help identify differences in herbage Cd concentrations between sites, unfertilised soils from each site were analyzed for total and extractable Cd contents. At one site Cd concentrations in bulk herbage (clover, grasses and weeds) were related to infestation of the pasture by capeweed (Arctotheca calendula L. Levyns). There were no significant differences between F in herbage from plots fertilized with single superphosphate, partially acidulated phosphate rock or North Carolina phosphate rock, or between sites. Concentrations of F in herbage were low, generally less than 10 mg F /kg. However, there were large differences in Cd concentrations in herbage between sites, while differences between fertilizer treatments were small in comparison. The site differences were only weakly related to total or extractable (0.01 mol/L CaCl 2 ) Cd concentrations in soil. Significant differences in Cd concentrations in clover due to fertilizer type were found at 5 sites. North Carolina phosphate rock treatments had significantly higher Cd concentrations in clover compared to

Rock Art

Science.gov (United States)

Henn, Cynthia A.

2004-01-01

There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

Better prospects for phosphate production

Energy Technology Data Exchange (ETDEWEB)

1980-06-01

The extraction of uranium as a by product of phosphate production is discussed. Techniques being commercially developed are described. The trend towards the wet process, in which sulphuric acid is used to dissolve the phosphate, producing phosphoric acid, is also the preferred method for uranium recovery. Recovery from a wet process phosphoric acid stream, integrated with phosphate fertilizer manufacture, is becoming increasingly commercially viable for the production of yellow-cake.

The Oxygen Isotopic Composition of Phosphate: A Tracer for Phosphate Sources and Cycling

Energy Technology Data Exchange (ETDEWEB)

Mclaughlin, K. [Southern California Coastal Water Research Project, Costa Mesa, University of California, CA (United States); Young, M. B.; Paytan, A.; Kendall, C. [U.S. Geological Survey, University of California, CA (United States)

2013-05-15

Phosphorus (P) is a limiting macro-nutrient for primary productivity and anthropogenic P-loading to aquatic ecosystems is one of the leading causes of eutrophication in many ecosystems throughout the world. Because P has only one stable isotope, traditional isotope techniques are not possible for tracing sources and cycling of P in aquatic systems. However, much of the P in nature is bonded to four oxygen (O) atoms as orthophosphate (PO{sub 4}{sup 3-}). The P-O bonds in orthophosphate are strongly resistant to inorganic hydrolysis and do not exchange oxygen with water without biological mediation (enzyme-mediated recycling). Thus, the oxygen isotopic composition of dissolved inorganic phosphate ({delta}{sup 18}O{sub p}) may be used as a tracer for phosphate sources and cycling in aquatic ecosystems. Recently, several studies have been conducted utilizing {delta}{sup 18}O{sub p} as a tracer for phosphate sources and cycling in various aquatic environments. Specifically, work to date indicates that {delta}{sup 18}O{sub p} is useful for determining sources of phosphate to aquatic systems if these sources have unique isotopic signatures and phosphate cycling within the system is limited compared to input fluxes. In addition, because various processes imprint specific fractionation effects, the {delta}{sup 18}O{sub p} tracer can be utilized to determine the degree of phosphorous cycling and processing through the biomass. This chapter reviews several of these studies and discusses the potential to utilize the {delta}{sup 18}O{sub p} of phosphate in rivers and streams. (author)

An optimized regulating method for composting phosphorus fractions transformation based on biochar addition and phosphate-solubilizing bacteria inoculation.

Science.gov (United States)

Wei, Yuquan; Zhao, Yue; Wang, Huan; Lu, Qian; Cao, Zhenyu; Cui, Hongyang; Zhu, Longji; Wei, Zimin

2016-12-01

The study was conducted to investigate the influence of biochar and/or phosphate-solubilizing bacteria (PSB) inoculants on microbial biomass, bacterial community composition and phosphorus (P) fractions during kitchen waste composting amended with rock phosphate (RP). There were distinct differences in the physic-chemical parameters, the proportion of P fractions and bacterial diversity in different treatments. The contribution of available P fractions increased during composting especially in the treatment with the addition of PSB and biochar. Redundancy analysis showed that bacterial compositions were significantly influenced by P content, inoculation and biochar. Variance partitioning further showed that synergy of inoculated PSB and indigenous bacterial communities and the joint effect between biochar and bacteria explained the largest two proportion of the variation in P fractions. Therefore, the combined application of PSB and biochar to improve the inoculation effect and an optimized regulating method were suggested based on the distribution of P fractions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Occurrence and functioning of phosphate solubilizing ...

African Journals Online (AJOL)

Occurrence and functioning of phosphate solubilizing microorganisms from oil palm tree ( Elaeis guineensis ) rhizosphere in Cameroon. ... While the use of soluble mineral phosphate fertilizers is the obvious best means to combat phosphate ... in order to improve agricultural production, using low inputs technology. Isolates ...

Role of phosphate solubilizing Burkholderia spp. for successful colonization and growth promotion of Lycopodium cernuum L. (Lycopodiaceae) in lateritic belt of Birbhum district of West Bengal, India.

Science.gov (United States)

Ghosh, Ranjan; Barman, Soma; Mukherjee, Rajib; Mandal, Narayan C

2016-02-01

Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38 μg ml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15 μg ml(-1)) and P10 (485.18±14.23 μg ml(-1)) at 28 °C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil. Copyright © 2015 Elsevier GmbH. All rights reserved.

Phosphoryl transfer is not rate-limiting for the ROCK I-catalyzed kinase reaction.

Science.gov (United States)

Futer, Olga; Saadat, Ahmad R; Doran, John D; Raybuck, Scott A; Pazhanisamy, S

2006-06-27

Rho-associated coiled-coil kinase, ROCK, is implicated in Rho-mediated cell adhesion and smooth muscle contraction. Animal models suggest that the inhibition of ROCK can ameliorate conditions, such as vasospasm, hypertension, and inflammation. As part of our effort to design novel inhibitors of ROCK, we investigated the kinetic mechanism of ROCK I. Steady-state bisubstrate kinetics, inhibition kinetics, isotope partition analysis, viscosity effects, and presteady-state kinetics were used to explore the kinetic mechanism. Plots of reciprocals of initial rates obtained in the presence of nonhydrolyzable ATP analogues and the small molecule inhibitor of ROCK, Y-27632, against the reciprocals of the peptide concentrations yielded parallel lines (uncompetitive pattern). This pattern is indicative of an ordered binding mechanism, with the peptide adding first. The staurosporine analogue K252a, however, gave a noncompetitive pattern. When a pulse of (33)P-gamma-ATP mixed with ROCK was chased with excess unlabeled ATP and peptide, 0.66 enzyme equivalent of (33)P-phosphate was incorporated into the product in the first turnover. The presence of ATPase activity coupled with the isotope partition data is a clear evidence for the existence of a viable [E-ATP] complex in the kinase reaction and implicates a random binding mechanism. The k(cat)/K(m) parameters were fully sensitive to viscosity (viscosity effects of 1.4 +/- 0.2 and 0.9 +/- 0.3 for ATP and peptide 5, respectively), and therefore, the barriers to dissociation of either substrate are higher than the barrier for the phosphoryl transfer step. As a consequence, not all the binding steps are at fast equilibrium. The observation of a burst in presteady-state kinetics (k(b) = 10.2 +/- 2.1 s(-)(1)) and the viscosity effect on k(cat) of 1.3 +/- 0.2 characterize the phosphoryl transfer step to be fast and the release of product and/or the enzyme isomerization step accompanying it as rate-limiting at V(max) conditions. From

on association of trialkyl phosphates

International Nuclear Information System (INIS)

Petkovic, D.M.; Maksimovic, Z.B.

1976-01-01

The association constants of tri-n-butyl (TBP), tri-n-propyl (TPP) and triethyl phosphate (TEP) with chloroform, carbon tetrachloride and benzene were determined by dielectric constant, proton magnetic resonance and vapor pressure measurements. Correlation of the trialkyl phosphate-chloroform association constants, using the Hammett equation, showed their increase with the number of carbon atoms in the aliphatic radicals. The change of trialkyl phosphate reactivity with temperature was used to determine the thermodynamic quantities. (author)

Thermally induced rock stress increment and rock reinforcement response

International Nuclear Information System (INIS)

Hakala, M.; Stroem, J.; Nujiten, G.; Uotinen, L.; Siren, T.; Suikkanen, J.

2014-07-01

This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the brittle

Thermally induced rock stress increment and rock reinforcement response

Energy Technology Data Exchange (ETDEWEB)

Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

2014-07-15

This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

Bio-treatment of phosphate from synthetic wastewater using ...

African Journals Online (AJOL)

In this study, the efficient phosphate utilizing isolates were used to remove phosphate from synthetic phosphate wastewater was tested using batch scale process. Hence the objective of the present study was to examine the efficiency of bacterial species individually for the removal of phosphate from synthetic phosphate ...

Comparison of disposal concepts for rock salt and hard rock

International Nuclear Information System (INIS)

Papp, R.

1998-01-01

The study was carried out in the period 1994-1996. The goals were to prepare a draft on spent fuel disposal in hard rock and additionally a comparison with existing disposal concepts for rock salt. A cask for direct disposal of spent fuel and a repository for hard rock including a safeguards concept were conceptually designed. The results of the study confirm, that the early German decision to employ rock salt was reasonable. (orig.)

Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

International Nuclear Information System (INIS)

Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

2011-01-01

Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electro painting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR). (author)

Application of Calcium Phosphate Materials in Dentistry

Directory of Open Access Journals (Sweden)

Jabr S. Al-Sanabani

2013-01-01

Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

Science.gov (United States)

Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

2016-05-01

Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

Kinetics of selenium release in mine waste from the Meade Peak Phosphatic Shale, Phosphoria Formation, Wooley Valley, Idaho, USA

Science.gov (United States)

Stillings, Lisa L.; Amacher, Michael C.

2010-01-01

Phosphorite from the Meade Peak Phosphatic Shale member of the Permian Phosphoria Formation has been mined in southeastern Idaho since 1906. Dumps of waste rock from mining operations contain high concentrations of Se which readily leach into nearby streams and wetlands. While the most common mineralogical residence of Se in the phosphatic shale is elemental Se, Se(0), Se is also an integral component of sulfide phases (pyrite, sphalerite and vaesite–pyritess) in the waste rock. It may also be present as adsorbed selenate and/or selenite, and FeSe2 and organo-selenides.Se release from the waste rock has been observed in field and laboratory experiments. Release rates calculated from waste rock dump and column leachate solutions describe the net, overall Se release from all of the possible sources of Se listed above. In field studies, Se concentration in seepage water (pH 7.4–7.8) from the Wooley Valley Unit 4 dump ranges from 3600 µg/L in May to 10 µg/L by Sept. Surface water flow, Q, from the seep also declines over the summer, from 2 L/s in May to 0.03 L/s in Sept. Se flux ([Se] ⁎ Q) reaches a steady-state of Laboratory experiments were performed with the waste shale in packed bed reactors; residence time varied from 0.09 to 400 h and outlet pH ∼ 7.5. Here, Se concentration increased with increasing residence time and release was modeled with a first order reaction with k = 2.19e−3 h− 1 (19.2 yr− 1).Rate constants reported here fall within an order of magnitude of reported rate constants for oxidation of Se(0) formed by bacterial precipitation. This similarity among rate constants from both field and laboratory studies combined with the direct observation of Se(0) in waste shales of the Phosphoria Formation suggests that oxidation of Se(0) may control steady-state Se concentration in water draining the Wooley Valley waste dump.

Phosphate acquisition efficiency and phosphate starvation tolerance ...

Indian Academy of Sciences (India)

3Department of Genetics and Plant Breeding, College of Agriculture, Lembucherra, Tripura 799 ... vated in soil like red and lateritic or acid, with low soluble phosphate content. ..... activation of genes involved in the adaptation of Arabidopsis to.

Rollerjaw Rock Crusher

Science.gov (United States)

Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

2009-01-01

The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

Range sections as rock models for intensity rock scene segmentation

CSIR Research Space (South Africa)

Mkwelo, S

2007-11-01

Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

Most consumed processed foods by patients on hemodialysis: Alert for phosphate-containing additives and the phosphate-to-protein ratio.

Science.gov (United States)

Watanabe, Marcela T; Araujo, Raphael M; Vogt, Barbara P; Barretti, Pasqual; Caramori, Jacqueline C T

2016-08-01

Hyperphosphatemia is common in patients with chronic kidney disease (CKD) stages IV and V because of decreased phosphorus excretion. Phosphatemia is closely related to dietary intake. Thus, a better understanding of sources of dietary phosphate consumption, absorption and restriction, particularly inorganic phosphate found in food additives, is key to prevent consequences of this complication. Our aims were to investigate the most commonly consumed processed foods by patients with CKD on hemodialysis, to analyze phosphate and protein content of these foods using chemical analysis and to compare these processed foods with fresh foods. We performed a cross-sectional descriptive analytical study using food frequency questionnaires to rank the most consumed industrialized foods and beverages. Total phosphate content was determined by metavanadate colorimetry, and nitrogen content was determined by the Kjeldahl method. Protein amounts were estimated from nitrogen content. The phosphate-to-protein ratio (mg/g) was then calculated. Processed meat protein and phosphate content were compared with the nutritional composition of fresh foods using the Brazilian Food Composition Table. Phosphate measurement results were compared with data from the Food Composition Table - Support for Nutritional Decisions. An α level of 5% was considered significant. Food frequency questionnaires were performed on 100 patients (mean age, 59 ± 14 years; 57% male). Phosphate additives were mentioned on 70% of the product labels analyzed. Proteins with phosphate-containing additives provided approximately twice as much phosphate per gram of protein compared with that of fresh foods (p processed foods are higher than those of fresh foods, as well as phosphate-to-protein ratio. A better understanding of phosphate content in foods, particularly processed foods, may contribute to better control of phosphatemia in patients with CKD. Copyright © 2016 European Society for Clinical Nutrition and

31P-Nuclear Magnetic Resonance Determination of Phosphate Compartmentation in Leaves of Reproductive Soybeans (Glycine max L.) as Affected by Phosphate Nutrition 1

Science.gov (United States)

Lauer, Michael J.; Blevins, Dale G.; Sierzputowska-Gracz, Hanna

1989-01-01

Most leaf phosphorus is remobilized to the seed during reproductive development in soybean. We determined, using 31P-NMR, the effect phosphorus remobilization has on vacuolar inorganic phosphate pool size in soybean (Glycine max [L.] Merr.) leaves with respect to phosphorus nutrition and plant development. Phosphate compartmentation between cytoplasmic and vacuolar pools was observed and followed in intact tissue grown hydroponically, at the R2, R4, and R6 growth stages. As phosphorus in the nutrient solution decreased from 0.45 to 0.05 millimolar, the vacuolar phosphate peak became less prominent relative to cytoplasmic phosphate and hexose monophosphate peaks. At a nutrient phosphate concentration of 0.05 millimolar, the vacuolar phosphate peak was not detectable. At higher levels of nutrient phosphate, as plants progressed from the R2 to the R6 growth stage, the vacuolar phosphate peak was the first to disappear, suggesting that storage phosphate was remobilized to a greater extent than metabolic phosphate. Under suboptimal phosphate nutrition (≤ 0.20 millimolar), the hexose monophosphate and cytoplasmic phosphate peaks declined earlier in reproductive development than when phosphate was present in optimal amounts. Under low phosphate concentrations (0.05 millimolar) cytoplasmic phosphate was greatly reduced. Carbon metabolism was coincidently disrupted under low phosphate nutrition as shown by the appearance of large, prominent starch grains in the leaves. Cytoplasmic phosphate, and leaf carbon metabolism dependent on it, are buffered by vacuolar phosphate until late stages of reproductive growth. Images Figure 4 PMID:16666705

Pentose phosphates in nucleoside interconversion and catabolism.

Science.gov (United States)

Tozzi, Maria G; Camici, Marcella; Mascia, Laura; Sgarrella, Francesco; Ipata, Piero L

2006-03-01

Ribose phosphates are either synthesized through the oxidative branch of the pentose phosphate pathway, or are supplied by nucleoside phosphorylases. The two main pentose phosphates, ribose-5-phosphate and ribose-1-phosphate, are readily interconverted by the action of phosphopentomutase. Ribose-5-phosphate is the direct precursor of 5-phosphoribosyl-1-pyrophosphate, for both de novo and 'salvage' synthesis of nucleotides. Phosphorolysis of deoxyribonucleosides is the main source of deoxyribose phosphates, which are interconvertible, through the action of phosphopentomutase. The pentose moiety of all nucleosides can serve as a carbon and energy source. During the past decade, extensive advances have been made in elucidating the pathways by which the pentose phosphates, arising from nucleoside phosphorolysis, are either recycled, without opening of their furanosidic ring, or catabolized as a carbon and energy source. We review herein the experimental knowledge on the molecular mechanisms by which (a) ribose-1-phosphate, produced by purine nucleoside phosphorylase acting catabolically, is either anabolized for pyrimidine salvage and 5-fluorouracil activation, with uridine phosphorylase acting anabolically, or recycled for nucleoside and base interconversion; (b) the nucleosides can be regarded, both in bacteria and in eukaryotic cells, as carriers of sugars, that are made available though the action of nucleoside phosphorylases. In bacteria, catabolism of nucleosides, when suitable carbon and energy sources are not available, is accomplished by a battery of nucleoside transporters and of inducible catabolic enzymes for purine and pyrimidine nucleosides and for pentose phosphates. In eukaryotic cells, the modulation of pentose phosphate production by nucleoside catabolism seems to be affected by developmental and physiological factors on enzyme levels.

Meal phosphate variability does not support fixed dose phosphate binder schedules for patients treated with peritoneal dialysis: a prospective cohort study.

Science.gov (United States)

Leung, Simon; McCormick, Brendan; Wagner, Jessica; Biyani, Mohan; Lavoie, Susan; Imtiaz, Rameez; Zimmerman, Deborah

2015-12-09

Removal of phosphate by peritoneal dialysis is insufficient to maintain normal serum phosphate levels such that most patients must take phosphate binders with their meals. However, phosphate 'counting' is complicated and many patients are simply prescribed a specific dose of phosphate binders with each meal. Therefore, our primary objective was to assess the variability in meal phosphate content to determine the appropriateness of this approach. In this prospective cohort study, adult patients with ESRD treated with peritoneal dialysis and prescribed phosphate binder therapy were eligible to participate. Participants were excluded from the study if they were unable to give consent, had hypercalcemia, were visually or hearing impaired or were expected to receive a renal transplant during the time of the study. After providing informed consent, patients kept a 3-day diet diary that included all foods and beverages consumed in addition to portion sizes. At the same time, patients documented the amount of phosphate binders taken with each meal. The phosphate content of the each meal was estimated using ESHA Food Processor SQL Software by a registered dietitian. Meal phosphate and binder variability were estimated by the Intra Class Correlation Coefficient (ICC) where 0 indicates maximal variability and 1 indicates no variability. Seventy-eight patients consented to participate in the study; 18 did not complete the study protocol. The patients were 60 (± 17) years, predominately male (38/60) and Caucasian (51/60). Diabetic nephropathy was the most common cause of end stage kidney disease. The daily phosphate intake including snacks ranged from 959 ± 249 to 1144 ± 362 mg. The phosphate ICC by meal: breakfast 0.63, lunch 0.16; supper 0.27. The phosphate binder ICC by meal: breakfast 0.68, lunch 0.73, supper 0.67. The standard prescription of a set number of phosphate binders with each meal is not supported by the data; patients do not appear to be adjusting their

Comparative study on in vitro biocompatibility of synthetic octacalcium phosphate and calcium phosphate ceramics used clinically.

Science.gov (United States)

Morimoto, Shinji; Anada, Takahisa; Honda, Yoshitomo; Suzuki, Osamu

2012-08-01

The present study was designed to investigate the extent to which calcium phosphate bone substitute materials, including osteoconductive octacalcium phosphate (OCP), display cytotoxic and inflammatory responses based on their dissolution in vitro. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics, which are clinically used, as well as dicalcium phosphate dihydrate (DCPD) and synthesized OCP were compared. The materials were well characterized by chemical analysis, x-ray diffraction and Fourier transform infrared spectroscopy. Calcium and phosphate ion concentrations and the pH of culture media after immersion of the materials were determined. The colony forming rate of Chinese hamster lung fibroblasts was estimated with extraction of the materials. Proliferation of bone marrow stromal ST-2 cells and inflammatory cytokine TNF-α production by THP-1 cells grown on the material-coated plates were examined. The materials had characteristics that corresponded to those reported. DCPD was shown to dissolve the most in the culture media, with a marked increase in phosphate ion concentration and a reduction in pH. ST-2 cells proliferated well on the materials, with the exception of DCPD, which markedly inhibited cellular growth. The colony forming capacity was the lowest on DCPD, while that of the other calcium phosphates was not altered. In contrast, TNF-α was not detected even in cells grown on DCPD, suggesting that calcium phosphate materials are essentially non-inflammatory, while the solubility of the materials can affect osteoblastic and fibroblastic cellular attachment. These results indicate that OCP is biocompatible, which is similar to the materials used clinically, such as HA. Therefore, OCP could be clinically used as a biocompatible bone substitute material.

Phosphate Reduction in Emulsified Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics.

Science.gov (United States)

Glorieux, Seline; Goemaere, Olivier; Steen, Liselot; Fraeye, Ilse

2017-09-01

Phosphate reduction is of important industrial relevance in the manufacturing of emulsified meat products because it may give rise to a healthier product. The effect of seven different phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had little effect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06% TSPP was sufficient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsified meat products can be significantly reduced with minimal loss of product quality.

Measurement of 226Ra, 232Th and 40K radioactivity contents in by-product phosphogypsum from phosphate fertilizer industry using gamma ray spectrometric method

International Nuclear Information System (INIS)

Demirel, H.; Parmaksiz, A.; Vural, M.; Cakir, I.T.; Demircioglu, B.; Yucel, H.

2004-01-01

Full text: Phosphatic fertilizers are produced from the industrial processing of rock phosphate ores which are known to contain naturally occurring radionuclides such as 238 U and its daughter products. A high volume by-product known as phosphogypsum (PG) from the production of phosphoric acid and phosphate fertilizer causes serious storage and environmental problems in phosphoric acid industries. During the phosphoric acid production process, 226 Ra (t 1/2 =1600 y) ends up in PG which has chemical analogous to calcium element. Since the stockpiles of PG near the phosphatic fertilizer plants are huge amounts, the radioactivity contained in PG has measured in view of environmental radioactivity problem. In this work, the natural radioactivity in eighty PG samples taken from a stock near Samsun phosphoric fertilizer plant was measured by a high resolution gamma ray spectrometer. The mean activity of 226 Ra in PG samples has been found to be 546 Bq.kg -1 . However, the activities of 232 Th and 40 K measured in PG samples are negligibly small. In the presented paper, the gamma spectrometric method employed for this work is discussed and the radiological risk impact of radon gas emanation from 226 Ra mainly contained in PG, has been assessed

[Phosphate-solubilizing activity of aerobic methylobacteria].

Science.gov (United States)

Agafonova, N V; Kaparullina, E N; Doronina, N V; Trotsenko, Iu A

2014-01-01

Phosphate-solubilizing activity was found in 14 strains of plant-associated aerobic methylobacteria belonging to the genera Methylophilus, Methylobacillus, Methylovorus, Methylopila, Methylobacterium, Delftia, and Ancyclobacter. The growth of methylobacteria on medium with methanol as the carbon and energy source and insoluble tricalcium phosphate as the phosphorus source was accompanied by a decrease in pH due to the accumulation of up to 7 mM formic acid as a methanol oxidation intermediate and by release of 120-280 μM phosphate ions, which can be used by both bacteria and plants. Phosphate-solubilizing activity is a newly revealed role of methylobacteria in phytosymbiosis.

Translocation of metal phosphate via the phosphate inorganic transport system of Escherichia coli

NARCIS (Netherlands)

van Veen, H.W; Abee, T.; Kortstee, G.J J; Konings, W.N; Zehnder, A.J B

1994-01-01

P-i transport via the phosphate inorganic transport system (Pit) of Escherichia coil was studied in natural and artificial membranes. P-i uptake via Pit is dependent on the presence of divalent cations, like Mg2+, Ca2+, Co2+, or Mn2+, which form a soluble, neutral metal phosphate (MeHPO(4)) complex.

Co-precipitation of phosphate and iron limits mitochondrial phosphate availability in Saccharomyces cerevisiae lacking the yeast frataxin homologue (YFH1).

Science.gov (United States)

Seguin, Alexandra; Santos, Renata; Pain, Debkumar; Dancis, Andrew; Camadro, Jean-Michel; Lesuisse, Emmanuel

2011-02-25

Saccharomyces cerevisiae cells lacking the yeast frataxin homologue (Δyfh1) accumulate iron in the mitochondria in the form of nanoparticles of ferric phosphate. The phosphate content of Δyfh1 mitochondria was higher than that of wild-type mitochondria, but the proportion of mitochondrial phosphate that was soluble was much lower in Δyfh1 cells. The rates of phosphate and iron uptake in vitro by isolated mitochondria were higher for Δyfh1 than wild-type mitochondria, and a significant proportion of the phosphate and iron rapidly became insoluble in the mitochondrial matrix, suggesting co-precipitation of these species after oxidation of iron by oxygen. Increasing the amount of phosphate in the medium decreased the amount of iron accumulated by Δyfh1 cells and improved their growth in an iron-dependent manner, and this effect was mostly transcriptional. Overexpressing the major mitochondrial phosphate carrier, MIR1, slightly increased the concentration of soluble mitochondrial phosphate and significantly improved various mitochondrial functions (cytochromes, [Fe-S] clusters, and respiration) in Δyfh1 cells. We conclude that in Δyfh1 cells, soluble phosphate is limiting, due to its co-precipitation with iron.

Fluid and rock interaction in permeable volcanic rock

International Nuclear Information System (INIS)

Lindley, J.I.

1985-01-01

Four types of interrelated changes -geochemical, mineralogic, isotopic, and physical - occur in Oligocene volcanic units of the Mogollon-Datil volcanic field, New Mexico. These changes resulted from the operation of a geothermal system that, through fluid-rock interaction, affected 5 rhyolite ash-flow tuffs and an intercalated basaltic andesite lava flow causing a potassium metasomatism type of alteration. (1) Previous studies have shown enrichment of rocks in K 2 O as much as 130% of their original values at the expense of Na 2 O and CaO with an accompanying increase in Rb and decreases in MgO and Sr. (2) X-ray diffraction results of this study show that phenocrystic plagioclase and groundmass feldspar have been replaced with pure potassium feldspar and quartz in altered rock. Phenocrystic potassium feldspar, biotite, and quartz are unaffected. Pyroxene in basaltic andesite is replaced by iron oxide. (3) delta 18 O increases for rhyolitic units from values of 8-10 permil, typical of unaltered rock, to 13-15 permil, typical of altered rock. Basaltic andesite, however, shows opposite behavior with a delta 18 of 9 permil in unaltered rock and 6 permit in altered. (4) Alteration results in a density decrease. SEM revealed that replacement of plagioclase by fine-grained quartz and potassium feldspar is not a volume for volume replacement. Secondary porosity is created in the volcanics by the chaotic arrangement of secondary crystals

Electrical properties of phosphate glasses

International Nuclear Information System (INIS)

Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

2009-01-01

Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

Hydrogen permeation resistant phosphate coatings

International Nuclear Information System (INIS)

McGuire, J.C.

1979-01-01

A method for reducing hydrogen diffusion through metal wherein the metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface thereof. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 0 7 . (author)

Hydrogen permeation resistant phosphate coatings

International Nuclear Information System (INIS)

McGuire, J.C.

1979-01-01

A method for reducing hydrogen diffusion through metal is described. The metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 O 7 . (author)

Phosphate vibrations as reporters of DNA hydration

Science.gov (United States)

Corcelli, Steven

The asymmetric phosphate stretch vibrational frequency is extraordinarily sensitive to its local solvent environment. Using density functional theory calculations on the model compound dimethyl phosphate, the asymmetric phosphate stretch vibrational frequency was found to shift linearly with the magnitude of an electric field along the symmetry axis of the PO2 moiety (i.e. the asymmetric phosphate stretch is an excellent linear vibrational Stark effect probe). With this linear relationship established, asymmetric phosphate stretch vibrational frequencies were computed during the course of a molecular dynamics simulation of fully hydrated DNA. Moreover, contributions to shifts in the frequencies from subpopulations of water molecules (e.g. backbone, minor groove, major groove, etc.) were calculated to reveal how phosphate vibrations report the onset of DNA hydration in experiments that vary the relative humidity of non-condensing (dry) DNA samples.

Sonochemical precipitation of amorphous uranium phosphates from trialkyl phosphate solutions and their thermal conversion to UP2O7

Czech Academy of Sciences Publication Activity Database

Doroshenko, I.; Žurková, J.; Moravec, Z.; Bezdička, Petr; Pinkas, J.

2015-01-01

Roč. 26, SEP (2015), s. 157-162 ISSN 1350-4177 Institutional support: RVO:61388980 Keywords : Uranium * Phosphates * Sonochemistry * Nuclear waste * Trimethyl phosphate * Triethyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 4.556, year: 2015

Disc cutter wear and rock texture in hard rock TBM tunneling

International Nuclear Information System (INIS)

Koizumi, Yu; Tsusaka, Kimikazu; Tanimoto, Chikaosa; Nakagawa, Shigeo; Fujita, Naoya

2008-01-01

Disc cutter wear in TBM tunneling is caused by initial fragmentation of a solid rock face (the primary fragmentation) and fragmentation of residual rock pieces between a cutterhead and the face (the secondary fragmentation). In two projects through sedimentary and granitic rocks, the authors investigated the relationships between the rate of cutter wear caused by the primary fragmentation, point load index and the grain size and contents of abrasive minerals. As a result, it was found that the tensile strength and the mineral contents of rocks significantly influenced the cutter wear in both projects and thus it is necessary to take into account of rock type. (author)

Rocks Can Wow? Yes, Rocks Can Wow!

Science.gov (United States)

Hardman, Sally; Luke, Sue

2016-01-01

Rocks and fossils appear in the National Curriculum of England science programmes of study for children in year 3 (ages 7-8). A frequently asked question is "How do you make the classification of rocks engaging?" In response to this request from a school, a set of interactive activities was designed and organised by tutors and students…

Cerebrospinal Fluid Phosphate in Delirium after Hip Fracture

Directory of Open Access Journals (Sweden)

Ane-Victoria Idland

2017-09-01

Full Text Available Aims: Phosphate is essential for neuronal activity. We aimed to investigate whether delirium is associated with altered phosphate concentrations in cerebrospinal fluid (CSF and serum. Methods: Seventy-seven patients with hip fracture were assessed for delirium before and after acute surgery. Prefracture dementia was diagnosed by an expert panel. Phosphate was measured in CSF obtained immediately before spinal anesthesia (n = 77 and in serum (n = 47. CSF from 23 cognitively healthy elderly patients undergoing spinal anesthesia was also analyzed. Results: Hip fracture patients with prevalent delirium had higher CSF phosphate concentrations than those without delirium (median 0.63 vs. 0.55 mmol/L, p = 0.001. In analyses stratified on dementia status, this difference was only significant in patients with dementia. Serum phosphate was ∼1 mmol/L; there was no association between serum phosphate concentration and delirium status. CSF phosphate did not correlate with serum levels. Conclusion: Patients with delirium superimposed on dementia have elevated phosphate levels.

Radical-induced dephosphorylation of fructose phosphates in aqueous solution

International Nuclear Information System (INIS)

Zegota, H.; Sonntag, C. von

1981-01-01

Oxygen free N 2 O-saturated aqueous solutions of D-fructose-1-phosphate and D-fructose-6-phosphate were γ-irradiated. Inorganic phosphate and phosphate free sugars (containing four to six carbon atoms) were identified and their G-values measured. D-Fructose-1-phosphate yields (G-values in parentheses) inorganic phosphate (1.6), hexos-2-ulose (0.12), 6-deoxy-2,5-hexodiulose (0.16), tetrulose (0.05) and 3-deoxytetrulose (0.15). D-Fructose-6-phosphate yields inorganic phosphate (1.7), hexos-5-ulose (0.1), 6-deoxy-2,5-hexodiulose (0.36), 3-deoxy-2,5-hexodiulose and 2-deoxyhexos-5-ulose (together 0.18). On treatment with alkaline phosphatase further deoxy sugars were recognized and in fructose-1-phosphate G(6-deoxy-2,5-hexodiulose) was increased to a G-value of 0.4. Dephosphorylation is considered to occur mainly after OH attack at C-5 and C-1 in fructose-1-phosphate and at C-5 and C-6 in fructose-6-phosphate. Reaction mechanisms are discussed. (orig.)

Uranium and REE recovery from Florida phosphates – Looking back and going forward

International Nuclear Information System (INIS)

Zhang, J.; Birky, B.

2014-01-01

Uranium recovered during the production of phosphoric acid represents a significant source of nuclear fuel as the gap between uranium supply and demand is expected to grow. The phosphate industry in Florida supplied uranium to both the defense and energy sectors in the past, but market conditions ended the recovery process. Currently, the uranium is retained in the phosphoric acid and the granulated fertilizer products, diammonium and monoammonium phosphate, and dispersed on farm fields as a trace element in blended fertilizers. This represents a loss to the nuclear fuel cycle that will never be recovered. In an era of heightened awareness of sustainability and increasing pressure to reduce greenhouse gas emissions, market conditions and social factors may converge to create favorable conditions for uranium recovery to resume. However, the future may not resemble the past as uranium concentrations are lower in the newer mining areas and ion exchange challenges solvent extraction for the extraction technology of choice. New factors will also influence both the economic decision to resume recovery operations, as well as the recovery technology. Rare earth elements (REE) are also present in the processing streams at recoverable levels, and can be co-extracted with uranium using the proven solvent extraction method. REE are vital to the phosphor industry, green energy development, and technology advances in many fields. However, the world has limited REE resources, and the recovery of REE from many of these resources is both economically challenging and environmentally troublesome. Phosphate as a secondary REE resource has a great potential to fill this gap. World annual phosphate rock production has surpassed 200 million tons, representing 60,000 tons of unrecovered REE assuming an average concentration of 300 ppm. In the case of Florida, REE in the phosphate ore reports to four mining and processing streams, with approximately 10% to flotation tailings, 30-40% to

Iron phosphate glass containing simulated fast reactor waste: Characterization and comparison with pristine iron phosphate glass

International Nuclear Information System (INIS)

Joseph, Kitheri; Asuvathraman, R.; Venkata Krishnan, R.; Ravindran, T.R.; Govindaraj, R.; Govindan Kutty, K.V.; Vasudeva Rao, P.R.

2014-01-01

Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe 3+ /Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300–700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass

Calcium phosphates for biomedical applications

Directory of Open Access Journals (Sweden)

Maria Canillas

2017-05-01

Full Text Available The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies.

Preparation of calcium phosphate paste

International Nuclear Information System (INIS)

Mohd Reusmaazran Yusof; Norzita Yaacob; Idris Besar; Che Seman Mahmood; Rusnah Mustafa

2010-01-01

Calcium phosphate paste were prepared by mixing between calcium sodium potassium phosphate, Ca 2 NaK (PO 4 ) 2 (CSPP) and monocalcium phosphate monohydrate, Ca(H 2 PO 4 ) 2 .H 2 O (MCPM). CSPP were obtained by reaction between calcium hydrogen phosphate (CaHPO 4 ), potassium carbonate (K 2 CO 3 ) and sodium carbonate (Na 2 CO 3 ) in solid state sintering process followed by quenching in air at 1000 degree Celsius. The paste was aging in simulated body fluid (SBF) for 0.5, 1, 3, 6, 12, 24, 48 hrs, 3, 7 and 14 days. The morphological investigation indicated the formation of apatite crystal were first growth after 24 hours. The obvious growth of apatite crystal was shown at 3 days. The obvious growth of apatite crystal was shown in 7 and 14 days indicated the prediction of paste would have rapid reaction with bone after implantation. (author)

Calcium phosphates for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

2017-07-01

The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

Assessment of two carrier materials for phosphate solubilizing biofertilizers and their effect on growth of wheat (Triticum aestivum L.).

Science.gov (United States)

Mukhtar, Salma; Shahid, Izzah; Mehnaz, Samina; Malik, Kauser A

2017-12-01

Biofertilizers are usually carrier-based inoculants containing beneficial microorganisms. Incorporation of microorganisms in carrier material enables easy-handling, long-term storage and high effectiveness of biofertilizers. Objective of the present study was to assess enriched biogas sludge and soil as biofertilizer carriers on growth and yield of wheat. Six phosphate solubilizing strains were used in this study. Three phosphate solubilizing strains, 77-NS2 (Bacillus endophyticus), 77-CS-S1 (Bacillus sphaericus) and 77-NS5 (Enterobacter aerogenes) were isolated from the rhizosphere of sugarcane, two strains, PSB5 (Bacillus safensis) and PSB12 (Bacillus megaterium) from the rhizosphere of wheat and one halophilic phosphate solubilizing strain AT2RP3 (Virgibacillus sp.) from the rhizosphere of Atriplex amnicola, were used as bioinoculants. Phosphate solubilization ability of these strains was checked in vitro in Pikovskaya medium, containing rock phosphate (RP) as insoluble P source, individually supplemented with three different carbon sources, i.e., glucose, sucrose and maltose. Maximum phosphate solubilization; 305.6μg/ml, 217.2μg/ml and 148.1μg/ml was observed in Bacillus strain PSB12 in Pikovskaya medium containing sucrose, maltose and glucose respectively. A field experiment and pot experiments in climate control room were conducted to study the effects of biogas sludge and enriched soil based phosphorous biofertilizers on growth of wheat. Bacillus strain PSB12 significantly increased root and shoot dry weights and lengths using biogas sludge as carrier material in climate control room experiments. While in field conditions, significant increase in root and shoot dry weights, lengths and seed weights was seen by PSB12 and PSB5 (Bacillus) and Enterobacter strain 77-NS5 using biogas sludge as carrier. PSB12 also significantly increased both root and shoot dry weights and lengths in field conditions when used as enriched soil based inoculum. These results

Impaired Phosphate Tolerance Revealed With an Acute Oral Challenge.

Science.gov (United States)

Turner, Mandy E; White, Christine A; Hopman, Wilma M; Ward, Emilie C; Jeronimo, Paul S; Adams, Michael A; Holden, Rachel M

2018-01-01

Elevated serum phosphate is consistently linked with cardiovascular disease (CVD) events and mortality in the setting of normal and impaired kidney function. However, serum phosphate does not often exceed the upper limit of normal until glomerular filtration rate (GFR) falls below 30 mL/min/m 2 . It was hypothesized that the response to an oral, bioavailable phosphate load will unmask impaired phosphate tolerance, a maladaptation not revealed by baseline serum phosphate concentrations. In this study, rats with varying kidney function as well as normo-phosphatemic human subjects, with inulin-measured GFR (13.2 to 128.3mL/min), received an oral phosphate load. Hormonal and urinary responses were evaluated over 2 hours. Results revealed that the more rapid elevation of serum phosphate was associated with subjects and rats with higher levels of kidney function, greater responsiveness to acute changes in parathyroid hormone (PTH), and significantly more urinary phosphate at 2 hours. In humans, increases in urinary phosphate to creatinine ratio did not correlate with baseline serum phosphate concentrations but did correlate strongly to early increase of serum phosphate. The blunted rise in serum phosphate in rats with CKD was not the result of altered absorption. This result suggests acute tissue deposition may be altered in the setting of kidney function impairment. Early recognition of impaired phosphate tolerance could translate to important interventions, such as dietary phosphate restriction or phosphate binders, being initiated at much higher levels of kidney function than is current practice. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Phosphate Reduction in Emulsifi ed Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics

Directory of Open Access Journals (Sweden)

Seline Glorieux

2017-01-01

Full Text Available Phosphate reduction is of important industrial relevance in the manufacturing of emulsifi ed meat products because it may give rise to a healthier product. The eff ect of seven diff erent phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP and sodium tripolyphosphate (STPP increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had litt le eff ect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06 % TSPP was suffi cient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsifi ed meat products can be signifi cantly reduced with minimal loss of product quality.

Rock Physics

DEFF Research Database (Denmark)

Fabricius, Ida Lykke

2017-01-01

Rock physics is the discipline linking petrophysical properties as derived from borehole data to surface based geophysical exploration data. It can involve interpretation of both elastic wave propagation and electrical conductivity, but in this chapter focus is on elasticity. Rock physics is based...... on continuum mechanics, and the theory of elasticity developed for statics becomes the key to petrophysical interpretation of velocity of elastic waves. In practice, rock physics involves interpretation of well logs including vertical seismic profiling (VSP) and analysis of core samples. The results...