Search results for "Calcium carbonate"
showing 10 items of 175 documents
Preventive effect of risedronate on bone loss and frailty fractures in elderly women treated with anastrozole for early breast cancer.
2011
The aim of this study was to assess the effect of adjuvant anastrozole, alone or associated with risedronate, on BMD and bone fracture risk in women more than 70 years old with hormone receptor-positive early breast cancer (EBC). In a group of 51 elderly women (aged 76.4 ± 5.0 years) considered for adjuvant aromatase inhibitors for EBC, 24 patients with T-scores ≥ -2 and no prevalent fractures received anastrozole 1 mg/day (group A), and 27 patients with T-scores < -2, or with T-scores ≥ -2 and prevalent fractures (group B), received anastrozole (1 mg/day) plus risedronate (35 mg/week). Both groups received supplementation with 1 g calcium carbonate and 800 IU vitamin D per day. Differen…
Insight on bacteria communities in outdoor bronze and marble artefacts in a changing environment
2022
Epilithic bacteria play a fundamental role in the conservation of cultural heritage (CH) materials. On stones, bacterial communities cause both degradation and bioprotection actions. Bronze biocorrosion in non-burial conditions is rarely studied. Only few studies have examined the relationship between bacteria communities and the chemical composi- tion of patinas (surface degradation layers). A better comprehension of bacterial communities growing on our CH is fundamental not only to understand the related decay mechanisms but also to foresee possible shifts in their compo- sition due to climate change. The present study aims at (1) characterizing bacterial communities on bronze andmarble s…
Trace metal(loid) mobility in waste deposits and soils around Chadak mining area, Uzbekistan
2017
Abstract The assessment of potential trace metal(loid) contamination in tailing dumps and soils was characterized in the Chadak mining area (Uzbekistan). Concentrations of trace elements (V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Pb) were determined by X-ray fluorescence analysis and compared with background and intervention values (IV). The concentrations of As, Zn, Sb, and Pb were higher in the abandoned than in the active tailing dump, ranging from 42–1689 mg/kg for As, 73–332 mg/kg for Zn, 14–1507 mg/kg for Sb, and 27–386 mg/kg for Pb. Selective extractions were applied in order to assess the mobility and availability of trace metal(loid)s in samples. Oxyanion-forming elements such as As and S…
Speciation and Mobility of Arsenic in Agricultural Lime
2009
Agricultural liming materials are used to correct soil acidity and to improve plant growth and microbial functionality. A relatively low-grade agricultural lime was found to contain up to 125 mg kg(-1) arsenic (As), which is above any fertilizing materials code threshold. The color of the milled material is brown due to ample oxide dendrites. Microprobe elemental maps confirmed that these accessory oxide mineral phases are responsible for the elevated As concentrations in the limestone. The black Mn-bearing dendrites contain minor amounts of As, whereas the brown Fe-bearing dendrites contain the major part of the As inventory, with an Fe/As molar ratio around 100. Because the elemental maps…
Determination and assessment of mercury content in calcareous soils.
2009
Abstract This paper provides the first available information on the determination of the total mercury content in different Mediterranean calcareous soils by thermal decomposition, amalgamation and atomic absorption spectrophotometry. Fifty-three samples from five soil use groups (natural, dry land, greenhouse, irrigated and rice farming soils) were analysed. The results show that the levels of mercury in these soils were 9.4–1585 μg kg −1 . Soil organic matter and the zinc equivalent index have been related to Hg content in soils, suggesting that Cu, Ni, Zn and Hg are of a similar origin. The background level (BL), geochemical baseline concentrations (GBC) and the reference value (RV) were…
A multifunctional plant for a sustainable reuse of marble waste toward circular economy
2021
The marble processing cycle involves the production of large quantities of wastes whose disposal represents an economic and environmental concern for marble companies due to the difficulty of identifying suitable landfills and the high transfer costs. In this context, the design of a sustainable industrial plant that allows the reuse of the calcium carbonate (CaCO3) contained in the marble waste is extremely challenging. With this recognition, the main industrial applications of CaCO3 are firstly analyzed in the present work to identify the physical–chemical properties required to CaCO3 in these contexts. Later, different plant solutions are suggested to recover CaCO3 from marble sludge in…
The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substan…
2019
Removal of petroleum products from contaminated soil is a long-term process requiring attention and constant monitoring. The aim of this study was to determine the effect of Fyre-Zyme enzyme preparation and/or calcium carbonate on microbiological changes and conversion of n-aliphatic hydrocarbons in soil contaminated of petroleum-derived substances. The material for testing was soil contaminated with petroleum substances. The total concentration of n-alkanes with a C8–C40 chain length was 420.1 mg·kg−1 DM. The pot tests were carried out by introducing stimulators. As a decomposition promoter for n-alkanes in contaminated soil, a 6% water solution of Fyre-Zyme and/or 1% sterile CaCO3 was use…
Assisted phytostabilization of soil from a former military area with mineral amendments.
2019
Abstract Due to the presence of toxic pollutants, soils in former military areas need remedial actions with environmentally friendly methods. Greenhouse experiments were conducted to investigate the aided phytostabilization of multi-heavy metals (HMs), i.e. Cd, Cr, Cu, Ni, Pb, Zn, in post-military soil by Festuca rubra and three mineral amendments (diatomite, dolomite and halloysite). The amendments were applied at 0 and 3.0% to each pot filled with 5 kg of polluted soil. After seven weeks of the phytostabilization, selected soil properties, biomass yield of F. rubra and immobilization of HMs by their accumulation in plant and redistribution among individual fractions in soil were determine…
Use of The Eggshells in Removing Heavy Metals from Waste Water - The Process Kinetics and Efficiency
2019
Abstract Studies of the efficiency of Ni, Cu and Cd cations removal from water solutions were carried out, with the use of clay limestone, hen eggshells from eggs for consumption and hen eggshells after hatching, which main element is calcium carbonate. Hen eggshells are a waste product, which can be used as a substitute of clay limestone in removing heavy metals from wet flue gas desulphurisation installation. Mixed solutions of Ni, Cu and Cd were used in the research, with the composition similar to the waste water from wet flue gas desulphurisation installation: Ni (0.009-0.053 mmol/dm3), Cu (0.008-0.057 mmol/dm3) and Cd (0.003-0.008 mmol/dm3). The metals were determined by flame atomic …
Substrate templating guides the photoinduced reaction of C60on calcite
2014
cited By 7; International audience; A substrate-guided photochemical reaction of C60 fullerenes on calcite, a bulk insulator, investigated by non-contact atomic force microscopy is presented. The success of the covalent linkage is evident from a shortening of the intermolecular distances, which is clearly expressed by the disappearance of the moiré pattern. Furthermore, UV/Vis spectroscopy and mass spectrometry measurements carried out on thick films demonstrate the ability of our setup for initiating the photoinduced reaction. The irradiation of C60 results in well-oriented covalently linked domains. The orientation of these domains is dictated by the lattice dimensions of the underlying c…