Leaching of Fluoride from Biotite Mica in Soil: Implications for Fluoride in Shallow Groundwater

Leaching of from biotite was investigated at room temperature by performing a series of short-term leach tests. The leaching of from biotite structure strongly depends on its weathering stage. Results of this study suggest that high concentration of is leached from highly weathered biotite, compared to fresh biotite. Results of dissolution experiments confirm that the organic acids in soil promote the leaching of from biotite compared to inorganic acids. Citric acid which is a week organic acid enhances leaching of from biotite structure compared to strong inorganic acid HNO3, independent of the weathering stage of biotite. Strong positive correlation between K+ and Fe2+ with in biotite treated with citric acid suggests that readily leachs into the solution through an ionic exchange and complex formation. Organic acids involve sorption and complex formation processes leading to release of into the solution. Our studies suggest that in the presence of organic acids is leached readily into water percolating through the soil. Therefore, shallow groundwater replenished by the water table may achieve high concentrations by this leaching process.

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The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

Antibiotics and Chemotherapy ◽

10.37489/0235-2990-2020-65-9-10-3-7 ◽

2020 ◽

Vol 65 (9-10) ◽

pp. 3-7

Author(s):

V. V. Gostev ◽

Yu. V. Sopova ◽

O. S. Kalinogorskaya ◽

M. E. Velizhanina ◽

I. V. Lazareva ◽

...

Keyword(s):

Staphylococcus Aureus ◽

In Vitro Selection ◽

Methicillin Resistant Staphylococcus Aureus ◽

High Concentration ◽

Short Term ◽

High Concentrations ◽

Selection Of ◽

Selection Of Resistance ◽

Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

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Organic acids effects on desorption of heavy metals from a contaminated soil

Scientia Agricola ◽

10.1590/s0103-90162006000300010 ◽

2006 ◽

Vol 63 (3) ◽

pp. 276-280 ◽

Cited By ~ 36

Author(s):

Clístenes Williams Araújo do Nascimento

Keyword(s):

Heavy Metals ◽

Molecular Weight ◽

Citric Acid ◽

Organic Acids ◽

Low Molecular Weight ◽

High Biomass ◽

High Concentration ◽

Accumulation Of Metals ◽

Pb Concentration ◽

Oxalic Acids

Phytoremediation of heavy metals is a biotechnology that extracts metals from soils and transfer them to plant. As hyperaccumulator species have demonstrated low potential for commercial phytoextraction, synthetic chelates have been successfully used to induce accumulation of metals by high-biomass plants. However, they pose serious environmental drawbacks regarding excessive amount of metals solubilized. In search for synthetic chelate-alternatives, this paper evaluate the performance of DTPA, EDTA, citric acid, oxalic acid, vanillic acid, and gallic acid in desorbing Cd, Pb, Zn, Cu, and Ni from soil. DTPA and EDTA were highly effective in desorbing Cd, Pb, Zn, Cu, and Ni from soil. However, the excessively high concentration of metals brought in solution by such chelates limits their application in the field. Citric and oxalic acids desorbed substantial quantities of Zn, Cu, and Ni if applied at 10 or 20 mmol kg-1. At the 20 mmol kg-1 dose, vanillic and gallic acids solubilized significant amounts of Zn, Ni, and Cd from soil. None of the tested low molecular weight organic acids substantially increased the Pb concentration in soil solution.

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Mechanisms of potassium release from calcareous soils to different salt, organic acid and inorganic acid solutions

Soil Research ◽

10.1071/sr18301 ◽

2019 ◽

Vol 57 (3) ◽

pp. 301 ◽

Cited By ~ 6

Author(s):

M. Najafi-Ghiri ◽

M. Niazi ◽

M. Khodabakhshi ◽

H. R. Boostani ◽

H. R. Owliaie

Keyword(s):

Citric Acid ◽

Organic Acids ◽

Calcareous Soils ◽

Acid Solutions ◽

Short Term ◽

Term Experiment ◽

Short And Long Term ◽

Fixation Capacity ◽

Short Term Experiment

Mechanisms of potassium (K) release and fixation in calcareous soils may differ from non-calcareous soils. In the current investigation, four soils with different properties were extracted three and 10 times (45 and 150min, defined as short- and long-term respectively) with 0.025molL−1 CaCl2, HCl and oxalic and citric acid solutions and the contents of calcium (Ca), magnesium (Mg), aluminium (Al) and K in the extracts were determined. Immediately after K extraction, 500mg kg–1 of K (as KCl) was added to the remaining soils and shaken for 24h and K-fixation capacity was determined. No significant difference was observed between CaCl2 and HCl solutions in K extraction from soils in the short- and long-term experiments; the concentrations of Ca, Mg and Al in the extractants showed that HCl was not able to dissolve soil minerals and the soils released K via exchange reaction of Ca (originated from CaCO3 dissolution by HCl) with interlayer K. The organic acids had similar behaviour to each other in the short-term experiment; however, partial dissolution of minerals by citric acid was observed. Oxalic acid extracted less K than other solutions in the short-term experiment due to precipitation of soluble Ca as oxalate salt and thereby less exchange of soluble Ca with non-exchangeable K. Oxalic and citric acids dissolved K-bearing minerals and released K in the long-term experiment, but oxalic acid was more effective. The K-fixation capacity of soils was lower when treated with organic acids than with CaCl2 and HCl, possibly due to the dissolution of K-fixing minerals like smectite and illite by oxalate and citrate. Long-term treatment of soils with different solutions decreased K-fixation capacity of soils due to dissolution of K-fixing minerals or flocculation of minerals by Ca and slower K diffusion to the interlayer. With respect to the highly calcareous nature of the studied soils, the soluble cations in calcareous soils (predominantly Ca and Mg) may have been exchanged with non-exchangeable K of clay minerals and buffered soluble K as well as organic acids produced by plant roots and microorganisms.

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VITAMIN B12Co60 DISTRIBUTION IN DOG TISSUES DURING MANY MONTHS

Journal of Experimental Medicine ◽

10.1084/jem.108.1.1 ◽

1958 ◽

Vol 108 (1) ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

W. D. Woods ◽

W. B. Hawkins ◽

G. H. Whipple

Keyword(s):

Gastric Mucosa ◽

Intrinsic Factor ◽

Radioactive Material ◽

Red Cell ◽

High Concentration ◽

Short Term ◽

Prolonged Retention ◽

High Concentrations ◽

And Storage

Experiments dealing with the distribution of B12Co60 in the dog indicate that with time (9 months after administration) there is a shift in the distribution of the vitamin as compared to the short term experiments, as well as prolonged retention of the vitamin within various dog tissues. The heart, gastric mucosa, liver, spleen, and brain show high concentrations of the isotope in long term experiments. This distribution, in the heart for example, does not fit with an hypothetical breakdown of B12Co60 complex and storage of a physiologically inactive fraction. Repeated periods of anemia produced by phenylhydrazine make it possible to demonstrate radioactive material in red cell stroma of dogs that have previously received vitamin B12Co60. This radioactive material must have come from other body stores, such as liver and stomach. The high concentration of B12Co60 in the gastric mucosa suggests a relationship between it and the intrinsic factor as described by Castle.

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The Toxicity of Castor Beans and its Treatment with Doxycycline in Local Rabbits

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.v9i2.13649 ◽

2018 ◽

Vol 9 (2) ◽

Cited By ~ 1

Author(s):

Nael Mohammed Sarheed ◽

Osamah Faisal Kokas ◽

Doaa Abd Alabas Muhammed Ridh

Keyword(s):

Castor Bean ◽

The Body ◽

Control Group ◽

High Concentration ◽

Biochemical Tests ◽

Doxycycline Treatment ◽

High Concentrations ◽

Physiological Tests ◽

Animal House ◽

Physiological And Biochemical

The plant of castor is widely spread in the Iraqi land, and characterized with containing ricin toxin, which has a very serious effects, and because the seeds of this plant scattered in the agricultural soil and rivers water, which increases the exposure of humans and animals to these beans. Objective: This experiment was designed to study the effect of high concentration of castor bean powder in some physiological and biochemical parameters and changes in some tissues of the body, as well as trying to use doxycycline to reduce the effects of ingestion of these seeds. Materials and Methods: In the experiment, 24 local rabbits were raised and fed in the Animal House of the Faculty of Medicine / Al-Muthanna University, then divided into four groups and treated for three weeks (21 days), Control group: treated with normal saline solution (0.9) orally throughout the experiment, G1: was treated orally with a concentration of 25 mg / kg of castor bean powder daily during the experiment, G2 : orally treated 25 mg / kg of castor bean and 25 mg / kg of doxycycline, G3: orally treated 25 mg / kg of castor powder with 50 mg / kg of doxycycline daily throughout the trial period. Results: The results of the experiment showed significant changes (P less than 0.05) in all physiological and biochemical blood tests when compared with control group. There was a significant decrease in PCV, Hb, RBC, T.protein and body weights, while demonstrated a significant increase in WBC, Urea, Creatinine, ALT, AST and ALP, with distortions in liver and kidney of animals that treated with Castor beans. In contrast, the treatment with doxycycline and caster beans showed significant improvement reflected by a normal proportion in physiological tests and biochemical tests with improvement in the tissues when compared to control group. Conclusions: It can be concluded from this study that castor bean has high toxic and pathogenic effects that may be dangerous to the life of the organism. Therefore, it is advisable to be cautious of these pills and avoid exposure to them, also recommended to take high concentrations of doxycycline treatment when infected with castor bean poisoning.

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Growth responses of periphyton and chironomids exposed to biologically treated bleached kraft pulp mill effluent

Water Science & Technology ◽

10.2166/wst.1997.0553 ◽

1997 ◽

Vol 35 (2-3) ◽

pp. 339-345 ◽

Cited By ~ 1

Author(s):

M. G. Dubé ◽

J. M. Culp

Keyword(s):

Kraft Pulp ◽

Pulp Mill ◽

Pulp Mill Effluent ◽

Growth Responses ◽

High Concentration ◽

Wood Extractives ◽

Kraft Pulp Mill ◽

Bleached Kraft Pulp ◽

Low Levels ◽

High Concentrations

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.

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Characterization of Phosphate Coatings: Influence of the Acid Pickling Conditions

Materials ◽

10.3390/ma14041048 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1048

Author(s):

Belén Díaz ◽

X. Ramón Nóvoa ◽

Carmen Pérez ◽

Sheila Silva-Fernández

Keyword(s):

Citric Acid ◽

High Strength ◽

Acid Pickling ◽

Acid Cleaning ◽

Inorganic Acids ◽

Phosphate Coatings ◽

Acid Bath ◽

Coating Morphology ◽

Coating Weight

This research emphasizes the importance of the acid cleaning prior to the phosphate development on high-strength steel rods. It compares the phosphate properties achieved after different acid-pickling conditions. The most common inorganic acids were considered in this study. Additionally, taking into account the environmental and safety concerns of these acids, the assessment of a less harmful organic acid is presented. This study revealed significant differences in the coating morphology and chemical composition whereas no great changes were found in terms of the coating weight or porosity. Thus, hydrochloric and sulfuric acid promote the growth of a Fe-enriched phosphate layer with a less conductive character that is not developed after the pickling with phosphoric acid. The phosphate developed after the citric acid pickling is comparable to that developed after the inorganic acids although with a porosity slightly higher. The temperature of the citric acid bath is an important parameter that affects to the phosphate appearance, composition, and porosity.

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Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽

10.3390/atmos12010062 ◽

2021 ◽

Vol 12 (1) ◽

pp. 62

Author(s):

Robert Cichowicz ◽

Maciej Dobrzański

Keyword(s):

Spatial Distribution ◽

Hydrogen Sulfide ◽

Particulate Matter ◽

Air Quality ◽

Spatial Analysis ◽

Ground Level ◽

Leeward Side ◽

High Concentration ◽

Above Ground Level ◽

High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

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Enhanced Electrokinetic Remediation for the Removal of Heavy Metals from Contaminated Soils

Applied Sciences ◽

10.3390/app11041799 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1799

Author(s):

Claudio Cameselle ◽

Susana Gouveia ◽

Adrian Cabo

Keyword(s):

Heavy Metals ◽

Citric Acid ◽

Organic Acids ◽

Contaminated Soils ◽

Electrokinetic Remediation ◽

Deionized Water ◽

Soil Specimen ◽

Removal Of Heavy Metals ◽

Ph Conditions ◽

Neutral Metal

The electrokinetic remediation of an agricultural soil contaminated with heavy metals was studied using organic acids as facilitating agents. The unenhanced electrokinetic treatment using deionized water as processing fluid did not show any significant mobilization and removal of heavy metals due to the low solubilization of metals and precipitation at high pH conditions close to the cathode. EDTA and citric acid 0.1 M were used as facilitating agents to favor the dissolution and transportation of metals. The organic acids were added to the catholyte and penetrated into the soil specimen by electromigration. EDTA formed negatively charged complexes. Citric acid formed neutral metal complexes in the soil pH conditions (pH = 2–4). Citric acid was much more effective in the dissolution and transportation out of the soil specimen of complexed metals. In order to enhance the removal of metals, the concentration of citric acid was increased up to 0.5 M, resulting in the removal of 78.7% of Cd, 78.6% of Co, 72.5% of Cu, 73.3% of Zn, 11.8% of Cr and 9.8% of Pb.

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Photocrosslinking and photopatterning of magneto-optical nanocomposite sol–gel thin film under deep-UV irradiation

Scientific Reports ◽

10.1038/s41598-021-84376-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. Bidaud ◽

D. Berling ◽

D. Jamon ◽

E. Gamet ◽

S. Neveu ◽

...

Keyword(s):

Uv Irradiation ◽

Cobalt Ferrite ◽

Sol Gel ◽

Optical Devices ◽

High Concentration ◽

Nanocomposite Thin Films ◽

Deep Uv ◽

High Concentrations ◽

193 Nm ◽

The Impact

AbstractThis paper is aimed at investigating the process of photocrosslinking under Deep-UV irradiation of nanocomposite thin films doped with cobalt ferrite magnetic nanoparticles (MNPs). This material is composed of a hybrid sol–gel matrix in which MNP can be introduced with high concentrations up to 20 vol%. Deep-UV (193 nm) is not only interesting for high-resolution patterning but we also show an efficient photopolymerization pathway even in the presence of high concentration of MNPs. In this study, we demonstrate that the photocrosslinking is based on the free radical polymerization of the methacrylate functions of the hybrid precursor. This process is initiated by Titanium-oxo clusters. The impact of the nanoparticles on the photopolymerization kinetic and photopatterning is investigated. We finally show that the photosensitive nanocomposite is suitable to obtain micropatterns with sub-micron resolution, with a simple and versatile process, which opens many opportunities for fabrication of miniaturized magneto-optical devices for photonic applications.

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