Integrated system for the biological solubilization and precipitation of heavy metals for the remediation of contaminated media

2008 ◽  
Vol 83 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Gema Cabrera ◽  
Jose M Gómez ◽  
Domingo Cantero
Keyword(s):  
Heavy Metals ◽  
Integrated System ◽  
Biological Solubilization

Integrated System to Biological Solubilization and Precipitation of Heavy Metals

2007 ◽  
Vol 20-21 ◽  
pp. 279-282
Author(s):  
G. Cabrera ◽  
José Manuel Gómez ◽  
Domingo Cantero
Keyword(s):  
Heavy Metals ◽  
Acid Medium ◽  
Polyurethane Foam ◽  
Acidic Medium ◽  
Integrated System ◽  
Continuous Processes ◽  
Column Reactor ◽  
Sulphate Reducing Bacteria ◽  
Biological Solubilization ◽  
Reducing Bacteria

The work consists on the study of a sulphur–oxidizing bacteria (At. thiooxidans) immobilisation over polyurethane foam and the integration of two continuous processes: the solubilization of heavy metals by acidic medium generated by sulphur-oxidizing bacteria and the subsequent precipitation of metals as sulphides with H2S biologically generated by sulphate-reducing bacteria (Desulfovibrio sp). At. thiooxidans was satisfactory immobilised over polyurethane foam and added to a column reactor. Acidic medium generated was added to a column with 50 g of an artificial contaminated sand (85 mg Cr(III), 20 mg Ni(II), 200 mg Zn(II)). The effluent of this step was collected in a reservoir tank, in which H2S from sulphate-reducing reactor was included to carry out the precipitation of metals. After 2.4 l of acid medium was passed through the column, it was observed that 14.6% of Cr(III), 26.7% of Ni(II) and 90.5% of Zn(II) were solubilized. The leachate was treated with 2.2 l of reducing medium, and 2.2% Cr(III),54% Ni(II) and 28% Zn(II) were precipitated.

scholarly journals Mathematical Model to Simulate the Transfer of Heavy Metals from Soil to Plant

2021 ◽  
Vol 13 (11) ◽  
pp. 6157
Author(s):  
Petru Cârdei ◽  
Cătălina Tudora ◽  
Valentin Vlăduț ◽  
Mirabela Augustina Pruteanu ◽  
Iuliana Găgeanu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Mathematical Model ◽  
Multiple Stressors ◽  
Experimental Studies ◽  
Chemical Species ◽  
Integrated System ◽  
Control Factors ◽  
Naturally Occurring ◽  
Optimal Harvest ◽  
Latent Effects

Heavy metals are naturally occurring elements, but their various applications have led to their wide circulation in the environment, raising concerns over their latent effects on the environment and human health. Their toxicity depends on numerous factors, including chemical species, concentration of heavy metal ions, environmental factors, etc. Experimental studies on the single or cumulative effects of heavy metals on plants are complex, time consuming and difficult to conduct. An alternative is mathematical modeling, which can include different factors into an integrated system and can predict plant and environmental behavior under multiple stressors. This paper presents a mathematical model that simulates the dependence of temperature, concentration of Zn in the soil and the subsequent bioaccumulation in lettuce (Lactuca sativa L.); respectively, the reaction of lettuce to Zn contamination. The main results consist of three mathematical models, based on systems of ordinary differential equations and checking their predictions with available experimental data. The models are applied to predict an optimal harvest time of lettuce with low concentration of Zn, in identifying the availability of the analyzed species to phytoremediation operations and the possibility of maneuvering certain control factors to reduce or increase the intensity of the bioaccumulation process.

FR-IR Molecular Microanalysis System

1990 ◽  
Vol 48 (2) ◽  
pp. 270-271
Author(s):  
John A. Reffner ◽  
William T. Wihlborg
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Integrated System ◽  
Morphological Examination ◽  
Fully Integrated ◽  
Ir Microscopy ◽  
Normal Functions ◽  
Infrared Microspectroscopy ◽  
Infrared Spectral ◽  
Ft Ir

The IRμs™ is the first fully integrated system for Fourier transform infrared (FT-IR) microscopy. FT-IR microscopy combines light microscopy for morphological examination with infrared spectroscopy for chemical identification of microscopic samples or domains. Because the IRμs system is a new tool for molecular microanalysis, its optical, mechanical and system design are described to illustrate the state of development of molecular microanalysis. Applications of infrared microspectroscopy are reviewed by Messerschmidt and Harthcock.Infrared spectral analysis of microscopic samples is not a new idea, it dates back to 1949, with the first commercial instrument being offered by Perkin-Elmer Co. Inc. in 1953. These early efforts showed promise but failed the test of practically. It was not until the advances in computer science were applied did infrared microspectroscopy emerge as a useful technique. Microscopes designed as accessories for Fourier transform infrared spectrometers have been commercially available since 1983. These accessory microscopes provide the best means for analytical spectroscopists to analyze microscopic samples, while not interfering with the FT-IR spectrometer’s normal functions.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

Nicotianamine: mediator of transport of iron and heavy metals in the phloem?

1993 ◽  
Vol 88 (3) ◽  
pp. 522-529 ◽  
Author(s):  
Udo W. Stephan ◽  
Gunter Scholz
Keyword(s):  
Heavy Metals

Association between heavy metals and depression, anxiety, and panic: A cross-sectional study

2011 ◽  
Author(s):  
Parker Woody ◽  
Michael Zhang ◽  
Craig Pulsipher ◽  
Dawson Hedges ◽  
Bruce Brown
Keyword(s):  
Heavy Metals ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional
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