Removal of Toxic Arsenic and Antimony from Groundwater Spiro Tunnel Bulkhead in Park City Utah Using Colloidal Iron Hydroxide: Comparison with Reverse Osmosis

2009 ◽  
Vol 83-86 ◽  
pp. 553-562 ◽  
Author(s):  
Z. Pawlak ◽  
P.S. Cartwright ◽  
Adekunle Oloyede ◽  
E. Bayraktar
Keyword(s):  
Reverse Osmosis ◽  
Removal Rate ◽  
Iron Hydroxide ◽  
Pilot Scale ◽  
Arsenic Acid ◽  
Colloidal Iron ◽  
Low Concentrations ◽  
Silver Mine ◽  
Ph Range ◽  
Filtration Technology

Verification testing of two model technologies in pilot scale to remove arsenic and antimony based on reverse osmosis and chemical coagulation/filtration systems was conducted in Spiro Tunnel Water Filtration Plant located in Park City, Utah, US. The source water was groundwater in abandoned silver mine, naturally contaminated by 60-80 ppb of arsenic and antimony below 10 ppb. This water represents one of the sources of drinking water for Park City and constitutes about 44% of the water supply. The failure to remove antimony efficiently by coagulation/filtration (only 4.4% removal rate) under design conditions is discussed in terms of the chemistry differences between Sb (III, V) and As (III, V). Removal of Sb(V) at pH > 7, using coagulation/filtration technology, requires much higher (50 to 80 times) concentration of iron (III) than As. The stronger adsorption of arsenate over a wider pH range can be explained by the fact that arsenic acid is tri-protic, whereas antimonic acid is monoprotic. This difference in properties of As(V) and Sb(V) makes antimony (V) more difficult to be efficiently removed in low concentrations of iron hydroxide and alkaline pH waters, especially in concentration of Sb < 10 ppb.

The Fine Structure of Glycocalyx in Human Spermatozoa. A High Resolution Cytochemical Study

1973 ◽  
Vol 31 ◽  
pp. 640-641
Author(s):  
P. Hernández-Jáuregui ◽  
A. Sosa ◽  
A. González Angulo
Keyword(s):  
Negative Charge ◽  
Iron Hydroxide ◽  
Human Spermatozoa ◽  
Surface Coat ◽  
Cell Surfaces ◽  
Colloidal Iron ◽  
Cytochemical Study ◽  
Specific Permeability ◽  
Extracellular Glycoprotein ◽  
Mammalian Spermatozoa

Glycocalyx is the name given by Bennett to the extracellular glycoprotein coat present in some cell surfaces. It appears to play an important role in cell properties such as antigenicity, cell adhesivity, specific permeability, and ATP ase activity. In the sperm this coat can be directly related to such important phenomena as capacitation and fertilization. The presence of glycocalyx in invertebrate spermatozoa has already been demonstrated. Recently Yanagimachi et al. has determined the negative charges on sperm surfaces of mammalian spermatozoa including man, using colloidal iron hydroxide. No mention was made however of the outer surface coat as composed of substances other than those confering a negative charge. The purpose of this work was therefore to determine the presence of a glycocalyx in human spermatozoa using alcian blue and lanthanum staining.

Biodegradation rates of aromatic contaminants in biofilm reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Jean-Pierre Arcangeli ◽  
Erik Arvin
Keyword(s):  
Aromatic Hydrocarbons ◽  
Competitive Inhibition ◽  
Removal Rate ◽  
First Order ◽  
Biofilm Reactors ◽  
First Order Kinetics ◽  
Reducing Conditions ◽  
Low Concentrations ◽  
Degradation Rates ◽  
Order Surface

This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols, chlorophenols, nitrophenol, chlorobenzenes and aromatic nitrogen-, sulphur- or oxygen-containing heterocyclic compounds (NSO-compounds). Furthermore, a comparison with degradation rates observed for easily degradable organics is also presented. At concentrations below 20-100 μg/l the degradation of the aromatic compounds was typically controlled by first order kinetics. The first-order surface removal rate constants were surprisingly similar, ranging from 2 to 4 m/d. It appears that NSO-compounds inhibit the degradation of aromatic hydrocarbons, even at very low concentrations of NSO-compounds. Under nitrate-reducing conditions, toluene was easily biodegraded. The xylenes and ethylbenzene were degraded cometabolically if toluene was used as a primary carbon source; their removal was influenced by competitive inhibition with toluene. These interaction phenomena are discussed in this paper and a kinetic model taking into account cometabolism and competitive inhibition is proposed.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

Studies On Plasma Membranes

1967 ◽  
Vol 2 (4) ◽  
pp. 499-512
Author(s):  
E. L. BENEDETTI ◽  
P. EMMELOT
Keyword(s):  
Sialic Acid ◽  
Tight Junctions ◽  
Plasma Membranes ◽  
Iron Hydroxide ◽  
Chelating Agent ◽  
Colloidal Iron ◽  
Outer Leaflet ◽  
Liver Membranes ◽  
Junctional Complexes ◽  
Pre Treatment

Plasma membranes were isolated from rat liver and a transplanted rat hepatoma of the hepatocellular type. After glutaraldehyde fixation the membranes were treated with colloidal iron hydroxide (CIH) at pH 1.7, which was found to react specifically with the neuraminidase-sensitive sialic acid of the liver membranes. The CIH-reactive, neuraminidase-sensitive sialic acid, comprising 70% of the membrane-bound sialic acid, was exclusively located in the outer leaflet of the liver membranes as shown by the rather regular distribution of electron-dense CIH granules. This granular, asymmetric type of staining was also observed in the hepatoma membranes, which contained some 50% more sialic acid than did the liver membranes. In addition, the hepatoma membranes showed an intense and uniform staining by CIH of short segments of both membrane leaflets; the latter type of staining was but little impaired by neuraminidase pre-treatment. None of the junctional complexes of the liver membranes was stained by CIH. Tight junctions were very rarely observed in the hepatoma membrane preparations, and the desmosomes and intermediate junctions of these membranes not infrequently exhibited a loosened appearance exposing CIH-reactive neuraminidase-sensitive sialic acid at their opposite plates. This aspect could be induced in the desmosomes and intermediate junctions, but not in the tight junctions, by pre-treatment of the liver membranes with the chelating agent ethylenediaminetetra-acetate.

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

scholarly journals GLYPHOSATE AND TURBIDITY REMOVAL IN WATER CONDITIONS BY CLARIFICATION WITH TANFLOC

2018 ◽  
Vol 15 (30) ◽  
pp. 489-497
Author(s):  
J. T. B. SILVA ◽  
K. C. ROCHA ◽  
R. M. F. CUBA
Keyword(s):  
Turbidity Removal ◽  
Natural Coagulant ◽  
Agriculture Sector ◽  
Jar Test ◽  
Low Concentrations ◽  
Water Conditions ◽  
Ph Conditions ◽  
Percentage Removal ◽  
Ph Range ◽  
Herbicide Glyphosate

With the progress in the agriculture sector, improper domains of pesticides, herbicides, and insecticides have grown, which have been negatively affected the environment until the present day. Therefore, the present work has as objective to evaluate the efficiency of the natural coagulant Tanfloc in the clarification stage with respect the herbicide glyphosate removal and the turbidity parameter by using jar test with different pH conditions and coagulant concentration. As a result, was obtained that for the pH range of 5-5.5 the natural coagulant has shown more efficient, with a glyphosate percentage removal of approximately 98.0% using low concentrations and turbidity removal of 21.69%. On the other hand, for the pH range of 6.8 to 7.3, the coagulant has not shown profitable results, considering that, for some concentrations, it was not possible to detect the herbicide removal. In the concentrations that were detected removal, the average glyphosate percentage removal was approximately 89% and an average of 20.24% of turbidity removal. In summary, although the natural coagulant has not shown remarkably efficient in the neutral pH range, the product may be considered an alternative device in water treatment with the respect of the use of metallic coagulants, which produce sludge with chemistry characteristics that may negatively affect the environment.

scholarly journals Negative charge distribution and density on the surface of oxygenated normal and sickle red cells

Blood ◽  
1981 ◽  
Vol 57 (4) ◽  
pp. 675-678
Author(s):  
LJ Clark ◽  
LS Chan ◽  
DR Powars ◽  
RF Baker
Keyword(s):  
Charge Distribution ◽  
Electron Micrographs ◽  
Negative Charge ◽  
External Surface ◽  
Iron Hydroxide ◽  
Red Cells ◽  
Glutaraldehyde Fixation ◽  
Colloidal Iron ◽  
Membrane Area ◽  
Significant Difference

Negative charges on the external surface of red cells were visualized by colloidal iron hydroxide labelling of 50% of the membrane area after osmotic hemolysis and glutaraldehyde fixation. Counts were made over randomly selected areas on electron micrographs at 350,000 x magnification. Statistical analyses showed that at the 95% level of confidence there was no significant difference between oxygenated normal (AA) and sickle (SS) cells in either the distribution or the density of negative charges.

scholarly journals New analytical methodology for studies of treatment procedures of landfill leachates - experiences from a pilot plant study

2019 ◽  
pp. 273-275
Author(s):  
Lennart Mårtensson ◽  
Staffan Bergström ◽  
Britt-Marie Svensson ◽  
Lennart Mathiasson
Keyword(s):  
Organic Compounds ◽  
Pilot Scale ◽  
Chemical Oxidation ◽  
Landfill Leachates ◽  
Analytical Methodology ◽  
Msw Landfill ◽  
Analytical Protocol ◽  
Low Concentrations ◽  
Before And After ◽  
Treatment Procedures

In this study we have in pilot scale tested different methods for treatment of leachate from amunicipal solid waste (MSW) landfill, Only to focus on sum parameters, nutrients and metalswhen designing treatment methodology for landfill leachate is not enough, it is also importantto measure the content of toxic organic compounds in low concentrations, However, it is notpractical to analyse all substances in the leachate and for making evaluation of treatmentsfeasible our own analytical protocol was created, The efficiency of tested treatmentprocedures was evaluated by measuring changes in concentrations of a number of chosenparameters and organic compounds before and after treatment The treatment methods testedthat showed the highest efficiency towards organic pollutants in leachate were ozonetreatment and chemical oxidation with Fenton's reagent However, more natural basedmethods like filtering the leachate through a bed with peat mixed with carbon containingbottom-ash showed promising results.

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