Zinc adsorption by goethite in the absence and presence of phosphate

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 279 ◽  
Author(s):  
MDA Bolland ◽  
AM Posner ◽  
JP Quirk
Keyword(s):  
Sodium Chloride ◽  
Isoelectric Point ◽  
Ph Value ◽  
The Other ◽  
Surface Complex ◽  
Cationic Form ◽  
Ph Values ◽  
Zinc Adsorption ◽  
Total Adsorption

Zinc adsorption by goethite in the presence of 0.1M sodium chloride was found to occur at pH values well below the isoelectric point of the goethite when the surface was positive and the zinc in a cationic form. This confirms data already presented by Forbes et al. (1976). The presence of phosphate or zinc on the goethite surface was found to increase slightly the adsorption of zinc and phosphate respectively. Depending on the pH value, the total adsorption could be larger than for either ion in the absence of the other and the capacity of the surface for each of the ions. As suggested by Stanton and Burger, a surface complex may be formed.

GROWTH OF STAPHYLOCOCCUS AUREUS IN ACIDIFIED PASTEURIZED MILK1

1970 ◽  
Vol 33 (11) ◽  
pp. 516-520 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth
Keyword(s):  
Staphylococcus Aureus ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Hydrochloric Acid ◽  
Ph Value ◽  
The Other ◽  
Antagonistic Effects ◽  
Pasteurized Milk ◽  
Ph Values ◽  
Effect On Growth

The effect of gradually reducing the pH of pasteurized milk with acetic, citric, hydrochloric, lactic, and phosphoric acids over periods of 4, 8, and 12 hr on growth of Staphylococcus aureus 100 in this substrate was determined. In addition, 1: 1 mixtures of lactic acid and each of the other acids, and of acetic and citric acids were evaluated for their effect on growth of this organism. To achieve a 90% reduction in growth over a 12 hr period, a final pH value of 5.2 was required for acetic, 4.9 for lactic, 4.7 for phosphoric and citric, and 4.6 for hydrochloric acid. A 99% reduction during a 12 hr period was obtained with a final pH value of 5.0 for acetic, 4.6 for lactic, 4.5 for citric, 4.1 for phosphoric, and 4.0 for hydrochloric acid. A pH value of 3.3 was required for a 99.9% reduction with hydrochloric acid, whereas the same effect was produced at a pH value of 4.9 with acetic acid. Correspondingly lower pH values were required to inhibit growth within 8 and 4 hr periods. Mixtures of acids adjusted to pH values at the borderline for growth (12 hr period) exhibited neither synergistic nor antagonistic effects between two acids.

scholarly journals Changes in selected physicochemical parameters of breast muscles of geese from Polish conservation flocks depending on duration of the post slaughter period

2008 ◽  
Vol 51 (3) ◽  
pp. 255-265 ◽  
Author(s):  
A. Okruszek ◽  
J. Książkiewicz ◽  
J. Wołoszyn ◽  
G. Haraf ◽  
A. Orkusz ◽  
...  
Keyword(s):  
Genetic Resources ◽  
Physicochemical Parameters ◽  
Ph Value ◽  
The Other ◽  
Mean Values ◽  
Qualitative Traits ◽  
Ph Values ◽  
Colour Parameters ◽  
The Mean

Abstract. In four Polish conservative flocks of Suwałki (Su), Kartuzy (Ka), Kielce (Ki) and Subcarpathian (Sb) geese, registered by FAO as domestic genetic resources the mean values of qualitative traits of breast muscles (pH15', pH30', pH45', pH24h; colour parameters: L*15', L*30', L*45', L24h, a*15', a*30', a*45', a*24h, b*15', b*30', b*45', b*24h and conductivity: EC45', EC3h, EC24h) were determined. The experimental flocks showed significant variations in the investigated parameters. The Kartuzy goose breast muscles were characterized by higher values of pH15' (6.74), pH30' (6.62), pH45' (6.56) and b*15' parameter (0.80) in comparison with the remaining flocks. Moreover, these muscles had the lowest pH24h (5.65) and values of L* parameter (L*15', L*30', L*45' and L*24h) and EC45' (3.23 mS/cm). The pH value and L* and a* parameters (except L*24h and a*24h) of the analysed flocks were decreasing, and conductivity increasing together with the time post slaughter, and the rate of changes depended on the birds’ origin. Greater differences between pH values, measured 15 min and 24 h after slaughter were stated in breast muscles from Ka (1.09) and Su (0.90) geese than from the other two flocks investigated (Ki – 0.74; Sb – 0.58). The highest increase in conductivity (from EC45' to EC24h) was affirmed in Ka and Ki muscles (3.84 mS/cm) and the lowest in breast muscles of Sb geese (2.72 mS/cm).

scholarly journals Zinc adsorption in highly weathered soils

2008 ◽  
Vol 43 (1) ◽  
pp. 131-139 ◽  
Author(s):  
José Carlos Casagrande ◽  
Marcio Roberto Soares ◽  
Ernesto Rinaldi Mouta
Keyword(s):  
Ionic Strength ◽  
Ph Value ◽  
Batch Adsorption ◽  
Adsorption Mechanisms ◽  
Ionic Strength Effect ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range ◽  
Highly Weathered Soils ◽  
Zinc Adsorption

The objective of this work was to assess the effects of pH and ionic strength upon zinc adsorption, in three highly weathered variable charge soils. Adsorption isotherms were elaborated from batch adsorption experiments, with increasing Zn concentrations (0-80 mg L-1), and adsorption envelopes were constructed through soil samples reactions with 0.01, 0.1 and 1 mol L-1 Ca(NO3)2 solutions containing 5 mg L-1 of Zn, with an increasing pH value from 3 to 8. Driving force of reaction was quantified by Gibbs free energy and separation factor. Isotherms were C-, H- and L-type and experimental results were fitted to nonlinear Langmuir model. Maximum adsorption ranged from 59-810 mg kg-1, and Zn affinity was greater in subsoil (0.13-0.81 L kg-1) than in the topsoil samples (0.01-0.34 L kg-1). Zinc adsorption was favorable and spontaneous, and showed sharply increase (20-90%) in the 4-6 pH range. No effect of ionic strength was observed at pH values below 5, because specific adsorption mechanisms predominated in the 3-5 pH range. Above pH 5, and in subsoil samples, Zn was adsorbed by electrostatic mechanisms, since ionic strength effect was observed. Despite depth and ionic strength effects, Zn adsorption depends mainly on the pH.

Electrophoretic Studies of Proteins Extractable from Post-Rigor Cod at Low Ionic Strength

1955 ◽  
Vol 12 (1) ◽  
pp. 75-84 ◽  
Author(s):  
J. R. Dingle ◽  
D. E. Eagles ◽  
J. M. Neelin
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Isoelectric Point ◽  
Ph Values ◽  
Low Ionic Strength

Extracts of post-rigor cod muscle made at low ionic strength have been examined by electrophoresis in sodium chloride phosphate buffers of ionic strength 0.15 (NaCl = 0.10) and pH between 5.3 and 7.5. The patterns were qualitatively similar to those reported for extracts made from freshly killed cod. At the lower pH values, ten components could be distinguished. The highest isoelectric point found was at pH 5.9, much lower than those reported for similar proteins from rabbit.

The Ag+ Reduction Process in a Plasma Electrochemical System Tuned by the pH Value

2021 ◽  
Author(s):  
H Wu ◽  
Z Liu ◽  
L Xu ◽  
X Wang ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Electrochemical Cell ◽  
Ph Value ◽  
Reduction Process ◽  
Solution Chemistry ◽  
The Other ◽  
Electrochemical System ◽  
Solvated Electrons ◽  
Ph Values ◽  
Discharge Plasmas ◽  
Nanomaterials Synthesis

Abstract The interactions between discharge plasmas and an aqueous solutions can enable the production of reactive species and charge transfer at the plasma-liquid interface, forming the plasma electrochemical system (PES). The PES are promising for diverse applications, such as nanomaterials synthesis, due to the activation of the solution chemistry by the plasma. In this paper, we investigate the influence of the solution’s pH value on the formation of silver nanoparticles (AgNPs) in a direct current (DC) PES. Dual argon DC plasmas are generated in an H-type electrochemical cell containing an aqueous solution of silver nitrate with pH values in the range of 1.99-10.71. By this design, the solution acts as a cathode at one end of the H-type cell, and as an anode at the other end. The results show that the AgNPs are formed at the anode except for the solution with the pH value of 1.99. However, at the cathode, the AgNPs only appear in the solution with the pH value of 10.71. We find that the solvated electrons and hydrogen peroxide produced by the plasma-liquid interactions are responsible for the Ag+ reduction at the solution anode and the solution cathode, respectively.

scholarly journals EXIT OF DYE FROM LIVING CELLS OF NITELLA AT DIFFERENT pH VALUES

1926 ◽  
Vol 10 (1) ◽  
pp. 75-102 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Ph Value ◽  
External Solution ◽  
Living Cells ◽  
The Other ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Ph Values ◽  
Pass Through ◽  
External Ph

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene. The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases. The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH3.

Separation of metals and phosphorus from incinerated sewage sludge ash

2013 ◽  
Vol 67 (11) ◽  
pp. 2488-2493 ◽  
Author(s):  
A. Ito ◽  
K. Yamada ◽  
N. Ishikawa ◽  
T. Umita
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Ethylenediaminetetraacetic Acid ◽  
Ph Value ◽  
Batch Reactor ◽  
The Other ◽  
Ferric Ion ◽  
Sewage Sludge Ash ◽  
Ph Values ◽  
Sludge Ash

Microbial acidification of incinerated sewage sludge ash and dissolution of metals from the acidified ash were investigated using a semi-batch reactor at different solid retention times (SRTs). The average pH values ranged from 0.91 to 1.2 at SRTs longer than 10 days, whereas the reduction of SRT to 4 days resulted in an increase in the pH value to about 2. The dissolution efficiencies of Al, As, Cd, Cu and Mn were greater than 60% at a SRT of 4 days. Moreover, the effect of pH on precipitation of metals and P (dissolution of 80%) in the filtrate removed from the acidified sewage ash suspension, and the separation of phosphorus and the other metals in the filtrate using ethylenediaminetetraacetic acid (EDTA) or ferric ion, were examined. Although neutralisation of the filtrate to a pH of 5 simultaneously precipitated 100% of Al and 80% of P recovered from the acidified sewage ash, the addition of EDTA decreased their precipitation to 70 and 50%, respectively, at the same pH value, which would promote precipitation of P as calcium phosphate. Furthermore, neutralising to a pH of 2.5 after the addition of ferric ion precipitated P separately from Al and heavy metals.

Controlled and uncontrolled physicochemical quality indicators of 0.9 % sodium chloride of various manufacturers

2020 ◽  
pp. 6-11
Author(s):  
Anton Kasatkin ◽  
Anna Nigmatullina ◽  
Mikhail Kopytov
Keyword(s):  
Sodium Chloride ◽  
Quality Indicators ◽  
Clinical Studies ◽  
Laboratory Tests ◽  
Ph Value ◽  
Chemical Parameters ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Physicochemical Quality ◽  
Physico Chemical

The article presents the results of studies of osmolality and pH of 0,9 % sodium chloride of various manufacturers. To obtain data on the pH value, the data used in the passports are used, and the indicators of its osmolality are de- termined using laboratory tests. 0,9 % sodium chloride from different manufacturers has different pH and osmolality. Knowing the actual values of physico-chemical parameters can increase the accuracy of the results of future clinical studies, which compare the pharmacokinetics and pharmacodynamics of modern plasma-substituting solutions and a solution of 0,9 % sodium chloride.

scholarly journals Bonding of Selected Hardwoods with PVAc Adhesive

2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová
Keyword(s):  
Adhesion Strength ◽  
Cold Water ◽  
Ph Value ◽  
Water Extract ◽  
Solid Wood ◽  
Contact Angles ◽  
Water Contact ◽  
Ph Values ◽  
Positive Tendency ◽  
The Impact

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.

scholarly journals Microstructure and Properties of Self-Assembly Graphene Microcapsules: Effect of the pH Value

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 587 ◽  
Author(s):  
Yan-Dong Guo ◽  
Jun-Feng Su ◽  
Ru Mu ◽  
Xin-Yu Wang ◽  
Xiao-Long Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Chemical Engineering ◽  
Ph Value ◽  
Liquid Paraffin ◽  
Energy Dispersive Spectrometer ◽  
Core Material ◽  
Microstructure And Properties ◽  
Ph Values

Graphene has attracted attention in the material field of functional microcapsules because of its excellent characteristics. The content and state of graphene in shells are critical for the properties of microcapsules, which are greatly affected by the charge adsorption equilibrium. The aim of this work was to investigate the effect of pH value on the microstructure and properties of self-assembly graphene microcapsules in regard to chemical engineering. Microcapsule samples were prepared containing liquid paraffin by a self-assembly polymerization method with graphene/organic hybrid shells. The morphology, average size and shell thickness parameters were investigated for five microcapsule samples fabricated under pH values of 3, 4, 5, 6 and 7. The existence and state of graphene in dry microcapsule samples were analyzed by using methods of scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Fourier Transform Infrared Spectoscopy (FT-IR) and Energy Dispersive Spectrometer (EDS) were applied to analyze the graphene content in shells. These results proved that graphene had existed in shells and the pH values greatly influenced the graphene deposition on shells. It was found that the microcapsule sample fabricated under pH = 5 experienced the largest graphene deposited on shells with the help of macromolecules entanglement and electrostatic adherence. This microcapsules sample had enhanced thermal stability and larger thermal conductivity because of additional graphene in shells. Nanoindentation tests showed this sample had the capability of deforming resistance under pressure coming from the composite structure of graphene/polymer structure. Moreover, more graphene decreased the penetrability of core material out of microcapsule shells.

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