Adsorption and desorption of boron by goethite

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 377 ◽  
Author(s):  
PM Bloesch ◽  
LC Bell ◽  
JD Hughes
Keyword(s):  
Elevated Temperature ◽  
Boron Concentration ◽  
Soil Testing ◽  
Adsorption And Desorption ◽  
Ph Values ◽  
Competing Anions ◽  
Effects Of Ph ◽  
Ph Range ◽  
Best Fit ◽  
Boron Adsorption

The effects of varying pH, concentration of boron, and competing anions on the adsorption of boron were examined. Boron adsorption initially increased with pH, peaked at approximately pH 8, and then declined. The presence of phosphate reduced adsorption over the pH range 5.2-10.6; the effect of sulfate was less than that of phosphate and ceased at about pH 7. The presence of mannitol caused virtually no difference in boron adsorption up to about pH 6, but reduced adsorption at higher values. The model by Bowden and coworkers was successful in describing both the charge characteristics of goethite in the absence of boron adsorption and the effects of pH and boron concentration on adsorption of the element. The best fit of the model was achieved when B(OH)4-, B3O3(OH)4-, B4O5(OH):- and B5O6(OH)4- were considered as the adsorbing species, although B(OH)4- and B4O5(OH)24- were predicted to be the major adsorbing ions. Boron adsorption was found to be reversible with respect to both concentration and pH. Elevated temperature increased the amount of desorption at both pH 6 and 8. The effect of mannitol on boron desorption mirrored the effect of the compound on adsorption of the element; there was no effect up to pH 6, but at higher pH values desorption was increased. The significance of the desorption data for soil testing for boron is discussed.

scholarly journals Effects of pH and Aeration on Sclerotium rolfsii sacc. Mycelial Growth, Sclerotial Production and Germination

2018 ◽  
Vol 7 (3) ◽  
pp. 123-129 ◽  
Author(s):  
Fakher Ayed ◽  
Hayfa Jabnoun-Khiareddine ◽  
Rania Aydi-Ben-Abdallah ◽  
Mejda Daami-Remadi
Keyword(s):  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range ◽  
Sclerotial Development ◽  
Sclerotial Germination

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.

EFFECTS OF pH AND NITROGEN SOURCES ON GROWTH OF MICROCYSTIS AERUGINOSA KÜTZ.

1962 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Jack McLachlan ◽  
P. R. Gorham
Keyword(s):  
Growth Inhibition ◽  
Microcystis Aeruginosa ◽  
Nitrate Nitrogen ◽  
Nitrogen Sources ◽  
Cesium Chloride ◽  
Potassium Nitrate ◽  
Degree Of Ionization ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range

Microcystis aeruginosa Kütz. (strain NRC-1) grew equally well throughout the pH range 6.5 to 10 when provided with suitable media. Toxicity of tris(hydroxymethyl)aminomethane (TRIS) towards the alga was found to decrease as the pH decreased and could be correlated with the degree of ionization of the TRIS molecule. Other organic buffers examined were either toxic at all concentrations and pH values tested or promoted lysis. When TRIS was used as a buffer, higher concentrations of cesium chloride and potassium nitrate were tolerated without growth inhibition at pH 6.5 than at 7.5. In the presence of TRIS, Microcystis grew equally well with nitrate, ammonium, or urea as nitrogen sources. Eight out of 20 amino compounds examined served as nitrogen sources in TRIS-buffered medium, but growth was poorer than with nitrate nitrogen.

scholarly journals Adsorption Properties of Sepiolite in Relation to Uranium and Lanthanide Ions

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 686 ◽  
Author(s):  
Gładysz-Płaska
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Properties ◽  
Lanthanide Ions ◽  
Ambient Conditions ◽  
Initial Concentration ◽  
Ph Values ◽  
Batch Technique ◽  
Effects Of Ph ◽  
Ph Range

The batch technique was used to study the adsorption of La(III), Eu(III), Lu(III), and U(VI) ions on sepiolite and ODTMA–sepiolite under ambient conditions. The effects of pH, time, and initial concentration were investigated. The highest U(VI) adsorption was found on ODTMA-sepiolite in the pH range of 6–8, while in the case of lanthanide ions, adsorption on sepiolite was 80% in the pH range of 4–8 and 98% for pH values above 8. The adsorption capacity of ODTMAsepiolite was found to be 285.6 mg/g for uranium, and raw sepiolite: 142.8 mg/g for U(VI), 91.6 mg/g for La(III), 91.4 mg/g for Eu (III), and 104.9 mol/g for Lu(III). ODTMA–sepiolite turned out to be a weak sorbent for lanthanide ions. Two short- and long-lived fluorescence species were observed in the TRLFS spectra of U(VI) adsorbed on sepiolite at pH 6.5. The average lifetimes of short- (τ1) and long-lived (τ2) fluorescence are τ1 = 2420 ± 430 ns and τ2 = 37950 ± 5710 ns for U-sepiolite; τ1 = 3523 ± 160 ns and τ2 = 45400 ± 1830 ns for U-ODTMA–sepiolite.

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.

Effect of Buffer and pH on the Protein Extraction for Chicken Meat

2013 ◽  
Vol 795 ◽  
pp. 206-210
Author(s):  
M.K. Nahar ◽  
Z. Zakaria ◽  
U. Hashim
Keyword(s):  
Protein Extraction ◽  
Chicken Meat ◽  
Anova Analysis ◽  
Citrate Buffer ◽  
Ph Values ◽  
Glycine Buffer ◽  
Significant Difference ◽  
Effects Of Ph ◽  
Ph Range ◽  
Protein Extractability

The study was undertaken to determine the extraction of proteins from chicken meat. The effect of buffer (phosphate, citrate and glycine) and four pH values (6.0, 7.0, 8.0 and 9.0) were investigated. The protein extractability of phosphate, citrate and glycine buffer with in the pH range (pH 6.0 to 9.0) was assessed to determine the best protein extractant for chicken meat. The maximum protein extractabilities at pH 8.0 for phosphate and citrate buffer, and at pH 9.0 for glycine buffer were observed. ANOVA analysis showed that there was no significant difference in protein extractabilities for citrate from phosphate and glycine buffer. Whereas, a significant difference was observed for phosphate buffer from glycine. However, no significant effects of pH were observed.

THE EFFECTS OF pH AND CALCIUM ON THE UPTAKE OF RADIOPHOSPHORUS BY FLUE-CURED TOBACCO

1964 ◽  
Vol 44 (1) ◽  
pp. 28-31 ◽  
Author(s):  
E. T. McEvoy
Keyword(s):  
Nutrient Solution ◽  
Culture Solution ◽  
Ph Values ◽  
Hydroxyl Ion ◽  
Effects Of Ph ◽  
Growth Differences ◽  
Ph Range ◽  
Region Growth ◽  
Complete Nutrient Solution ◽  
Acid Region

The uptake of radiophosphorus by flue-cured tobacco as a function of pH of the culture solution was determined at five different pH values from 4 to 8. When the plants were cultured in a complete nutrient solution containing 240 p.p.m. calcium, P32 uptake increased significantly from pH 4 to a maximum value at pH 5, then decreased with increasing pH to a minimum value of pH 8. At pH values above 5, precipitation occurred as phosphates of calcium, making phosphorus less available to the plant. A reduction in the concentration of calcium in the nutrient solution to 80 p.p.m. and 0, respectively, resulted in a decrease in the amount of phosphorus precipitated and an increase in the P32 uptake at pH 6 to 8. In calcium-free culture solutions, P32 uptake was inhibited by hydrogen ion in the acid region of the pH range and by hydroxyl ion in the alkaline region. Growth differences were not related to variation in P32 uptake.

scholarly journals Effects of pH on the stability of cyanidin and cyanidin 3-O-β-glucopyranoside in aqueous solution

2015 ◽  
Vol 69 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Violeta Rakic ◽  
Mihaela Skrt ◽  
Milena Miljkovic ◽  
Danijela Kostic ◽  
Dusan Sokolovic ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Visible Range ◽  
Colour Intensity ◽  
Colour Variation ◽  
Acidic Solutions ◽  
Absorbance Maximum ◽  
Ph Values ◽  
Effects Of Ph ◽  
The Stability ◽  
Ph Range

The colour variation, colour intensity and stability at various pH values (2.0, 4.0, 7.0 and 9.0) of cyanidin 3-O-?-glucopyranoside (Cy3Glc) and its aglycone cyanidin was investigated during a period of 8 hours storage at 25?C. Our data showed that pH of aqueous solution had impact on spectroscopic profile of cyanidin and Cy3Glc. Beginning with the most acidic solutions, increasing the pH induce bathochromic shifts of absorbance maximum in the visible range for all examined pH values (with the exception pH 4.0 for cyanidin), while the presence of the 3-glucosidic substitution induce hypsochromic shift. Compared to cyanidin, Cy3Glc has higher colour intensity and higher stability in the whole pH range, except at pH 7.0. The 3-glucosidic substitution influences on the colour intensity of Cy3Glc in the alkaline region. After 8-hour incubation of Cy3Glc and cyanidin at pH 2.0 and 25 ?C, 99% of Cy3Glc and only 27% of cyanidin remained unchanged.

EFFECT OF pH ON LOW TEMPERATURE GROWTH OF SALMONELLA1

1972 ◽  
Vol 35 (1) ◽  
pp. 49-52 ◽  
Author(s):  
J. R. Matches ◽  
J. Liston
Keyword(s):  
Low Temperature ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Food Poisoning ◽  
Combined Effects ◽  
Temperature Growth ◽  
Ph Values ◽  
Effects Of Ph ◽  
Salmonella Serotypes ◽  
Ph Range

The combined effects of pH and temperature on growth of three serotypes of salmonellae are reported. Salmonela heidelberg grew on the surface of agar over the pH range of 5.0 to 9.0. Minimum growth temperatures of 5.3, 5.2, and 5.3 C were obtained at pH values of 6.0, 7.0, and 8.0, respectively. In broth, S. heidelberg increased in number over the pH range of 6.0 to 8.0, with the lowest growth temperature of 6.0 C obtained at pH 7.0. Salmonella typhimurium increased in number in broth at pH values of 6.0 to 9.0. A time-temperature effect was shown by this organism after 16 days. Salmonella derby grew over the pH range of 6.0 to 8.0 in broth, with the lowest growth temperature of 9.0 C obtained at pH 6.0 and pH 7.0. The results indicate that food-poisoning Salmonella serotypes grow only over a narrow pH range at low temperatures.

The Malachite Green Biodegradation in Bioreactors on Various pH Domains

2019 ◽  
Vol 70 (8) ◽  
pp. 2996-2999
Author(s):  
Viorel Gheorghe ◽  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Vasile Matei ◽  
Mihaela Bombos
Keyword(s):  
Malachite Green ◽  
Contact Time ◽  
Dominant Species ◽  
Wastewater Treatment Plants ◽  
Organic Substances ◽  
Biological Degradation ◽  
Growth Promoters ◽  
Ph Values ◽  
Biological Sludge ◽  
Ph Range

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

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