Radiolysis of aqueous chloroform solutions

1970 ◽  
Vol 48 (2) ◽  
pp. 271-276 ◽  
Author(s):  
B. J. Rezansoff ◽  
K. J. McCallum ◽  
R. J. Woods
Keyword(s):  
Oxalic Acid ◽  
Formic Acid ◽  
Hydroxyl Radicals ◽  
Ph Effect ◽  
Hydrogen Ions ◽  
Γ Radiation ◽  
High Ph ◽  
Hydrated Electrons ◽  
Presence And Absence ◽  
Ph Range

Saturated aqueous chloroform solutions (0.07 M) with pH ranging from 0.8 to 12.6 have been irradiated with 60Co γ-radiation in the presence and absence of air. G(Cl− + ClO−) increases with increasing pH in the pH range 1–3 (aerated solutions) or 3–6 (deaerated solutions) and again at pH greater than 10.5. The variation in yield from aerated solutions in the region pH 1–3 is attributed to competition between chloroform and hydrogen ions for hydrated electrons. However, such competition cannot account for the pH effect observed in deaerated solutions between pH 3 and 6. Increased yields from both aerated and deaerated solutions at high pH are attributed to the formation of O− by reaction of hydroxyl radicals and hydroxide ions. Formic acid and oxalic acid have been identified as minor products when aerated chloroform solutions are irradiated.

scholarly journals Effect of Hydrogen Ion Presence in Adsorbent and Solution to Enhance Phosphate Adsorption

2021 ◽  
Vol 11 (6) ◽  
pp. 2777
Author(s):  
Taehoon Kim ◽  
Byungryul An
Keyword(s):  
Hydrochloric Acid ◽  
Adsorption Mechanism ◽  
Ph Effect ◽  
Total Surface Area ◽  
Point Of Zero Charge ◽  
Phosphate Adsorption ◽  
Hydrogen Ions ◽  
Solution Ph ◽  
Initial Ph ◽  
Ph Range

In this paper, the effect of hydrogen ions on the adsorption onto granular activated carbon (GAC) with the inorganic contaminant phosphate, which exists as a form of four species depending on the solution pH, is investigated. Various batch isotherm and kinetic experiments were conducted in an initial pH 4 as an acid, a pH 7 as neutral, and a pH 9 solution as a base for the GAC conditioned with deionized water and hydrochloric acid, referred to as GAC and GACA, respectively. The physical properties, such as the total surface area, pore volume, pore size distribution, and weight of the element, obtained from Brunauer–Emmett–Teller (BET) and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM–EDX) represent no significant differences. However, the hydrochloric acid (HCl) condition results in an alteration of the pH of the point of zero charge from 4.5 to 6.0. The optimized initial pH was determined as being acid for the GAC and as being neutral for the GACA. According to the Langmuir isotherm, the relatively high Qm was obtained as being acid for the GAC and clearly distinguishes the pH effect as being the base for the GACA. An attempt was made to assess the adsorption mechanism using the pseudo-first-order (PFO), the pseudo-second-order (PSO), and the intraparticle diffusion models. The higher R2 for the PSO in the entire pH range indicated that chemisorption was predominant for phosphate adsorption, and the pH did not change the adsorption mechanism. A prolonged Bed Volume (BV) for the GACA demonstrated that the hydrogen ions on the surface of the GAC enhanced phosphate adsorption.

Chemical/Physical Retting of Flax Using Detergent and Oxalic Acid at High pH

1998 ◽  
Vol 68 (12) ◽  
pp. 942-947 ◽  
Author(s):  
Gunnar Henriksson ◽  
Karl-Erik L. Eriksson ◽  
Linda Kimmel ◽  
Danny E. Akin
Keyword(s):  
Oxalic Acid ◽  
High Ph

Factors influencing the inorganic speciation of trace metal cations in fresh waters

1999 ◽  
Vol 50 (4) ◽  
pp. 367 ◽  
Author(s):  
Jonathan P. Kim ◽  
Keith A. Hunter ◽  
Malcolm R. Reid
Keyword(s):  
Natural Waters ◽  
Major Ions ◽  
Divalent Cations ◽  
Ion Composition ◽  
High Ph ◽  
River Waters ◽  
Inorganic Complexes ◽  
Effects Of Ph ◽  
Ph Range ◽  
Inorganic Speciation

The effects of pH and major ion composition on the chemical speciation of the divalent cations of Co, Ni, Cu, Zn, Pb and Cd have been examined after consideration of the available thermodynamic database for solution complexes of these ions. Calculations were made for two model river waters representing the 1% and 99% extremes in composition of global river waters. The results show that inorganic speciation behaviour is of two characteristic types: (a) Cu, Zn and Co are dominated by bis-hydroxy- complexes at high pH and show the greatest reduction in the fraction of free aquo ion with increasing pH; (b) Pb, Ni and Cd are dominated by carbonato- complexes at high pH and show a more gradual decrease in the fraction of free aquo ion with increasing pH. For Cu, Pb and Ni significant fractions of the labile forms of these metal ions are present as inorganic complexes in the pH range of most natural waters, whereas for Zn, Co and Cd this is true only at moderately high pH (pH >7.5). Complexing with the major ions SO42– and Cl– is important only at low pH in river waters of high ionic strength.

γ-Radiation-induced carboxylation of pyrrolidine

1976 ◽  
Vol 29 (12) ◽  
pp. 2603 ◽  
Author(s):  
A Davison ◽  
NT Barker ◽  
DF Sangster
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Carboxylic Acid ◽  
Hydroxyl Radicals ◽  
Hydrogen Abstraction ◽  
Major Product ◽  
Amino Group ◽  
Γ Radiation ◽  
Neutral Aqueous Solution ◽  
Radiation Induced

Amino acids produced in the γ-radiation-induced carboxylation of pyrrolidine and formate in neutral aqueous solution have been studied. Two products only were found in the ratio 1 : 5.5. The minor product, proline, and the major product, pyrrolidine-3-carboxylic acid, have been characterized. Their presence indicates that the predominant site of hydrogen abstraction from pyrrolidine by radiation-generated hydroxyl radicals is β to the amino group.

Direct determination of the quantum yield of hydroxyl radicals in the laser photolysis of formic acid at 222 nm

1987 ◽  
Vol 91 (13) ◽  
pp. 3463-3465 ◽  
Author(s):  
Gurvinder S. Jolly ◽  
Donald L. Singleton ◽  
George. Paraskevopoulos
Keyword(s):  
Quantum Yield ◽  
Formic Acid ◽  
Hydroxyl Radicals ◽  
Direct Determination ◽  
Laser Photolysis

Suppression of growth rate of colony-associated fungi by high fructose corn syrup feeding supplement, formic acid, and oxalic acid

2008 ◽  
Vol 47 (2) ◽  
pp. 126-130
Author(s):  
Jay A. Yoder ◽  
Brady S. Christensen ◽  
Travis J. Croxall ◽  
Justin L. Tank ◽  
Diana Sammataro
Keyword(s):  
Growth Rate ◽  
Oxalic Acid ◽  
Formic Acid ◽  
High Fructose Corn Syrup ◽  
Corn Syrup ◽  
High Fructose
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