ELECTROLYTIC CONDUCTANCE IN HYDROGEN PEROXIDE – WATER MIXTURES: PART II. SOME MONOBASIC AND DIBASIC ACIDS

1958 ◽  
Vol 36 (5) ◽  
pp. 744-749 ◽  
Author(s):  
D. K. Thomas ◽  
O. Maass
Keyword(s):  
Hydrogen Peroxide ◽  
Marked Decrease ◽  
Current Method ◽  
Strong Acid ◽  
Weak Acid ◽  
Electrolytic Conductance ◽  
Degrees Of Dissociation ◽  
System Water ◽  
Water Hydrogen ◽  
Made In

Measurements of the equivalent conductance of sulphuric, nitric, and hydrofluoric acids were made in water – hydrogen peroxide mixtures by means of a direct-current method. It was found that in solvents containing a high percentage of hydrogen peroxide the conductivities of these acids were extremely low, and it is proposed that this results from a marked decrease in their degrees of dissociation. This proposal is supported by similar measurements made on the system water – strong acid – weak acid.

ELECTROLYTIC CONDUCTANCE IN HYDROGEN PEROXIDE–WATER MIXTURES: PART I. THE ALKALI CHLORIDES

1958 ◽  
Vol 36 (3) ◽  
pp. 449-455 ◽  
Author(s):  
D. K. Thomas ◽  
O. Maass
Keyword(s):  
Hydrogen Peroxide ◽  
Direct Current ◽  
Current Method ◽  
Solvent Composition ◽  
Electrolytic Conductance ◽  
Equivalent Conductance ◽  
Alkali Chlorides ◽  
Water Hydrogen

The equivalent conductance of a series of alkali chlorides has been measured in water–hydrogen peroxide mixtures over the whole range of solvent composition. The measurements were made by a simple direct-current method, and the results obtained are interpreted in terms of the viscosity of the solvent.

Diurnal pH changes in duodenum of conscious dogs

1980 ◽  
Vol 238 (2) ◽  
pp. G91-G96 ◽  
Author(s):  
Z. Itoh ◽  
R. Honda ◽  
I. Aizawa
Keyword(s):  
Strong Acid ◽  
Force Transducer ◽  
Weak Acid ◽  
Conscious Dogs ◽  
Ph Change ◽  
Motor Patterns ◽  
Ph Changes ◽  
Duodenal Ph ◽  
Measured Volume ◽  
Made In

Continuous measurements of intraduodenal pH changes were made in five healthy conscious dogs by means of a miniature pH electrode inserted into the duodenum through a chronically implanted duodenal cannula. Gastric motor activity was also recorded simultaneously by means of a chronically implanted force transducer. When dogs were fed once a day with a measured volume of dog food, it was found that 24-h pH changes in the duodenal contents could be divided into three major periods: the weak acid period, the strong acid period, and alkaline period. The weak acid period lasted for 9.2 +/- 0.43 h after feeding with the duodenal pH ranging from 7.0 to 4.0. The weak acid period was gradually changed to the strong acid period in which the duodenal pH fluctuated widely from 8.0 to 1.0. This period lasted for 5.2 +/- 0.26 h. After the strong acid period, pH of the duodenum abruptly turned alkaline and remained between 7.0 and 8.3 until the next meal. These three periods of pH change are closely related to those of three different gastric motor patterns; the digestive, intermediate, and interdigestive patterns, respectively.

Equilibrium Studies on the System Water + Hydrogen Peroxide + Urea + Carbon Dioxide

2010 ◽  
Vol 55 (12) ◽  
pp. 5715-5718 ◽  
Author(s):  
Haibin Liu ◽  
Jilin Cao ◽  
Changhong Gao ◽  
Jianjun Zhao
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Peroxide ◽  
Equilibrium Studies ◽  
System Water ◽  
Water Hydrogen

Removal of Tributyltin in Shipyard Waters: Characterization and Treatment to Meet Low Parts per Trillion Levels

2003 ◽  
Vol 19 (03) ◽  
pp. 179-186
Author(s):  
Gary C. Schafran ◽  
R. Prasad ◽  
F. H. Thorn ◽  
R. Michael Ewing ◽  
J. Soles
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Hydroxyl Radical ◽  
Ultraviolet Irradiation ◽  
Treatment Plant ◽  
Full Scale ◽  
Radical Formation ◽  
Estuarine Waters ◽  
Treatment Conditions ◽  
Made In

Removal of tributyltin (TBT) from shipyard waters has been conducted in Virginia shipyards for over 2.5 years and has resulted in a 99% reduction of TBT discharged to coastal-estuarine waters. This has been achieved by conventional coagulation clarification for particulate TBT removal and removal of dissolved TBT using activated carbon. Although advances have been made in the understanding of TBT removal under various treatment conditions, TBT removal with the existing full-scale treatment plant to levels that would comply with a 50 parts per trillion (pptr) discharge limit are not possible. Results from study efforts that are currently ongoing suggest that the 50 pptr limit might be reached using ultraviolet irradiation or ozonation and that both processes would be substantially improved with the addition of hydrogen peroxide to promote hydroxyl radical formation.

Combining UASB technology and advanced oxidation processes (AOPs) to treat food processing wastewaters

2002 ◽  
Vol 45 (10) ◽  
pp. 329-334 ◽  
Author(s):  
G.O. Sigge ◽  
T.J. Britz ◽  
P.C. Fourie ◽  
C.A. Barnardt ◽  
R. Strydom
Keyword(s):  
Hydrogen Peroxide ◽  
Food Processing ◽  
Advanced Oxidation Processes ◽  
Water System ◽  
Post Treatment ◽  
Significant Progress ◽  
Oxidation Processes ◽  
Legal Limit ◽  
Direct Discharge ◽  
Made In

UASB treatment of fruit cannery and winery effluents was shown to be feasible. However, the treated effluents still have residual COD levels well above the legal limit of 75 mg.L−1 for direct discharge to a water system and a form of post-treatment is necessary to reduce the COD further. Ozone and ozone/hydrogen peroxide were used in combination with a granular activated carbon contacting column to assess the effectiveness as a post-treatment option for the UASB treated fruit cannery and winery effluent. Colour reduction in the effluents ranged from 66 to 90% and COD reductions of 27–55% were achieved. The combination of ozone and hydrogen peroxide gave better results than ozonation alone. Significant progress was thus made in achieving the legal limit of 75 mg.L−1.

A Oxidative Desulfurization System for Model Oil with Hydrogen Peroxide in the Presence of Solid Acid Catalyst

2013 ◽  
Vol 699 ◽  
pp. 68-71 ◽  
Author(s):  
Liang Wang ◽  
Zi Zhen Li ◽  
Chun Hu Li ◽  
Li Juan Feng
Keyword(s):  
Hydrogen Peroxide ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Oxidative Desulfurization ◽  
Acid Catalyst ◽  
Oxidizing Agent ◽  
Model Compounds ◽  
Model Oil ◽  
System Water ◽  
Oxidative System

Oxidative desulfurization of model oil was conducted in emulsion oxidative system (water –in-oil [W/O]) using hydrogen peroxide as the oxidizing agent, N-methyl-2-pyrrolidone (NMP) and water as extractive solvent, span60 as surfactant. The system was evaluated for oxidative desulfurization of BT, DBT and 4.6-DMDBT using hydrogen peroxide as oxidant and exhibit excellent activities in oxidative desulfurization of model compounds.

Comparative analysis of strong and weak acid pretreatment methods under pressurized and non-pressurized conditions for agro-industrial waste of apple pulp

2018 ◽  
Vol 29 (6) ◽  
pp. 1038-1052
Author(s):  
Ece Ümmü Deveci ◽  
Çağdaş Gönen
Keyword(s):  
Statistical Design ◽  
Strong Acid ◽  
Weak Acid ◽  
Raw Material ◽  
Sugar Concentration ◽  
Optimum Level ◽  
Acid Pretreatment ◽  
Industrial Plants ◽  
Sulfuric Acid Pretreatment ◽  
The Face

It is well known that energy-related emissions have been increasing the global warming and pushing the climate change. In the face of this situation biomass-based biofuels, which is a kind of renewable energy source, are great alternatives instead of fossil derivative fuels. Moreover, biomass can be found easily and widely, which makes it an economical alternative. Biological conversation rate of the biomass to the biofuel is insufficient because of the molecular structure of the biomass. Pretreatment is required to increase the bioavailability of the biomass as the raw material. In this study, weak and strong acid pretreatments are studied under pressurized and non-pressurized conditions for apple pulp as biomass, which is an agro-industrial residue coming from industrial plants. Box-Behnken statistical design is used to determine the optimum level of some factors as time, chemical dose, and raw material dose. While the maximum total sugar concentration was found to be 23.71 g/L with sulfuric acid pretreatment, the reduced sugar concentration under pressurized conditions with strong acid pretreatment was found as 17.00 g/L.

REACTIONS IN DISSOCIATED WATER VAPOR

1951 ◽  
Vol 29 (11) ◽  
pp. 996-1009 ◽  
Author(s):  
R. A. Jones ◽  
C. A. Winkler
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Room Temperature ◽  
Reaction Chamber ◽  
Glass Wool ◽  
Cold Trap ◽  
Slight Effect ◽  
Reaction Chambers ◽  
Limiting Value ◽  
Water Hydrogen

Water vapor dissociated by an electric discharge and passed into a cold trap yielded products which gave off oxygen at temperatures above −120°C. and at room temperature consisted of hydrogen peroxide and water. With products formed under given conditions, the amount of oxygen evolved with warming was proportional to the total amount of product and independent of the warming procedure. The evolution proceeded to completion at −78°C. Water was found at all trap temperatures between −78°C. and −195°C. Hydrogen peroxide was formed only if the trap temperature was below −120°C., and oxygen was evolved only from products formed below −150°C. The yields of water, hydrogen peroxide, and evolved oxygen all increased with decreasing trap temperature. As the volume of reaction chambers inserted between the discharge tube and the trap was increased, the yield of hydrogen peroxide decreased continuously, while the yield of water at first decreased and then increased to a limiting value. Packing a given reaction chamber with glass wool drastically reduced the yield of hydrogen peroxide, but had little effect on the yield of water. Packing the trap itself had only a slight effect on the yields. The results are compared with those obtained by others with the H–O2 system at low temperatures, and a mechanism is proposed to correlate the two systems.

Effect of autotransformation on the layer charge of smectites determined by the alkylammonium method

Clay Minerals ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 623-632 ◽  
Author(s):  
M. Janek ◽  
P. Komadel ◽  
G. Lagaly
Keyword(s):  
Aqueous Dispersion ◽  
Strong Acid ◽  
Acid Sites ◽  
Weak Acid ◽  
Layer Charge ◽  
Exchange Method ◽  
Density Distributions ◽  
Titration Curves ◽  
The Mean ◽  
Strong Acid Sites

AbstractHydrogen-forms of <2 µm fractions of six bentonites of various Fe contents were prepared by H+→OH-→H+ ion exchange using resins. Potentiometric titration curves revealed that the number of strong acid sites varied and accounted for 60-95% of the total acidity in the freshly prepared H-forms. The number of strong acid sites decreased and that of the weak acid sites increased on ageing. The process of autotransformation in aqueous dispersion at 90~ was completed within four days. Layer-charge distributions of all samples were inhomogeneous with layer charges from 0.25-0.39 Eq/unit O10(OH)2. Oxalate pretreatment of the samples resulted in changes in the layer-charge distribution due to the removal of readily soluble phases which may have blocked exchange sites. After autotransformation, the alkylammonium exchange method revealed inhomogeneous charge density distributions; the fraction of layers of the highest charge decreased. Comparison of total CEC obtained from potentiometric curves and interlamellar CEC calculated from the mean layer charge confirmed attack of protons from particle edges. However, for several samples the structural attack may also occur from the interlayer space. Autotransformation of the Hsmectites decreased the mean layer charge. Protons probably attack the Mg(O,OH)6 octahedra preferentially during the autotransformation.

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