Potassium Acetate Solutions Research Articles

Field Demonstration of Permeable Wall Flushing for Biostimulation of a Shallow Sandy Aquifer

AbstractA pilot‐scale nutrient injection will (NIW) (4 m by 4 m by 1 m) was installed in the Borden Aquifer lo serve as a pulsed injection source of a potassium acetate solution for the stimulation of anaerobic microbial activity. The success of the flushing procedure was evaluated by monitoring the breakthrough of the acetate solution at several multilevel piezometers installed in the wall. Although some variation in the ground water velocity was observed with depth, the wall was flushed with reasonable uniformity after about six hours of injection and withdrawal, representing about one pore volume, Calculations bused on head level data collected during the flush, and on the solute breakthrough curves, indicated that about 90% of the flow induced by the pumping and injecting was confined to the permeable wall. These results show that a permeable wall injection system is a viable method of introducing solutes uniformly to a cross section of aquifer, with minimal perturbation of the natural flow system. In addition lo its importance for the biostimulation system tested in this project the flushing of permeable walls may have applications in other semi‐passive remedial systems, such as the rejuvenation of reactive barriers.

Rheological properties of chromosomal and plasmid DNA during alkaline lysis reaction

The recovery of plasmid DNA from cells is achieved by a two-step chemical reaction which usually employs sodium hydroxide and sodium dodecyl sulphate followed by neutralisation with a chilled solution of potassium acetate. It is important that the gelatinous floc of chromosomal DNA with proteins debris is not broken down since fragments of chromosomal DNA are difficult to separate from plasmid DNA. To accomplish the operation at scale demands knowledge of the rheology as the reactions proceed. In this paper a co-axial cylinder rheometer is used to record the changes for two strains of Escherichia coli cells. Analysis of the liquor, prior to neutralisation indicates that at shear rates below 367 s−1 the flow properties during lysis are non-Newtonian, but above 367 s−1 flow behaviour becomes Newtonian. Additionally, following neutralisation, the rheological data show that the clear liquor obtained at low shear levels is Newtonian, but the gelatinous floc has strong viscoelasticity. These properties strongly influence subsequent stages for the removal of solids.

High-throughput plasmid mini preparations facilitated by micro-mixing.

We have developed a reliable high-throughput plasmid isolation system using a 96-well plate format. This system combines a novel glass bead micro-mixing method with modified alkaline lysis and Sephacryl S-500 DNA purification procedures. Mechanical forces generated by vortexing glass beads inside each well of the 96-well plates ensure that the bacterial pellets are homogeneously resuspended, the cells are completely lyzed, and the resulting bacterial lysates are thoroughly mixed with the potassium acetate solution. The vortexing speed and duration for glass bead mixing have been standardized to facilitate plasmid DNA yields without significant adjustments.

Electrochemical and conducting properties of polyaniline in the neutral aqueous solutions of potassium acetate and zinc salts

Electrochemical and conducting properties of polyaniline in the neutral aqueous solutions have been presented in comparison with those in the acid media. The distinctive property of a cyclic voltammetric characteristic ( cv) in the neutral electrolytes is the lack of a constant potential difference ( cpd) between anodic and cathodic peak potentials in conditions when peak current is proportional to the scan rate ( v). It has been suggested that the polymer film in conditions when cpd is observed should be characterized by two ox-red potentials. When zinc salts were used as electrolytes well defined electrochemical activity is accompanied by comparatively high electronic conductivity of polyaniline due to cation-radical salt formation.

Cuprous Ions Activate Glibenclamide-Sensitive Potassium Channel in Liver Mitochondria

Cuprous ions at micromolar concentrations induced swelling of rat liver mitochondria in isotonic solutions of potassium thiocyanate and potassium acetate. The swelling in K-acetate in the presence of the protonophere carbonyl cyanidem-chloropenylhydrazone was partly inhibited by glibenclamide. In K+-containing media, Cu+collapsed the mitochondrial membrane potential formed by operation of the respiratory chain with succinate or tetramethylp-phenylenediamine + ascorbate as substrates or by the proton-pumping ATPase. In contrast, in K+-free media, isotonic sucrose or choline chloride, but not in NaCl, Cu+induced a transient potassium gradient potential. These results indicate that cuprous ions at low concentrations, apart from promoting the electroneutral K+/H+exchange, facilitate the uniport of K+, presumably by activating the mitochondrial potassium channel sensitive to glibenclamide.

Field Investigation of Nutrient Pulse Mixing in an in Situ Biostimulation Experiment

A permeable wall was installed in a shallow, uncontaminated portion of the Borden aquifer, and periodically flushed with a solution of potassium acetate. The acetate pulses were injected at intervals of 5–7 weeks and were observed to merge within 5–10 m of the injection wall. The chief mechanism for the merging of these pulses was longitudinal dispersion. Geochemical changes in the aquifer, manifested as the development of a sustained reducing environment, indicated that the dispersive mixing occurred at the scale of the microorganisms and was not merely an artifact of the sampling method. This work indicates that large‐period pulsed injections of a substrate solution might be useful in bioremediation programs where the promotion of injected and ambient water mixing is desirable. It is also advantageous, from the standpoint of biofouling prevention, that this mixing occur at some distance from the injection wells.

Salt Effect of Potassium Acetate on Vapor-Liquid Equilibria of Ethanol-Water and Methanol-Ethanol Systems.

The activities of methanol, ethanol or water in potassium acetate solutions and the vapor-liquid equilibrium relations of methanol-ethanol-potassium acetate and ethanol-water-potassium acetate systems were determined by use of a flow-type apparatus at 298.15 K. The activity data are presented for single solvent and vapor-liquid equilibrium data are shown for mixed solvents. Salting-out and salting-in effects of potassium acetate were shown for ethanol-water and methanol-ethanol systems, respectively. Further, the experimental data were correlated by using the model of Chen et al.

A Specific Fluorometric Assay for Hexosamines in Glycosaminoglycans, Based on Deaminative Cleavage with Nitrous Acid

Glycosaminoglycan (GAG) hexosamines were measured after deacetylation (2 h acid hydrolysis), deaminative cleavage by nitrous acid, and coupling of the 2,5-anhydro sugars thus produced with 3,5-diaminobenzoic acid (DABA) to give a fluorescent product. Analyses were performed after the addition of an aliquot of potassium acetate solution to the acid hydrolysates, to adjust the pH. Results on a series of GAGs were compared with an Elson-Morgan (E-M) procedure. Our method is faster, more convenient, 10-20 times more sensitive, and always gave higher figures for hexosamine content. In particular it avoids long, destructive hydrolysis in concentrated strong acid and the complications of the Moggridge-Neuberger effect. Results agreed with calculations and titrimetric data. Using internal standards, our method is tolerant of cetylpyridinium chloride, peptides, and salts. A simple fluorometer easily handled less than 1 μg GAG per sample in 1.0 ml volume. Results are available in 4-5 h. The method is suitable for automation. A strongly polycationic environment, as in chitosan, markedly slowed nitrous acid deamination, possibly because of Donnan-type exclusion from the domain of the polycation of the cationic nitrosonium species. Whereas all other α- and β-hexosaminides gave yield-hydrolysis time profiles that peaked in ∼1 h in the DABA method, the E-M profiles, particularly for 2-sulfamato-α-hexosaminides, took longer and/or achieved lower optimal yields. All the usually encountered forms of the 2-amino-2-deoxy group (free, acetylated, sulfamato) are readily assayed using the same reagents, with appropriate prefluorometric stages.

Variable refractive index systems by sol-gel process

A radial gradient-index (r-GRIN) glass rod of about 13.5 mm in diameter having a parabolic index profile with the maximum index change of 0.055 has been prepared by the sol-gel process. A gel of about 35 mm in diameter and 50 mm in length was formed from TMOS, TEOS, boron ethoxide, and aqueous lead acetate. After aging for 5 days at room temperature, the gel was subjected to stepwise replacement of the liquid in the micropores by a mixed solution of iso-propanol and acetone. The gel was then immersed in an ethanolic solution of potassium acetate for 16 h to form the concentration gradient of lead and potassium ions. The gel, once soaked in a bath of acetone to temporarily fix the concentration profile of the ions, was again immersed in an ethanolic solution of potassium acetate for 2 h to modify the profile of the ions near the edge of the cylindrical gel. The refractive index profile of the glass rods obtained by drying and densifying the gel was parabolic in the range from the central axis to 80% of the radius, with the highest value of 1.65 at the center.

An exploratory study of acetate decomposition and dissolution of quartz and Pb-rich potassium feldspar at 150°C, 50 MPa (500 bars)

AbstractExperiments to explore the dissolution behaviour of Pb-rich orthoclase (1% PbO) and quartz have been carried out in the presence of pH buffered and unbuffered potassium acetate and lithium acetate solutions at 150°C and 50 MPa (500 bars). In pH-unbuffered potassium acetate solutions Pb and Na solubilities (and pH) increase with increasing fluid acetate content, reflecting increased bulk dissolution of the feldspar; silica solubility decreases despite an increase in measured pH from 7.5 to 8.9. Similarly, in experiments at pH 6 using a potassium acetate pH buffer, quartz solubility decreases with increasing acetate content. The use of lithium acetate pH buffers (pH 6 at 25°C) in experiments with orthoclase plus quartz results in the precipitation of the lithium chlorite cookeite, complicating interpretation of the fluid chemistry. It is also apparent that in the presence of orthoclase plus quartz (but not albite alone) acetate decarboxylation takes place at much higher rates than expected for the experimental configuration used. The observed effects are unlikely to be due to the presence of acetate alone; the influence of species produced by acetate decay (especially carbonate) must also be considered. This study provides little support for models which call upon acetate to enhance the solubility of aluminosilicate minerals, and suggests that acetate decarboxylation in nature may limit its involvement in dissolution processes. It emphasises the potential of feldspars as sources of elements for mineralisation, such as Pb.

Grin Rod of Large Diameter and Large Delta-N

ABSTRACTA gradient-index glass rod of about 13 mm in diameter and 20 mm in length with the refractive index difference of about 0.05 between center and perimeter has been prepared by the solgel process from a precursor solution consisted of tetramethoxysilane, tetraethoxysilane, boron ethoxide and aqueous solution of lead acetate. A bubble free wet gel of about 35 mm in diameter and 50 mm in length was obtained by adding acetic acid to the precursor solution as a buffering agent. The liquid in the micropores of the wet gel was totally replaced with acetone. Then the compositional gradient of lead was formed in radial direction of the gel by soaking in an ethanolic solution of potassium acetate. A transparent r-GRIN rod of about 10 mm in diameter was obtained by the sintering of the gel at 580°C.

A New Hydrogen Electrode Applied to the Protolysis of Acetic Acid in Potassium Acetate Solutions.

A New Hydrogen Electrode Applied to the Protolysis of Acetic Acid in Potassium Acetate Solutions.

ChemInform Abstract: Isotopic Fractionation Factor of the Hydrogen‐Bonded Complex AcO‐...(HOAc)n and Kinetic and Equilibrium Solvent Isotope Effects on Reactions of Acetate Ion in Acetic Acid.

A value of φ 0.58 ± 0.05 has been obtained for the deuterium fractionation factor of the hydrogen-bonded complex AcO–⋯(HOAc)n from 1H n.m.r. studies of solutions of potassium acetate in AcOH and 97% AcOD–3% AcOH. The result is used to account for the kinetic solvent isotope effect kAcO–AcOH/kAcO–AcOD 0.66 ± 0.10 measured for formation of acetic anhydride from 2,4,6-trinitrophenyl acetate in AcOH and AcOD in the presence of potassium acetate. The equilibrium solvent isotope effect on complex formation between 2,4,6-trinitrophenol and acetate ion in AcOH and 97% AcOD-3% AcOH, KAcOH/KAcOD 0.83 ± 0.1, leads to a value φca. 0.7 for the complex [2,4,6-(NO2)3C6H2O ⋯ H ⋯ OAc]–.

Well- and Formation-Damage Removal With Nonacid Fluids

Well damage, in the form of various impediments to fluid flow through the formation rock, can reduce or completely eliminate production or injection rates of the well. Prevention and/or removal of well damage have consequently become a major field of study and concentration within the petroleum industry. Although acid solutions have been used for well-damage removal since before the turn of the century, there are situations in which acid is not the best choice for damage removal. The most obvious condition under which acid is not applicable is where the damaging mechanism is not appreciably soluble in acid solutions. Use of acid here would be a waste of time and material.

Isotopic fractionation factor of the hydrogen-bonded complex AcO–⋯(HOAc)nand kinetic and equilibrium solvent isotope effects on reactions of acetate ion in acetic acid

A value of φ 0.58 ± 0.05 has been obtained for the deuterium fractionation factor of the hydrogen-bonded complex AcO–⋯(HOAc)n from 1H n.m.r. studies of solutions of potassium acetate in AcOH and 97% AcOD–3% AcOH. The result is used to account for the kinetic solvent isotope effect kAcO–AcOH/kAcO–AcOD 0.66 ± 0.10 measured for formation of acetic anhydride from 2,4,6-trinitrophenyl acetate in AcOH and AcOD in the presence of potassium acetate. The equilibrium solvent isotope effect on complex formation between 2,4,6-trinitrophenol and acetate ion in AcOH and 97% AcOD-3% AcOH, KAcOH/KAcOD 0.83 ± 0.1, leads to a value φca. 0.7 for the complex [2,4,6-(NO2)3C6H2O ⋯ H ⋯ OAc]–.

Concentration Oscillations During Diffusion With Slow First-Order Chemical Reaction in Aqueous Solutions of trans-Dichloro-bis(ethane-1,2-diamine)cobalt(III) Chloride, trans-[Co(en)2Cl2]Cl

The rate equations for diffusion and chemical reaction have been solved for isothermal diffusion with the first-order reactionA → Bin stirred diaphragm cells. Provided pseudo-steady-state conditions are established in the diaphragms, the concentration differences across the diaphragm for the reactant and product are predicted to show damped oscillations in time for certain values of the solute diffusivities. Diffusion coefficients have been determined for aqueous solutions of trans-dichlorobis (ethane-1,2-diamine)cobalt(III) chloride in which the 1 : 1 salt slowly converts into a 1:2 salt through the reaction [Co(en)2Cl2]+ + Cl - → [Co(en)2Cl]2+ +2Cl- with k = 3.6×10-5 s-1 at 25°C. Supplementary ternary diffusion coefficients have been determined for aqueous solutions of potassium acetate + potassium sulfate, a ternary mixed electrolyte with ionic mobilities similar to those of the aqueous cobalt salts.

ChemInform Abstract: Bis(undecatungstogermanate) Lanthanates of Potassium.

AbstractThe compounds K13(Ln(GeW11O39)2) (Ln: Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Tm, Yb) have been prepared by addition of a concentrated solution of potassium acetate to an aqueous solution of Ln(NO3)3 and H4GeW12O40 (Ge:Ln = 2:1, 70 °C).

Electrogenerated iodine as a reagent for coulometric titrations in alcoholic media

Conditins are established for the generation of iodine with high current efficiency (>99%) in solutions of potassium acetate in methanol or ethanol, in the presence of potassium iodide or tetraethylammonium iodide at platinum or glassy carbon working electrodes, respectively. Iodine solutions in methanol are stable, but solutions in ethanol are less so. Procedures are given for coulometric titration of various thiols with anodically generated iodine in these solvents; biamperometric or potentiometric end-point detection can be used. The error of the titrations did not exceed ± 2.0% for ca. 1-mg samples.

Reducing the potential for bacterial soft rot in potato tubers by chemical treatments and drying

The potential for bacterial soft rot caused byErwinia carotovora in freshly inoculated potato tubers was reduced up to 99% by immersion for 5 min in solutions of sodium hypochlorite (chlorine bleach) containing up to 10,000 ppm chlorine. Reductions up to 93% were achieved using a combination treatment of immersion in 1% citric acid for 5 min followed by airdrying. Immersion treatment alone in 1% aqueous solutions of citric, acetic, ascorbic, or malonic acid also significantly reduced the soft rot potential. In contrast, no reductions accompanied treatment with solutions of potassium or calcium acetate. All treatments including the combination immersion/airdrying treatment were much less effective if tubers had been infiltrated initially with soft rotErwinia or had numerous mechanical injuries. If tubers had not been infiltrated with the causal organism, immersing them in 1% citric acid reduced the potential nearly as much as a similar treatment with 1000 ppm chlorine. A 30-sec immersion in the latter was less effective than a similar treatment with 500 ppm a.i. CGA 78039, an experimental bactericide. However, air-drying, coupled with provisions for keeping tuber surfaces free from moisture, remains the most effective means of reducing losses to bacterial soft rot.

Anodically generated cobalt(III) acetate as reagent for coulometric titrations in acetic acid

Conditions for the anodic generation of cobalt(III) acetate with high current efficiency in non-aqueous solutions of potassium acetate in acetic acid have been investigated. The presence of water or acetic anhydride in the anolyte diminishes the amount of the generated oxidant. The stability of the generated cobalt(III) acetate solution is decreased in the presence of water and at elevated temperatures. Procedures for coulometric titrations of reducing substances with cobalt(III) acetate, using the biamperometric or the potentiometric end point detection, are described.