• Environmental Engineering Research
• /
• v.17 no.3
• /
• pp.145-150
• /
• 2012

Pb-contaminated soil at a clay shooting range was analyzed by the sequential extraction method to identify metal binding properties in terms of detrital and non-detrital forms of the soil. Most of the metals in the soils existed as non-detrital forms, exchangeable and carbonate-bound forms, which could be easily released from the soil by a washing method. Therefore, the characteristics of Pb desorption for remediation of the Pb-contaminated soil were evaluated using hydrochloric acid (HCl) by a washing method. Batch experiments were performed to identify the factors influencing extraction efficiency. The effects of the solid to liquid (S/L) ratio (1:2, 1:3, and 1:4), soil particle size, and extraction time on the removal capacity of Pb by HCl were evaluated. Soil samples were collected from two different areas: a slope area (SA) and a land area (LA) at the field. As results, the optimal conditions at 2.8 to 0.075 mm of particle size were 1:3 of the S/L ratio and 10 min of extraction time for SA, and 1:4 of the S/L ratio and 5 min of extraction time for LA. The characteristics of Pb desorption were adequately described by two-reaction kinetic models.

• The Korean Journal of Physiology and Pharmacology
• /
• v.25 no.5
• /
• pp.403-411
• /
• 2021

This study was designed to evaluate the gastroprotective activity of cirsilineol in hydrochloric acid (HCl)/ethanol-induced gastric ulcer model. Cirsilineol was administered at the doses of 20 and 40 mg/kg in HCl/ethanol-induced rats. The gastroprotective ability was verified by determining the ulcer score, total acidity, hemoglobin, inflammatory cytokines, lipid peroxides, and enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT) in gastric tissue and serum biochemical analysis. The results showed a favorable increase in the hemoglobin level, antioxidant enzymes (SOD and CAT), restored electrochemical balance (carbon dioxide & anion gap) while a noticeable decrease in ulcer index, total acidity, lipid peroxides, inflammatory cytokines (interleukin-1 beta [IL-1β], IL-6, and tumor necrosis factor alpha) in rats treated with the cirsilineol. The serum biochemical analysis on liver markers (alkaline phosphatases, alanine aminotransferase, and aspartate aminotransferase), kidney markers (urea, creatinine, albumin, globulin, total protein), and lipid profile (triglyceride, high-density lipoprotein, total cholesterol) were attenuated by cirsilineol treatment in rats. Histopathology showed enhanced gastric protection and preserved the integrity of gastric mucosa upon cirsilineol administration. These results ultimately suggest that cirsilineol has gastroprotective effects that prevent the development of gastric ulcer.

• Resources Recycling
• /
• v.27 no.3
• /
• pp.78-85
• /
• 2018

Effect of ball milling treatment on the hydrochloric acid leaching performance of black dross was investigated to recover alumina. Ball milling time and speed showed limited effect on the leaching behavior of the alumina in the mechanically dross. Under the optimum mechanical activation condition (for 1h at 700 rpm), the leaching of alumina in hydrochloric acid solution was significantly affected by leaching time and reaction temperature. MgO was completely dissolved in most of the leaching conditions, while a small amount of Ca, Fe, Si and Ti oxides was dissolved. Although 80% of alumina was dissolved, the dissolved minor components such as Ca, Fe, Mg, Si and Ti oxides should be separated to recover pure alumina solution.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.1
• /
• pp.138-147
• /
• 2022

The synergistic effect of 2-chloromethylbenzimidazole (2-CBI) and potassium iodide (KI) for mild steel in 1 M hydrochloric acid solution was investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that, with the addition of 100 ppm potassium iodide, the inhibition efficiecy (IE) of 100 ppm 2-CBI in 1 M hydrochloric acid had been improved from 91.14% to 96.15%. And synergistic parameter of 100 ppm 2-CBI with different amounts of potassium iodide is always greater than 1. The adsorption of potassium iodide combining with 100 ppm 2-CBI obeys to the Langmuir adsorption isotherm. Thermodynamic adsorption parameters, including ∆G⁰_ads, ∆H_a and ∆S_a of the adsorption of the combinned inhibitor, as well as the E_a of the mild steel corrosion in 1 M HCl with the combinned inhibitor, were calculated.

• Food Science of Animal Resources
• /
• v.23 no.4
• /
• pp.356-360
• /
• 2003

The purpose of this paper was to determine the quantity of selenium in milk by inductively coupled plasma optical emission spectrometry. The sample was digested in teflon vessel containing nitric-hydrogen peroxide acid mixture. After digestion, the sample is treated with additional hydrochloric acid. Total selenium was reduced with sodium borohydride and concentrated hydrochloric acid in a simplified hydride generation(HG) manifold. The optimum conditions of HG are 2 M for HCl, 1.5％ for NaBH$_4$, 1.2 mL/mim for sample flow. Recovery rates by the standard addition method were 88.0％ at 10 ppb and 92.2％ at 10 ppm. The relative standard deviations were 4.8 and 3.2％, respectively. This method showed a good accuracy and precision. And so it was highly suitable for determination of small quantity of selenium in milk.

• Resources Recycling
• /
• v.20 no.1
• /
• pp.61-68
• /
• 2011

Impurity removal from metallurgical grade silicon by acid washing at $50^{\circ}C$ was investigated by employing sulfuric, nitric acid and the mixture of hydrochloric and hydrofluoric acid. Acid washing treatment had no effect on the removal of boron and the concentration of this clement after treatment was rather increased. In our experimental range, the removal percentage of phosphorus was 60%. In the acid washing with sulfuric and nitric acid, the removal percentage of major impurities was below 50%, which indicates that refining effect was not great with these acids. Acid washing with the mixture of hydrochloric and hydrofluoric acid led to removal percentage of higher than 90%. Data on the purity of silicon after acid washing at various conditions are reported.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.9
• /
• pp.3429-3432
• /
• 2011

Distribution diagram of $FeCl_2$ in HCl solution indicated that $FeCl^+$ was a predominant species in strong HCl solution up to 10 M. Solvent extraction of $FeCl_2$ has been performed in the HCl concentration range from 5 to 9 M by using Alamine336 as an extractant. Interaction parameter of $FeCl^+$ for Bromley equation was estimated from our solvent extraction data. This parameter thus obtained in our study can be employed in calculating the activity coefficient of $FeCl^+$ in high concentration of HCl.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.113-116
• /
• 2011

Slope analysis method was applied to determine the stoichiometry of the solvent extraction reaction of Ni(II) by Alamine336 from strong HCl solution range from 1 to 10 M. Solvent extraction data was obtained from the literature. The effective equilibrium constant for the solvent extraction reaction was estimated by considering the ionic equilibria of $NiCl_2$ in the HCl solution. The measured distribution coefficients of Ni(II) agreed well with those calculated in this study. Our results suggest that further study on the measurement of the activities of nickel complexes at high HCl solution need to be done.

• Korean Journal of Metals and Materials
• /
• v.47 no.6
• /
• pp.349-355
• /
• 2009

In the solvent extraction of Ru(IV) with Alamine336, it was found that Ru took part in the reaction as $RuCl_{6}_^{2-}$ in the HCl concentration range of 1 to 5 M. Interaction parameter between hydrogen ion and $RuCl_{6}_^{2-}$ was estimated by applying Bromley equation to the extraction data. From the mixed solutions of Pd(II) and Ru(IV), the distribution coefficients of Pd were found to be higher than those of Ru in the experimental ranges. Separation factor between Pd and Ru rapidly increased with the decrease of Alamine336 concentration. About 60% of the Ru from the mixed solutions was extracted by TBP at 8.3 M HCl, while Pd was not extracted in the HCl concentration range of 1.6 to 8.3 M.

• Analytical Science and Technology
• /
• v.6 no.5
• /
• pp.463-469
• /
• 1993

HDBPDA ion exchange resin, {(4, 5) : (13, 14)-Dibenzo-6, 9, 12-trioxa-3, 15, 21, -triazabicyclo [15. 3. 1]heneicosa-(1, 17, 19)(18, 20, 21) triene ion exchange resin : HDBPDA ion exchange resin} had a capacity of 3.8meq/g dry resin. The distribution coefficients of alkali and alkaline earth metal ions on HDBPDA and strongly acidic cation exchange resin, Dowex 50W-X8(200-400mesh) in water, and the various concentrations of hydrochloric acid were determined. Concentration of hydrochloric acid have almost not influenced on the distribution coefficients of alkali and alkaline earth metal ions for the HDBPDA ion exchange resin, but generally the distribution coefficient slightly increased with decreasing concentration of hydrochloric acid. The distribution coefficients of metal ions in water are larger than those in various hydrochloric acid concentration. The distribution coefficients of alkali and alkaline earth metal ions for the Dowex 50W-X8 ion exchange resin increased with decreasing hydrochloric acid concentration. Especially, the distribution coefficients of alkaline earth metal ions increased rapidly compared to those for alkali metal ions. The distribution coefficients of alkali and alkaline earth metal ions on HDBPDA ion exchange resin increased in a linear manner with decreasing acid concentration, and the slope, d log Kd/d log $M_{HCl}$ is about -0.2. Of the distribution cofficients of alkali metal ions on Dowex 50W-X8, at range of moderate hydrochloric acid concentration, the slope is about -1, while the slope for alkaline earth metal ions is about -2. However, at very low hydrochloric acid concentration, the linear variation between distribution coefficient and acid concentration was not occurred, but the slope was deviated from above values at low acid concentration.