• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.565-572
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• 2016

While there have been great demands on improving domestic water pollution issues, the necessity for real time monitoring of particular drug residues in water resources has been raised since drug residues including antibiotics could provoke new trains of drug-resistant bacteria in water environments. Among many different types of drugs used for pharmaceutical treatment, antibiotics are considered to be one of the most hazardous to our ecosystem since they can rapidly promote the spreading of drug-resistant bacteria in water environments. In this mini-review, we will highlight recent developments made on creating in-situ sensing platforms for the fast monitoring of antibiotic residues in aquatic environmental samples focusing on optical and electrochemical techniques. Related recent technology developments and the resulting economy effects will also be discussed.

• Bulletin of the Korean Chemical Society
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• v.14 no.3
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• pp.377-384
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• 1993

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.98-105
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• 2005

Groundwater sampled from 24 tube wells of three districts namely Sherpur, Gaibandha and Naogaon in Bangladesh was appraised for their water quality for irrigation and agro-based industrial usage. All waters under test were slightly alkaline to alkaline (pH = 7.2 to 8.4) in nature and were not problematic for crop production. As total dissolved solid (TDS), all groundwater samples were classified as fresh water (TDS<1,000 mg/L) in quality. Electrical conductivity (EC) and sodium adsorption ratio (SAR) values reflected that waters under test were under medium salinity (C2), high salinity (C3) and also low alkalinity (S1) hazard classes expressed as C2S1 and C3S1. As regards to EC and soluble sodium percentage (SSP), groundwater samples were graded as good and permissible in category based on soil properties and crop growth. All water samples were free from residual sodium carbonate (RSC) and belonged to suitable in category. Water samples were under soft moderately hard, hard and very hard classes. Manganese, bicarbonate and nitrate ions were considered as major pollutants in some water samples and might pose threat in soil ecosystem for long-term irrigation. For most of the agro-based industrial usage, Fe and Cl were considered as troublesome ions. On the basis of TDS and hardness, groundwater samples were not suitable for specific industry. Some water samples were found suitable for specific industry but none of these waters were suitable for all industries. The relationship between water quality parameters and major ions was established. The correlation between major ionic constituents like Ca, Mg, K, Na, $HCO_3$ and Cl differed significantly. Dominant synergistic relationships were observed between EC-TDS, SAR-SSP, EC-Hardness, TDS-Hardness and RSC-Hardness.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.157-161
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• 2006

The performance of abiotic degradation of oxadiazon was investigated by applying zerovalent iron(ZVI), potassium permanganate($KMnO_4$) and titanium dioxide($TiO_2$) in the contaminated water. Experimental conditions allowed the disappearance of oxadiazon in the abiotic system. The degradation of this herbicide was monitored in buffer solutions having pH 3, 5 and 7 in the presence of iron powder in which the maximum degradation rate was achieved at acidic condition(pH 3) by 2% of ZVI treatment. The oxidative degradation of oxadiazon was observed in aqueous solution by $KMnO_4$ at pH 3, 7 and 10 in which the highest disappearance rate was found at neutral pH when treated with 2% of $KMnO_4$. The catalytic degradation of oxadiazon in $TiO_2$ suspension was obtained under dark and UV irradiation conditions. UV irradiation enhanced the degradation of oxadiazon in aquatic system in the presence of $TiO_2$. Conclusively, the remediation strategy using these abiotic reagents could be applied to remove oxadiazon from the contaminated water.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1192-1198
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• 2010

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

• Corrosion Science and Technology
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• v.16 no.6
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• pp.285-293
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• 2017

The effects of sulfate reducing bacteria (SRB) on the corrosion and scaling of the Q235 carbon steel has been investigated in the simulated sewage water and oil field gathering pipelines production water, using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), and three-dimensional stereoscopic microscope. Results indicated that the concentration of SRB reached the maximum value on the ninth day in simulated sewage water with a large amount of scaling on the surface of specimen. In oil field gathering pipelines, a large amount of scaling and mineralization of mineral salts and thick deposition of extracellular polymeric substance (EPS) layers were also observed on the surface of specimen. The thickness of biofilm was about $245{\mu}m$ within 30 days. After adding microbicides, the thickness of corrosion products film was only up to $48-106{\mu}m$ within 30 days, suggesting that SRB could induce biomineralization. Under-deposit corrosion morphology was uniform in the absence of microbicides while local corrosion was observed in the presence of microbicides.

• Bulletin of the Korean Chemical Society
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• v.6 no.1
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• pp.33-36
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• 1985

The luminescence intensity of $Tb^{3+}$ bound to picolinic acid, squaric acid, and 2,3-pyrazinedicarboxylic acid has been studied in water and water-ethanol mixtures. It has been found that the emission intensity of $Tb^{3+}$ in the complexes is enhanced with the increase of ethanol content in water-ethanol mixtures. Several factors affecting on the emission intensity of $Tb^{3+}$ in waterethanol mixtures are discussed.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.188-194
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• 2010

The electrolyzed sterilizing water is useful functional aqueous solution, which is produced by electrolyzing aqueous solution. Electrolytic supplement such as salt or hydrochloric acid is added into tap water. Electrolyzed sterilizing water is classified as three types; strongly acidic electrolyzed water, weakly acidic electrolyzed water, and sodium hypochlorite water. In this study, preparation principles, advantages, and disadvantages of electrolyzed sterilizing water were analyzed. The technology trend in electrolyzed sterilizing water was analyzed based on patent application year, countries, main applicants, and each technologies.

• Journal of the Korean Chemical Society
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• v.30 no.4
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• pp.352-358
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• 1986

An extensive experimental survey on the retention behaviors of phenols in the binary solvent system such as methanol-water, acetonitrile-water and tetrahydrofuran-water as well as the ternary solvent system such as methanol-acetonitrile-water and methanol-tetrahydrofuran-water is presented. A linear equation, which describes the capacity factor as a function of the solvent composition in the mobile phase and is able to predict the retention behaviors of phenols, was obtained. The iso-eluotropic lines for the binary and ternary solvent system are based on the equal strength of the methanol-water solvent which shows an optimum separation of the phenols used. The specific effect of each solute in the binary solvent system appeared to be larger than those in the ternary system.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1761-1766
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• 2005

Solvolysis rates of isopropenyl chloroformate (3) in water, $D_2O$, $CH_3OD$ and in aqueous methanol, ethanol, 2,2,2-trifluoroethanol (TFE), acetone, 1,4-dioxane as well as TFE-ethanol at 10 ${^{\circ}C}$ are reported. Additional kinetic data for pure water, pure ethanol and 80%(w/w) 2,2,2-trifuoroethanol (T)-water (W) at various temperatures are also reported. These rates show the phenomena of maximum rates in specific solvents (30% (v/v) methanol-water and 20% (v/v) ethanol-water) and, variations in relative rates are small in aqueous alcohols. The kinetic data are analyzed in terms of GW correlations, steric effect, kinetic solvent isotope effects (KSIE), and a third order model based on general base catalysis (GBC). Solvolyses based on predominately stoichiometric solvation effect relative to medium solvation are proceeding in 3 and the results are remarkably similar to those for p-nitrobenzoyl chloride (4) in mechanism and reactivity.