• Journal of Korean Society of Water and Wastewater
• /
• v.24 no.1
• /
• pp.15-24
• /
• 2010

Coagulation can be used for pretreatment of NF membrane filtration. Foulants such as organic matter and particulate can be removed effectively with the process while high flux recovery is maintained. Recently various types of polyaluminium coagulants including polyaluminium chloride(PAC) are commercially available for water treatment. This study examines effects of polymeric Al and hydrolysis products of PAC on nanofiltration membrane performance. Dominant hydrolysis products were polymeric Al, $Al(OH)_3$, and ${Al(OH)_4}^{-1}$ at acidic, neutral, and alkaline pH conditions, respectively. Under acidic pH condition, flux decline was increased with increasing PAC concentrations, possibly due to polymeric Al adsorption on membrane pore and/or surfaces. For neutral and alkaline pH conditions, little flux decline was observed with increasing PAC concentrations except the highest ${Al(OH)_4}^{-1}$ concentration, with which rapid flux decline was shown. Removal of ionic matters was also varied with pH conditions in this study. Especially, conductivity removal was substantially low and $Ca^{2+}$ concentration in the permeate was quite high at neutral pH condition.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.10
• /
• pp.1583-1587
• /
• 2015

Bile acids are endogenous metabolites that aid in the digestion and absorption of ingested fat and fat-soluble vitamins. However, high concentrations of deoxycholic acid (DCA) in the colon are associated with high incidence of colorectal cancer. In the present study, the binding of persimmon extracts to DCA in order to decrease inflammatory stress induced by DCA in a small intestinal epithelial cell line, Caco-2, was investigated. Young and ripened persimmons were extracted with distilled water (DW), ethanol, and acidic ethanol. Further, DW extract residue was re-extracted with acidic ethanol. Of the obtained extracts, acidic ethanol extract of young persimmon showed the highest bile-acid binding capacity. Moreover, acidic ethanol extract of young persimmon significantly inhibited nitric oxide production in Caco-2 cells stimulated with DCA and prevented significant reduction of trans-epithelial electric resistance. Based on these results, acidic ethanol extract of young persimmon can be used as a functional ingredient to enhance gastrointestinal health.

• Journal of Korean Society on Water Environment
• /
• v.32 no.6
• /
• pp.628-648
• /
• 2016

Increased attention has been paid to the presence of veterinary antibiotics in various environmental matrices due to their toxicological behavior in the ecosystem and development of antibiotic-resistant strains of pathogenic bacteria. In the this review, 37 target antimicrobials were selected based on annual sales of antibiotics for livestock in South Korea 2014. Also, extraction and clean-up methods for the determination of the antibiotic residues in liquid samples including water, milk, and honey were comprehensively reviewed in the literature. Solid-phase extraction (SPE) was commonly used as a pre-treatment method for the samples. Most of the analytes were extracted in acidic conditions (2.5~4.0) except for aminoglycosides, which were extracted in neutral conditions (7.0~8.0). ${\beta}-Lactams$ showed the highest recoveries in neutral pH due to their degradation characteristics in acidic media. Starta-X, Oasis HLB, and Oasis MCX were frequently applied as an SPE cartridge and Oasis HLB showed the highest recoveries for the majority of antibiotic classes. The homogenized honey and milk were extracted by mixing with acids for deproteinization. Solids and other interfering substances in the extract were eliminated by centrifugation followed by membrane filtration or SPE before injection into HPLC.

• Journal of the Korean Society of Safety
• /
• v.35 no.6
• /
• pp.85-92
• /
• 2020

Wet Scrubber reacts the incoming pollutant gas with cleaning water (water + absorbent) to absorb pollutants and release the clean air to the atmosphere. Wet scrubbers and packed tower scrubbers using this principle are widely used in businesses that emit acid gases. In particular, in the etching process using hydrochloric acid (HCl), alkaline washing water (NaOH) having a pH of about 8 to 11 is used to absorb a large amount of acid gas. However, These salts are attached to the injection nozzle (nozzle), filling material (packing), and the demister (Demister), causing air pollution, human damage, and inoperability due to clogging and acid gas discharge. Therefore, In this study, an improvement plan was proposed to manage the washing water with pH 3~4 acidic washing water. The test method takes samples from the Wet Scrubber flue measurement laboratory twice a month for 1 year. Hydrogen chloride (HCl) concentration (ppm) was measured, and nozzle clogging and scale conditions were measured, compared, and analyzed through a differential pressure gauge and a pressure gauge. As a result of the check, it was visually confirmed that the scale was reduced to 50% or less in the spray nozzle, filler, and demister. In addition, the emission limit of hydrogen chloride in accordance with the Enforcement Regulation of the Air Quality Conservation Act [Annex 8] met 3 ppm or less. Therefore, even if the washing water is operated in an acidic pH range of 3 to 4, it is expected to reduce air pollution and human damage due to clogging of internal parts, and it is expected to reduce maintenance costs such as regular cleaning or replacement of parts.

• Journal of Korean Society on Water Environment
• /
• v.36 no.2
• /
• pp.137-147
• /
• 2020

A direct contact membrane distillation (DCMD) was applied to treat strong nitrogenous wastewater of anaerobic digestion supernatant (ADS) and human urine (HU). The ammonia transfer was evaluated in terms of specific ammonia transfer (SAT) value, which is the ratio of total ammoniacal nitrogen divided by the amount of water transferred. The acidification resulted in low SAT values and high quality of produced water. The ammonia transfer control in the acidic condition was stronger for HU than ADS due to higher alkalinity (pH 8.8) and ammonia concentration (5700 mg-N/L) of HU. Acidified HU at pH 4 exhibited a SAT value of 1.64 × 10^-5, which was significantly smaller than the SAT value of 3.00 × 10^-3 for the original HU. The low pH enhanced the water flux for ADS, but HU showed a steep decrease in water flux due to enhanced fouling. It was considered that the fouling intensity in acidic conditions depends on the characteristics of the wastewater source. The major foulants on the MD membrane were NaCl, CaCO₃ and CuSO₄ as recognized by the SEM-EDS. Acidified ADS and HU at pH 4 showed relatively high N content of 8.18 % and 28.03 %, respectively, as organic fouling.

• Journal of Ginseng Research
• /
• v.30 no.1
• /
• pp.41-48
• /
• 2006

In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred In initial stage of steaming fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after steaming. Browning reaction of red ginseng occurred between $60{\sim}90$ min of steaming at $100^{\circ}C$, and browning pigments of red ginseng were mostly water soluble substances. The structural characteristics of water soluble browning reaction products(WS-BRPs) isolated from Korean red ginseng were showed the presence of hydroxyl, amide carbonyl and aliphatic methane groups. From sugar analysis it was identified that L and S-1, melanoidins isolated from red ginseng, contained two kinds of sugars, glucose and xylose, and the other melanoidin S-2 contained the previous and fructose. In order to find out pertinent methods for the acceleration of browning during ginseng processing, various treatment were made on fresh ginseng with sugars, amino acids and inorganic nitrogenous compounds and the extent of browning was measured. Among sugar tested, maltose resulted in the greatest acceleration of browning followed in decreasing order by glucose and lactose, whereas pentoses, fructose, sucrose and raffinose had negligible effect. A marked browning occurred in ginseng treated with basic amino acids, while the extent of browning was not greatly increased when ginseng was treated with aliphatic amino acids, hydroxyl amino acids, or acidic amino acids. The brown color intensity gradually increased with an increase of glucose concentration far up to 0.5M. L, S-1, and S-2 were found to have an ability to donate hydrogen to DPPH, and also they had anti-oxidative activity in the experiments of hydrogen peroxide scavenging, inhibitory activity in the formation of MDA from linoleic acid, auto oxidation of ok-brain homogenates, lipid peroxidation by the enzymatic and non-enzymatic system in liver microsome fraction, and mitochondrial fraction etc. The amounts of acidic polysaccharide(AP) in red ginseng were higher than those of wild and cultured Panax quinquefolius, Panax notoginseng as well as white ginseng (Panax ginseng). In white ginseng, the AP amount is no difference in root ages or sizes, also, the AP amount of ginseng body was similar to that of rhizome, but was higher than that of leaf and epidermis. Addition of red ginseng acidic polysaccharide(RGAP) increased production of nitric oxide(NO) and tumor necrosis factor (TNF)-$\alpha$ in the rodent macrophage cultures, and treatment of RGAP in vivo stimulated tumoricidal activities of natural killer (NK) cells.

• Economic and Environmental Geology
• /
• v.43 no.2
• /
• pp.149-162
• /
• 2010

The most serious problem in oil stockpiles with artificial underground cavern is maintaining the stability of ground water system. In order to understand the ground water system around K-1 site, we determined the regional flow direction and level distribution of groundwater, and investigated the major geologic factors influencing their flow system. Reactivated surface along the contact between granite and gneiss, and fractures and faults along the long acidic dyke may contribute as important pathways for groundwater flow. Within K-1 site, groundwater level fluctuation is closely related to the rainfall events and injection from surface or influx water. In this project, the effect of groundwater pumping from the southern wells was examined. Based on equations relating water level drawdown to pumping rate at those wells, their pumped outflow of groundwater ranged from $80\;m^3$/day to less than $250\;m^3$/day. The modeling results with MODFLOW imply that the previous groundwater pumping at distance of 1.2 km may not affect the groundwater level variations of the K-1 site. However, continuous pumping work at quantity over $250\;m^3$/day in this area will be able to affect the groundwater system of the K-1 site, particularly along the acidic dyke.

• Preventive Nutrition and Food Science
• /
• v.3 no.4
• /
• pp.315-319
• /
• 1998

Previously, the methanolic extract of Paeonia moutan seeds was found to potently inhibit soybean lipoxy-genase (SLO). Hence to isolate SLO inhibitor, the defattd methaniolic extract of the seeds was consecutively partitioned wiht ether, ethyl acetate,n-butanol ,adn water. The ether souble fraction showing strong inhibitory activity against SLO was further fractionated into a strongly acidic, a weakly acidic, and a neutral fractions. The strongly acidic components of the ether extract were successively subjected to chromatography on a silica gel, Sephadex LH-20, and preparative HPLC. Four phenolic compounds were isolated , and twio of them showing a strong SLO inhibition activity were identified as luteolin (IC50=2.32$\mu\textrm{g}$/ml) and 5,6,4'-trihydroxy-7,3'- dimethoxylflavone (IC50=0.31$\mu\textrm{g}$/ml) by UV, IR, 1H-& 13C-NMR, and MS spectroscopy. In addition, two flavonoids showed significantly antioxidative activity as strong as that of of $\alpha$-tocopherol (p<0.05) in the autoxidation system of linoleic acid. These results suggest that luteolin and 5,6,4'-trihydroxy-7,3'-dimethoxy-flavone may be used as a potential source of anti-inflammatory agents with antioxidative activity.

• Toxicological Research
• /
• v.19 no.3
• /
• pp.173-180
• /
• 2003

The present study was conducted to investigate the single and 2-week repeated dose toxicity of red ginseng acidic polysaccharide (RGAP) in Sprague-Dawley rats. The test article was administered orally to rats at dose levels of 0, and 2000 mg/kg/day for single dose toxicity study and at dose levels of 0, 250, 500, and 1000 mg/kg/day for repeated dose toxicity study. In both studies, there were no treatment-related effects on mortality, clinical signs, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, necropsy findings and organ weights of all animals treated RGAP. Based on these results, it was concluded that the 2-week repeated oral dose of RGAP may have no toxic effect in rats at a dose level of 1000 mg/kg/day. In the condition of this study, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day for both sexes.

• YAKHAK HOEJI
• /
• v.36 no.4
• /
• pp.350-356
• /
• 1992

Anticoagulant activities were tested for the fifteen kinds of medicinal plants by measuring activated partial thromboplastin time (aPTT). Of them five kinds or species (Artemisia princeps, Sanguisorba officinalis, Artemisia apiacea, Eclipa alba, Schizonepeta tenuifolia) were selected and fractionated for the preparation of acidic polysaccharides. They were extracted with water by refluxing and the extracts were precipitated with ethanol. The precipitates were separated based on charge using a DEAE-Sephadex. The low salt and high salt fractions were sulfated with anhydrous pyridine and chlorosulfonic acid complex. In vitro anticoagulant activities of sulfated polysaccharides were tested by measuring aPTT, prothrombin time (PT), and factor Xa clotting time using normal human plasma. No relationship was found between the amount of uronic acids and anticoagulant activities, but the sulfated ones show the increase of activities. In vivo anticoagulant properties of the sulfated polysaccharide from Artemisia apiacea were also tested by the intraveneous administration of three different doses (3,5 and 10 mg/kg) to rats. APTT and PT were increased significantly and the action of factor Xa and thrombin mediated through antithrombin III were inhibited slightly.