• Membrane and Water Treatment
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• v.11 no.2
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• pp.167-172
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• 2020

The effectiveness of in situ sediment capping as a technique for heavy metal risk mitigation in Hyeongsan River estuary, South Korea was studied. Sites in the estuary were found previously to show moderate to high levels of contamination of mercury, methylmercury and other heavy metals. A 400 m x 50 m section of the river was selected for a thin layer capping demonstration, where the total area was divided into 4 sections capped with different combinations of capping materials (zeolite, AC/zeolite, AC/sand, zeolite/sand). Pore water concentrations in the different sites were studied using diffusive gradient in thin film (DGT) probes. All capping amendments showed reduction in the pore water concentration of the different heavy metals with top 5 cm showing %reduction greater than 90% for some heavy metals. The relative maxima for the different metals were found to be translated to lower depths with addition of the caps. For two-layered cap with AC, order of placement should be considered since AC can easily be displaced due to its relatively low density. Investigation of methylmercury (MeHg) in the site showed that MeHg and %MeHg in pore water corresponds well with maxima for sulfide, Fe and Mn suggesting mercury methylation as probably coupled with sulfate, Fe and Mn reduction in sediments. Our results showed that thin-layer capping of active sorbents AC and zeolite, in combination with passive sand caps, are potential remediation strategy for sediments contaminated with heavy metals.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1222-1227
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• 2005

Optimal sludge recycling ratio for maximum total nitrogen(TN) removal efficiency was calculated stoichiometrically using nitrification and denitrification reaction with given influent water qualities in anoxic-oxic process which was one of the popular nitrogen removal system. The water quality items for stoichiometric calculation were ammonia, nitrite, nitrate, alkalinity, COD, and dissolved oxygen which could affect nitrification and denitrification. Optimal sludge recycling ratio for maximum TN removal efficiency was expressed by those five influent water qualities. TN concentration calculated stoichiometrically had kept good relationship with reported TN concentration in each tank and final effluent. In addition, it was possible to expect the TN concentration in final effluent by stoichiometric calculation within ${\pm}5.0\;mg/L$.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.230-239
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• 2006

Nutrient over-enrichment as a consequence of anthropogenic loading leads to eutrophication, which has the detrimental effects on river and stream ecosystems. To examine dynamics of factors causing cultural eutrophication in a over-licked mountain stream due to anthropogenic loading, physicochemical parameters were measured from 5 stations in the upper Daecheon stream, Busan, from January 2002 to May 2003. The five study sites were located along the stream gradient. DC1 is upper most clean site, and DC5 is located at the lowest area. Wastewater was released into the stream from just upstream of DC2 site. Water column ammonium and phosphate concentrations were higher during winter than other seasons, while water column nitrate +nitrite concentration did not show clear seasonal variation. Water column ammonium, nitrate+nitrite and phosphate concentrations were lowest at DC1 and highest at DC2 in which waste water loading occurred. TOC and DOC, conductivity, turbidity, and BOD in the water column were also increased drastically at DC2, and then decreased at DC5. Sediment pore water phosphate concentrations during winter and spring were higher than those in summer and fall, while sediment pore water ammonium and nitrate +nitrite concentrations showed no seasonal trend. Sediment pore water ammonium and phosphate concentration were also increased at DC2 and slightly decreased at DC5, while sediment pore water nitrate+nitrite concentration was highest at DC5. Organic matter and inorganic nutrients at up-stream of Daechon stream significantly increased as a result of wastewater discharge, and the nutrient concentrations decreased at low-stream suggesting self-purification ability of the stream.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.400-408
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• 2006

Nutritional components of 4 kinds of red seaweeds, Meristotheca papulosa, Chondrus ocellatus, Gracilaria verrucosa, Gigartina tenella, were investigated to elucidate their functionality. Antioxidant activity and nitrite scavenging activity were analyzed from 70% ethanol extracted from these red seaweeds. Large difference in ash contents was found to exhibit among all samples analyzed in this study; $9.8{\pm}0.2g/100g$ for Gracilaria verrucosa and Gigartina tenella for $17.8{\pm}0.6g/100g$. While its crude fiber content was almost the same as those in other sample within a range between $2.0{\pm}0.4g/100g$ and $6.0{\pm}0.7g/100g$. Phenolic compounds content of Gracilaria verrucosa was also the highest as $78.4{\pm}1.0mg/g$, while the total flavonoids contents of Chondrus ocellatus and Gracilaria verrucosa were $14.9{\pm}0.5mg/g$ and $13.9{\pm}0.8mg/g$, respectively. These amounts were two folds higher than Meristotheca papulosa and Gigartina tenella. The total content of minerals was the highest in Meristotheca papulosa(12,107.7 mg/kg). The amount of glutamic acid was relatively high despite of small variation in measured levels of composition amino acid ($49.1{\sim}125.6mg/g$) for most samples investigated. SOD-like ability was significantly increased with increasing sample concentration, but its activity was lower. Gigartina tenella with highest electron donation ability exhibited increases in activity as $53.96{\pm}0.98%$ in concentration of 250 ${\mu}g/ml$ and $70.52{\pm}1.09%$ in 1000 ${\mu}g/ml$, respectively. In case of concentration of 100 ${\mu}g/ml$, particularly, the level of hydroxy radical scavenging activity were $57.87{\pm}1.70{\sim}62.07{\pm}0.87%$ which was significantly higher activity than ascorbic acid and BHT. Nitrite scavenging activity was the highest in Gracilaria verrucosa. Its activity was also increased from $24.04{\pm}1.9{\sim}27.52{\pm}0.82%$ in $100{\sim}500{\mu}g/ml$ concentration tp $34.81{\pm}1.36%$ in concentration of 1000 ${\mu}g/ml$.

• Food Science and Preservation
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• v.19 no.6
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• pp.901-908
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• 2012

This study was conducted to analyze the antioxidant activities of fermented black jujube and to compare these with those of dried jujube, for the development of functional materials. The antioxidative activities of dried jujube and fermented black jujube extracts were analyzed by electron-donating ability (EDA) using 1,1-diphenyl-2-picryl hydrazyl (DPPH), superoxide-dismutase-(SOD)-like activity by pyrogallol, nitrite-scavenging ability, and xanthin oxidase. The yield of the fermented black jujube extracts was higher than that of the dried jujube extracts, and that of the ethanol extracts was higher than that of the hot-water extracts. The total phenol contents of the hot-water extracts from fermented black jujube were higher. The EDA values of the hot-water and ethanol extracts from fermented black jujube and dried jujube increased with an increase in extract concentration, and were about 85% in a $1000{\mu}g/mL$ extract concentration. The SOD-like activity increased with an increase in extract concentration. The SOD-like activity of the hot-water extract from fermented black jujube was higher than that of the other extracts. The nitrite-scavenging ability at pH 1.2 of the hot-water extracts from dried jujube was higher than that of the other extracts. The xanthine oxidase inhibitory activities of the hot-water and ethanol extracts from fermented black jujube were higher than those of the other extracts, and increased along with the concentrations of the extracts.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.60-66
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• 2021

As the concentration of nitrogen in the sewage flowing into the sewage treatment plant increases due to urbanization and industrialization, the degree of adverse effects such as eutrophication and toxicity to the aquatic ecosystem is also increasing. In order to treat sewage containing high concentration of nitrogen, various studies on the biological nitrogen removal process are being conducted. Existing biological nitrogen removal processes require significant costs for supplying oxygen and supplementing external carbon sources. In this respect, as a high-level nitrogen removal process with economic improvement is required, an anaerobic ammonium oxidation process (ANAMMOX), which is more efficient and economical than the existing nitrification and denitrification processes, has been proposed. The purpose of this study is to confirm the stability of the ANAMMOX process in the water treatment process and to derive the ratio of ammonia nitrogen (NH4+) to nitrite nitrogen (NO2-) for the implementation of the mainstream ANAMMOX process. A laboratory-scale Mainstream ANAMMOX reactor was operated by applying the ratio calculated based on the substrate ratio suggested in the previous study. In the initial range, the removal efficiency of NH4+ was 58~86%, and the average removal efficiency was 70%. In the advanced range, the removal efficiency of NH4+ was 94~99%, and the average removal efficiency was 95%. As a result of the study, as the NH4+/NO2- ratio increased, the stability of the mainstream ANAMMOX process was secured, and it was confirmed that the NH4+ removal efficiency and the total nitrogen (TN) removal efficiency increased. As a result, the results of this study are expected to be used as basic data in the application of the ANAMMOX process in the mainstream.

• Culinary science and hospitality research
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• v.17 no.1
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• pp.270-279
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• 2011

This study investigates the antioxidant activities of wild grape seed (Vitis coignetiea seed) extracts by solvents. Organic extracts of hexane, chloroform, ethyl acetate and butanol were obtained from the ethanol extracts of wild grape seed (Vitis coignetiea seed). Total phenolic compound contents of extracts from wild grape seed (Vitis coignetiea seed) by solvents were the highest in ethyl acetate extract, 64.9 mg/100 g. Electron donating abilities of organic solvent fraction obtained from 80% ethanol extracts of wild grape seed were proportionally increased with concentration, and the ethyl acetate extract(90.0%) showed stronger activities than BHT and Ascorbic acid at concentration of $100\;{\mu}L$/mL. Reducing power of organic solvent fraction obtained from 80% ethanol extracts of wild grape seed was the highest in the ethyl acetate extract(2.83) at concentration of $1,000\;{\mu}L$/mL. TBARS of the ethyl acetate extract was highest. Nitrite scavenging ability of organic solvent fraction obtained from 80% ethanol extracts of wild grape seed(pH 1.2, $1,000\;{\mu}L$/mL) was the highest in ethyl acetate extract(76.9%).

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.237-243
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• 2006

This study investigated the development of increased health promotion and higher quality of Gardenia jasminoides noodles. Gardenia jasminoides powder was extracted with water and 70% ethanol, after which their electron donating ability (EDA) and nitrite scavenging ability (NSA) were tested. EDA at $300{\sim}1,000$ ppm of water extract ranged from 65% to 86% and that of ethanol extract from 69% to 91%. NSA of water extract was 79% and ethanol extract was 88% at 1,000 ppm both peaked at pH 1.2. NSA was increased with increasing concentration of extracts and decreasing pH. The quality characteristics of Gardenia jasminoides noodles were evaluated by shelf life, color and sensory evaluation. Total viable cells in Gardenia jasminoides noodles during storage at 5? were $0.2{\sim}0.3$ log cycles, which were lower than those of the control and the shelf-life was expanded. Redness (a) of the dried and cooked noodles was decreased with increasing Gardenia jasminoides concentration (p<0.05). Yellowness (b) of the noodles was increased with increasing Gardenia jasminoides concentration in both the dried and cooked noodles. In sensory evaluation, dried and cooked noodles with $0.2{\sim}0.3%$ Gardenia jasminoides powder d significantly higher scores in overall acceptability(p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.656-660
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• 2014

Physiological properties of Sarcodon aspratus extracts were investigated. Yields of water, 30, 60, and 90% ethanolic extracts were 52.10, 46.90, 41.50, and 32.20%, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of 60% ethanolic extract was 40.40% at a concentration of 4 mg/mL, which was highest of all the extracts. The polyphenol content of 60% ethanolic extract was the highest at 16.23 mg/g at a concentration of 1 mg/mL. Superoxide anion radical scavenging activities were 56.30~77.05% at concentrations of 1, 2, and 4 mg/mL, which were better than the ascorbic acid activity (56.19% at 10 mg/mL) (P<0.05). Nitrite-scavenging ability was the most effective in 30% ethanolic extract. A pH level of 3.0 was the most effective for all extracts. Angiotensin-converting enzyme inhibitory activities of Sarcodon aspratus extracts were from 52.67 to 89.52%.

• Journal of the Korean Society of Fashion and Beauty
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• v.5 no.4
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• pp.139-144
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• 2007

There was an increasing interest that herbal medicine and natural material extracts were proved processes of antioxidant, cosmeceutical activity and the other effects. The aim of this study was to assess the antioxidant of extraction of four kinds from Prunus armeniaca L., Reynoutria elliptica, Curcuma aromatica, Lithospermum erythrorhizon. RE (Reynoutria elliptica) and CA (Curcuma aromatica) have good electron donating ability. The water and ethanol extract of RE at a 100 ppm concentration showed over 70%, the water extract at 500 ppm concentration showed 83% and the ethanol extract at 100 ppm concentration showed 86% of CA. Xanthine oxidase inhibition activity of the water extract of LE (Lithospermum erythrorhizon) at a 1,000 ppm concentration showed over 44%, on the other hand, RE showed in all lowest effect and there was no inhibition activity of a couple more extracts. In the measurement of nitrite scavenging activity, all extracts showed highly scavenging activity. Especially the water and ethanol extract of RE showed over 99% at 500 ppm, also LE showed over 40% at 10 ppm concentration.