• Journal of Environmental Science International
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• v.19 no.1
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• pp.17-26
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• 2010

To understand the initial changes in the microbial activities of wetland soil after construction, dehydrogenase activity (DHA) and denitrification potential (DNP) of soil from 1 natural wetland and 2 newly constructed wetlands were monitored. Soil samples were collected from the Daepyung marsh as a natural wetland, a treatment wetland in the West Nakdong River, and an experimental wetland in the Pukyong National University, Busan. The results showed that the DHA of the natural wetland soil was 6.1 times higher than that of the experimental wetland and similar to that of the treatment wetland 6 months after wetland construction (fall). Few differences were observed in the DNP between the soil samples from the natural wetland and 2 constructed wetlands four months after wetland construction (summer). However, 6 months after the construction (fall), the DNP of the soil samples from the natural wetland was 12.9 times and 1.8 times higher than that of the experimental wetland and the treatment wetland, respectively. These results suggested that the presence of organic matter as a carbon source in the wetland soil affects the DHA of wetland soil. Seasonal variation of wetland environment, acclimation time under anaerobic or anoxic wetland conditions, and the presence of carbon source also affect the DNP of the wetland soil. The results imply that the newly constructed wetland requires some period of time for having the better contaminant removal performance through biogeochemical processes. Therefore, those microbial activities and related indicators could be considered for wetland management such as operation and performance monitoring of wetlands.

• Advances in environmental research
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• v.3 no.2
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• pp.173-183
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• 2014

A comprehensive mathematical model was developed for this study to estimate on-site and off-site GHG emissions from wastewater treatment plants (WWTPs). The model was applied to three different hybrid WWTPs (S-WWTP, J-WWTP, and T-WWTP) including anaerobic, anoxic, and aerobic process, located in Seoul City, South Korea. Overall on-site and off-site GHG emissions from S-WWTP, J-WWTP, and T-WWTP were $305,253kgCO_2e/d$, $282,682kgCO_2e/d$, and $117,942kgCO_2e/d$, respectively. WWTP treating higher amounts of wastewater produced more on-site and off-site GHG emissions. On average, the percentage contribution of on-site and off-site emissions was 3.03% and 96.97%. The highest amount of on-site GHG emissions was generated from anoxic process and the primary on-site GHG was nitrous oxide ($N_2O$). Off-site GHG emissions related to electricity consumption for unit operation was much higher than that related to production of chemicals for on-site usage. Recovery and reuse of biogas significantly reduced the total GHG emissions from WWTPs. The results obtained from this study can provide basic knowledge to understand the source and amount of GHG emissions from WWTPs and strategies to establish lower GHG emitting WWTPs.

• International Journal of Oral Biology
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• v.47 no.1
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• pp.1-8
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• 2022

Inflammation is a protective mechanism against pathogens, but if maintained continuously, it destroys tissue structures. Aggregatibacter actinomycetemcomitans is a gram-negative, facultative anaerobic bacterium often found in severe periodontitis. A. actinomycetemcomitans invades epithelial cells and triggers inflammatory response in the immune cells. In this study, we investigated the effect of water-soluble rosehip extract on A. actinomycetemcomitans-induced inflammatory responses. A human monocytic cell line (THP-1) was differentiated to macrophages by phorbol 12-mystristate 13-acetate treatment. The cytotoxic effect of extract was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effects of extract on bacterial growth were examined by measuring the optical densities using a spectrophotometer. THP-1-derived macrophages were infected A. actinomycetemcomitans after extract treatment, and culture supernatants were analyzed for cytokine production using enzyme-linked immunosorbent assay. Protein expression was measured by western blotting. Extract was not toxic to THP-1-derived macrophages. A. actinomycetemcomitans growth was inhibited by 1% extract. The extract suppressed A. actinomycetemcomitans-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-8 production. It also decreased mitogen-activated protein kinase (MAP kinase) and nuclear factor-κB (NF-κB) phosphorylation. Moreover, the extract inhibited the expression of inflammasome components, including nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3, Absent in Melanoma 2, and apoptosis associated speck-like protein containing a CARD. And cysteine-aspartic proteases-1 and IL-1β expression were decreased by the extract. In summary, extract suppressed A. actinomycetemcomitans growth and decreased inflammatory cytokine production by inhibiting activation of MAP kinase, NF-κB, and inflammasome signaling. Rosehip extract could be effective in the treatment of periodontal inflammation induced by A. actinomycetemcomitans infection.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.75-81
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• 2023

This study was conducted to verify the effectiveness of a combined exercise program to improve the health of the elderly. For this purpose, 10 people in the exercise group and 10 in the control group were selected among seniors aged 65 years or older. The subject of this study was a 12-week combined exercise program in which aerobic and anaerobic exercise were performed three times a week for 60 minutes. Before participating in exercise, blood lipid and inflammatory index tests were conducted, and blood lipid and inflammatory index tests were conducted upon completion of the combined exercise program. The test results were verified with basic statistics and treatment effects between groups using the SPSS statistical program. Based on this, the following conclusions were obtained. First, the combined exercise program for elderly health promotion showed significant differences in TC, LDL, and TG in blood lipids between the exercise group and the control group, and there was an interaction effect on the treatment program. Second, the combined exercise program for improving the health of the elderly showed significant differences in inflammatory indicators IL-6 and TNF-a between the exercise group and the control group, and there was an interaction effect with the treatment program.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.278-284
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• 2011

To obtain optimum configuration method and livestock wastewater loading in small-scale livestock wastewater apparatus by natural purification method for treating livestock wastewater, the small-scale livestock wastewater apparatuses were constructed with 9 kinds of combined systems such as aerobic bed (ae)-anaerobic bed (an), ae-ae, ae-anoxic bed (ox), an-an, an-ae, an-ox, ox-ae, ox-an and ox-ox livestock wastewater treatment apparatuses. Under different configuration methods, the removal rate of COD in Ae-Ae and Ae-An livestock wastewater treatment apparatus was higher than that in other configuration methods. The removal rate of T-N in Ae-An livestock wastewater treatment apparatus was higher than that in other configuration methods. Removal rates of SS and T-P were not different regardless of configureation methods in small-scale livestock wastewater treatment apparatus. Under different livestock wastewater loading, the removal rates of pollutants were higher in the order of $50L\;m^{-2}\;day^{-1}{\fallingdotseq}100L\;m^{-2}\;day^{-1}\;>\;200L\;m^{-2}\;day^{-1}$. Therefore, optimum configuration method was Ae-An livestock wastewater treatment apparatus, and optimum livestock wastewater loding was $100L\;m^{-2}\;day^{-1}$ in small-scale livestock wastewater treatment apparatus.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.5
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• pp.209-217
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• 2015

Development of food industry and increased city life induced enlarged generation of food waste which is currently reused in a wide range of way. In this study, treatment of food waste generated from the public agricultural product wholesale markets (they are categorized as business places which imposes the duty for reducing the food waste discarded) in Korea was investigated, and subsequently, a scheme for improving the food waste recycling business was suggested. The food waste treatment plants are mainly located in Kyeongki-do at 39.5% of total plants in Korea and the other provinces have less than 10% of the total numbers, among which public treatment plant was 38.0% and private plant was 62.0%. The treatment methods included recycling as animal feed at 47.5%, as compost at 36.4%, and the rest of food waste (12.6%) was treated in other ways. Remarkably, it was noticed that the amount of food waste treated in anaerobic digestion have been increased up to 5.4% since 2011. This implied that food waste treated in anaerobic digestion method is gradually increased according to government policy. Amongst 33 public agricultural product wholesale markets distributed all over the country, the trading volume dealt in Garakdong market in Seoul, Gangseo market in Seoul, Daegu market in Daeju, Eomgung market in Busan, Guri market in Guri accounted for 34.67, 7.47, 6.98, 5.41, and 5.30% of the total trading volume in Korea, respectively. 2.65% of the total trading agricultural products dealt in the markets were remained as food waste and treated. In 2006, Ministry of Agriculture, Food and Rural Affairs implemented the package policy for radish and Chinese cabbage in order to reduce the amount of food waste and indeed, food waste generated in Garakdong market declined to one third of the food waste before the package policy implementation. In 2010, the food waste amount treated by 'dehydration', 'discarding as raw materials', and 'drying after dehydration' accounted for 56.3%, 33.7%, and 10.0% of the total food waste generated in the public agricultural product wholesale market. However, in 2013, discarding as raw materials accounted for the most at 56.3% followed by dehydration at 37.5%, and by drying after dehydration at 6.3%. The remarkable increment of the food waste discarded as raw materials was attributed to the increase of them in Garakdong market in Seoul. In general, the agricultural food waste contains high amount of moisture at 88% in average and low amount of salt at 0.02% in average. Therefore, it is highly recommended to treat the agricultural food waste through drying after dehydration in order for improving the treatment capability. Also, this recommendation can be supported by the fact that the end-products via drying after dehydration can be utilized as compost material. Overall, the agricultural food waste recycling business can be developed through integration of the treatment via 'drying after dehydration' and compost production.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.42-49
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• 2012

This experiment was conducted to find out the effects of nitrous oxide ($N_2O$) on the postharvest quality of 'Janghowon hwangdo' peach fruits. Fruits were harvested at commercial maturity for marketing in late September, and treated with 70% $N_2O$ + 20% $O_2$ + 10% air, 80% $N_2O$ + 20% $O_2$, and 90% $N_2O$ + 10% $O_2$ for 48 h, and then stored at $15^{\circ}C$. No significant treatments for soluble sugar and titratable acidity contents were detected. However, good appearance and taste in peach fruit were maintained better in 80% $N_2O$ treatment than in air treatment. The treatment with 90% $N_2O$ had negative effects on weight loss and taste because of rotting by anaerobic fermentation. 80% $N_2O$ treated fruit had significantly higher fungus (Botrytis cinerea) growth inhibition of saprogenic approximately than air treatment until 12 days of storage. The browning and rotting at surface of peach were also retarded when peaches were treated with 80% $N_2O$ before they were artificially wounded. The activity of polyphenol oxidase (PPO) was inhibited about 80% in peach of 80% $N_2O$ treatment compared with in air treatment. The result showed that 80% $N_2O$ treatment was able to extend the shelf life of peach fruits through maintaining taste and inhibition of softening and browning by rotting and wounding during storage.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1049-1057
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• 2012

The study investigated the biochemical methane potential (BMP) assay of pig slurry supplemented with mixed methanogens and cellulolytic bacteria to improve anaerobic digestion for methane production. For the BMP assay, 7 different microbial supplementation groups consisted of the cultures of mixed methanogens (M), Fibrobacter succinogenes (FS), Ruminococcus flavefaciensn (RF), R. albus (RA), RA+FS, M+RA+FS, and control. The cultures were added in the batch reactors with the increasing dose levels of 1% (0.5 mL), 3% (1.5 mL) and 5% (2.5 mL). Incubation for the BMP assay was carried out for 60 days at $38^{\circ}C$ using anaerobic digestate obtained from an anaerobic digester with pig slurry as inoculum. In results, 5% RF and RA+FS increased total biogas up to 8.1 and 8.4%, respectively, compared with that of control (p<0.05). All 5% microbial culture supplements significantly increased methane production up to 12.1~17.9% compared with that of control (p<0.05). Total solid (TS) and volatile solid (VS) digestion efficiencies showed no relationship to the increased supplementation levels of microbial cultures. After incubation, pH values in all treatment groups ranged between 7.527 and 7.657 indicating that methanogensis was not inhibited during the incubation. In conclusion, the results indicated that both hydrolysis and methanogenesis stages for methane production in anaerobic batch reactors were influenced by the supplemented microorganisms due to the chemical characteristics of pig slurry, but only the 5% supplementation level of all microbial culture supplements used in the experiment affected methane production.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.90-96
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• 2000

The composition of leachates varies depending on the waste characteristics, landfill age and landfilling method. Generally, leachates contain high dissolved organic substance and ammonia nitrogen whereas phosphorus concentration was very low. Leachate A produced from young landfill is characterized by high BOD5/COD ratio (0.8) whereas leachate C produced from old landfill has lower BOD5/COD ratio (0.1). Maximum biochemical methane potential of leachate A, B (from medium landfill) and C were 271,106 and 4 ml CH4/g-COD, respectively. On the other hand, the maximum biodegradability of leachate A, B, and C were 75,30, and 1%, respectively. These results indicated that anaerobic treatment of leachate from young landfill was effective in removing organic pollutants. In case of leachate C, carbon might reside in the form of large molecular weight organic compounds such as lignins, humic acids and other polymerized compounds of soils, which are resistant to biodegradation. The lag-phase period increased with the increasing organic concentration in leachate. In case of leachate A of concentration greater than 25%, the lag-phase period increased sharply. This implied that the start-up period of anaerobic process using an unacclimated inoculum could be extended due to the higher concentration of leachate. This relatively long lag-phase is probably related to the fact that most of the inhibitory compounds have been diluted beyond their inhibitory concentrations of less than 50%. Furthermore, the ultimate methane yield and methane production rate decreased as leachate concentration increased. It was anticipated the potential inhibition was related with the steady-state inhibition as well as the initial shock load.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.15-26
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• 2023

Methane production by anaerobic digestion occurs through interspecies electron transfer (DIET), a synthetic metabolism between acetic and methanate bacteria through hydrolysis and acid production steps. In this study, to improve methane yield, the effect of addition of magnetite (Fe₃O₄), a conductor promoting DIET on methane production in food wastewater was investigated, and the effect on methane yield was assessed by methane potential (B_u) and maximum methane production rate [R_m(t₀)] by the operation of batch type anaerobic reactor adding Fe₃O₄. The B_u and R_m(t₀) of food wastewater without Fe₃O₄ were 0.496 Nm³/kg-VSadded and 38.24 mL/day, respectively. The t0 which reached to R_m appeared at 21.06 days during the operation of the anaerobic reactor. The B_u of food wastewater with Fe₃O₄ was 0.502, 0.498, 0.512, 0.510, 0.518, 0.523, 0.524, 0.540, and 0.549 Nm³/kg-VSadded in the treatment of 5, 10, 15, 20, 25, 30, 40, 70, and 100mM-Fe₃O₄, respectively, and the B_u significantly increased to 36.95% with the addition of magnetite in the addition of 15mM-Fe₃O₄. And, the addition of Fe₃O₄ shortened the duration to reach R_m from 21.06 days to the maximum of 14.67 days by the addition of Fe₃O₄. Therefore, the methane yield and production rate of food wastewater significantly improved with the addition of Fe₃O₄.