• Journal of Korea Water Resources Association
• /
• v.55 no.10
• /
• pp.785-799
• /
• 2022

The aim of this study was to characterize the emission pathways and the footprint of greenhouse gases (GHG) in Daecheong Reservoir using the G-res Tool, and to evaluate the GHG emission intensity (EI) compared to other energy sources. In addition, the change in GHG emissions was assessed in response to the total phosphorus (TP) concentration. The GHG flux in post-impoundment was found to be 262 gCO₂eq/m²/yr, of which CO₂ and CH₄ were 45.7% and 54.2%, respectively. Diffusion of CO₂ contributed the most, followed by diffusion, degassing, and bubbling of CH₄. The net GHG flux increased to 510 gCO₂eq/m²/yr because the forest (as CO₂ sink) was lost after dam construction. The EI of Daecheong Reservoir was 86.8 gCO₂eq/kWh, which is 3.7 times higher than the global EI of hydroelectric power, due to its low power density. However, it was remarkable to highlight the value to be 9.5 times less than that of coal, a fossil fuel. We also found that a decrease in TP concentration in the reservoir leads to a decrease in GHG emissions. The results can be used to improve understanding of the GHG emission characteristics and to reduce uncertainty of the national GHG inventory of dam reservoirs.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.18 no.4
• /
• pp.77-85
• /
• 2010

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Recently, there has been the movement toward reusing the pig slurry as an alternative fertilizer sources for agricultural lands. For instance, SCB(Slurry Composting & Biofiltration) liquid fertilizer has been developed and widely used in Korea. However, the impacts of swine slurry liquid fertilizers on both agricultural environment and crop yield have not been investigated yet. Therefore, the current study was conducted to accumulate the basic data which can be subsequently used to determine appropriate application amount of swine slurry liquid fertilizers (SCB liquid fertilizer and storage liquid fertilizer) as well as the application method for each liquid fertilizer. For this, growth of rice was cultivated under the treatment of SCB liquid fertilizer, storage liquid fertilizer, and chemical fertilizer. Also, control treatment (no fertilizer) was included for comparison and all treatments were conducted in five replication. Rice growth was good with the treatment in the order of chemical fertilizer>storage liquid fertilizer>SCB liquid fertilizer>control and likewise, the yield amount of rice straw was in the same order of rice growth. The rice yield amount appeared to be no difference among the treatment except control which showed the least yield amount. Also there was no difference in nitrogen and phosphorus concentrations in rice among the treatment except control which showed the least concentration.

• Korean Journal of Agricultural Science
• /
• v.26 no.1
• /
• pp.58-64
• /
• 1999

The chemical composition and ruminal dry matter digestibilities of leaves, stems and roots of Aralia cordata Thunberg were determined and compared each other as a roughage sources for ruminants. The crude protein contents were higher for leaves(12.4%) than for leaves+stems (9.7%), stem(5.1%) and roots (3.8%) (P<0.05). The crude fat contents were higher for leaves (3.7%) than for roots (2.1%) and stems (1.3%) (P<0.05). The crude fiber contents were lower for roots (12.3%) than for leaves (15.0%), leaves+stems (27.7%) and stems (40.3%) (P<0.05), respectively. The contents of neutral detergent fiber were lower for leaves (30.2%) than for leaves+stems (42.0%), roots (50.8%) and stems (60.0%) (P<0.05), respectively. The contents of acid detergent fiber were lower for root(18.3%) than for leaves(21.4%). leaves+stems (37.5%) and stems (49.6%) (P<0.05), respectively. The calcium content of leaves(2.4%) were higher than those of stems and roots (0.97% and 0.69%), however the phosphorus contents were similar among leaves, stems and roots(0.25%, 0.19% and 0.35%). Ruminal dry matter digestibilities for 12, 24, 48 and 72hr of leaves(38.9%, 65.9%, 79.8% and 82.4%) and roots(38.9%, 59.8%, 77.6% and 78.5%) were higher than stems(31.1%, 44.1%, 49.5% and 52.6%). Furthermore the digestibilities of leaves were higher than those of alfalfa hay(37.4%, 48.8%, 67.8% and 71.8%) and although the digestibilities of stems which were the lowest among the parts were higher than those of acasia wood chip(12.6%, 18.2%, 21.6% and 24.3%).

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.875-884
• /
• 2003

Operational parameters for struvite crystallization, as a process to recover nitrogen and phosphorus resources from animal wastewater, were studied in this research. Crystallization distinctive of NH$_4$-N and PO$_4$$^{3-}$ in accordance to chemical sources, influent pH, aeration and stirring was examined using 2L of working volume of struvite reactor. Also, to find an effective treatment process combining with electrolysis method, removal characteristics of NH$_4$-N and PO$_4$$^{3-}$ in 6 different processes was tested. As chemical sources for the derivation of struvite formation, MgSO$_4$ and MgCl$_2$ were superior to CaCO$_3$ and CaCl$_2$. From experiment which was conducted to know the effects of aeration and stirring on struvite formation, it was revealed that aeration stimulated the crystallization reaction by inducing faster pH increase. While 90% of P removal was achieved within 1 hour under aeration, 14 hours was consumed under stirring condition. Struvite formation under aeration was affected by influent pH. No crystallization was observed at pH 5 level, but active crystallization reaction was induced over pH 6.0. 95% of P removal by struvite formation at pH 6, 7 and 9 was achieved within 3h, 2h and 10 min., respectively. However, over pH 10, operational problem due to excessive foam formation occurred, and blunting of crystallization reaction was observed at pH 11. When consider the pH range of animal wastewater, pH 7 to 9, efficient struvite formation could be achieved by simple aeration, without any chemical usage for pH adjustment. Among tested processes, the treatment process which electrolyzing the supernatant from struvite reactor, providing air to both reactors, showed best pollutant removal efficiencies. In this combined process, the removal efficiencies of NH$_4$-N and PO$_4$$^{3-}$ was 86% and 98%, respectively, and 92.4% of color removal was obtained.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.14 no.4
• /
• pp.213-223
• /
• 2011

The status and changes of water quality of national fishing harbors and designated ports in East Coast of Korea were analyzed to support establishment effective water environmental management. COD (Chemical Oxygen Demand) concentration was satisfied to designated water quality criteria in most areas, but TN (Total Nitrogen) and TP (Total Phosphorus) exceeded the criteria frequently. Also, peak concentration was summer in COD and SS (Suspended Solid), but winter in TP. Eutrophication index of Ganggu and Pohang (old) area were the highest. Pollution index by function of COD, TN, and TP of Ganggu, Pohang, Jumunjin, and Guryongpo was high with gradual increasing recently, on the contrary, that of Samcheok, Imwon, and Chuksan was decreased. Pollution index involving multi-indictors relation to organics and inorganics was necessary for water quality assessment. Designated water quality criteria needed to be improved because the criteria of Jukbyun and Chuksan was applied more strictly compared to the other regions although without difference of environmental characteristics. Furthermore, the criteria notified lately needed to be related to management pollutants from land-based sources. The continuous diagnosis and monitoring on sediment quality within the study area were necessary for prevention of water pollution and eco-friendly disposal of dredged sediment. Especially, monitoring of Designated Ports was implemented partially, however monitoring ratio of National Fishing Har-bors was 7% to whole part. Therefore, systematic and integrated environmental monitoring for ports and harbors with charge of national management was reestablished by strengthening and securing a legal basis.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.3
• /
• pp.179-184
• /
• 2013

BACKGROUND: Accurate estimates of total direct $CH_4$ emissions from croplands on a country scale are important for global budgets of anthropogenic sources of $CH_4$ emissions and for the development of effective mitigation strategies. Methane production resulted by the anaerobic decomposition of organic compounds where $CO_2$ acts as inorganic electron acceptor. This process could be affected by the addition of rice straw, water management and rice variety itself. METHODS AND RESULTS: Rice (Oryza sativa L. Japonica type, var Samkwangbyeo) was cultivated in four plots: (1) Nitrogen-Phosphorus-Potassium (NPK) ($N-P_2O_5-K_2O$:90-45-57 kg/ha); (2) NPK plus 3 Mg/ha rice straw (RS3); (3) NPK plus 5 Mg/ha rice straw (RS5); (4) NPK plus 7 Mg/ha rice straw (RS7) for 3 years (2010-2012) and the rice straw incorporated in fall (Nov.) in Gyeonggi-do Hwaseong-si. Gas samples were collected using the closed static chamber which were installed in each treated plot of $152.9m^2$. According to application of 3, 5, 7 Mg/ha of rice straw, methane emission increased by 46, 101, 190%, respectively, compared to that of the NPK plot. CONCLUSION(S): We obtained a quantitative relationship between $CH_4$ emission and the amount of rice straw applied from rice fields which could be described by polynomial regression of order 2. The emission scaling factor estimated by the relationship were in the range of IPCC GPG (2000).

• Korean Journal of Ecology and Environment
• /
• v.43 no.3
• /
• pp.428-436
• /
• 2010

This study was to evaluate water quality characteristics and ecological health using a mulimetric fish model in Taehwa-River watershed during May~September 2009. The ecological health assessments were based on the Index of Biological Integrity (IBI) using fish community and the multimetric model of Qualitative Habitat Evaluation Index (QHEI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. We also analyzed spatial patterns of chemical water quality over the period of 2000~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. Values of BOD and COD averaged $1.7\;mg\;L^{-1}$ (scope: $0.1{\sim}31.8\;mg\;L^{-1}$) and $3.6\;mg\;L^{-1}$ (scope: $0.4{\sim}33\;mg\;L^{-1}$), respectively during the study. Total nitrogen (TN) and total phosphorus (TP) averaged $2.8\;mg\;L^{-1}$ and $96.8\;{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypertrophic state. Also, TN and TP showed longitudinal increases toward the downriver reach. In the watershed, QHEI values varied from 67.5 (fair condition) to 164.5 (good condition) by the criteria of US EPA (1993). There was a abruptly decreasing tendency from T9 site in the QHEI values. According to 1st and 2nd surveys of Taewha River, multimetric model values of IBI was averaged 26.1 (n=14) with "good" condition (B) and the spatial variation was evident. Our results suggest that the mainstream sites was getting worse health condition along the river gradient due to inputs of the point and non-point sources from the urban (Ulsan city). Overall, dataset of IBI, QHEI, and water chemistry indicated that the ecological river health showed a downriver decline and the pattern was closely associated with habitat degradations and chemical pollutions as the waters pass through the urban region.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.17 no.4
• /
• pp.324-332
• /
• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.14 no.1
• /
• pp.40-50
• /
• 2011

We study the characteristic and total flux of non-point pollutants such as total suspended solids (TSS), chemical oxygen demand (COD), dissolved nutrients, total phosphorus (TP) and total nitrogen (TN) in the storm water runoff from urban streams and sewer outlets of Banweol Industrial Complex around Shihwa Lake. The concentrations of non-point pollutants were generally increased with increasing of the duration and intensity of rainfall. Mean TSS concentration of Ansan stream was higher than that of sewer outlets but mean concentrations of COD, TP and TN were approximately 2~5 times higher of sewer outlet than of urban stream. TSS showed statistically positive relationships with COD and TP but it had negative correlation with dissolved nutrients. There was a significant correlation between total flux of non-point pollutants in the storm water runoff and total basin area of each sewer outlet, showing that the highest runoff flux was observed at 3rd sewer outlet which represents the largest basin area from Banweol industrial complex. Total runoff fluxes for TSS, COD, TP and TN in this study were 187,536 kg, 17,118 kg, 922 kg, 13,519 kg, respectively. Given the basin area of sewer outlet in Banweol industrial complex which corresponds only 3% from total catchment area around Shihwa Lake, enormous amount of non-point pollutants will be entered into Shihwa Lake without any treatment. It is necessary to manage and reduce of various non-point sources and pollutants because the runoff of nonpoint pollutants during storm events should be deteriorating the water quality of Shihwa Lake. Our results provides useful informations on the development of best managements practices (BMPs) for effective implementation of total pollution loads management system of Shihwa Lake.

• Journal of Nutrition and Health
• /
• v.42 no.6
• /
• pp.577-595
• /
• 2009

This study aimed to reanalyze energy and nutrient intakes of 2007 Korean Nutrition and Health Examination Survey (KNHANES) using CAN-Pro 3.0, a commonly used nutrient analysis software in Korea. Food items and their codes were selected from 2007 KNHANES dietary intake file and converted to food codes of CAN-Pro 3.0 nutrient database (NDB). Of the 1,324 total food items, 1,155 items were converted by direct matching, 123 items were matched using other items in CAN-Pro 3.0 NDB and 42 items were matched using external sources. Consumption frequencies of items converted by direct matching contributed 94.5% of total consumption. Nutrient intakes of 4,091 participants of 2007 KNHANES, over 1 year old, were recalculated using CAN-Pro 3.0 NDB and compared with intakes in 2007 KNHANES dietary intake file. Intakes for energy and all nutrients except protein and Vitamin C calculated by two NDBs were significantly different by paired t-test (p < 0.001), but significantly correlated by Pearson' correlation coefficients (p < 0.001). Percent differences between the NDBs ranged from 0.3% to 15.1%, low for protein, energy, vitamin C, iron, vitamin B$_2$ (below 5%) but high for phosphorus, retinol, vitamin A, and $\beta$-carotene (over 10%). Age group, sex, and their interactions significantly influenced six nutrients (p < 0.05). Intake levels of zinc, vitamin B6, vitamin E, folate and cholesterol were not available in 2007 KNHANES but were calculated by CAN-Pro 3.0. Mean intake levels of zinc, vitamin B$_6$, vitamin E, and folate by age and sex groups revealed that some groups had mean levels below RI (Recommended Intake) or AI (Adequate Intake) levels. Intake level of cholesterol was higher than the recommended level (below 300 mg/day) in some groups, especially males. Results of the present study indicate the need for comparable and more comprehensive NDB to be used for dietary assessment of KNHANES and other researches. More rigorous evaluation of nutrients which have not been reported in KNHANES is needed.