• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.1
• /
• pp.100-109
• /
• 2012

Removal rates of $PO_4-P$ and TP in a free water surface wetland system were investigated. The system was established in 2008 on a floodplain in the middle reach of the Gwangju Stream flowing through Gwangju City. Its dimensions were 46 meters in length and 5 meters in width. Two year old Typha angustifloria L. growing in pots were planted on half of the area and Zizania latifolia Turcz on the other half in 2008. Stream water was funneled into the wetlands by gravity flow, and its effluent was discharged back into the stream. The influent volume was controlled by valves and water depth was adjusted by wires. Volume and water quality of inflow and outflow were analyzed from January to December in 2010. Inflow into the system averaged approximately $710m^3/day$ and hydraulic residence time was about 1.5 hours. Average influent and effluent $PO_4-P$ concentration were 0.144 and 0.103mg/L, respectively, and $PO_4-P$ abatement amounted to 28.6%. Influent and effluent TP concentration averaged 0.333 and 0.262mg/L, respectively, and TP retention reached to 20.7%.$PO_4-P$ removal rate(%) during plant growing season(31.448) was significantly high(p<0.001) when compared with that during plant non-growing season(25.829). TP abatement rate(%) during plant growing season(27.230) was also significantly high(p<0.001) when compared with that of the non-growing season(14.856). Major phosphorous removals in the system resulted from adsorption of phosphorous in the litter-soil layers; sedimentation of particulate phosphorous and Ca, Al, Fe bounded phosphates; and absorption of phosphorous by emergent plants. The adsorption and sedimentation occurred throughout the year, however, the absorption took place during plant growing season. This resulted in higher removals of $PO_4-P$ and TP during plant growing season.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.1
• /
• pp.42-53
• /
• 2012

Lawsuits related to defects in apartment buildings involve a range of legal issues, based on which the current subjective judgment system has been established. This study aims to organize the judgment system by stage of lawsuit from a legal perspective by reviewing the factors dealt with in precedent research. The main issues at hand include assignment of obligation, the day on which the computation of exclusion period begins and the day on which the defect repair is completed. The rationality of the current subjective judgment system could be determined by reviewing the recent cases. Based on the findings of the review, the following are suggestions for improvements and complements of the system. First, the process of assignment of obligation should be systemized, and the guarantee insurance system that provides a warranty deed should be improved as well. In addition, improvements and systemization should be made to clarify the responsibilities for any defect arising from the agreements that are not stipulated on the contract, computation of abatement rate of compensation and the system by which the responsibility for the defects is completed when residents acquire ownership from rental status.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.9
• /
• pp.473-479
• /
• 2017

Due to environmental pollution, hazards of the human body, and global warning, changes in the power train of automobiles are intensifying, and the market forelectronic vehicles is rising. Also, in order to meet the stricter emission regulations forautomobiles with internal combustion engines based on fossil fuel, the proportion of after-treatments for vehicles and vessels is increasing gradually. The objective of this study is to investigate the effectsfrom additive ceric oxide ($CeO_2$) loading amounts to improve the methane ($CH_4$) and nitric oxide (NOx) abatement ability of the natural gas oxidation catalysts(NGOC) reducing toxic gases emitted from compressed natural gas (CNG) buses. Three kinds of NGOC were prepared under the following conditions: fresh and $700^{\circ}C$ for 12hr thermal aging, and the reduction performance of toxic gases was evaluated. Fresh $1Pt-3Pd-1Rh-3MgO-6CeO_2/(Al+Z)$ NGOC containing 6wt% $CeO_2$ had the highest dispersivity of palladium (Pd) with high selectivity to $CH_4$ and improved harmful gas reduction performance. The NGOC with 6wt% $CeO_2$ loaded the least decreased in the dispersivity of the noble metal, and showed the highest reduction of harmful gases due to the thermal durability of $CeO_2$.

• Applied Chemistry for Engineering
• /
• v.20 no.4
• /
• pp.407-410
• /
• 2009

18~19 wt% $KMnO_4$/$SiO_2-Al_2O_3$ with Si/Al = 1/5 and 1/10, and 20 wt% $KMnO_4$/$Al_2O_3$ were prepared by solvent evaporation method. Catalytic activity of ethylene abatement over those samples were evaluated and compared under the conditions of GHSV $1125h^{-1}$, ethylene gas (ethylene 0.2%, air 99.8%, relative humidity 50%) at 30, 40, 60 and $120^{\circ}C$ using a fixed-bed reactor. $KMnO_4$/$SiO_2-Al_2O_3$ was showed better performance than $KMnO_4$/$Al_2O_3$ by 170~210% at 30, $40^{\circ}C$, and by 60% at 60, $150^{\circ}C$, respectively.

• Journal of Animal Environmental Science
• /
• v.11 no.2
• /
• pp.103-110
• /
• 2005

The study was carried out to develop the real time measuring technique of ammonia and carbon dioxide concentration emitted from growing-finishing pig house in winter and estimate ammonia emission rate emitted from the pig house. As the study was carried out, environmental management technique for the pig house and odor abatement skill could be properly developed to reduce the residence's annoyance. The room temperature of the growing-finishing pig house was $10^{\circ}C$ higher than outdoor air temperature in spite of additional heating, because of heat emitted from body temperature of the pigs. The daily variation pattern of room temperature in the pig house shows the similar tendency with outdoor air temperature. The daily mean ventilation rate per head was $16\;m^3/h$ and ranged from $12\;m^3/h$ to $22.4\;m^3/h$. The difference of day and night for ventilation rate was about 2 times. The ammonia emission rate was $208{\pm}28\;mg/h{\cdot}pig$ per daily basics calculated with ventilation rate and ammonia concentration.

• Journal of the Korean Ceramic Society
• /
• v.42 no.1
• /
• pp.56-61
• /
• 2005

Highly durable photocatalytic paper containing anatase $TiO_{2}$, active carbon and ceramic fiber, which can adsorb VOCs and decompose them by photo oxidation simultaneously, was manufactured and characterized. Optimum concentration of PDADMAC to let $TiO_{2}$ adhere on the surfaces of active carbon and ceramic fiber selectively was $10\~15$ ppm in a slurry mixture for making photocatalytic paper. The thickness and basis weight of the produced catalytic paper by paper-making method were 0.4 mm and 380 $g/m^{2}$, respectively. Adsorption reaction by active carbon and photocatalytic decomposition reaction by $TiO_{2}$ were proceeded simultaneously, by which the abatement rate was found to be greatly enhanced compared to the similar environment with single adsorption reaction or single photocatalytic reaction only. The selective attachment of $TiO_{2}$ on ceramic fiber and active carbon was found to be very effective in preventing decomposition of substrate by the $TiO_{2}$ attack during exposure to UV light.

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.4
• /
• pp.525-529
• /
• 2016

Biomass co-firing to existing thermal power plants is one of the most economical and efficient way to reduce $CO_2$ emission from the plant. There are several methods of co-firing and it can be categorized into (1) Parallel co-firing, (2) Indirect co-firing, and (3) Direct co-firing. Parallel co-firing is the most expensive way to high-ratio co-firing because it requires biomass dedicated boiler. Direct co-firing is widely used because it does not need high capital cost compared with the other two methods. Regarding the direct co-firing, it can be classified into three methods- Method 1 does not need retrofit of the facilities because it uses existing coal mills for pulverizing biomass fuels. In this case high-ratio co-firing cannot be achieved because of poor grindability of biomass fuels. Method 2 needs biomass-dedicated mills and revision of fuel streams for the combustion system, and Method 3 needs additional retrofit of the boiler as well as biomass mills. It can achieve highest share of the biomass co-firing compared with other two methods. In Korea, many coal power plants have been adopting Method 1 for coping with RPS(Renewable portfolio standards). Higher co-firing ratio (> 5% thermal share) has not been considered in Korean power plants due to policy of limitation in biomass co-firing for securing REC(Renewable Energy Certificate). On the other hand, higher-share co-firing of biomass is widely used in Europe and US using biomass dedicated mills, following their policy to enhance utilization of renewable energy in those countries. Technical problems which can be caused by increasing share of the biomass in coal power plants are summarized and discussed in this report. $CO_2$ abatement will become more and more critical issues for coal power plants since Paris agreement(2015) and demand of higher share of biomass in the coal power plants will be rapidly increased in Korea as well. Torrefaction of the biomass can be one of the best options because torrefied biomass has higher heating value and grindability than other biomass fuels. Perspective of the biomass torrefaction for co-firing is discussed, and economic feasibility of biomass torrefaction will be crucial for implementation of this technology.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.294-304
• /
• 2019

Abstract Greenhouse Gas (GHG) emissions from agriculture and forestry sources in the energy sector have been estimated based on a top-down approach, which is an efficient way to estimate GHG emissions with the limited number of emission factors and activity data. On the other hand, for GHG abatement policies, more detailed information and data on GHG emissions are required. This study discusses how to improve the estimates of GHG emissions from the agricultural and forestry sources in the energy sector. To this end, this paper reviews the current estimation method of GHG emissions and presents three suggestions to enhance the current method. First, the development of country specific emission factors and corresponding activity data is proposed based on the 2006 IPCC Guidelines, National Greenhouse Gas Inventory Reports from other countries, and Domestic Statistics. Second, the uncertainty in CO₂ emissions from agriculture in energy sector based on 2006 IPCC Guidelines is estimated, and ways of reducing the uncertainty in CO₂ emissions are suggested. Finally, a potential way to reflect the GHG emissions from the use of renewable energy is suggested.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.9 no.2
• /
• pp.23-32
• /
• 2006

Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.

• Environmental and Resource Economics Review
• /
• v.22 no.3
• /
• pp.459-479
• /
• 2013

To assess the feasibility of 'low carbon, sustainable growth' policy pursued of the Chinese government, this paper first measures technical efficiency, $CO_2$ shadow prices, and indirect Morishima elasticity of substitution between capital and energy for 24 of manufacturing sectors in Beijing and Chongqing, in which China launched pilot carbon emissions trading scheme, by estimating the input distance function. Based on these results, then the potential for $CO_2$ reduction, cost savings from emissions trading, and the effectiveness of capital investment in reducing $CO_2$ are compared across industries and provinces. In 2010, manufacturing industries in Beijing and Chongqing could potentially reduce the largest $CO_2$ emissions, amounting 5.2 and 17 million tons, respectively, by achieving 100% technical efficiency. While, on average, Chongqing has a comparative advantage in the cost savings from carbon trading over Beijing, Beijing is more likely to reduce $CO_2$ by expanding capital investment.