• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.27-33
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• 2012

According to the statistics of the Ministry of Environment, the emission of sewage sludge is increased by 7~9% yearly. In the future, it will be increased continuously because of extension of sewage disposal plants, high class treatment for removing nitrogen and phosphorus. Until now, we have depended on reclamation for lots of quantity and some part has been treated by ocean emission. But, direct reclamation of organic waste will be prohibited and even ocean emission will be prohibited now, so the treatment of sludge is put on emergency alert. Bio-gas can be produced by applying anaerobic digestion method for the recycling or refuse derived fuel can be conducted by applying carbonization method. However, the process is difficult, causes bad smell and makes it the second waste, so it cannot be practical method in fact. This study applied a fluidized bed combustor for sewage sludge treatment technologies that can actually take advantage of key technologies in order to verify its purpose is to demonstrate selected. If applying the fluidized bed combustor, it can be easily utilized as the replaced resource of energy(fuel) in the countries whose energy resources are insufficient, like our country. Especially, if applying only original strengths of the fluidized bed combustor sufficiently, the sewage sludge can be treated simply, eco-friendly, sanitarily and economically. Particularly, it is verified as the energy technology suitable for government's green growth policy.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.2
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• pp.43-51
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• 2001

Now our ocean environment pollution is very serious. Its harm hinders in marine breeding and the safe navigation of ships at the coast. We have used an assembly system for a measure taken against environment pollution like this. But, here are some problems awaiting solution. First, most of combustible materials among ocean waste are high polymer, so it is necessary some special equipment to incinerate them. In the process we can't overlook air pollution by exhaust gas. Also, when we reclaim these wastes, we remember that they can't be decomposed naturally and leaking water may pollute soil. Thus now a days new treatment method has been developed, it recycles and doesn't product secondary pollution materials by recovering oil from pyrolysis. For it, this study investigated chemicalㆍphysical properties of wastes. And it found condition of recovering the most oil. Also it probed that the variation of temperature raising speed affects the weight reduction characteristics of wastes. Also, while studying recovered oil by waste pyrolysis and the rate of non-condensing gas in accordance with the variation of temperature raising speed. Finally we had confidence the development of pyrolysis oil recovery would succeed because we carried out evaluation at an economic point of view about it.

• Resources Recycling
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• v.22 no.5
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• pp.20-28
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• 2013

This study was carried out to evaluate the possibility of resource recovery for municipal solid waste(MSW) that sorted by a MBT system. First, physical property of MSW was similar to wastes carried into Sudokown landfill site. However, moisture of MSW was little higher than that. As a result of BMP test using organic fraction of MSW(OFMSWs), approximately 60 ~ 80 mL $CH_4/g$-VS of methane was occurred. Compared to the other studies, the value of methane is lower. It seems to be caused that high ratio of vinyl/plastic in OFMSWs. The other BMP test using sample of MBT system located in Sudokwon landfill was conducted each physical properties. According to the result of experiment, food waste makes 193 mL $CH_4/g$-VS, and paper is 102 mL $CH_4/g$-VS. However, there was not methane production in vinyl and rubber. Additionally, others that can't sort no more show 30 m $CH_4L/g$-VS of methane production. From the result of experimental data OFMSWs has high fraction of vinyl, rubber and other substance that difficult for biodegradation. Therefore it is need to sort of them.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.2
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• pp.259-268
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• 2005

In this study, we investigated the seasonal variations in the composition and emission patterns of VOC ventilated as landfill gas (LFG) from an urban municipal landfill site during the winter (2002) and summer (2003) period. The results of our study, when examined using the major aromatic VOC components as BTEX, indicated the existence of diverse characteristics in the LFG emissions of VOC. It was found that the relative extent of benzene emission showed most significant increase in the summer season, while most species underwent notable reductions. Despite the presence of certain patterns in the seasonal emissions of BTEX, the gross picture of their emission between summer and winter was not different distinctively so that the wintertime emissions exceed their summer counterparts by about three times. The observations of moderate enhancement in wintertime LFG emissions of BTEX appeared to reflect such environmental changes in the winter season as favorable conditions for LFG ventilation with reduced surface emissions due to frozen soil layers.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.189.1-189.1
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• 2011

Global warming effect was intensified due to rapid growth of fossil fuel consumption caused by urbanization and industrialization. Various efforts was being done to solve the problems leading to anomaly climate such as flood, downpour, heavy snow. As a results of international efforts for management of global warming, Kyoto Protocol, which was passed in Kyoto, Japan in 1997, designated $CO_2$, $CH_4$, $N_2O$, HFCs, PFCs, $SF_6$ as a global warming gases. And IPCC(Intergovernmental Panel on Climate Change) suggested IPCC guideline for systematic establishment of national greenhouse gas inventory. Among five categories in IPCC guideline, the representative emission source of waste category is SWDS(solid waste disposal site). The concentrative research should progress for effective management of greenhouse gas related with waste. In this study, Tier1 and Tier2 methods which was suggested by 2006 IPCC(Intergovernmental Panel on Climate Change) guideline, was used to predict methane generation from C sanitary landfill located in Chungju area. To predict methane generation from C sanitary landfill, all factors were defaults values that were provided by 2006 IPCC guideline and Korea emission factors for Tier1 and Tier2 method. And economics of generated methane was estimated. From the predicted result using IPCC guideline, the methane generation was persistingly increased over a 9-year period(2000 ~ 2008). Aggregated amount of methane generation was about 3,017ton and 3,170ton predicted by Tier1 and Tier2, respectively. From the results of estimated economic value gained by generated methane from the C sanitary landfill for ten years from now(2010 ~ 2020), the profit was about 2.39 ~ 2.76 hundred million won.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.665-668
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• 2008

Portland cement production-1.5billion tonnes yearly worldwide-contributes substantially to global atmospheric pollution($\sim$7% of total of CO$_2$ emissions). Attempts to increase the utilization of fly ash, a by-products from thermal power plant to partially replace the cement in concrete are gathering momentum. But most of fly ash is currently dumped in landfills, thus creating a threat to the environment. Therefore, In this study, influence of curing temperature(30, 60, 90$^{\circ}$C) on the strength of properties fly ash based cement ZERO mortar was investigate, measured a weight change and pH change according to each care of curing temperature. The test results that a curing at 90$^{\circ}$C is appropriate in case of the high strength concrete is required in the early-age of the curing and 60$^{\circ}$C is efficient for the case of requiring high strength at age 28 days. Furthermore pH variation and value of compressive strength are judged to correlate but change of weight is not the case.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.185-192
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• 1999

To assess the soil quality of Chonan City, soil analyses were conducted according to the 14 different sampling sites. The soil pH of the agricultural area near the expressway was lower than that of the other farming area, which indicated that this acidification was probably attributed to the acid rain caused by the traffic exhaust gas such as SOx and NOx. Acidification was more severe in the dry farming area than in the rice paddy area. All concentration of 6 different heavy metals (As, Cu, Cd, $Cr^{6+}$, Hg, Pb) and organic contaminants (cyanide, organic-p, PCBs, phenols) were found to be lower than the standard of soil pollution. The concentration of BTEX also lower than the standard of soil pollution. An assessment using the SPI (Soil Pollution Index). which was developed to estimate an overall soil quality, was performed. Each SPC (Soil Pollution Score) were evaluated with the results of the data from this study. The soil quality of most area of Chonan City was determined to Class 1 , which indicated that the soil was healthy.

• Resources Recycling
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• v.9 no.6
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• pp.23-30
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• 2000

Since most of the waste plastics are incinerated and landfilled for the plastic treatment, the environmental friendly processes must be introduced. The plastic utilization of plastic to the blast furnace as a substitutional fuel was developed as a useful recycling method of waste plastics, and commercialized in several ironmaking company in Europe and Japan. Present study was carried out to understand the effect of plastic injection on blast furnace process continuously by using the foundry blast furnace in POSCO. The coke replacement ratio turned out to be 0.98 with the waste plastic injection up to 13.8 kg/thm of injection rate, and there were no significant effect of the kinds of injection plastics on the replacement ratio in this test operation. The permeability in the furnace became worse and the heat load in the lower part of blast furnace was increased with increasing the injection rate of waste plastics. As the rate of plastic injection were increased, the top gas utilization and shaft efficiency were also decreased from the Rist diagram analysis.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.503-515
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• 2014

A lot of existing wastewater treatment plants (WWTPs) are rebuilt or retrofitted for advanced wastewater treatment processes to cope with reinforced effluent criteria of nitrogen and phosphorous. Moreover, how to treat the wasted sludge from WWTPs has been also issued since the discharge of the wasted sludge into ocean is impossible from 2011 due to the London Convention 97 protocol. These trend changes of WWTPs get a motivation to assess environmental and economic impacts from the construction stage to the waste stage in WWTPs. Therefore, this study focuses on evaluation of environmental and economic impacts of the advanced wastewater treatment processes and waste sludge treatment process by using life cycle assessment. Four advanced wastewater treatment processes of Anaerobic/Anoxic/Oxic ($A_2O$), 5 stages-Bamard Denitrification Phosphate (Bardenpho), Virginia Initiative Plant (VIP), and Modified University of Cape Town (MUCT) are chosen to compare the conventional activated sludge (CAS) and three waste sludge treatment methods of land fill, incineration, and composting are used. To evaluate environmental and economic impacts of each advanced wastewater treatment processes, life cycle assessment (LCA) and life cycle cost (LCC) are conducted based on International organization for standardization (ISO) guidelines. The results clearly represent that the $A_2O$ process with composting shows 52% reduction in the environmental impact than the CAS process with landfill. On the other hand, the MUCT process with composting is able to save 62% of the life cycle cost comparing with the CAS process with landfill. This result suggested the qualitative and quantitative criteria for evaluating eco-environmental and economic technologies of advanced treatment processes and also sludge treatment method, where their main influence factors on environmental and economic impacts are analyzed, respectively. The proposed method could be useful for selecting the most efficient and eco-friendly wastewater treatment process and sludge treatment method when retrofitting the existing WWTPs to advanced treatments.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.119-126
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• 2012

Portland cement production-1.5billion tonnes yearly worldwide-contributes substantially to global atmospheric pollution(7% of total of $CO_2$ emissions). Attempts to increase the utilization of fly ash, by-products from thermal power plant to partially replace the cement in concrete are gathering momentum. But most of fly ash is currently dumped in landfills, thus creating a threat to the environment. Many researches on alkali-activated concrete that does not need the presence of cement as a binder have been carried out recently. Instead, the sources of material such as fly ash, that are rich in Silicon(Si) and Aluminium(Al), are activated by alkaline liquids to produce the binder. Hence concrete with no cement is effect reduction of $CO_2$ gas. In this study, we investigated the influence of the compressive strength of mortar on alkaline activator and curing condition in oder to develop cementless fly ash based alkali-activated concrete. In view of the results, we found out that it was possible for us to make alkali-activated mortar with 70MPa at the age of 28days by using alkaline activator manufactured as 1:1 the mass ratio of 9M NaOH and sodium silicate and applying the atmospheric curing after high temperature at $60^{\circ}C$ for 48hours.