• Journal of Korean Society for Atmospheric Environment
• /
• v.29 no.3
• /
• pp.317-324
• /
• 2013

This research assessed the surface properties of modified activated carbons with three different acids and five different metals for ammonia gas removal. Raw bituminous coal-based activated carbon ($4{\times}8$ mesh) had low adsorption capacity of 0.72 mg $NH_3/g$ based on the analysis in the column adsorption experiment. Adsorption capacities of carbons modified with $CH_3COOH$, $H_3PO_4$, and $H_2SO_4$ increased up to 3.34, 21.00, and 35.21 mg $NH_3/g$, respectively. Those of carbons with Cu, Zn, Zr, Fe, and Sn were 9.63, 9.13, 7.09, 25.12 and 15.03 mg $NH_3/g$. Ammonia adsorption was enhanced by the presence of surface oxygen groups on carbon materials, which influenced pH of carbon surface. BET surface area of raw carbon was analyzed to be $1087m^2/g$, but it decreased by carbon surface modification. Fe-impregnated carbon showed $503.02m^2/g$ of surface area. These observations were mostly caused by chemical adsorption.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.5
• /
• pp.401-410
• /
• 2002

Concerns for energy conservation, environmental pollution, and the fact that organic wastes account for a major portion of our waste materials, have created the interest of biogas, which usually contains about 60 to 70 percent methane, 30 to 40 percent carbon dioxide, and other gases, including ammonia, hydrogen sulfide, mercaptans and other noxious gases. Cyclone combustors are used for homing a wide range of fuels such as low calorific value gas, waste water, sludge. coal, etc. The 3-dimensional swirling flow, combustion and emission in a tangential inlet cyclone incinerator under different inlet conditions are simulated using a standard k-s turbulence model and ESCRS (Extended Simple Chemically-Reacting System) model. The commercial code Phoenics Ver.3.4 was used for the present work. The main parameters considered in this work are inlet velocity and air to fuel ratio. The results showed that the change of operating conditions had an influence on the shape and size of recirculation zones, mixture fraction and axial velocity which are important factors for combustion efficiency and emission behavior. The application of this kind of computer program seams to be promising as a potential tool for the optimum design of a cyclone combustor with low emission.

• Journal of Environmental Science International
• /
• v.22 no.3
• /
• pp.269-279
• /
• 2013

In this paper, an environmental assessment was carried out on the whole process of industrial business activities to establish a basic plan for climate change mitigation and energy independency. The whole process was divided into each discharge process in terms of water, air, solid waste, green house gases and refractory organic compounds. The flowcharts and basic unit of process were analysed for three years (2008-2010), being utilized as basic information for the life cycle assessment. It was found that the unit loading for the whole process significantly depends on changes in the operation rate change and highly concentrated wastewater inflow. About 35% of solid waste production was reduced by improving the incineration method with co-combustion in coal boiler, generating about 57% of electricity used for the whole process, and consequently reducing the energy costs. As the eco-efficiency index was found to be more than 1, compared to the previous years, it can be said that improvement in general has taken place.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.75-80
• /
• 2002

Enormous volumes of mining wastes from the abandoned and closed mines are disposed without a proper treatment at Southeastern part of Kangwon Province. Erosion of these wastes contaminates soil, surface water, and sediments with heavy metals. Objectives of this research were to fractionate heavy metals in the mine waste and to assess the potential S. P. A. G.(Soil Pollution Assesment Guidance) of each metal fraction. Mine wastes analyzed for physical and chemical properties. pH of wastes ranged from 3.3 to 8.0. Contents of total N and loss on ignition matter were in the ranges of 0.2~5.6%, and 0.8~15.3%, respectively. Heavy metals in the wastes were higher in the coal mines than those in the other mine wastes. Total concentrations of metals in the wastes were in the orders of Pb > Zn > Cu > Cd, exceeded the corrective action level of the Soil Environment Conservation Law and higher than the natural abundance levels reported from uncontaminated soils. Relative distribution of heavy metal fractions was residual > organic > reducible > carbonate > adsorbed, reversing the degree of metal bioavailability. Mobile fractions of metals were relatively small compared to the total concentrations. Soil Pollution Assesment Guidance(SPAG) values were ranged from 0.08 to 9.14 based on labile fraction of metal concentrations. SPAG values of labile concentration were lower than those of total concentration.

• Resources Recycling
• /
• v.6 no.1
• /
• pp.23-28
• /
• 1997

Iron and slag were prepared by melting mixed industrial wastes in an induction furnace. The wastes were steel can, limestone sludge, waste foundry sand, coal fly ash, and glasses. The effects of their mixing ratio on the charactenstics of the meltcd slag were investigated. The wastes were melted to slag under the constant basicity of 1.2. It was found that the major phases of the slag were P-C,S and C,AS and then ratio was determined by the mixing ratio af waste materials. The recovery of iron was about 93-95%. The feasibility of using the slag as the aggregate was confirmed by thc elution and campression tests.

• Computers and Concrete
• /
• v.31 no.4
• /
• pp.327-335
• /
• 2023

The most popular building material, concrete, is intrinsically linked to the advancement of humanity. Due to the ever-increasing complexity of cementitious systems, concrete formulation for desired qualities remains a difficult undertaking despite conceptual and methodological advancement in the field of concrete science. Recognising the significant pollution caused by the traditional cement industry, construction of civil engineering structures has been carried out successfully using Geopolymer Concrete (GPC), also known as High Performance Concrete (HPC). These are concretes formed by the reaction of inorganic materials with a high content of Silicon and Aluminium (Pozzolans) with alkalis to achieve cementitious properties. These supplementary cementitious materials include Ground Granulated Blast Furnace Slag (GGBFS), a waste material generated in the steel manufacturing industry; Fly Ash, which is a fine waste product produced by coal-fired power stations and Silica Fume, a by-product of producing silicon metal or ferrosilicon alloys. This result demonstrated that GPC/HPC can be utilised as a substitute for traditional Portland cement-based concrete, resulting in improvements in concrete properties in addition to environmental and economic benefits. This study explores utilising experimental data to train artificial neural networks, which are then used to determine the effect of supplementary cementitious material replacement, namely fly ash, Ground Granulated Blast Furnace Slag (GGBFS) and silica fume, on the compressive strength, tensile strength, and modulus of elasticity of concrete and to predict these values accordingly.

• Resources Recycling
• /
• v.17 no.4
• /
• pp.47-56
• /
• 2008

The aim of this study is to produce cokes which can be used for the production of ferroalloy, for this purpose, domestic anthracite mixed with plastic was sintered at various condition. The combustion and physical properties of anthracite and plastic, coal separation, and the influence of factors on the strength of coke were investigated. The results of this study are as follows: 1. The three kinds of anthracite from the Samcheok region contained 25 to 30% ash of $100{\mu}m$ over size, and have the caloric value of 5,205 cal/g(TaeAn), 4,893 cal/g(JangSung), 4,873cal/g(KyongDong). 2. The recommendable conditions for heavy-fluid separation of the Samcheok coal are to set the specific gravity of heavy fluid to 2.4 and control the size of coal to $35{\sim}140mesh$. 3. It is concluded that phenolic resin powder, liquefied phenolic resin, SAN, and melamine resin can be used as a binder for the anthracite cokes, from the thermal analysis of various plastics. Especially, the liquefied phenolic resin was considered as the most suitable binder as it would simplify the process.

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.6
• /
• pp.559-569
• /
• 2018

Catalytic supports made of carbon have many advantages, such as high coking resistance, tailorable pore and surface structures, and ease of recycling of waste catalysts. Moreover, they do not require pre-reduction. In this study, ash-free coal (AFC) was obtained by the thermal extraction of carbonaceous components from raw coal and its performance as a carbon catalytic support was compared with that of well-known activated carbon (AC). Nickel was dispersed on the carbon supports and the resulting catalysts were applied to the steam reforming of toluene (SRT), a model compound of biomass tar. Interestingly, nickel catalysts dispersed on AFC, which has a very small surface area (${\sim}0.13m^2/g$), showed higher activity than those dispersed on AC, which has a large surface area ($1,173A/cm^2$). X-ray diffraction (XRD) analysis showed that the particle size of nickel deposited on AFC was smaller than that deposited on AC, with the average values on AFC ${\approx}11nm$ and on AC ${\approx}23nm$. This proved that heteroatomic functional groups in AFC, such as carboxyls, can provide ion-exchange or adsorption sites for the nano-scale dispersion of nickel. In addition, the pore structure, surface morphology, chemical composition, and chemical state of the prepared catalysts were analyzed using Brunauer-Emmett-Taylor (BET) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and temperature-programmed reduction (TPR).

• Geotechnical Engineering
• /
• v.14 no.4
• /
• pp.91-102
• /
• 1998

Electrical resistivity method, one of the most widely used geophysical prospecting methods. has been usually applied to explorations for groundwater and underground resources. However, it has been extending its scope to civil & environmental engineering areas since it twas been developed so as to image underground structures effectively. A FEM algorithm for the dipole-dipole array was developed to correct topographic effects which have a serious influence on electrical methods. Applicability of the electrical resistivity imaging technique to civil & environmental engineering areas was verified through three case histories in this study First, thickness of soil layers was profiled to judge the possibility of developing borrow-pits tn an industrial complect site. Second, weak zones such as fractures and coal seams were detected to provide geological information for design and construction in a high mountain tunnel site. Third, horizontal/vertical distribution of the contaminated zone and depth of waste disposal were delineated in a completed industrial waste disposal site.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.5
• /
• pp.209-222
• /
• 1993

This article is a case study of the ground improvement project which was carried out for manmade landfill. The project area is located near to Kapchun, Teajon and composed of the municipal wastes dumped, demolished building debris, coal ash and industrial waste made between 1983 and 1989. The DDC(dynamic deep compaction) based on the results of the test compaction at two representative locations was carried out from March 16, 1992 to Oct. 25, 1992. Field measurements and laboratory tests were carried out for ground improvement assessment and quality control for the DDC(dynamic deep compaction) work. From the results of field measurements and laboratory tests, it was found that the DDC work was successful: waste landfill was compressed considerably (${\fallingdotseq}$ 15% of full depth); and the strength was increased satisfactorily (${\fallingdotseq}$ 100% of original penetration resistance), Also, it is expected that the results of this work could be a guide to the future DDC work with the similar ground conditions, i.e. man-made landfills.