• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.8-25
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• 2020

Industrialization has increased the production of road-deposited sediments (RDS) and the level of heavy metals in those RDS, which can have a significant impact on the surrounding aquatic environments through non-point pollution. Although the relationship between contamination characteristics and particle size of RDS is important for pollution control, there is very little information on this. In this study, we investigated the characteristics of grain size distribution and heavy metal concentrations in the road-deposited sediments (RDS) collected from 25 stations in Shihwa Industrial Complex. The environmental impact of RDS with particle size is also studied. I_geo, the contamination assessment index of each metal concentration, represents the RDS from Shihwa Industrial Complex are very highly polluted with Cu, Zn, Pb and Sb, and the levels of those metals were 633~3605, 130~1483, 120~1997, 5.5~50 mg/kg, respectively. The concentrations of heavy metals in RDS increased with the decrease in particle size. The particle size fraction below 250 ㎛ was very dominant with mass and contamination loads, 78.6 and 70.4%, respectively. Particles less than 125 ㎛ of RDS were highly contaminated and toxic to benthic organisms in rivers. RDS particles larger than 250 ㎛ and smaller than 250 ㎛ were contaminated by the surrounding industrial facility and vehicle activities, respectively. As a result of this study, the clean-up of fine particles of RDS, smaller than 125-250 ㎛, is very important for the control and reduction of non-point pollution to nearby water in Shihwa Industrial Complex.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.2
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• pp.42-53
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• 2020

In this study, heavy metal in road-deposited sediments (RDS) and marine sediment around Gwangyang Bay area have been investigated to assess the pollution status of metals and to understand the environmental impact of RDS as a potential source of metal pollution. Zn concentration for <63 ㎛ size fraction was the highest (2,982 mg/kg), followed by Cr, Ni, Pb, Cu, As, Cd, and Hg. Metal concentrations in RDS increased with decreasing particle size and relatively higher concentrations were observed around the metal waste and recycling facilities. For particle size in RDS smaller than 125 ㎛, EF values indicated that Zn was very high enrichment and Cr, Cd, Pb were significant enrichment. The concentrations of metals in marine sediments were mostly below the TEL value of sediment quality guidelines of Korea. However, the Zn concentrations has increased by 30~40% compared to 2010 year. The amounts of Zn, Cd and Pb in less than 125 ㎛ fraction where heavy metals can be easily transported by stormwater runoff accounted for 54% of the total RDS. The study area was greatly affected by Zn pollution due to corrosion of Zn plating materials by traffic activity as well as artificial activities related to the container logistics at Gwangyang container terminal. The fine particles of RDS are not only easily resuspended by wind and vehicle movement, but are also transported to the surrounding environments by runoff. Therefore, further research is needed on the adverse effects on the environment and ecosystem.

• Toxicological Research
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• v.34 no.2
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• pp.163-172
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• 2018

Air pollution is increasing, along with consumption of fossil fuels such as coal and diesel gas. Air pollutants are known to be a major cause of respiratory-related illness and death, however, there are few reports on the genotoxic characterization of diverse air pollutants in Korea. In this study, we investigated the mutagenic activity of various particles such as diesel exhaust particles (DEP), combustion of rice straw (RSC), pine stem (PSC), and coal (CC), tunnel dust (TD), and road side dust (RD). Ultra-fine particles (UFPs) were collected by the glass fiber filter pad. Then, we performed a chemical analysis to see each of the component features of each particulate matter. The mutagenicity of various UFPs was determined by the Ames test with four Salmonella typhimurium strains with or without metabolic activation. The optimal concentrations of UFPs were selected based on result of a concentration decision test. Moreover, in order to compare relative mutagenicity among UFPs, we selected and tested DEP as mutation reference. DEP, RSC, and PSC induced concentration-dependent increases in revertant colony numbers with TA98, TA100, and TA1537 strains in the absence and presence of metabolic activation. DEP showed the highest specific activity among the particulate matters. In this study, we conclude that DEP, RSC, PSC, and TD displayed varying degrees of mutagenicity, and these results suggest that the mutagenicity of these air pollutants is associated with the presence of polycyclic aromatic hydrocarbons (PAHs) in these particulate matters.

• International Journal of Automotive Technology
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• v.3 no.1
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• pp.1-8
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• 2002

There is Increasing world-wide interest in diesel particulate filters (DPF) because of their proven effectiveness in reducing exhaust smoke and particulate emissions. Fine particulates have been linked to human health . DPF use requires a means to secure the bum-out of the accumulated soot, a process called regeneration. If this is not achieved, the engine cannot continue to operate. A number of techniques are available, but most are complex, expensive or have a high electrical demand. The use of fuel additives to catalyse soot bum-out potentially solves the problem of securing regeneration reliably and at low cost. Work on organo-metallic fuel additives has shown that certain metals combine to glove exceptional regeneration performance. Best performance was achieved with a combination of iron and strontium based compounds. Tests were carried out un a bed engine and on road vehicles, which demonstrated effective and reliable regeneration from a tow dose fuel additive, using a single passive DPF. No control valves, flow diverters. heaters or other devices were employed to assist regeneration. Independent particle size measurements showed that there were no harmful side effects from the use of the iron-strontium fuel additive.

• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.222-226
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• 2014

In this study, the purposes are investigating and analyzing car emission factors for estimating road emissions and the legal framework for the control of particulate matters. At the result, when input emission data are not realistic, the modeling output concentration distributions can lead to a serious distortion of the results. So, the spatial analysis of the dust emission vehicles have to be based on the actual traffic volumes. Because dust emission factors used in the car by National Institute of Environmental Research Method (2010) are mainly targeted for 2003-2007 cars these could not reflect the effect of DPF and the dust emission of gasoline passenger car. So, the real dust emission factors of diesel and gasoline cars need to be developed.

• 한국도로학회:학술대회논문집
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• 2002.10a
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• pp.89-92
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• 2002

The objective of this research is to evaluate engineering properties of recycled aggregates, slag as coarse & fine aggregate and waste foundry sand(WFS) as fine aggregate, in hot mix asphalt(HMA). In this research, soundness, gradation and particle analysis, abrasion, specific gravity and absorption test were carried out. The optimum asphalt binder content(OAC) for various HMA combinations of recycled aggregate was determined by Marshall Mix Design. The ranges determined is between 7.2% and 7.5%. Indirect tensile test, resilient modulus test, creep test were carried out for characterization of rutting behavior of various combination of HMA. Judging from the limited tests, the HMA with recycled aggregates is not as good rutting resistance as the HMA with common aggregates. After finishing the Wheel tracking test, the application or feasibility for the use of recycled aggregate as asphalt paving material will be determined.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.189-198
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• 2008

Generally, UFF A(Ultra Fine Fly Ash) has merit that advances a greater concrete workability and activates a greater pozzolanic reaction than common fly ash due to its ultra fine particle size. These properties enhance concrete durability by reducing permeability and increasing resistance of alkali silica reaction(ASR) and sulfate attack, etc. Due to these reasons, UFFA can be used in a rapid setting concrete. The purpose of this study is to develop and evaluate the rapid setting concrete with UFF A as a repair material for early-opening-to-traffic. In previous studies, if only UFFA is added to the rapid setting concrete mixture, pozzolanic reaction doesn't happen actively. Therefore, in this study, the chemical and physical tests were performed for rapid setting concrete with UFFA including calcium hydroxide and the activity of pozzolanic reaction was evaluated. Finally, the effectiveness of this mixture on enhancing concrete durability was investigated. As results, adding UFF A decreased the water/cement ratio of concrete, and compensated the reduced portion of the early strength of concrete. Also, rapid setting concrete with UFFA including calcium hydroxide activated a greater pozzolanic reaction than normal-UFF A concrete. As calcium hydroxide increases, electrical indication of concrete's ability to resist chloride ion penetration is promoted significantly.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.3
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• pp.219-236
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• 2009

Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.227-233
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• 2008

Porous concrete has large continuous voids of 20-30 % by volume, and this concrete is attractive as environmental material in Japan i.e. permeable road pavement, river bank protection with vegetation and green roof system which influence thermal environment. It is necessary to confirm the frost resistance when constructing porous concrete structure in cold region. However applicable test method and evaluation criterion of porous concrete has not defined yet. Therefore, the object of this study is to investigate the frost resistance of porous concrete and this investigation attempts to address this concern by comparing 4 kinds of specified freezing and thawing tests methods (JIS A1148 procedure A/B and RILEM CIF/CDF test) in consideration of actual environment. RILEM freeze-thaw tests are different from JIS A1148 freeze-thaw tests, which are widely adopted for evaluating the frost resistance of conventional concrete in Japan, in water absorption, cooling rate, length of freezing and thawing period, and number of freezing and thawing cycles. RILEM CIF test measures internal damage and is primarily applicable for pure frost attack. CDF test is appropriate for freeze-thaw and de-icing salt attack. JIS A1148 procedure A/B showed extremely low frost resistance of porous concrete if the large continuous voids were filled with water and the ice expansion in the large continuous voids set in during cooling. Frost resistance of porous concrete was improved by mixing coarse aggregate (G7) which particle size is smaller and fine aggregate in JIS freezing and thawing tests. RILEM CIF/CDF test showed that freeze-thaw and de-icing resistance of porous concrete was seems to be superior in that of conventional concrete.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.483-489
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• 2020

Particulate matter is divided into PM10 (particle diameter of 10 ㎛ or less) and PM2.5 (particle diameter of 2.5 ㎛ or less), which are approximately 1/5 of the thickness of the hair. Due to its effect on the human body, lung disease, arteriosclerosis and heart It is known as a carcinogen that causes various diseases such as diseases. It is known that the main cause of such fine dust is nitrogen dioxide (NOx), which is emitted from automobiles in about 57.3% of urban roadsides. Therefore, in this study, as part of the development of functional construction materials to reduce NOx generated from road transport pollutants, comparative evaluation of NOx reduction performance was conducted according to the replacement rate of cement mortar in which cement was replaced with a porous material. In addition, the NOx reduction performance of cement mortar according to the photocatalyst application method and the number of applications was compared an d evaluated. As a result of the experiment, when activated ocher was substituted by 30%, it showed a reduction effect of about 32.7%, showing the best reduction performance.