• Korean Chemical Engineering Research
• /
• v.48 no.2
• /
• pp.268-274
• /
• 2010

Emission of heavy metals as hazardous air pollutants has been focused with tightening regulatory limits due to their hazardousness. Measurements and characteristic investigations of heavy metals emitted from a commercial power plant burning anthracite coal have been carried out. The plant consists of a circulating fluidized bed combustor, a cyclone, a boiler and an electrostatic precipitator(ESP) in series. Dust and gaseous samples were collected to measure main heavy metals including gaseous mercury before ESP and at stack. Dust emissions as total particulate matter (TPM), PM-10 and PM-2.5 at inlet of ESP were very high with 23,274, 9,555 and $7,790mg/Sm^3$, respectively, as expected, which is much higher than those from pulverized coal power plants. However TPM at stack was less than $0.16mg/Sm^3$, due to high dust removal efficiency by ESP. Similarly heavy metals emission showed high collection efficiency across ESP. From particle size distribution and metal enrichment in sizes, several metal concentrations could be correlated with particle size showing more enrichment in smaller particles. Mercury unlike other solid metals behaved differently by emitting as gaseous state due to high volatility. Removal of mercury was quite less than other metals due to it's volatility, which was 68% only. Across ESP, speciation change of mercury from elemental to oxidized was clearly shown so that elemental mercury was half of total mercury at stack unlike other coal power plants which equipped wet a scrubber.

• Bulletin of Korea Environmental Preservation Association
• /
• v.12 no.13
• /
• pp.21-27
• /
• 1990

• Environmental engineer
• /
• s.87
• /
• pp.22-27
• /
• 1993

• Journal of Korea Soil Environment Society
• /
• v.2 no.2
• /
• pp.61-72
• /
• 1997

This research aims to remove the heavy metals, nonbiodegradable COD(NBDCOD), and color using the coal waste. The experimental by heat treatment was performed to advance the adsorption capacity. The results are as follows ; i) The coal waste had the adsorption capacity of heavy metals and the rates were in the range of 20 to 30 percents. ii) The heat treatment was the optimum condition that the reaction time was 6 hours at $500^{\circ}C$, , iii) In the column experimen, non-treated coal waste removed the COD and color in the range of 20 to 60 percents. iv) Heat-treated coal waste showed higher removal rate of the color in biological effluent, and heavy metal and COD removal rates were changed by the filteration rates.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.16 no.2
• /
• pp.115-120
• /
• 2013

This study examined the removal rate of mixed heavy metals from aqueous solution using recycled aggregate. The recycled aggregate is favorable for the absorbent because it contains about 95% (CaO, $SiO_2$, $Al_2O_3$ and $Fe_2O_3$), which are major ingredient of adsorbent for heavy metal. The kinetic data presented that the slow course of adsorption follows the Pseudo first and second order models. The equilibrium data were well fitted by the Langmuir model and showed the affinity order: $Cu^{2+}$ > $Pb^{2+}$ > $$Zn^{2+}{\simeq_-}Ni^{2+}$$ > $Cd^{2+}$. The results also showed that adsorption rate slightly increased with increasing pH from 6 to 10. Moreover, this trend is similar to results obtained as function of loading amount of recycled aggregate. Meanwhile, an unit adsorption rate was slightly decreased. From these results, it was concluded that the absorbents can be successfully used the removal of the heavy metals from the aqueous solutions.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.12
• /
• pp.1076-1086
• /
• 2010

Soil remediation technologies were experimented to evaluate whether the technologies could be used to apply remediation of contaminated marine sediment. In this research, marine sediments were sampled at "Ulsan" and "Jinhae" where remediation projects are considered, and then the possibility of heavy metal removal was evaluated throughout the technologies. Heavy metal concentration of silt and clay fraction was higher than that of sand fraction at "Ulsan". Heavy metal removal of the silt and clay fraction was arsenic (As) 81.5%, mercury (Hg) 93.8% by particle separation, cadmium (Cd) 72.2%, mercury (Hg) 93.8% by soil washing technology, cadmium (Cd) 70.8%, lead (Pb) 65.6% by another soil washing technology. Based on experimental results, tested particle separation and soil washing technologies could be used to remove heavy metals of sand fraction and silt and clay fraction. Heavy metal removal by soil washing technology which was composed of separation, washing and physical or chemical reaction by additives such as acid, organic solvents was more effective comparing to that of particle separation. Since heavy metal concentration of all treated samples was suitable for national soil standards, all the tested technologies were could be used not only to remove heavy metals of marine contaminated sediment but also to reuse treated samples in land.

• Journal of Wetlands Research
• /
• v.9 no.3
• /
• pp.43-49
• /
• 2007

A ditch is a facility for managing washed-off runoff from parking lot area. Washed-off runoff inflows into ditches where it is retained for a short period of time. At this point, it is assumed that a ditch is a preliminary unit for runoff treatment. This research carries out the distribution of particle size and chemical compound for sediment in parking lot ditch. This work is important to understand the amount of generated sediment from this area to be able to determine different particle size ranges for treatment. Metal concentrations for sediment according to particle size are analyzed. From the distribution of particle size, the weight ratio with the range of $425-850{\mu}m$ is the highest. Considering its weight ratio, the metal concentration of coarser particles is high, otherwise metal concentration increases as particle size decreases. Metal load of the range is higher and the ratio of total metal load in the case of Cu, Pb, Zn is nearly 30%. Moreover metal concentration associated with particle size depends on particle ratio. To manage non-point source pollution for parking lot area, these results can be used with this ditch unit.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.629-634
• /
• 2003

본 연구에서는 대표적인 산업부산물인 굴패각과 플라이애쉬를 활용한 흡착제를 개발하여 중금속 이온의 제거 기작을 평가하였다. 1차적으로 연구된 중금속 이온은 카드뮴, 납, 구리이며, 산업부산물을 활용하여 흡착특성을 평가하였고, 동시에 현장 적용성을 모사하기 위해 점성토와 화강풍화토에 대한 흡착실험도 함께 수행하여 각각의 흡착특성을 비교ㆍ평가하였다. 실험 결과를 등온흡착식으로 분석하여본 결과 굴패각의 경우 카드뮴, 납, 구리이온의 용액 내 제거율이 해성점토나 화강풍화토를 사용한 흡착제에 비해 우수하므로 흡착제로서의 사용 가능성을 확인할 수 있었다.

• Clean Technology
• /
• v.18 no.4
• /
• pp.341-346
• /
• 2012

Many researchers have studied that many processes to effectively remove heavy metals in water/wastewater. Especially, among many processes, physical and chemical processes are relatively simple and obtain high treatment efficiency for removal heavy metals compared with biological treatment. Recently, interests in physical and chemical methods are sharply increasing again because of dangerousness for radioactive element. In this study, various physical and chemical processes such as chemical precipitation, ion-exchange, electrodialysis, and membrane separation are introduced.

• Journal of the Korean GEO-environmental Society
• /
• v.18 no.12
• /
• pp.25-36
• /
• 2017

This research was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage (AMD) by multi-functional zeolite-slag ceramics (ZS ceramics), in which natural zeolite and converter slag were mixed and calcined at high temperature. The batch test showed that the removal efficiency of heavy metals by pellet-type ZS ceramics increased as the mixing weight ratio of converter slag to natural zeolite increased. The optimal mixing ratio of natural zeolite to converter slag for the removal of heavy metals and sulfate ion from AMD was observed to be 1:2~1:3. The adequate calcination temperature and time of ZS ceramics for the treatment of AMD were found to be $600{\sim}800^{\circ}C$ and 2 hours, respectively. The removal test of heavy metals and sulfate ion from AMD by the ZS ceramics prepared in optimal condition exhibited very high removal efficiencies close to 100% for all heavy metals (Al, As, Cd, Cu, Fe, Mn, Pb, Zn) and 77.1% for sulfate ion. The experimental results in this study revealed that the ZS ceramics could function as an effective agent for the treatment of AMD.