• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1463-1474
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• 2008

In order to investigate stabilization effect and sustainability on As-contaminated farmland soils which were affected the abandoned mine site and stabilized by zerovalent iron(ZVI) and industrial by-products, batch-scale and pilot-scale tests were carried out. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used in treatment materials to reduce the As leaching. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. The results of batch-scale tests was shown that the reduction of As concentration was observed in all samples and it was expected that ZVI and steel refining slag were more effective than other treatment materials to stabilize As compounds. In pilot-scale tests, columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag in the same mixing ratio of 3%. Distilled water was discharged into the columns with the velocity of 0.3 pore volume/day. During the test, pH, EC, Eh and As concentration were measured in the regular term(1pore volume). after six months, pilot-scale tests were retested to investigate sustainability of treatment materials. As a result, It was shown that the leachate from control column was continuously released during the test period and its concentration was greater than $100ug{\cdot}L^{-1}$ which was exceeded the national regulation of water discharged to river or stream ($50ug{\cdot}L^{-1}$). On the other hand, soil treated with ZVI and steel refining slag showed that the concentrations of leachate were lower than national regulation of water discharged to river or stream. Therefore it was expected that ZVI and steel refining slag could be applied to the farmland site as the alternative treatment materials.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.9-16
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• 2009

Further treatment facility using various filter materials was evaluated to treat effluent of constructed wetland. Further treatment facility was installed with 1m length in outlet of 3 constructed wetland (unplanted constructed; reed bed constructed wetland; cattail bed constructed wetland) using 3 filter materials (slag, activated carbon, oyster shell). Flow rate of three further treatment facility was 63 $m^3$/day (slag), 19 $m^3$/day (activated carbon), and 81 $m^3$/day (Oyster shell). COD removal rate of slag, activated carbon, and oyster shell was 6 %, 24 %, 1 %, and removal mass was 32 g/day, 30 g/day, and 5 g/day, respectively. All of further treatment facility was effective to removal organic materials. T-N and T-P removal rate of activated carbon was 24 % and 4 %, and slag and oyster shell was not effective to remove T-N and T-P. Overall, further treatment facility was effective to remove organic mater, constructed wetland combined with further treatment facility can remove nutrient and organic matters effectively.

• Resources Recycling
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• v.18 no.4
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• pp.52-61
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• 2009

Purpose of this research is deducing optimum pretreatment method of electric arc furnace slag from comparing and investigating the properties of electric arc furnace slag and electric arc furnace slag concrete by existing pretreatment method and surface pretreatment method being used by this research. Besides, as the surface pretreatment method, the method of naturally drying for 6 hours after impregnating with an inorganic type silica solution for 1 day was used. From the results, comparing the hot water treatment method, surface treatment method being used by this research is more effective. Therefore, it is judged that surface treatment method is more effective in the decrease of expansibility of electric arc furnace slag and practical use.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.122-122
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• 2005

The remediation for contaminated soil and groundwater in contaminated site and waste site has to be compact and economic in maintaining and operating the system. In this study, the atomized slag was tested if they are an effective reactive material in permeable reactive barrier This novel reactive system technology was applied to the treatment of leachate from unplanned waste landfill. The system was optimized and developed to be commercialized.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.229-241
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• 2008

In order to investigate stabilization effect on As-contaminated soils treated by zero-valent iron(ZVI) and industrial by-products, batch tests and column tests were carried out with As-contaminated soils collected from farmland around the abandoned mine site. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used as treatment materials to reduce As. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. After incubation, all samples showed the reduction of As concentration and it was expected that ZVI and steel refining slag were effective treatment materials to remove As among treatment materials used in batch test. In column tests, columns were made by acrylic with the dimension of diameter=10cm, height=100cm, thickness=1cm and these columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag(mixing ratio=3%). Distilled water was discharged into the columns with the velocity of 1 pore-volume/day. During test, pH, EC, Eh and As concentration were measured in the regular term(1 pore-volume). As a result, ZVI and steel refining slag were shown 93%, 62% reduction of As concentration respectively by comparison with untreated soils. Therefore, if ZVI and steel refining slag are used as treatment materials in As-contaminated soils, it is expected that the As concentration in soils is reduced effectively.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.257-264
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• 2011

Recycling of industrial products as the stabilizers can be proper handling of industrial products and has positive side in terms of recycling of wastes. In this study, the final aims were to evaluate the usability as stabilizer of Bio-solids which was generated from contaminated soil with heavy metals after primary process and to compare the treatment efficiency with slag being currently applied in many existing sites. Soluble and exchangeable forms have closely related to pollution of groundwater and plant growth and they can be used to determine the effect of the stabilization efficiency. Slag and Bio-solids were tested to investigate the capacity of stabilizing arsenic. Slag treatment process 4 (PS-ball 5%) showed higher leachate concentration rather to 0.84% compared to treatment 1 (blank) based on an average of 0.63%. The other hand treatment 4 (Bio-solids 5%) showed the lowest soluble and exchangeable forms to 0.57% when Bio-solids was applied to stabilize arsenic. Thus, the leaching of arsenic will be more reduced if the Bio-solids are used as stabilizer in stead of slag which is being currently used in many fields.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.68-74
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• 2004

A blast furnace slag(BFS) has been used as a filter medium for the treatment of domestic waste waters during the period of 9-month. More than 90% of phosphorus was removed while the hardness of the treated water increased by 5 times and the pH was significantly raised from 6.8 to 10.8. The high hardness and pH of the treated water indicated dissolution of BSF by the sewage. The experimental results suggest that BFS could be utilized for the removal of phosphorus in the waste water treatment plant using aquatic plants and gravels.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.59-68
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• 2020

The study objective was to evaluate the enhanced removal of high concentrations of phosphorus from synthetic wastewater (solely phosphorus-containing) and real wastewater (pig manure) by using carbon nanotube (CNT)-coated steel slag. Generally, phosphorus removal by steel slag is attributed to Ca²⁺ eluted from the slag. However, in this study, CNT was used to control the excess release of Ca²⁺ from steel slag and increase the phosphorus removal. The phosphorus removal rate by the uncoated steel slag was lower than that of the CNT-coated steel slag, even though the Ca²⁺ concentrations were higher in the solution containing the uncoated steel slag. Therefore, the phosphorus removal could be attributed to both precipitation with Ca²⁺ eluted from steel slag in aqueous solution and adsorption onto the surface of the CNT-coated steel slag. Furthermore, the protons released from the CNT surface by exchanging with divalent cations acted to reduce the pH increase of the solution, which is attributed to the OH^- eluted from the steel slag. The adsorption isotherm and kinetics of the CNT-coated steel slags followed the Freundlich isotherm and pseudo-second-order model, respectively. The maximum adsorption capacity of the uncoated and CNT-coated steel slags was 6.127 and 9.268 mg P g^-1 slag, respectively. In addition, phosphorus from pig manure was more effectively removed by the CNT-coated steel slag than by the uncoated slag. Over 24 hours, the PO₄-P removal in pig manure was 12.3% higher by the CNT-coated slag. This CNT-coated steel slag can be used to remove both phosphorus and metals and has potential applications in high phosphorus-containing wastewater like pig manure.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.16-20
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• 1997

The purpose of this study is to develop of porous media for water treatment. It was made of porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag (media-s) and humus soil (media-h) with material, only material kaolinite(media-k). In order to examine the characteristics of physical-chemical were used to sem, x-ray. The results of study are given porous size on media-h which was able to water treatment.

• Resources Recycling
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• v.20 no.3
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• pp.55-61
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• 2011

In order to develop economical production process from metallurgical grade silicon(MG-Si) to solar grade(SOG-Si), removal of boron by slag treatment was investigated at 1823 K using CaO-$SiO_2$ based slags. In the present study boron removal ratio in CaO-$SiO_2$ stags and $CaCO_3-SiO_2$ slags were increased to 63% and 73% respectively with slag basicity (%CaO/$%SiO_2$). However, bubbling time with Ar gas of slag and metal was not affected on removal ratio of boron. The addition of $Na_2CO_3$ to CaO-$SiO_2$ slags did not improve the removal ratio of boron from molten silicon. Boron contend was decreased from 20.6 ppm to 1.03 ppm by three times treatment using $CaCO_3-SiO_2$ slag (basicity=1.2).