• Environmental engineer
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• v.22 s.232
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• pp.76-77
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• 2005

공장내 황산출하장에서 황산저장탱크(7,500톤)에서 로딩탱크로 황산을 이송작업을 하던 중 황산이 로딩탱크 상부로 흘러넘쳐 방유제 내부로 누출되어 다음날 방유제 내부로 누출된 황산을 다시 로딩탱크로 이송하기 위해 이동용 펌프로 이송하던 중 호스연결부위에서 황산이 비산되면서 화상을 입고 사망한 재해임

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.219-228
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• 2010

It has been well known that concrete structures exposed to acid and sulfate environments such as sewer, sewage and wastewater, soil, groundwater, and seawater etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to concrete matrix by forming expansive hydration products due to the reaction between portland cement hydration products and acid and sulfate ions. Objectives of this experimental research are to investigate the effect of mineral admixtures on the resistance to acid and sulfate attack in concrete and to suggest high-resistance concrete mix against acid and sulfate attack. For this purpose, concretes specimens with three types of cement (ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC) composed of different types and proportions of admixtures) were prepared at water-biner ratios of 32% and 43%. The concrete specimens were immersed in fresh water, 5% sulfuric acid, 10% sodium sulfate, and 10% magnesium sulfate solutions for 28, 56, 91, 182, and 365 days, respectively. To evaluate the resistance to acid and sulfate for concrete specimens, visual appearance changes were observed and compressive strength ratios and mass change ratios were measured. It was observed from the test results that the resistance against sulfuric acid and sodium sulfate solutions of the concretes containing mineral admixtures were much better than that of OPC concrete, but in the case of magnesium sulfate solution the concretes containing mineral admixtures was less resistant than OPC concrete due to formation of magnesium silicate hydrate (M-S-H) which is non-cementitious.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.353-354
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• 2003

대기 중에서 여러 과정을 통해 아황산가스 (SO$_2$)가 황산 (H$_2$SO$_4$)으로 산화된다. 황산은 증기압이 낮아 대기 중에서는 대부분 황산염 (SO$_4$$^{2-}$ ) 에어로졸로 존재한다. 황산염 에어로졸은 직간접적으로 지구복사평형에 관여하여 기후와 기상에 영향을 미친다. 이 연구의 목적은 수도권에서의 아황산가스가 황산염으로 전환되는 각각의 경로의 상대적 기여도를 예측해보고자 하였으며 아황산가스에 의해 황산염이 얼마나 형성되는지를 알아보고자 하였다. (중략)

• Magazine of the Korea Concrete Institute
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• v.10 no.5
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• pp.117-128
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• 1998

화학적으로 유해한 환경에 놓인 콘크리트 구조물은 필연적으로 그 기능이 악화되므로 혼화재를 포함한 고강도 콘크리트 또는 혼화재 그 자체가 화학물질에 오염된 환경하에서 어떤 변화를 일으키는가에 대한 연구의 필요성이 점점 증대되고 있다. 따라서 본 논문에서는 건설현장에서 가장 흔히 사용되는 보통강도 콘크리트와 실리카-흄을 포함한 포틀랜드시멘트 경화체인 고강도 콘크리트가 황산염의 침해를 받는 경우에 일어나는 강도특성과 물성변화를 조사하기 위하여 담수와 함께 황산나트륨, 황산마근네슘, 황산나트륨과 황산마그네슘의 혼합용액 등 여러종류의 황산염 용액에 실리카-흄을 사용한 고강도 콘크리트, 낮은 물-시멘트 비의 고강도 콘크리트, 보통강도의 콘크리트 등의 시험체들을 270일간 침지시켜 침지시간에 따른 압축강도 변화와 실리카-흄의 첨가량에 따른 압축강도 변화, 그리고 실리카-흄의 첨가량에 따른 선형팽창량 및 중량변화등에 관한 실험을 수행하였다. 이에 대한 실험결과를 토대로 실리카-흄을 사용한 고강도 콘크리트에 황산염이 미치는 영향을 분석하여 고강도 콘크리트의 실용성을 극대화하기 위한 방안에 대하여 고찰해보았다. 그 결과 실리카-흄을 포함한 고강도 콘크리트는 황산나트륨의 침해에 대해서는 강한 저항성을 나타내지만 황산마그네슘에 대해서는 심각한 침해를 일으키는 것으로 나타났으므로 황산마그네슘에 노출될 우려가 있는 콘크리트 구조물에 고강도를 발현하기 위하여 실리카-흄을 사용하는 것은 구조적으로 큰 문제가 발생할 것으로 사료된다.

• KSBB Journal
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• v.24 no.5
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• pp.458-462
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• 2009

Silk fibroin is a structural protein from Bombyx mori and can be sulfated to provide biofunctional polypeptides showing antiviral and anticoagulating activities. However, the sulfated fibroins have not been characterized enough to present their compositions and structures. In this report, sulfation reaction was investigated by varying the reaction temperature and sulfuric acid concentration and analysis of the resulting peptides were carried out. The degree of sulfation was proportion to sulfuric acid concentration but the maximum product yield was obtained at $60^{\circ}C$ and 5% of sulfuric acid concentration. FT-IR spectrum, UV absorption and NMR spectrum support that o-sulfate ester was formed at the hydroxyl group of serine and tyrosine residues. Size exclusion chromatography identified that sulfated fibroin was composed of a highly hydrolyzed polypeptide mixtures and peptides of relatively higher molecular weight.

• Polymer(Korea)
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• v.27 no.6
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• pp.583-588
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• 2003

Sulfated chitosan and sulfated sodium alginate were synthesized by sulfating reaction of low molecular chitosan and low molecular sodium alginate with SO$_3$-pyridine complex. When the weight ratio of SO$_3$-pyridine complex to polysaccharide was 1:5, the degrees of sulfation were the highest at 2.75 and 2.53 respectively. The anticoagulation effect was the highest when the molecular weight was 8.0${\times}$10$^3$ Da, and the anticoagulation activity was the highest at 91% of that of heparin when sulfated chitosan and sulfated sodium alginate were mixed at a weight ratio of 1:1. The anticoagulation activity was highest at 84% of that of heparin in the active plastin trombo test (aPTT) when sulfated chitosan and sulfated sodium alginate were mixed at a weight ratio of 1:1.

• The Journal of Natural Sciences
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• v.14 no.2
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• pp.33-40
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• 2004

The eliminating of organic compound is essential process of the recovery of zinc sulfate from zinc sulfate waste water contained organic compound. The ozone oxidation and adsorption treatment is good for eliminating of organic compound in waste water. The zinc oxide treated an excess of sulfuric acid for zinc sulfate. We got zinc sulfate 740g from water 1kg.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.371-377
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• 2004

Sulfate adsorption in forest soils is a process of sulfur dynamics playing an important role in plant uptake, cation movement, acid neutralization capacity and so on. The relationship between sulfate adsorption and some physicochemical properties of four forest soils was investigated. Extractable sulfate contents and sulfate adsorption capacity (SAC) in the forest soils varied much among study sites. Extractable sulfate contents were more in sub-surface soils with lower organic matter and greater Al and Fe oxides than in surface soils. The average contents of $Al_d$ and $Fe_d$ in the sub-surface soils were 8.49 and $12.45g\;kg^{-1}$, respectively. Soil pH, cation exchange capacity and clay content were positively correlated with the extractable sulfate contents and SAC. Organic carbon content, however, was negatively correlated with the extractable sulfate contents, implying the competitive adsorption of sulfate with soil organic matter. Considerably significant correlation was found between inorganic + amorphous Al and Fe oxides and the sulfate adsorption, but crystalline Al and other fractions of Fe oxide showed no correlation. Relatively close relationship between the adsorbed sulfates and soil pH, cation exchange capacity, or amorphous Al oxides indicates that the accelerated soil acidification may substantially reduce the potential for sulfate adsorption contributing to sulfur flux in forest ecosystems.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.444-449
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• 2010

In this study, the petroleum sulfonate(PS) was synthesized from pyolyzed fuel oil by sulfonation reaction with sulfuric acid. The PS synthesized had surfactant behaviors relating to the interfacial properties such as surface tension, surface adsorption, and wetting, etc. These interfacial properties were affected by the sulfonation ratio in the synthesis. As the sulfonation ratio increased, the surface tension of the PS aqueous solution decreased. However, when the ratio was too high, the surface tension was increased due to the extremely higher value of hydrophilicity of PS. At the optimum sulfonation ratio, the PS had a good wettability on the cement particles and a good fluidity of the cement mortar with a high adsorption.

• Resources Recycling
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• v.26 no.5
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• pp.39-47
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• 2017

In this study, the precipitation of rare earth-sodium sulfate with sodium sulfate was conducted in order to separate rare earth from Fe in rare earth sulfate solution. Neodymium (Nd) was easily precipitated as Nd-sulfate salt with sodium sulfate, on the other hand, excessive sodium sulfate was needed for the precipitation of Dy-sulfate salt. Also neodymium not only promoted the precipitation of dysprosium sulfate salt but also increased recovery of dysprosium sulfate salt in sulfuric acid solution. At the condition of $60^{\circ}C$ precipitation temperature, 3 h reaction time, 7 equivalents sodium sulfate, the recovery of neodymium and dysprosium sulfate salt was 99.7% and 94.3% respectively from the sulfuric acid solution containing Nd of 23.39 mg/ml and Dy of 8.67 mg/ml. Lastly, from the results of separation of Dy to Nd by the method of sulfate double salt, the effect of salting out with NaCl is important to increase the grade of Dy, and 98.7% of Dy grade could be obtained in this study.