• 한국대기환경학회지
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• 제26권3호
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• pp.245-252
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• 2010

For the purpose of evaluating to remove elemental mercury using SCR (Selective Catalytic Reduction) catalysts, the result of the concentration variation of elemental mercury in lab experiment and field measurement was compared. The effect of the elemental mercury oxidation on commercial catalysts was studied in simulated gas. Three species of SCR catalyst, $V_2O_5-TiO_2$ type, were selected. The elemental mercury reduced 30% without HCl gas in SCR operating condition. But the width of reduction increased 60% at 20 ppm HCl gas. According to the result of field measurement, reduction rate of elemental mercury at SCR outlet showed 60%. The total mercury concentration decreased about 20%. The results were similar to the lab test. The results of chemical analysis of test sample showed increase of mercury concentration but surface change was not observed.

• 청정기술
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• 제20권3호
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• pp.269-276
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• 2014

본 연구는 수은연속측정시스템의 가장 중요한 구성 요소의 하나인 산화수은을 원소수은으로 환원시킬 수 있는 건식 환원촉매시스템 개발을 목적으로 수행되었다. 산화-환원 표준전위를 기준으로 산화수은의 원소수은으로의 환원반응을 자발적으로 일으킬 수 있는 촉매 대상물질로 Fe, Cu, Ni 및 Co 4종류의 전이금속이 선택되었다. 이들 전이금속 촉매들은 산소가 없는 반응가스 조성에서 산화수은의 원소수은으로의 환원반응에 대해 높은 활성을 보였다. 그러나 산소가 존재하는 경우 환원 활성이 크게 감소하는데 이는 산소에 의해 해당 전이금속이 산화수은 환원 활성이 낮은 전이금속산화물로 변환되기 때문이다. 반응가스에 산소가 존재하여도 수소를 공급하면 산화수은 환원 활성이 크게 증가되는데 이는 산화수은의 환원반응이 진행되는 고온에서 산소와 수소 사이의 연소반응에 의해 산소가 소모되기 때문으로 확인되었다. Fe를 환원촉매로 하고 배기가스에 수소를 공급하는 산화수은 환원촉매시스템은 $SnCl_2$ 수용액을 사용하는 습식화학 환원기술에 필적할 수준의 활성을 나타내기 때문에 상업적으로 적용 가능한 산화수은 환원시스템으로 기대된다.

• Carbon letters
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• 제15권4호
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• pp.238-246
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• 2014

People have been concerned about mercury emissions for decades because of the extreme toxicity, persistence, and bioaccumulation of methyl Hg transformed from emitted Hg. This paper presents an overview of research related to mercury control technology and identifies areas requiring additional research and development. It critically reviews measured mercury emissions progress in the development of promising control technologies. This review provides useful information to scientists and engineers in this field.

• Environmental Engineering Research
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• 제24권1호
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• pp.54-62
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• 2019

The effects of UV wavelength and dissolved organic carbon (DOC) on the formation of dissolved gaseous mercury (DGM) were investigated in a controlled environment. To remove any other influences than UV wavelength and DOC, purified water was used as the working solution. DGM was instantly produced with irradiation of all UV lights even without DOC; whereas, there was no noticeable increase of DGM during irradiation of visible light. The amount of formed DGM increased as the DOC concentration increased even in dark conditions; however, UV-B irradiation significantly promoted DGM production with DOC present. The rate constants of reduction ranged from $1.4{\times}10^{-6}s^{-1}$ to $3.5{\times}10^{-5}s^{-1}$, with the lower values occurring under the dark condition without DOC and the higher values resulting under UV-B irradiation and high DOC concentration. However, DGM production was not linearly correlated with the DOC concentration at higher range of DOC in this study. Future studies should investigate the effects of DOC concentration on mercury (Hg) reduction over the broad range of DOC concentrations with different DOC structures and with other influencing parameters.

• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.247-254
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• 2007

This study was performed with the questionnaire survey on mercury knowledge and mercury exposure avoidance behavior, which was conducted among 1076 dental personnel in September, 2004. As for the factors effecting the mercury knowledge, it seems that they are closely related with the personnel's educational backgrounds, and their understandings of causing environmental hazardousness in the dental offices. And also, the factors effecting the behavior of mercury exposure avoidance are strongly connected with the knowledge points on mercury, the knowledge of air states in the dental clinic offices, the use of pincettes and gloves in squeezing, and rubber dam and gloves in mulling, the experience of environmental education on mercury, etc. In the survey, the higher points in mercury knowledge is closely related with the higher points in the behavior of mercury exposure avoidance. Nevertheless, the very fact that the lower points in the behavior among personnel takes on the aspect of the relatively higher points in knowledge on mercury may be understood that the generally acquired knowledge on mercury cannot be the critical factor of the behavior of mercury exposure avoidance.

• 환경생물
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• 제22권4호
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• pp.559-564
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• 2004

The effects of intra-peritoneal injection of inorganic mercury on haemato-logical parameters and hepatic oxidative stress enzyme activities were studied in common carp, Cyprinus carpio. The fish were injected thrice intra-peritoneally with mercuric chloride TEX>$(5,\;10mg\;Hg\;kg\;b.W.^{-1})$. After exposure of three different mercury concentrations a physiological stress response was exerted on C. carpio by causing changes in the blood status such as erythropenia in blood and oxidative stress in liver. Red blood cell counts, hemoglobin concentration and hematocrit level were reduced in most cases by inorganic mercury. Remarkable low level of serum chloride, calcium and osmolality were also observed in the mercury- exposed fish. However, serum magnesium and phosphate were not altered by exposure to mercury. An increased activity of hepatic glutathione peroxidase was observed in the lowest treatment group of carp $(1mg\;Hg\;mg\;b.w.^{-1})$, hence, hepatic catalase and glutathione peroxidase of carp exposed to higher concentration of mercury $(5,\;10mg\;Hg\;kg\;b.W.^{-1})$ showed significant reduction in such activities.

• 청정기술
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• 제27권3호
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• pp.207-216
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• 2021

석탄화력발전소로부터 배출되는 질소산화물(NO + NO₂ = NO_x)은 NH₃를 환원제로 사용하여 선택적으로 환원시키는 SCR(selective catalytic reduction) 탈질촉매시스템에서 효과적으로 제거될 수 있다. 이 SCR 촉매공정에서 원소수은을 산화시켜 후속공정에서 제거하기 위하여 수많은 산화촉매들이 제안되었으나 MW급 석탄연소시설이나 상업운전 중인 석탄발전소 탈질시스템에서 원소수은 산화성능을 실증한 사례들은 매우 드물다. 실배가스에서 수행한 실증연구들을 심층적으로 조사·분석한 바는 기존 SCR 탈질촉매뿐 아니라 수은산화능을 향상시킨 신촉매의 원소수은 산화활성은 석탄연소, 실배가스 등의 특성에 따라 매우 복잡한 양상을 띤다는 점이다. 그럼에도 불구하고 석탄연소시설에 사용하는 원료탄, 탈질시스템과 실증조건이 원소수은 산화능에 가장 큰 영향을 미치는 핵심 요소이다. 특히, 원료탄에 함유된 할로겐 함량은 탈질촉매공정의 중요성을 넘어서는 것으로 보여진다. 석탄에 존재하는 대표적인 할로겐 성분은 Cl, Br과 F이고 이들 중에서 Cl이 지배적이며 다른 할로겐계처럼 염으로 존재하지만 석탄연소 과정에서 미량의 Cl₂와 함께 HCl로 전환된다. 이러한 HCl은 원소수은 산화에 있어서 강력한 산화제로 작용하지만 석탄마다 Cl 함량이 다르기 때문에 HCl 농도 또한 강하게 의존한다.

• 한국환경보건학회지
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• 제32권1호
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• pp.8-18
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• 2006

The aim of this study is to evaluate the emission characteristics of mercury, lead, arsenic, and selenium from medium size municipal solid waste incinerators(MSWIs) in Korea. The concentrations of mercury, lead, arsenic, and selenium emitted from medium size MSWI stack were $2.67\;{\mu}g/Sm^3,\;0.38\;mg/Sm^3,\;1.33\;{\mu}g/Sm^3,\;0.28\;{\mu}g/Sm^3$, respectively. The concentration levels of mercury, lead, arsenic in flue gas from medium size MSW incinerator stacks selected were nearly detected under the Korea criteria level. Removal efficiencies of mercury, lead, arsenic, and selenium in waste heat boiler(WHE) and cooling tower(CT) were $90.36\%,\;69.76\%,\;43.04\%,\;40.64\%$, respectively. In general, the removal efficiencies of mercury and lead in WHE were higher than those of arsenic and selenium in WHE. Emission gas temperature reduction from waste heat boiler(WHB) and cooling tower(CT) can control mercury and lead of medium size MSWIs. To evaluate the relationship between mercury, lead, arsenic, selenium of fly ash and those of flue gas, it was carried out to correlation analysis of each metal concentration in the fly ash and in the flue gas from medium size MSWIs. From the correlation analysis, the coefficients of mercury, lead, arsenic, and selenium were 0.61, -0.38, 0.87, 0.28, respectively. The results of correlation analysis revealed that it should be highly positive to the correlation coefficients of mercury and arsenic in the fly ash and those of the flue gas emitted from medium size MSWIs. As it were, the concentrations of mercury and arsenic of flue gas from medium size MSWIs are high unless mercury and arsenic in fly ash are properly controlled in dust collection step in medium size MSWIs. It was also concluded that mercury, lead, arsenic, and selenium from MSWIs stacks could be controlled by waste heat boiler(WHE) and dust collecting step in medium size MSWIs.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.439-442
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• 2007

A solid state Hg(Au)/HgO reference electrode was prepared utilizing gold amalgam solid particles. Solid fine powder of the gold amalgam was prepared by chemical reduction of Au(III) with NaBH4 followed by reduction of Hg(II) in the presence of gold fine particles. The solid content in the suspension of the gold amalgam particles and fine mercury oxide particles in DMF containing PVC was precipitated by the addition of a large amount of water to give solid Hg(Au)/HgO/PVC mixture. After drying, the mixture was pressure-molded to a physically stable Hg(Au)/HgO composite reference electrode material. The electrochemical characteristics of the electrode as a reference electrode were very similar to an ordinary Hg/HgO reference electrode. The electrode material can be molded and fabricated in any desired shape and size. The surface can be renewed by a simple polishing process whenever contaminated or deactivated. The applicability of the electrode in the electrochemical detection of carbohydrates after anion exchange separation was evaluated.

• 한국대기환경학회지
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• 제20권2호
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• pp.205-213
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• 2004

The emission characteristics of mercury in waste incinerators were investigated to get basic data for the policy development on the emission reduction of mercury (Hg). For the study several important factors were analysed from 4 incinerators such as mercury concentration, emission factors and removal rate for control devices. The results are listed below. Mercury concentrations in the flue gas were 0.39～5.96 $\mu\textrm{g}$/S㎥ in MWI and 2.5～8.8 $\mu\textrm{g}$/S㎥ in IWI. The distributions of gaseous and particulate mercury in flue gas were above 99% and below 1 %, respectively. Therefore, in order to remove mercury effectively, it is important to control the gaseous mercury. Mercury concentrations in fly ash collected from control device were found as 16.2～35.6 mg/kg- ash in FF of MWI. Also mercury concentrations at the front and back point of control device of MWI were 33.45～62.65 $\mu\textrm{g}$/S㎥ and 0.88～3.49 $\mu\textrm{g}$/S㎥, respectively. Emission factors were estimated as 3.67～11.67 mg/ton in FF, 2.6～24.5 mg/ton in MWI with SNCR, SDR and FF, 54.9～192.7 mg/ton in IWI with Cyclone and FF. Emissions from Municipal Waste Incinerator were found both in minimum and maximum ranges. Annual mercury emissions emitted from MWI was estimated as 20.0 kg (6.0～33.9 kg).