• Title, Summary, Keyword: Mercury reduction

Search Result 98, Processing Time 0.035 seconds

Investigation of Elemental Mercury Oxidation on Commercial SCR Catalysts in Flue Gas of Fossil Fired Power Plant (상용 SCR 촉매상에서 화력발전소 배기가스 중 원소수은의 산화반응연구)

  • Lee, Seung-Min;Lee, Jung-Bin
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.26 no.3
    • /
    • pp.245-252
    • /
    • 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.

Catalytic Reduction of Oxidized Mercury to Elemental Form by Transition Metals for Hg CEMS (수은 연속측정시스템에서 전이금속에 의한 산화수은의 원소수은으로의 촉매환원)

  • Ham, Sung-Won
    • Clean Technology
    • /
    • v.20 no.3
    • /
    • pp.269-276
    • /
    • 2014
  • This study was aimed to develop catalytic system for the dry-based reduction of oxidized mercury ($Hg^{2+}$) to elemental mercury ($Hg^0$) which is one of the most important components comprising mercury continuous emission monitoring system (Hg-CEMS). Based on the standard potential in oxidation-reduction reaction, transition metals including Fe, Cu, Ni and Co were selected as possible candidates for catalyst proceeding spontaneous reduction of $Hg^{2+}$ into $Hg^0$. These transition metal catalysts revealed high activity for reduction of $Hg^{2+}$ into $Hg^0$ in the absence of oxygen in reactant gases. However, their activities were greatly decreased in the presence of oxygen, which was attributed to the transformation of transition metals by oxygen to the corresponding transition metal oxides with less catalytic activity for the reduction of oxidized mercury. Hydrogen supplied to the reactant gases significantly enhanced $Hg^{2+}$ reduction activity even in the presence of oxygen. It might be due to occurrence of combustion reaction between $H_2$ and $O_2$ causing the consumption of $O_2$ at such high reaction temperature at which oxidized mercury reduction reaction took place. Because the system showed high activity for $Hg^{2+}$ reduction to $Hg^0$, which was compatible to that of wet-chemistry technology using $SnCl_2$ solution, the catalytic reduction system of Fe catalyst with the supply of $H_2$ could be employed as a commercial system for the reduction of oxidized mercury to elemental mercury.

Effects of organic carbon and UV wavelength on the formation of dissolved gaseous mercury in water under a controlled environment

  • Lee, Jae-In;Yang, Ji-Hye;Kim, Pyung-Rae;Han, Young-Ji
    • Environmental Engineering Research
    • /
    • v.24 no.1
    • /
    • pp.54-62
    • /
    • 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.

Overlook of carbonaceous adsorbents and processing methods for elemental mercury removal

  • Bae, Kyong-Min;Kim, Byung-Joo;Park, Soo-Jin
    • Carbon letters
    • /
    • v.15 no.4
    • /
    • pp.238-246
    • /
    • 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.

Dental Hygienists' Knowledge on Dental Amalgam Mercury and Its Treatment Practice (치과위생사의 치과용 아말감 수은에 대한 지식 및 행위)

  • Shin, Kyoung-Hee;Yang, Ji-Yeon;Kwon, Ho-Keun;Shin, Dong-Chun
    • Environmental health and toxicology
    • /
    • v.22 no.3
    • /
    • pp.247-254
    • /
    • 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.

Effects of Intra-peritoneal Injection of Inorganic Mercury on Blood Parameters and Hepatic Oxidative Stress Enzyme Activities in Common Carp (Cyprinus carpio L.)

  • Jee, Jung-Hoon;Kang, Ju-Chan
    • Korean Journal of Environmental Biology
    • /
    • v.22 no.4
    • /
    • pp.559-564
    • /
    • 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.

Characteristics of Hg, Pb, As, Se Emitted from Medium Size Waste Incinerators (중형폐기물 소각시설의 수은, 납, 비소, 셀렌 배출특성)

  • Lee Han-Kook
    • Journal of Environmental Health Sciences
    • /
    • v.32 no.1
    • /
    • pp.8-18
    • /
    • 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.

Preparation and Characterization of a Surface Renewable Solid State Hg/HgO Reference Electrode Utilizing Gold Amalgam

  • Kim, Won;Park, Jong-Man
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.3
    • /
    • pp.439-442
    • /
    • 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.

A Study on the Emission Characteristics of Mercury in Municipal and Industrial Waste Incinerators (폐기물소각시설의 수은배출특성 연구)

  • Seok Kwangseol;Hong Jihyung;Lee Sukjo;Lee Daegyun;Kim Daigon;Park Jihyun
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.20 no.2
    • /
    • pp.205-213
    • /
    • 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).

Quantification of Total Mercury in Antarctic Surface Snow using ICP-SF-MS: Spatial Variation from the Coast to Dome Fuji

  • Han, Yeong-Cheol;Huh, Young-Sook;Hong, Sung-Min;Hur, Soon-Do;Motoyama, Hideaki;Fujita, Shuji;Nakazawa, Fumio;Fukui, Kotaro
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.12
    • /
    • pp.4258-4264
    • /
    • 2011
  • The total mercury concentration ($Hg_T$) of surface snow samples collected along a ~1500 km transect in east Queen Maud Land was determined using inductively coupled plasma sector field mass spectrometry to address the behavior of Hg on the Antarctic Plateau. Due to the volatile nature of mercury, measures were taken against Hg loss from standard solutions by choosing appropriate container material and stabilizing agents. Glass bottles with Teflon-lined caps were superior to Teflon and polyethylene containers in protecting against Hg loss, but addition of gold chloride ($AuCl_3$) or bromine chloride (BrCl) was necessary to ensure preservation of Hg. As Hg loss was also observed in snowmelt samples, our analysis may underestimate the actual amount of HgT in the snow. Even so, the measured HgT was still very low (< 0.4-10.8 pg $g^{-1}$, n = 44) without a signal of depositional enhancement accompanying photo-oxidation of atmospheric elemental mercury in austral midsummer. Moreover, the dynamic variation along the traverse implies spatial and temporal heterogeneity in its source processes.