Mercury Emissions from Background and Altered Geologic Units Throughout Nevada

Nacht, David M.; Gustin, Mae Sexauer

doi:10.1023/b:wate.0000009907.49577.a8

Cited by 47 publications

(35 citation statements)

References 25 publications

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“…4a-c, p b 0.01 for all), indicating that TGM restrained soil mercury emission and induced strong atmospheric mercury depositions. This result was in agreement with some previous researches which observed net deposition during periods of elevated air concentrations from different substrates in mine areas (Nacht and Gustin, 2004;Wang et al, 2005Wang et al, , 2007aWang et al, , 2007bEckley et al, 2011). Wang et al (2007a) suggested that mercury exchange flux between soil and air was controlled by two aspects: one was the rate of mercury diffusion on interface between TGM in soil air and the above atmosphere and the other one was the rate of mercury adsorption by soil surface.…”

Section: Influence Of Atmospheric Tgm On the Mercury Flux: Experimentssupporting

confidence: 82%

“…7a and b). Previous studies (Zhang et al, 2002;Nacht and Gustin, 2004;Gustin and Stamenkovic, 2005) observed that addition of water to relative dry soils in amounts less than the needed to saturate the soil surface has been shown to cause an immediate enhancement of mercury emissions. The reason may be that the soil gas which contained higher mercury concentrations (Moore and Castro, 2012), was displaced by infiltrating water physically.…”

Section: Influence Of Atmospheric Tgm On the Mercury Flux: Experimentsmentioning

confidence: 99%

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Investigation of factors affecting mercury emission from subtropical forest soil: A field controlled study in southwestern China

Zhou

Wang

Zhang

et al. 2017

Journal of Geochemical Exploration

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Recent studies demonstrated that subtropical forest in China was considered as a large pool of atmospheric mercury and soils of forested watershed is a large reservoir of atmospherically deposited mercury. However, forest ecosystems not only act as sinks but also as sources of previously deposited mercury emitted back to the atmosphere. In this study a field controlled method was performed in Tieshanping National Forest Park (TNFP) to identify the effects of the most important parameters that controlled mercury emissions from soil surfaces, including chamber flushing flow turnover times (TOTs), soil water content and watering, total gaseous mercury (TGM) in air and understory. Flushing flow rates significantly affected the calculation of mercury flux and the optimal TOTs were 0.94 min in the forest. TGM in atmosphere was significantly inhibited mercury emission from soils, and the deposited mercury was not absorbed firmly by the soils in a short time and emitted back to atmosphere rapidly when TGM concentration decreased. Higher soil moisture reduced the emission of mercury and initial watering produces a spike in the mercury emissions due to the interstitial soil gas mercury displaced by infiltrating water physically. However, subsequent watering was reducing the fluxes, because surface soil was saturated and soil pores were blocked by water film and inhibited the soil mercury emission. Soils under the understory had a higher mercury concentrations and deep organic layers. However, the fluxes of soil under the understory significantly were inhibited in daytime because solar radiation was blocked by the understory and the higher litter layer.

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Section: Influence Of Atmospheric Tgm On the Mercury Flux: Experimentssupporting

confidence: 82%

Section: Influence Of Atmospheric Tgm On the Mercury Flux: Experimentsmentioning

confidence: 99%

Investigation of factors affecting mercury emission from subtropical forest soil: A field controlled study in southwestern China

Zhou

Wang

Zhang

et al. 2017

Journal of Geochemical Exploration

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“…As emissões de Hg na superfície de solos contaminados ou não, já foram evidenciadas [25][26][27] . Em estudos recentes, a intensidade e a natureza das radiações solares, assim como a temperatura do solo, foram indicadas como fatores determinantes no aumento das emissões de mercúrio dos solos para a atmosfera 8,11,13,[24][25][26][27][28][29] .…”

Section: Introductionunclassified

“…Em estudos recentes, a intensidade e a natureza das radiações solares, assim como a temperatura do solo, foram indicadas como fatores determinantes no aumento das emissões de mercúrio dos solos para a atmosfera 8,11,13,[24][25][26][27][28][29] . A variação da umidade do solo, por sua vez, parece apresentar tanto uma influência positiva quanto negativa sobre as emissões de Hg, dependendo do grau de saturação do solo 11 .…”

Section: Introductionunclassified

Quantificação de fluxos de mercúrio gasoso na interface solo/atmosfera utilizando câmara de fluxo dinâmica: aplicação na bacia do Rio Negro

Magarelli¹,

Fostier²

2005

Quím. Nova

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Recebido em 1/7/04; aceito em 28/3/05; publicado na web em 10/8/05QUANTIFICATION OF ATMOSPHERE -SOIL MERCURY FLUXES BY USING A DYNAMIC FLUX CHAMBER: APPLICATION AT THE NEGRO RIVER BASIN, AMAZON. Gaseous mercury sampling conditions were optimized and a dynamic flux chamber was used to measure the air/surface exchange of mercury in some areas of the Negro river basin with different vegetal coverings. At the two forest sites (flooding and non-flooding), low mercury fluxes were observed: maximum of 3 pmol m -2 h -1 -day and minimum of -1 pmol m -2 h -1 -night. At the deforested site, the mercury fluxes were higher and always positive: maximum of 26 pmol m -2 h -1 -day and 17 pmol m -2 h -1 -night. Our results showed that deforestation could be responsible for significantly increasing soil Hg emissions, mainly because of the high soil temperatures reached at deforested sites.Keywords: mercury fluxes; atmosphere-soil exchange; flux chamber. INTRODUÇÃOUma das características mais marcantes do Hg em relação a outros metais é sua capacidade de ser emitido ou reemitido para a atmosfera, principalmente na sua forma gasosa elementar (Hg 0 ). Devido a algumas de suas propriedades tais como baixa reatividade e baixa solubilidade em água, o Hg 0 apresenta um tempo de residência na atmosfera da ordem de um ano, facilitando sua distribuição e deposição numa escala global, razão pela qual foi desenvolvido o conceito de "poluente global" para esse elemento 1 . Na atmosfera, o Hg pode participar de vários processos e/ou interações de natureza química, física ou fotoquímica, propiciando sua transferência para os compartimentos aquáticos e terrestres, bem como sua possível conversão a metil-mercúrio (MeHg) 2 . A propriedade do MeHg de ser bio-acumulado em até um milhão de vezes ao longo da cadeia alimentar em meio aquático constitui uma das principais preocupações ambientais da ecotoxicologia do mercúrio, justificando o estudo do seu ciclo biogeoquímico e, em particular, dos processos de transferência desse elemento entre os diferentes compartimentos 1,2 .O "Expert Panel" 3 estimou que aproximadamente 95% das 200.000 t de Hg mobilizados desde 1890 acumulam-se atualmente nos solos superficiais. A reemissão de uma parcela desse estoque seria equivalente ao total das emissões antrópicas dos Estados Unidos 4 . As florestas cobrem aproximadamente 4x10 9 ha da superfície terrestre, e o destino do Hg estocado, seja no solo, seja na vegetação, é ainda amplamente desconhecido. Considerando que a Amazônia brasileira é coberta por 0,4x10 9 ha de floresta 5 , ou seja, 10% da área coberta por florestas no planeta, justifica-se a importância de se estudar os processos de transferência do Hg nesse ecossistema. Esta necessidade aumenta se for considerada a pequena quantidade de dados já obtidos em áreas de florestas tropicais úmidas, sendo que a maioria dos dados disponíveis são relativos a florestas temperadas e boreais 2,6,7 .Vários estudos já foram realizados com o objetivo de medir in situ as taxas de emissão ou de deposição do mercúrio gasoso t...

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“…Authors such as Nacht and Gustin (2004) and Liang et al (2014) indicated that adding small amounts of water to dry soils without reaching saturation, results in the release of Hg from the soils to the atmosphere. These emissions arose from the displacement of elemental Hg by water infiltrating the soil pores.…”

Section: Total Hg Concentrations In the Mining Wastes And Soilsmentioning

confidence: 99%

Mercury Pollution Assessment of Mining Wastes and Soils From Former Silver Amalgamation Area in North-Central Mexico

Vicencio

Carrizales-Yáñez

Razo-Soto

2017

Rev. Int. Contam. Ambie.

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Mining wastes and soils from Cedral, San Luis Potosí, Mexico, were studied to assess mercury (Hg) pollution in areas of historical silver (Ag) amalgamation and in areas where amalgamation mining wastes were recently reprocessed for Hg and Ag recovery. The total, soluble and bioaccessible Hg concentrations from eight mining waste and nine soil cores were determined at varying depths, which fluctuated from the surface up to 1.0 m depth. The total Hg concentrations in the mining wastes samples ranged from 8 to 548 mg/kg. The total Hg concentrations in the soil samples were lower (1 to 116 mg/kg) than those in the mining wastes. Eighty percent of the soil samples exceeded the maximum permissible limit for residential soils according to the Mexican regulations, demonstrating the impacts of the amalgamation process in Cedral. The soluble Hg concentrations were low, from 0.009 to 0.32 mg/kg in the mining wastes, and from 0.003 to 0.02 mg/kg in soils. The latter represents 0.007 % to 0.54 % and < 0.03 % of total Hg, from mining wastes and soils, respectively, indicating low aqueous Hg transport during rainfall events. The bioaccessible Hg concentrations in the mining waste samples (0.1 to 60 mg/kg) and soil samples (0.1 to 17 mg/kg), suggested that humans could be exposed to this toxic element through the accidental ingestion of mining wastes and soil particles. Although the total Hg concentrations in the mining wastes decreased after reprocessing, the soluble and bioaccessible Hg concentrations increased.Palabras clave: beneficio de patio, jales, reprocesamiento, solubilidad, bioaccesibilidad RESUMENSe estudiaron residuos mineros y suelos de Cedral, San Luis Potosí, México, para evaluar la contaminación por mercurio (Hg) en áreas de amalgamación histórica de plata (Ag) y de reprocesamiento reciente de residuos de amalgamación para la recuperación de Hg y Ag. Se obtuvieron ocho perfiles de hasta 1 m de profundidad de depósitos de 656residuos mineros y nueve de suelo, de los cuales se recolectaron muestras a diferentes profundidades para la determinación de concentraciones totales, solubles y bioaccesibles de Hg. Las concentraciones totales de Hg en residuos mineros variaron entre 8 y 548 mg/kg, mientras que en suelos las concentraciones se presentaron en un rango de entre 1 y 116 mg/kg. Se encontró que el 80 % de las muestras de suelo analizadas superaron el límite máximo permisible de Hg para suelo de uso residencial establecido en la normatividad mexicana, lo que demuestra el severo impacto de la amalgamación y del reprocesamiento de jales de amalgamación en Cedral. Con relación a las concentraciones solubles de Hg, en las muestras de residuos se obtuvieron de 0.009 a 0.32 mg/kg y de 0.003 a 0.02 mg/kg para suelos, lo que representa de 0.007 % a 0.54 % y < 0.03 % del total de Hg contenido en residuos mineros y suelos, respectivamente. Esto indica un bajo potencial de transporte de especies solubles de Hg durante eventos de lluvia. Finalmente, las concentraciones de Hg bioaccesible obtenidas en el estudio (0.1...

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Mercury Emissions from Background and Altered Geologic Units Throughout Nevada

Cited by 47 publications

References 25 publications

Investigation of factors affecting mercury emission from subtropical forest soil: A field controlled study in southwestern China

Investigation of factors affecting mercury emission from subtropical forest soil: A field controlled study in southwestern China

Quantificação de fluxos de mercúrio gasoso na interface solo/atmosfera utilizando câmara de fluxo dinâmica: aplicação na bacia do Rio Negro

Mercury Pollution Assessment of Mining Wastes and Soils From Former Silver Amalgamation Area in North-Central Mexico

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