Cotransport of cadmium and hexachlorobiphenyl by dissolved organic carbon through columns containing aquifer material

Dunnivant, Frank M.; Jardine, Philip M.; Taylor, Donald R.; McCarthy, John F.

doi:10.1021/es00026a018

Cited by 119 publications

(81 citation statements)

References 27 publications

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“…Contaminant mobility increased with the solution NOM concentration, and the enhanced contaminant mobility could be explained by incorporating a three-phase system (contaminants distributed between one stationary and two mobile phases: the aqueous phase and a conservatively transported NOM-bound phase) in the convection-dispersion (CD) transport equation. While the association of a metal or organic contaminant with an NOM molecule could affect the transport properties of that NOM molecule (e.g., alter its charge density or size), this effect did not appear important in the Dunnivant et al [1992b] study.…”

Section: Resultsmentioning

confidence: 83%

“…Extended contact will eventually bring even a novel source of NOM into a steady state with respect to adsorption by the aquifer, and contaminants bound to the novel NOM can then be expected to travel conservatively. This principle was demonstrated in laboratory columns by Dunnivant et al [1992b]. After ''passivating'' adsorption surfaces by batchcontacting Georgetown aquifer material with NOM-rich water from the wetland pond, they introduced a step input of different concentrations of that NOM with organic and inorganic contaminants (a polychlorinated bipheny and cadmium) onto columns of the NOM-equilibrated aquifer material.…”

Section: Resultsmentioning

confidence: 99%

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Field Tracer Tests on the Mobility of Natural Organic Matter in a Sandy Aquifer

McCarthy¹,

Gu²,

Liang³

et al. 1996

Water Resources Research

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Abstract. The field-scale transport of natural organic matter (NOM) was examined in a two-well forced gradient injection experiment in a sandy, coastal plain aquifer in Georgetown, South Carolina. Spatial moments described the migration of the center of mass of NOM and conservative tracer. Temporal moments were used to estimate mass loss and retardation of the NOM along a transect of six sampling locations at two depths and at the withdrawal well. Large differences were observed in transport behavior of different subcomponents of NOM. Larger and more strongly binding NOM components in the injection solution are postulated to adsorb and displace weakly binding, low-molecular weight NOM in groundwater. Conversely, NOM components that were similar to the groundwater NOM were transported almost conservatively, presumably due to ''passivation'' of the aquifer by previously adsorbed components of the groundwater NOM. NOM may thus exhibit two types of effects on contaminant dynamics in the subsurface. When the equilibria between solution and solid phase NOM is disrupted by introduction of a novel source of NOM, descriptions of the multicomponent transport process are complex and predictive modeling is problematic. Because of the differences in transport behavior of NOM subcomponents, the chemical properties and, more importantly, the functional behavior of NOM with respect to contaminant migration will vary with time and distance along a flow path. However, when groundwater NOM exists at a steady state with respect to adsorption on aquifer surfaces, the migration of NOM, and the contaminant-NOM complex, may be approximated as the transport of a conservative solute.

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Section: Resultsmentioning

confidence: 83%

Section: Resultsmentioning

confidence: 99%

Field Tracer Tests on the Mobility of Natural Organic Matter in a Sandy Aquifer

McCarthy¹,

Gu²,

Liang³

et al. 1996

Water Resources Research

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“…Embora esse tipo de comportamento não tenha sido objeto de estudo neste trabalho, esse tipo de dinâmica precisa ser averiguado, pois tem sido considerado por muitos autores como principal meio de transporte de pesticidas em condições de laboratório (Dunnivant et al, 1992;Kim et al, 1994a,b;Saiers & Hornberger, 1996), como em situações de campo (van Gunten, et al, 1988;Buddemeier & Hunt, 1988 …”

Section: Resultsunclassified

Avaliação do transporte de atrazina em solos sob diferentes condições de manejo agrícola

Correia

Langenbach

Campos

2010

Rev. Bras. Ciênc. Solo

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RESUMOA pouca informação sobre o movimento de pesticidas em solos brasileiros com manejo de plantio direto torna o conhecimento desse assunto de grande relevância na avaliação de risco de contaminação do solo e de lençóis de água. Os experimentos simularam chuvas intensas com fluxo contínuo por meio de uma nova técnica para a determinação simultânea das propriedades de advecção, difusão e sorção, representando o transporte de contaminantes ao longo do perfil de solo estudado. Os resultados mostraram que as propriedades físico-químicas não se correlacionam com a permeabilidade do solo e a lixiviação da atrazina. A condutividade 10 vezes maior no plantio direto (PD) e sistema natural (SN) do que no sistema convencional (SC) e solo subsuperficial (SUB) sugere que o processo de advecção ocorre predominantemente através dos macroporos por fluxo preferencial, que são destruídos na aração do SC. Dessa forma, a condição de fluxo contínuo, representando fortes chuvas, faz com que a lixiviação em PD seja maior que em SC, contrariando dados da literatura em experimentos de campo com chuvas intermitentes, os quais mostraram menor lixiviação em PD comparado ao SC. Os riscos de contaminação dos lençóis de água não são determinados apenas pelo manejo do solo, mas também pelas condições pluviométricas intensas nos trópicos, com perspectivas de ainda serem maiores nos cenários de mudanças climáticas.Termos de indexação: pesticidas, contaminação, plantio direto.(1) Recebido para publicação em janeiro de 2009 e aprovado em dezembro de 2009.

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“…Many studies have reported the transport of strongly sorbing contaminants such as radionuclide's, transition metals, heavy metals, pesticides and hydrophobic organics among others in a saturated soil column (Cherrey et al 2003;Dunnivant et al 1992;Grolimund and Borkovec 2005;Grolimund et al 1996;Howard and Sova 1993;Magee et al 1991;Nelson et al 1985;Sen et al 2002a;Vinten et al 1983). The co-transport and desorption of metals by colloidal particles have been studied using Zn-saturated soil (Barton and Karathanasis 2003).…”

Section: Introductionmentioning

confidence: 99%

Adsorption studies of toxic metals and dyes on soil colloids and their transport in natural porous media

Murali¹,

Murthy

Sengupta

2014

Int. J. Environ. Sci. Technol.

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Mobile colloids in soils and aquifers can act as carriers for adsorbed contaminants and thereby facilitate the transport of contaminants. In order to understand the problem, colloids isolated from soil were used as adsorbents for toxic metals such as Pb(II), Ni(II), Cu(II), Cr(VI) and dyes such as alizarin red and methylene blue. Column experiments were conducted to investigate the mobilization of in situ colloids from soil and their size distribution. Experiments were also conducted to study the transport of alizarin red dye through soil columns at different ionic strengths (0.01 and 0.001 M) and pH (pH 7.5, 9.5 and 11.5) and toxic metals at the ionic strength of 0.001 M. The colloids showed significant adsorption toward the contaminants with the adsorption of methylene blue reaching as high as 625 mg g -1 . The mobilized colloids had significant difference in their size distribution, and the cumulative mass curve of colloids followed a nonlinear pattern in contrast to the previously reported linear behavior on model systems. The dye and toxic metal transport experiments suggested their sensitivity to low ionic strength influent solution, with the capacity of colloids to transport the dye and toxic metals increasing at low ionic strength and the transport of dye at high pH. With decreasing ionic strength, the release rate coefficient of dye increased. This study represents an important step to understand colloid-associated contaminant transport in natural soils.

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Cotransport of cadmium and hexachlorobiphenyl by dissolved organic carbon through columns containing aquifer material

Cited by 119 publications

References 27 publications

Field Tracer Tests on the Mobility of Natural Organic Matter in a Sandy Aquifer

Field Tracer Tests on the Mobility of Natural Organic Matter in a Sandy Aquifer

Avaliação do transporte de atrazina em solos sob diferentes condições de manejo agrícola

Adsorption studies of toxic metals and dyes on soil colloids and their transport in natural porous media

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