Transport of simazine in unsaturated sandy soil and predictions of its leaching under hypothetical field conditions

Suárez, Francisco; Bachmann, Jaime; Muñoz, José F.; Ortiz, Cristián; Tyler, S. W.; Alister, Claudio; Kogan, Marcelo J.

doi:10.1016/j.jconhyd.2007.05.009

Cited by 29 publications

(20 citation statements)

References 23 publications

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“…The physical non-equilibrium model assumes that the adsorption is instantaneous, and mass transfer to adsorption sites is primarily due to diffusion. The chemical non-equilibrium model assumes that adsorption is not an instantaneous process, but is time dependent and represented by a first order kinetic term (Suárez et al, 2007).…”

Section: Model Under Non-equilibrium Conditionsmentioning

confidence: 99%

“…The u value was determined to be 100 for all cases, confirming that the local equilibrium assumption model was sufficient to describe the tracer transport. According to Suárez et al (2007), a high Peclet number (P > 50) indicates a convection-dominated transport process, while a lower value (P < 1) implies diffusion-controlled process. At high Peclet numbers, molecular diffusion is typically negligible (Biggar and Nielsen, 1976;Kirda et al, 1973).…”

Section: Bromide Breakthrough and Elution Curvesmentioning

confidence: 99%

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Sorption and retardation of strontium in saturated Chinese loess: experimental results and model analysis

Huo

Qian

Hao

2013

Journal of Environmental Radioactivity

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Section: Model Under Non-equilibrium Conditionsmentioning

confidence: 99%

Section: Bromide Breakthrough and Elution Curvesmentioning

confidence: 99%

Sorption and retardation of strontium in saturated Chinese loess: experimental results and model analysis

Huo

Qian

Hao

2013

Journal of Environmental Radioactivity

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“…On the other hand, mechanist models are based on the numerical resolution of the Richards equation for the variably saturated flow in porous media and advection-dispersion equation for solute transport, such as Hydrus-1D (Simunek et al 2005). This model was used by many authors for the simulation of water movement in soil (Suleiman 2008) and solute transport in the unsaturated zone, including heavy metals (Jacques et al 2008), nitrogen (Crevoisier et al 2008) and herbicides (Suárez et al 2007). Hydrus-1D could be an interesting tool to study salts dynamics in the semiarid region of Bouhajla (Central Tunisia), characterised by a strong pressure on the groundwater resources and soil and by shallow groundwater unsuitable for irrigation with a TDS of 6 g/l (Hachicha et al 2005;Kanzari et al 2011).…”

Section: Simulation Of Water and Salts Dynamics In Bouhajla (Central mentioning

confidence: 99%

Simulation of water and salts dynamics in Bouhajla (Central Tunisia): exceptional rainfall effect

Kanzari¹,

Hachicha²,

Bouhlila³

et al. 2012

Soil & Water Res.

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Arid and semi-arid regions face the risk of soils and aquifers salinization. Rainy events are rare which is characteristic of these regions. They play a significant role in the leaching of salts from topsoil to deeper layers, which increases the risk of aquifers salinization. For this reason, a plot was selected in the semi-arid region of Bou Hajla (Central Tunisia). The simulation of water and salts dynamics was carried out by Hydrus-1D. Model calibration was realised on a flood irrigation experiment during 10 days and in a depth of 4 m. The hydrodynamic parameters were determined by inverse modelling. Model validation was performed successfully during 577 days. The simulation of water and salts dynamics has allowed the analysis of two scenarios: (i) the effect of a very rainy event (> 50mm/day) on the dynamics of salts. This type of event allows leaching of the accumulated salts in the topsoil which promotes their burial in the depth; (ii) the long-term evolution of the saline profile in 20 years showed the cyclical nature of salts leaching in the topsoil, the permanent accumulation of salts in the depth of around 2 m, and a continuous leaching in the deeper layers (around 4 m), which may increase groundwater contamination risk.

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“…O código Hydrus 1D é um modelo computacional aplicado em solos de porosidade média, ideal para solos arenosos e aplicável em solos de fluxo uniforme com textura homogênea, determinando os atributos clássicos de advecção e dispersão da equação de Richards, para diversos tipos de solutos. Este código também permite a verificação de fluxos em sistemas de solos com porosidade e permeabilidade dupla, ou seja, diferentes estruturas de solos (SUÁREZ et al, 2007;ŠIMŮNEK et al, 2008;SAIFADEEN;GLADNYEVA, 2012). Rubio (2005) As amostras coletadas foram, posteriormente, misturadas em pares (mistura realizada com espátula em balde plástico), até a obtenção de uma amostra composta homogênea.…”

Section: Introductionunclassified

Evaluation of exposure to benzene in silica sand field: calculation of toxicological risk

2016

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ResumoNa mineração de areia de sílica, os impactos ambientais podem ser causados pelo controle inadequado do combustível utilizado. Esse problema de gestão ocorre em processos de extração e pode causar vazamentos e derramamentos superficiais nos campos, resultando em consequente contaminação do solo e das águas superficiais e subterrâneas por compostos orgânicos voláteis, como o benzeno. Tal contaminante é um dos principais componentes toxicológicos do diesel e da gasolina, com efeitos adversos para a saúde humana. O objetivo deste artigo é apresentar uma avaliação de risco de exposição ao benzeno em campo de areia silicosa, localizado no distrito de Santa Maria Eterna, em Belmonte, no sul da Bahia. O processo metodológico começa pela obtenção dos parâmetros físico-químicos e hidráulicos do solo, recolhido numa área de 280 m 2 . Os parâmetros de adsorção, difusão, lixiviação e volatilização do contaminante foram obtidos a partir do banco de dados da U.S. EPA. O modelo computacional Hydrus 1D foi utilizado na simulação de transporte do benzeno no solo visando estimar as concentrações nas zonas não saturadas e saturadas, depois de um período de 396 dias. Os resultados obtidos mostram que os valores do risco carcinogênico estão acima dos níveis aceitáveis para uma exposição crônica.Palavras chave: areia silicosa; risco toxicológico; exposição ao benzeno; Hydrus 1D; saúde humana.

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Transport of simazine in unsaturated sandy soil and predictions of its leaching under hypothetical field conditions

Cited by 29 publications

References 23 publications

Sorption and retardation of strontium in saturated Chinese loess: experimental results and model analysis

Sorption and retardation of strontium in saturated Chinese loess: experimental results and model analysis

Simulation of water and salts dynamics in Bouhajla (Central Tunisia): exceptional rainfall effect

Evaluation of exposure to benzene in silica sand field: calculation of toxicological risk

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