Computed Effects of Adsorption Kinetics on Pesticide Movement in Soils

Leistra, M.; Dekkers, W.A.

doi:10.1111/j.1365-2389.1977.tb02242.x

Cited by 20 publications

(14 citation statements)

References 15 publications

(13 reference statements)

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“…Ionic and neutral solutes are sorbed by soil organic matter and exhibit similar kinetics 75. To allow for nonequilibrium effects, RZWQM uses a modification of the three‐site model proposed by Boesten and others51, 76–78 in which a pesticide simultaneously undergoes (a) an essentially instantaneous reversible sorption (complete in seconds) onto ‘class 1’ soil sites; (b) a slower reversible sorption (complete in hours or days) onto ‘class 2’ soil sites, and (c) a still slower irreversible ‘binding’ process onto ‘class 3’ soil sites, which takes weeks to months. RZWQM assumes bound residues become a permanent, and biologically insignificant, component of the soil.…”

Section: Soil Sorptionmentioning

confidence: 99%

Documenting the pesticide processes module of the ARS RZWQM agroecosystem model

Wauchope

Rojas

Ahuja

et al. 2004

Pest Management Science

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We describe the theory and current development state of the pesticide process module of the USDA‐Agricultural Research Service Root Zone Water Quality Model, or RZWQM. Several processes which are significant in determining the fate of a pesticide application are included together in this module for the first time, including application technique, root uptake, ionic dissociation, soil depth dependence of persistence, volatilization, wicking upward in soil and aging of residues. The pesticide module requires a large number of parameters to run (as does the RZWQM model as a whole) and it is becoming clear that RZWQM will find most interest and use as part of a ‘scenario’ in which all data requirements are supplied and the predictions of the system compared with a real (usually partial) data set. Such a scenario may then be modified to examine the response of the system to changes in inputs. It also has significant potential as a technology transfer or teaching tool, providing detailed understanding of a specific agronomic system and its potential impacts on the environment. Published in 2004 for SCI by John Wiley & Sons, Ltd.

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Section: Soil Sorptionmentioning

confidence: 99%

Documenting the pesticide processes module of the ARS RZWQM agroecosystem model

Wauchope

Rojas

Ahuja

et al. 2004

Pest Management Science

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“…This type of model was modified by several authors to account for the existence of two categories of adsorption sites. This was done assuming that either one category with instantaneous equilibrium is associated with another characterized by a first-order rate law (36) or two categories obeying a first-order rate law are present (37,38). Higher order kinetics have sometimes been observed (12).…”

Section: Surface Reaction Modelsmentioning

confidence: 99%

Adsorption of Organic Chemicals in Soils

Calvet¹

1989

Environmental Health Perspectives

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This paper presents a review on adsorption of organic chemicals on soils sediments and their constituents. The first part of this review deals with adsorption from gas and liquid phases and gives a discussion on the physical meaning of the shape of adsorption isotherms. Results show that no general rules can be proposed to describe univocally the relation between the shape of isotherms and the nature of adsorbateadsorbent system. Kinetics of adsorption is discussed through the description of various models.Theoretical developments exist both for the thermodynamics and the kinetics of adsorption, but there is a strong need for experimental results. Possible adsorption mechanisms are ion exchange, interaction with metallic cations, hydrogen bonds, charge transfers, and London-van der Waals dispersion forces/ hydrophobic effect. However, direct proofs of a given mechanism are rare. Several factors influence adsorption behavior. Electronic structure of adsorbed molecules, properties of adsorbents, and characteristics of the liquid phase are discussed in relation to adsorption. Such properties as water solubility, organic carbon content of adsorbing materials, and the composition of the liquid phase are particularly important. Evaluation of adsorption can be obtained through either laboratory measurements or use of several correlations. Adsorption measurements must be interpreted, taking into account treatment of adsorbent materials, experimental conditions, and secondary phenomena such as degradations. Correlations between adsorption coefficients and water-octanol partition coefficient or water solubility are numerous. They may be useful tools for prediction purposes. Relations with transport, bioavailability, and degradation are described.

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“…Leistra and Dekkers (1977)). This concept has been used for decades in the simulation models that are used for the regulatory assessment of leaching to groundwater and surface water at national and EU levels (e.g.…”

Section: Concentrations In Pollen and Nectar In Plants In Permanent Cmentioning

confidence: 99%

Guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees)

2013

EFS2

309

198

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The Guidance Document is intended to provide guidance for notifiers and authorities in the context of the review of plant protection products (PPPs) and their active substances under Regulation (EC) 1107/2009. The scientific opinion on the science behind the development of a risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees) (EFSA Panel on Plant Protection Products and their Residues (PPR), 2012a) provided the scientific basis for the development of the Guidance Document. Specific Protection Goals were agreed in consultation with the Standing Committee on the Food Chain and Animal Health. The Guidance Document suggests a tiered risk assessment scheme with a simple and cost-effective first tier to more complex higher tier studies under field conditions. Each of the tiers will have to ensure that the appropriate level of protection is achieved.

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Computed Effects of Adsorption Kinetics on Pesticide Movement in Soils

Cited by 20 publications

References 15 publications

Documenting the pesticide processes module of the ARS RZWQM agroecosystem model

Documenting the pesticide processes module of the ARS RZWQM agroecosystem model

Adsorption of Organic Chemicals in Soils

Guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees)

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