Alginate and lignin-based formulations to control pesticides leaching in a calcareous soil.

Important risk of groundwater pollution has been observed as a result of rapid leaching of highly soluble pesticides when used in agronomic practices as conventional formulations. This risk can be minimized through the application of the pesticide at a set rate using controlled release formulations (CRFs). In this research, CRFs of isoproturon, imidacloprid and cyromazine have been evaluated in a calcareous soil.

Lignin-based formulations to prevent pesticides pollution.

The pesticides isoproturon, imidacloprid and cyromazine, identified as groundwater pollutants, were incorporated in lignin-based formulations to obtain controlled release (CR) properties. The formulations were prepared by mixing the pesticide with a commercially available pine kraft lignin under melting conditions. A high efficiency of the preparations was therefore reached; it oscillated between 93.

Adsorption of chloridazon from aqueous solution on modified kerolite-rich materials.

The adsorption of chloridazon (5-amine-4-chloro-2-phenylpyridazin-3(2H)-one) on kerolite samples heated at 110 degrees C (K-110), 200 degrees C (K-200), 400 degrees C (K-400), 600 degrees C (K-600) and acid-treated with H(2)SO(4) solutions of two different concentrations (0.25 and 0.5 M) (K-0.

Modeling pesticide leaching and dissipation in a mediterranean littoral greenhouse.

The one-dimensional chromatographic flow model PEARL was used to simulate the movement of the insecticide imidacloprid and the fungicide procymidone through a greenhouse soil. The model was parametrized using measured and literature values of soil hydrological parameters. Soil water movement and soil temperature were reasonably well described by the model.

Controlled release of isoproturon, imidacloprid, and cyromazine from alginate-bentonite-activated carbon formulations.

Different alginate-based systems of isoproturon, imidacloprid, and cyromazine have been investigated in order to obtain controlled release (CR) properties. The basic formulation [sodium alginate (1.50%), pesticide (0.

Cosorption study of organic pollutants and dissolved organic matter in a soil.

In this study we have evaluated the effects of dissolved organic matter (DOM) on sorption of imidacloprid, 3,4-dichloroaniline (3,4-DCA) and 4-bromoaniline (4-BA) on a typical calcareous soil (Luvic Xerosol) from south-eastern Spain. Two different types of DOM were used, that is to say, dissolved natural organic matter extracts from a commercial peat (DNOM) and a high-purity tannic acid (TA) solution. The experiments were carried out in a 0.

Application of a single model to study the adsorption equilibrium of prednisolone on six carbonaceous materials.

The knowledge of sorption processes of nonelectrolytes in solution by solid adsorbents implies the study of kinetics, equilibrium, and thermodynamic functions. However, quite frequently the equilibrium isotherms are studied by comparing them with those corresponding to the Giles et al. classification (1); these isotherms are also analyzed by fitting them to equations based on thermodynamic or kinetic criteria, and even to empirical equations.

Application of a single model to study the adsorption kinetics of prednisolone on six carbonaceous materials.

The knowledge of the adsorption processes of nonelectrolytes from liquid solution on solid materials involves the study of their kinetic and equilibrium aspects as well as the understanding of their thermodynamic functions. However, in most published papers adsorption isotherms are analyzed by using the Giles classification and other proposed equations which are either empirical or based on kinetic or thermodynamic criteria. Our opinion is that both the kinetic and the equilibrium studies must be complementary and that, in general, equations describing the adsorption isotherms come from the kinetic laws governing the different partial processes which determine the global process.

Adsorption of chloridazon from aqueous solution on heat and acid treated sepiolites.

The adsorption of chloridazon on heat treated sepiolite samples at 110 degrees C (S-110), 200 degrees C (S-200), 400 degrees C (S-400), 600 degrees C (S-600) and acid treated samples with H2SO4 solutions of two different concentrations (0.25 and 1.0M) (S-0.

Effects of dissolved organic carbon on sorption of 3,4-dichloroaniline and 4-bromoaniline in a calcareous soil.

To evaluate the effects of dissolved organic carbon on sorption of 3,4-dichloroaniline (3,4-DCA) and 4-bromoaniline (4-BA) on soils, batch sorption experiments were carried out. The soil used was a typical calcareous soil from south-eastern Spain. Two different types of dissolved organic carbon were used, that is, dissolved organic carbon extracts from a commercial peat (DOC-PE) and high-purity tannic acid (DOC-TA).

Effects of ionic strength and temperature on adsorption of atrazine by a heat treated kerolite.

The adsorption of 6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) on a heat treated kerolite sample at 600 degrees C (K-600) from pure water solution at 10 degrees C, 25 degrees C and 40 degrees C has been studied. The influence of the presence of 0.1 M KCl in the medium was also investigated for a better understanding of variables affecting the adsorption of this herbicide.

Effects of dissolved organic carbon on phosphate retention on two calcareous soils.

To evaluate the effects of dissolved organic carbon (DOC) on phosphate retention (including both sorption and/or precipitation reactions) on soils, experiments were performed by using two typical calcareous soils from southeastern Spain (Calcic Regosol and Luvic Xerosol) and two different types of DOC: (1) extracts from a commercial peat (DOC-PE) and (2) high-purity tannic acid (DOC-TA). The experiments were carried out from a 0.01 M CaCl2 aqueous medium at 25 degrees C.

Use of activated bentonites in controlled-release formulations of atrazine.

The herbicide atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) was incorporated in alginate-based granules to obtain controlled-release (CR) properties. The basic formulation [sodium alginate (1.40%)-atrazine (0.

The potential removal of imidacloprid from water by heat-treated kerolites.

The adsorption of imidacloprid [1-(6-chloro-3-pyridinylmethyl)-N-nitroimidazolidin-2-ylideneamine] on heat-treated kerolite samples at 110 degrees C (K-110), 200 degrees C (K-200), 400 degrees C (K-400) and 600 degrees C (K-600) from pure water solution at 25 degrees C has been studied. The evolution of the surface properties of the kerolite samples, such as specific surface area and porosity, after heat treatment were analysed. The clays were characterised by using FTIR spectroscopy, X-ray diffraction, thermogravimetric and differential thermogravimetric analysis, surface analysis and Hg porosimetry.

Adsorption of atrazine from aqueous solution on heat treated kerolites.

The adsorption of 6-chloro-N(2)-ethyl-N(4)-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) on heat treated kerolite samples at 110 degrees C (K-110), 200 degrees C (K-200), 400 degrees C (K-400) and 600 degrees C (K-600) from aqueous solution at 25 degrees C has been studied. The evolution of surface properties of kerolite samples such as specific surface area and porosity after heat treatment was analysed. The clays were characterised by using usual techniques: FTIR spectroscopy, XRD diffraction, TG and DTG analysis, surface analysis and Hg porosimetry.

Effects of dissolved organic carbon on sorption and mobility of imidacloprid in soil.

To evaluate the effects of dissolved organic carbon on sorption and mobility of the insecticide imidacloprid [1-(6-chloro-3-pyridinyl) methyl-N-nitro-2-imidazolidinimine] in soils, adsorption and column experiments were performed by using a typical calcareous soil from southeastern Spain and two different types of dissolved organic carbon, that is, dissolved organic carbon extracts from a commercial peat (DOC-PE) and high-purity tannic acid (DOC-TA). The experiments were carried out from a 0.01 M CaCl2 aqueous medium at 25 degrees C.

Limitations on the role of incorporated organic matter in reducing pesticide leaching.

The use of organic amendments has been suggested as a method of controlling pesticide leaching through soils. The enarenados soils of the intensive horticulture of the Almeria province of southern Spain contain buried organic matter horizons above a soil layer amended with clay. This region is ideal for understanding the potential for and limitations of organic amendments in preventing pesticide pollution.

Mobility of atrazine from alginate-bentonite controlled release formulations in layered soil.

The mobility of atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine] from alginate-bentonite-based controlled release (CR) formulations was investigated by using soil columns. Two CR formulations based on sodium alginate (14.0 g kg(-1), atrazine (6.

Mobility of isoproturon from an alginate-bentonite controlled release formulation in layered soil.

The mobility of isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] from an alginate-based controlled release (CR) formulation was investigated by using soil columns. A layered bed system simulating the typical arrangement under a plastic greenhouse, which is composed of sand, peat, amended soil and native soil was used. The CR formulation was based on sodium alginate (1.

Controlled release of carbofuran from an alginate-bentonite formulation: water release kinetics and soil mobility.

The insecticide-nematicide carbofuran was incorporated in alginate-based granules to obtain controlled-release (CR) properties. The basic formulation [sodium alginate (1.61%)-carbofuran (0.

Sorption and leaching of atrazine and MCPA in natural and peat-amended calcareous soils from Spain.

The sorption and leaching of atrazine and MCPA (0.02 M CaCl(2) aqueous solution at 25 degrees C) by a calcareous soil from Southeastern Spain, after organic carbon (OC) amendment with a commercial peat (from 0.18% to 4.

Controlled release of diuron from an alginate-bentonite formulation: water release kinetics and soil mobility study.

The herbicide diuron was incorporated in alginate-based granules to obtain controlled release (CR) properties. The standard formulation (alginate-herbicide-water) was modified by the addition of different sorbents. The effect on diuron release rate caused by incorporation of natural and acid-treated bentonites in alginate formulation was studied by immersion of the granules in water under static conditions.