The effect of management practices on soil potential for regulating the residual concentration of pesticides was examined in samples from a Calcic Haploxeralf in Toledo (central Spain). Sorption-desorption of alachlor and linuron was found to depend on inputs of lignocelullosic wastes or cattle manure for the past 16 years. For a given herbicide, the soil sorption capacity (K(f)) follows the or...

In this work two modified agricultural residues, rice hull and sawdust were examined as sorbents to remove heavy metals Pb(II), Cd(II), Zn(II), Cu(II) and Ni(II) from synthetic solutions or wastewater samples. To modify their sorptive characteristics, samples were treated with HCl, NaOH and heat. The sorption of the heavy metals from the synthetic solutions was increased with pH and initial con...

In order to select appropriate amendments for cropping hyperaccumulator or normal plants on contaminated soils and establish the relationship between Cd sorption characteristics of soil amendments and their capacity to reduce Cd uptake by plants, batch sorption experiments with 11 different clay minerals and organic materials and a pot experiment with the same amendments were carried out. The p...

PAL measurements were used to study the process of graft polymerization of methyl methacrylate (MMA) to low density polyethylene (LDPE). When the monomer was just sorbed to LDPE, both I, and z, were increased. When MMA was grafted to LDPE, on the other hand, they were decreased. These contrasting results suggests usefulness of the PAL method to study the micro-structures of polymers. Introducti...

zinc­ (zn) is an essential micro­nutrient needed by plants, animals and humans. bioavailability of zn to plant root is controlled through sorption process in soils. to evaluate the effect of citric acid on zn sorption,­ a batch experiment was conducted with two soil samples (s1, s2), that differed in their clay and calcium carbonate contents. three levels of citric acid (0,­ 0.5, 1 mm) and twel...

1986). In contrast, an apparent disagreement may be produced by applying an equilibrium model to data This study reconciles an apparent inconsistency between the dialthough sorption equilibrium was not reached within methylphthalate (DMP) batch and column data reported in the literature. Some researchers found that retardation coefficients obtained the time scale of the batch or column experime...

Ordered nanoporous silica (MSU-H) with high surface area has been utilized as a solid substrate of a surface-modified hybrid sorbent for the application to the removal of U(VI). Carboxymethylated polyethyleneimine (CMPEI) with a strong complexing property has been introduced to the pore surface of MSU-H substrate. CMPEI-modified MSU-H (CMPEI/MSU-H) has been characterized by scanning electron mi...

Volatilization of pesticides from soils under dry conditions (water content below the permanent wilting point) can be significantly influenced by sorption to hydrated mineral surfaces. This sorption process strongly depends on the water activity, expressed as equilibrium relative humidity in the pore space of the soil, and on the available surface area of the hydrated minerals. In this study, t...

The thermodynamic parameters viz. the standard free energy (∆Gº), Standard enthalpy change (∆Hº) and standard entropy change (∆Sº) were determined using the obtained values of distribution coefficient (kd) of U (VI) in two different types of soils (agricultural and undisturbed) by conducting a batch equilibrium experiment with aqueous media (groundwater and deionised water) at two different tem...