1. Plant Nutrients. 2. The Soil as a Plant Nutrient Medium. 3. Nutrient Uptake and Assimilation. 4. Plant Water Relationships. 5. Plant Growth and Crop Production. 6. Fertilizer Application. 7. Nitrogen. 8. Sulphur. 9. Phosphorus. 10. Potassium. 11. Calcium. 12. Magnesium. 13. Iron. 14. Manganese. 15. Zinc. 16. Copper. 17. Molybdenum. 18. Boron. 19. Further Elements of Importance. 20. Elements with More Toxic Effects. General Readings. References. Index.

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Principles of plant nutrition

The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. The objectives of this review are to introduce the key aspects pertaining to nanomaterials in the environment and to discuss what is known concerning their fate, behavior, disposition, and toxicity, with a particular focus on those that make up manufactured nanomaterials. This review critiques existing nanomaterial research in freshwater, marine, and soil environments. It illustrates the paucity of existing research and demonstrates the need for additional research. Environmental scientists are encouraged to base this research on existing studies on colloidal behavior and toxicology. The need for standard reference and testing materials as well as methodology for suspension preparation and testing is also discussed.

Nanomaterials in the environment: Behavior, fate, bioavailability, and effects

Water Retention: Laboratory Methods

The article focuses on adsorption of heavy metal ions on soils and soils constituents such as clay minerals, metal (hydr)oxides, and soil organic matter. Empirical and mechanistic model approaches for heavy metal adsorption and parameter determination in such models have been reviewed. Sorption mechanisms in soils, the influence of surface functional groups and surface complexation as well as parameters influencing adsorption are discussed. The individual adsorption behavior of Cd, Cr, Pb, Cu, Mn, Zn and Co on soils and soil constituents is reviewed.

Adsorption of heavy metal ions on soils and soils constituents

http://files.aprendiendoquimica7.webnode.com.co/200000006-1247d13423/Limousin,%20G%20et%20al.%20Sorption%20Isotherms%20A%20review%20on%20Physical%20Bases,%20modeling%20and%20measurement.pdf

Sorption isotherms: A review on physical bases, modeling and measurement

At the solid/solution interface of (hydr)oxides various types of surface groups exist, each reacting according to its own affinity constant (K) for protons. A model is presented that estimates the value of the log K of various types of surface groups (singly, doubly, and triply metal-coordinated O(H) and OH(H) surface groups) of (hydr)oxides. The intrinsic affinity constants (K) depend on many factors, e.g., the valence of the central cation (Me) of the (hydr)oxides, its electron configuration, and the MeH distance of the reacting surface group. Besides these also the number of surrounding ligands, the number of central cations coordinating with a ligand, and the type of reacting ligand (an oxo or hydroxo species) determine the proton affinity constant. Proton adsorption reactions can in principle be considered as a two-step proton adsorption reaction, forming OH and OH2 species at the surface. Analysis of the calculated affinity constants shows, however, that generally a surface group will react in a limited pH range (for instance pH 3–10) only according to a one-step protonation reaction (1-pK model). A general MUltiSIte Complexation model (MUSIC) is presented, which is based on crystallographic considerations. The new site binding model (MUSIC) can unify the classical 2-pK model and the recently presented 1-pK model, both being special cases of the model described here. The surface charge of a surface with more than one type of surface group can be described with one proton adsorption reaction and one discrete K for each type of surface group.

Multisite proton adsorption modeling at the solid/solution interface of (hydr)oxides: a new approach. I: Model description and evaluation of intrinsic reaction constants

Synopsis It has been shown that the presence of exchangeable ions in clay systems leads to the presence of long-range repulsion forces between the particles. A comparison between the compression curves as observed and as calculated from theoretical considerations indicates that in the case of suspensions of pure clays the compressibility can be accounted for quantitatively by the consideration of these long-range forces only. On a montre que la presence d'ions interchangeables dans des constitutions d'argile provoque l'apparition de forces repulsives a grande distance entre les particules. Une comparaison entre les courbes de compression observees et calculees d'apres des considerations theoriques indique que dans le cas de suspensions d'argiles pures on peut evaluer la compressibilite quantitativement par la seule consideration de ces forces a grande distance.

Physico-Chemical Analysis of the Compressibility of Pure Clays

Electrolyte adsorption on heterogeneous surfaces: adsorption models

Soil chemistry. B. Physico-chemical models.

The sensitivity of metal ion adsorption on metal oxides for the degree of random surface heterogeneity (smeared out potential) using three electrolyte adsorption models is investigated It is shown that the effect of random surface heterogeneity is hard to detect when the metal ion adsorption constants are adjusted together with the adjustment of Kq, ie, a shift in the position of the energy distribution curve This shift is necessary in order to keep the experimentally determined pristine point of zero charge at a fixed position Some reasons for the low sensitivity are indicated Cadmium adsorption isotherms for hematite and amorphous iron oxide in combination with CdH exchange data obtained at several pH values can be described satisfactorily with a simple homogeneous surface one- or two-pK basic Stern model For both iron oxides the predominant surface species of cadmium is SO−CdOH+

G. H. Bolt

Papers

Multisite proton adsorption modeling at the solid/solution interface of (hydr)oxides: a new approach. I: Model description and evaluation of intrinsic reaction constants

Physico-Chemical Analysis of the Compressibility of Pure Clays

Electrolyte adsorption on heterogeneous surfaces: adsorption models

Soil chemistry. B. Physico-chemical models.

Metal ion adsorption on heterogeneous surfaces; Adsorption models.