This work is devoted to the preparation of magnetite-covered clay particles in aqueous medium. For this purpose, magnetite nanoparticles were synthesized by a coprecipitation method. These magnetic particles are adhered to sodium montmorillonite (NaMt) particles in aqueous suspensions of both materials, by appropriate control of the electrolyte concentrations. The best condition to produce such...

Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt...

Given a montmorillonite clay at high porosity and saturated by monovalent counterions, the particle level responses of the clay to different external loadings are investigated. As analytical solutions are not possible for complex arrangements of particles, computational micromechanical models are employed (based on solution of the Poisson-Nernst-Planck equations) using the finite element method...

* Corresponding author. E-mail address: [email protected] (V. Ferro 1537-5110/$ e see front matter a 2010 IAgrE doi:10.1016/j.biosystemseng.2010.03.013 A comparison between laser diffraction method (LDM) and the sieve-hydrometer method (SHM) was carried out for 228 soil samples representing a different texture classification sampled in a Sicilian basin. The analysis demonstrated that the sand con...

-Three methods were developed that allow for the imaging of any clay mineral in aqueous solutions with atomic force microscopy (AFM). The methods involve fixing the particles onto special substrates that do not complicate the imaging process, but hold the particles sufficiently so that they do not move laterally or float away during imaging. Two techniques depend on electrostatic attraction und...

Particles with nanometer dimensions (nanoparticles) are all around us. The finest particles of sand are blown by the wind over thousands of kilometers. The finest particles of soils are either eroded by the wind in extremely dry conditions or by water under wet conditions and deposited hundreds of kilometers or more from the origin. The air contains nanoparticles of carbon, ice, and oxides and ...

To gain insight into the process of sedimentation occurring when clay-laden estuaries and deltas entermarinewater, we perform laboratory experiments tomeasure the settling rate of initially unflocculated kaolin clay in fresh and salt water. In fresh water, sedimentation is a slow process with the clay particle concentration gradually decreasing nearly uniformly over hours, consistent with the t...

Naturally occurring clay colloidal particles are heavily involved in sediment processes in the subsurface soil. Due to the importance of these processes in the subsurface environment, the transport of clay colloidal particles has been studied in several disciplines, including soil sciences, petrology, hydrology, etc. Specifically, in environmental engineering, clay colloid release and transport...