Interaction of Fe-oxyhydroxide colloidal particles with montmorillonite

Abstract

A B S T RA CT: Interaction between positively charged Fe-oxyhydroxide (13-FeOOH) particles and negatively charged particles of montmorillonite was studied as a function of particle concentration, pH and time. The results showed that the clay particles appear to bridge between FeOOH particles leading to associations in which the ratio of positive to negative particles varied between 1.4 and 2.56 depending on pH and particle concentrations. The data could be represented by isotherms of interaction of the high affinity type and, together with the interaction kinetics, could be described by Langmuir type formulations.

Surface irregularity of soils in molecular domain

“…The absorption method is introduced by Ferreiro et al [6] for BP, de Bussetti et al [17] for OP, Helmy et al [18] for Q, and Ferreiro et al [19] for O. The absorption of OP, BP, Q and O by soils was carried out by adding 25 ml of aqueous solution with different concentrations of OP, BP and Q to 1g soils in 50-ml Pyrex bottles [3].…”

Interaction of colloidal particles of -montmorillonite with activated carbon

“…Data from a previous paper [1] show that in the range pH 3.7-8, absorbance of a sol of 0.693 g dm −3 of NH + 4 -montmorillonite is independent of the pH, allowing one to obtain absorbance data and hence clay particle concentration with a safety margin.…”

“…To determine the interaction energy, we can use the DubininRadushkevich (D-R) equation [1][2][3][4][5][6][7]14,15]. Assuming that the interaction occurs by adsorption of the small particles and that these form a single layer on the surfaces of larger particles, we have…”

“…where q is the quantity (mol g −1 ) of small particles (clay) that interact with 1 g of large particles (carbon) for a given concentration of small particles (C, in mol dm −3 ), Q is the maximum adsorbed quantity (mol g −1 ) of small particles, k is the proportionality coefficient of the energy interaction (mol 2 kJ −2 ), and ε is the Polanyi potential (kJ mol −1 ) (see Appendix A) [1][2][3][4][5][6][7],…”

“…Interactions between particles can generally be described by the Langmuir adsorption model [1] and could also be studied by other equations such as the Freundlich and DubininRadushkevich [2][3][4][5][6][7][8] adsorption models and the Smoluchowski flocculation model [9][10][11][12]. In all cases the repellent and attractive interactions between similar and different particles are considered and evaluated.…”