By allowing the surface charge of one surface to affect the adsorption equilibrium of the other, we establish the existence of a long-range attractive interaction between two identical surfaces in an electrolyte containing polyvalent counterions with a mean-field Poisson-Boltzmann approach. A Stern electrostatic condition from linearization of the mass-action adsorption isotherm is used to capt...

Adsorption mechanisms of Pb on montmorillonite were investigated by conducting equilibrium and X-ray absorption fine structure (XAFS) spectroscopy studies. Data from the batch equilibrium studies indicate that Pb could be adsorbing via two mechanisms, depending on ionic strength. At low ionic strength (I = 0.006 M) Pb adsorption is pH-independent: 97% of the available Pb was removed from soluti...

the present study was carried out to investigate the potential of single-walled carbon nanotube (swcnts) and carboxylate group functionalized single-walled carbon nanotube (swcnt-cooh) as alternative adsorbents for the removal of basic red 46 (br 46) from contaminated water by using batch adsorption studies. effects of some key operating parameters such as ph, ionic strength and contact time on...

The negative electrical field around clay particles whose edge thickness is small relative to the Debye length of the diffuse double layer associated with the planar surfaces may spill over into the edge region. Such a spillover may affect B adsorption by the clay. This study was conducted to determine the effect of edge surface properties of 2:1 clay on B adsorption. Pyrophyllite, which shows ...

Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity ...

The adsorption of hydrophobically modified polyacrylic acid (HM-PAAc) has been compared to the adsorption of unmodified polymers by means of reflectometry. The polymers were adsorbed onto a noncharged hydrophobic polystyrene surface. The adsorption kinetics of both types of polymer is the same until a certain surface coverage. Then the unmodified sample shows a saturation while the hydrophobica...

As one of the most important soil components, kaolinite plays an important role in transport and fixation of organic pollutants in soils. P-Aminoazobenzene (PAAB) is a sort of the carcinogenic aromatic amine which is commonly used as the intermediates of azo dyes. It can cause mutations and cancer of aquatic biota as well as humans. In this study, adsorption of PAAB on kaolinite in aqueous solu...

In this work, a low-cost activated carbon as well as non-hazardous material, with high adsorption capacity, was prepared from Melia azedarach fruit (MF) by ZnCl2 activation for the removal of Pb(II) toxic metal from aqueous solutions. The microstructure of the activated carbon was observed by Scanning Electron Microscopy (SEM). Batch experiments have been performed as a function of pH, contact ...