Adsorption of OH on the PdxCu3-x(x=0-3) small clusters is investigated by density functional theory calculations. It is found that OH adsorbs in three possible modes including on top, bridge and hollow sites while the structures where OH bridges between two atoms are the most stable structures. The Pd-Pd, Pd-Cu and Cu-Cu equilibrium distances for most of the systems...

Due to urbanisation, there are large amounts of waste concrete, particularly in rapidly industrialising countries. Currently, demolished concrete is mainly recycled as aggregate for reconstruction. This study has shown that larger sizes (2-5 mm) of recycled concrete aggregate (RCA) removed more than 90% of P from effluent when at pH 5. Analysis of the data, using equilibrium models, indicated a...

The kinetics of Ga adsorption/desorption on GaN 0001 surfaces is investigated over the temperature range of 680–750 °C using real-time spectroscopic ellipsometry. The adsorption and desorption kinetics are described in the framework of the Wolkenstein theory, which considers not only the equilibrium between Ga adsorbed on the surface and Ga in the gas phase but also the electronic equilibrium a...

Wastewaters obtained from fenvalerate manufacturing process were treated for its safe disposal using activated coconut shell carbon (acc) as adsorbent. In this work, the removal efficiency of organic matter in terms of chemical oxygen demand (COD) utilizing acc has been investigated. Various parameters which can influence the adsorption like adsorbent dosage, contact time of solution with adsor...

Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity, and thesmall pore size mean was prepared via sol-gel polymerization under solvent saturated vaporatmosphere and was dried by ambient drying method. The silica sols were prepared based onTetraethoxysilane (TEOS) and Methyltrimethoxysilane (MTES) as hydrophilic and hydrophobicprecursors, respectively. Phenol-formalde...

The sorption hysteresis effect, i.e. different wood equilibrium moisture contents (EMCs) in desorption and adsorption for the same relative humidity, is well known. However, quantitative sorption isotherms, in the form of tables or analytical correlations, are almost always given as the average of the desorption and adsorption curves. Consequently most drying simulation models use these average...

Three isotherm models were used to describe adsorption equilibrium of a toxic chemical compound, phenol, onto a non porous adsorbent (Mediterranean Posidonia oceanica fibres) and a porous adsorbent, activated carbon prepared from Caribbean Vetiveria zizanoides roots. The adsorption characteristic parameters obtained were calculated using classical adsorption isotherm, i.e. the Langmuir (LI), Fr...

One of the causes of water pollution is the presence of heavy metals in water. In the present study, an adsorbent prepared from the raw bark of the Pongamia pinnata tree is used for the removal of ferrous or ferric ions from aqueous and waste water containing heavy metals. Adsorption studies were conducted at different pH, concentration of metal ion, amount of adsorbent, contact time, agitation...

Experiments have been conducted to examine the liquid-phase adsorption of phenol from water by silica gel, HiSiv 3000, activated alumina, activated carbon, Filtrasorb-400, and HiSiv 1000. Experiments were carried out for the analysis of adsorption equilibrium capacities and kinetics. The adsorption isotherm model of the Langmuir-Freundlich type was the best to describe adsorption equilibrium da...