Naturally occurring contamination of arsenic is of great concern in many Southeast Asian countries especially in Bangladesh. Because of the lack of understanding for the mechanism of As contamination, we have developed two studies through field surveys and laboratory experiments. First topic is focused on the underlying mechanisms controlling large spatial variation of As-contaminated groundwat...

the removal of cd2+ and pb2+ ions from wastewater using p-tert-butyl-calix[4] arene was investigated in terms of initial ph, initial concentration, adsorbent dosage, contact time and temperature. the maximum adsorption occurred at the ph value of 6. the adsorbent studied exhibits high efficiency for cd (ii)and pb (ii) adsorption and the equilibrium states could be achieved in 10 min. adsorption...

Powdered activated carbon (PAC) prepared from Eucalyptus camaldulensis Dehn. bark was tested for its adsorption capacity for Cu(II) and Pb(II). The experiment was conducted to investigate the effects of pH, contact time, initial metal concentration, and temperature. The best adsorption of both Cu(II) and Pb(II) occurred at pH 5, where the adsorption reached equilibrium within 45 min for the who...

This work investigates the competitive adsorption under dynamic and equilibrium conditions of ibuprofen (IBU) and amoxicillin (AMX), two widely consumed pharmaceuticals, on nanoporous carbons of different characteristics. Batch adsorption experiments of pure components in water and their binary mixtures were carried out to measure both adsorption equilibrium and kinetics, and dynamic tests were...

This study investigated the feasibility of Date-palm) Phoenix dactylifera (Leaf Ash (DLA) (an inexpensive agricultural-byproduct) as an application to adsorb Pb(II) ions. An adsorption process was carried out to evaluate initial concentration Pb(II) ions, adsorbent dose, contact time, pH and temperature on the systematic removal of Pb(II). The effects were examined and results showed that remov...

An experimental study was conducted on the adsorption of color from biologically treated POME using palm kernel shell (PKS) and empty fruit bunches (EFB) as natural biosorbents, and activated carbon prepared from them by microwave and chemical activation with potassium hydroxide (KOH). BET surface area of all sorbents was determined and 1252 m 2 .g -1 was recorded for activated carbon prepared ...

We develop statistical mechanical models amenable to analytic treatment for the dissociative adsorption of O2 at hollow sites on fcc(100) metal surfaces. The models incorporate exclusion of nearest-neighbor pairs of adsorbed O. However, corresponding simple site-blocking models, where adsorption requires a large ensemble of available sites, exhibit an anomalously fast initial decrease in sticki...

We study theoretically the effect of adsorbed homopolymer on surfactant bilayers, restncting ourselves to homogeneous equilibrium adsorption of polymer on both sides of the bilayer, with no penetration We formulate the energy of adsorption per unit area as a Taylor senes m curvature for both sphencal and cylindrical surfaces In the limit of weak adsorption

unmodified zeolites show little affinity for anions due to the fact that their surfaces are negatively charged. however modification of zeolites with amines turns their negative surface charge to positive and creating higher adsorption capacity for anions. in this study, polyaniline-clinoptilolite composite was prepared by polymerization of anilinium on the surface of zeolite. the composite was...

Water adsorption measurements have been performed under equilibrium conditions for unsolvated Ac-A(n)K+H(+) and Ac-KA(n)+H(+) peptides with n = 4 - 10. Previous work on larger alanine peptides has shown that two dominant conformations (helices and globules) are present for these peptides and that water adsorbs much more strongly to the globules than to the helices. All the Ac-KA(n)+H(+) peptide...