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...

A new model of time-dependent sorption-desorption hysteresis is presented. This type of hysteresis is not related to transitions between metastable adsorption states, which are a common cause of capillary condensation hysteresis in mesoporous materials. We show that time-dependent hysteresis is a consequence of slow kinetics and failure to reach equilibrium at given experimental conditions. The...

The effect of temperature on the equilibrium sorption of Pb 2+ from aqueous solution onto a low-cost electric furnace slag was investigated. In this paper, two-parameter isotherm models namely the Langmuir and the Freundlich and three-parameter isotherm model namely Redlich–Peterson were applied to describe the isotherms and to calculate their constants. The best estimation of the parameters of...

We develop a model for solute transport in porous media, which takes into account equilibrium and non-equilibrium multiple-site adsorption. Binary ion exchange is included. Adsorption rate formulations and their isotherms are reviewed and their mathematical properties investigated. This forms the basis of the study of travelling wave solutions in the second part of the paper.

in the present work, we have investigated the sorption efficiency of the treated activated carbon from walnut shell(acw) towards direct red 81 (dr81) and direct blue 71 (db71) for the removal from aqueous solution. thesorption study of acw at the solid-liquid interface was investigated using kinetic, sorption isotherms, ph effectand amount of adsorbent. experimental data were analyzed by langmu...

The phenomenon of hydrogen absorption by metals, discovered about 100 years ago, nowadays demands some interest for technological reasons (hydrogen storage, fuel cells, hydrogen embrittle­ ment of construction materials). The palladium/hydrogen system claims for an exceptional position among the metal hydrides of the protonic type: because of its relative simplicity the Pd/H2-system serves as a...

Microarray hybridization studies have attributed the nonlinearity of hybridization isotherms to probe saturation and post-hybridization washing. Both processes are thought to distort 'true' target abundance because immobilized probes are saturated with excess target and stringent washing removes loosely bound targets. Yet the paucity of studies aimed at understanding hybridization and dissociat...

The performance of two phenol-formaldehyde resin-based activated carbons prepared in our laboratory, as potential adsorbents for precombustion CO2 capture has been evaluated under static (adsorption isotherms) and dynamic (adsorption-desorption cycles conducted in a fixed bed) conditions. Most of the literature on CO2 capture with solid sorbents is based on equilibrium CO2 adsorption capacities...

Control of the regulatory enzyme threonine deaminase from Escherichia coli is achieved by isoleucine inhibition and valine activation. The mechanism by which these heterotropic effectors regulate the enzyme was investigated by measuring the binding of isoleucine and valine by spectroscopic, kinetic, calorimetric and equilibrium dialysis techniques. The addition of isoleucine or valine to threon...