Adsorption, desorption, resorption

Abstract

The complete characterization of batch adsorption from solution, desorption, and related phenomena have been interpreted in the light of a general equation. The forward and reverse adsorption-rate constants and the adsorptive capacity comprise the only parameters. Where adsorption alone is of importance and the desorption-rate constant can be neglected, a simplified form of the theory results in a special equation which may suffice for most adsorption purposes. In either case, the characteristic parameters are determinable from the data and serve as criteria for comparing similar systems. The theory has been confirmed by the data of various investigators taken from the literature. The parameters derived from column adsorption are in agreement with the corresponding batch-derived parameters. The limitations as well as the capabilities of the theory are presented; but even where deviations from the assumed model exist, the results are useful.

Fixed bed sorption: Setting the record straight on the Bohart–Adams and Thomas models

“…The actual Thomas model is given by Eq. (17). The two models differ in the assumptions invoked in deriving the respective analytical solution to a fixed bed model.…”

“…To circumvent its user-unfriendliness, one may use the charts prepared by Hiester and Vermeulen [8], which are a graphical representation of the Thomas solution, in lieu of Eq. (17). Another option is to use an approximation to calculate the mathematically complicated function J, which is an integral over a Bessel function.…”

“…A formal solution to the batch model incorporating Thomas' pseudo second-order rate expression (Eq. (16)) has been given by Loebenstein [16,17]:…”

Arsenic Occurrence in New Hampshire Drinking Water

“…The two primary anthropogenic sources of arsenic are agricultural chemicals and wood preservatives. Approximately 50% of the total U.S. consumption of arsenic was used in agriculture in 1980 (11). As a pesticide, acid lead arsenate (PbHAsO4) was widely used in orchards until the development of DDT in 1947 (12).…”

Adsorptive Removal of Phosphate From Wastewater Using Ethiopian Rift Pumice: Batch Experiment

“…The desorption efficiency in percent is defined as the amount of phosphate desorbed from per gram of spent adsorbent at equilibrium, that is, the ratio of q e of desorption to q e of adsorption of adsorbent multiplied with 100. 66,67 The q e of desorption was calculated as…”