Ozone Degradation by Fluoride onto Plasma-Treated Activated Carbon in CF4

Anodic Surface Treatment on Activated Carbons for Removal of Chromium(VI)

In this work, the effect of anodic surface treatment on activated carbons and its Cr(VI) adsorption properties were investigated under reaction-treatment time conditions with 35 wt% HCl solution. The acid-base surface values were determined by Boehm's titration technique. The pore and surface characteristics were studied in terms of BET volumetric measurement with N(2) adsorption. As an experimental result, the acidic surface functional groups of activated carbons increased with increasing the HCl reaction-treatment time. It was found that the surface characteristics, including specific surface area, total pore volume, net heat of adsorption, and BET's C, slightly decrease in anodic surface treatments on activated carbons. In addition, an increase in reaction-treatment time led to increases of the first rate (K(1)) of Cr(VI) adsorption and diffusion coefficient (D). These values are evidence that adsorption is controlled more by the acid-base interactions between electron-donor substances and acidized activated carbons as electron acceptor than by the pore and surface structures of activated carbons. Copyright 2001 Academic Press.

Influence of Anodic Surface Treatment of Activated Carbon on Adsorption and Ion Exchange Properties

The effect of anodic surface treatment of activated carbon on adsorption and ion exchange characteristics was investigated in the condition of 35 wt% NaOH electrolyte for 60 s. The acid and base values were determined by a titration technique, and surface and pore structures were studied in terms of BET volumetric measurement with N(2) adsorption. The ion exchange capacity of the anodized activated carbons was characterized by a dry weight capacity technique. It was observed that an increase in current intensity leads to an increase in the surface functional groups of activated carbons, resulting in increasing pH, acid-base values, and anion-cation exchange capacities, without significant change of surface and pore structures (i.e., specific surface area, total pore volume, micropore volume, and average pore diameter). Also, anodically treated activated carbons are more effectively evaluated on the base value or cation exchange capacity than on the opposite properties in this electrolytic system. Copyright 1999 Academic Press.