Effects of non-oxidant and oxidant acid treatments on the surface properties of an activated carbon with very low ash content

Abstract

Abstract-An activated carbon obtained from olive stones and with very low ash content (0.10%) was treated with either HCI, HF or HNO,. The changes in surface area and porosity resulting from the acid treatments were studied by N, and CO, adsorption at 77 and 273 K, respectively and by mercury porosimetry. The changes in surface chemistry were studied by temperature-programmed desorption and Fourier transformed infrared spectroscopy. The treatments with HCl yielded activated carbons on which some chlorine remained chemisorbed, whereas the HF treatment did not fix any fluorine. Due to this, the HCI treatment had a slight effect on the microporosity of the samples. Moreover, the HF treatment increased the amount of CO-evolving surface groups. The treatment with HNO, destroyed the pore walls to a large extent, fixing a large amount of oxygen surface groups. The nature and structure of the CO-and CO,-evolving groups will be discussed in detail. 0 1997 Elsevier Science Ltd All rights reserved

Malachite green dye adsorption from model aqueous solutions using corn cob activated carbon (ccac)

“…The higher it is its value, the higher is the adsorption capacity of material. The reduced CCAC ash content, obtained by impregnation with H 2 SO 4 , is comparable to the literature results [28]. Excessive ash content reduces CCAC adsorption capacity.…”

Ozonation of 1,3,6-naphthalenetrisulphonic acid catalysed by activated carbon in aqueous phase

“…In a previous study [33], we discovered that carbon demineralisation treatment using HCl and HF did not affect the concentration of oxygen surface groups. Moreover, the pH PZC values of our demineralised activated carbons, determined in the present study, are similar to those of the original carbons.…”

A study on the dependence of structure of multi-walled carbon nanotubes on acid treatment

“…The exfoliation of MWNTs bundles, as functional group, increases the solubility of MWNTs in polar media [2,3], and more easily incorporated in a polymer matrix. The treatment of MWNTs is more widely done by aqueous solution of acids or oxidizing agents such as nitric acid [14,15], sulfuric acid [16], H 2 SO 4 /HNO 3 [17,18], H 2 O 2 [17], etc.…”