The influence of the activated carbon post-treatment on the phenolic compounds removal

Abstract

The aim of this research was to investigate how post treatment modification, such as those with sodium hydroxide or urea, can influence the capacity of activated carbon (AC) for phenolic compounds removal from liquid media. The ACs modification was performed using urea impregnation followed by pyrolysis at high temperature. With all ACs used, this treatment induced a pore volume increase, a mean pore size broadening, an increase in the point of zero charge and also in the basic character. The modification with sodium hydroxide brings to light the influence of the precursor nature as the achievements are really diverse. With the ACs obtained from PET, a pore volume and mean pore size reduction occurred, with the AC-cloth no textural effect was observed and with the AC obtained from cork, an enlargement of the mean pore size and an increase of the pore volume were confirmed. The difference in the acidic/basic character exhibited by the modified ACs was in agreement with the presence of acidic/basic superficial groups identified by FTIR. The textural and chemical properties of the ACs affect in a direct way the phenolic compounds removal capacity. Particularly, those modified with urea, which exhibited a superior removal capacity for both phenolic compounds.

Preparation and post-treatments of ordered mesoporous carbons (OMC) for resorcinol removal

“…This could be due to surface hydroxylic groups and -CH 2 -in polyacrylic acid (Swiatkowski et al 2004). The strong peaks in 2000-2400 cm -1 could be related to C-O group (Cansado et al 2012). This is probably associated with the polymerization of the acrylic acid.…”

Adsorption of MCPA, 2,4-D and diuron onto activated carbons from wood composites

“…A complete characterization of the AC was achieved through different methods, normally used for this purpose, such as N 2 adsorption at 77 K, CHNS-O elemental analysis, point of zero charge and thermogravimetrical analysis of the precursors. The detailed description of the experimental procedure is given elsewhere [4,7,8].…”

“…Adsorption is considered an attractive method for removing pollutants and in particular pesticides from dilute solutions which involve the previous determination of the adsorptive behaviour on various adsorbents. Activated carbon (AC) materials have an important place among the adsorbents tested as they can be prepared from a wide variety of relatively low cost, natural or synthetic precursors, as largely described in the literature, and their improved properties allow them to adsorb various organic and inorganic compounds for a long time, being able to be regenerated and reused for several times [4][5][6][7][8][9][10][11]. The industries are still looking for environmentally friendly and cheaper AC retaining or increasing the adsorption capacities when compared with those often used for the same purpose.…”

Development and Environmental Applications of Activated Carbon Cloths

“…Degradation of phenolic compounds leads to the appearance ISRN Chemical Engineering of phenol and its derivatives in the environment, and therefore their removal from wastewater is an important issue for protection. Among the processes applied for the removal of phenol from waste effluents, adsorption remains as the most versatile method, and activated carbon materials are widely used as adsorbents [75,149]. The pH of the solution, the adsorbent real surface area, and the surface functional groups play a major role in the adsorption of phenolic compounds.…”