Effects of surface characteristics of activated carbon on the adsorption of 2-methylisobornel (MIB) and geosmin from natural water

Abstract

Five powdered activated carbons (PACs), including one fruit-based, one wood-based, and three bituminous coal-based, were selected for the investigation of the effects of surface characteristics of activated carbon on the adsorption of 2-methylisobornel (MIB) and geosmin. Characterization of the carbons was performed using nitrogen adsorption, Fourier transform infra-red (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). All the carbons showed a broad absorption band in the 1300-1000 cm −1 region, which can be assigned to C-O stretching and O-H bending modes of alcoholic, phenolic, and carboxylic groups in FTIR spectra. The contents of O and C on the surfaces of carbons were acquired from the data of XPS analysis. Statistical analyses on the relationship between the adsorption capacities and different carbon surface parameters (O content, C O and C-O chemical group contents, the surface area, different pore volumes, iodine number and methylene blue number) were performed using Spearman rank correlation method. A good linear relationship between the adsorption capacities for MIB and geosmin and the micropore volumes was acquired. Both of iodine number and methylene blue number, the two most often used parameters for the evaluation of activated carbon quality, and other parameters, such as meso and total pore volumes, surface area, O and C-O contents were found to be insignificant in correlation with the adsorption capacities of MIB and geosmin. The volume of micropores could be used as an effective indicator for the selection of PAC for the removal of both MIB and geosmin.

Geosmin and 2-methylisoborneol removal using superfine powdered activated carbon: Shell adsorption and branched-pore kinetic model analysis and optimal particle size

“…PAC's effectiveness as an adsorbent is influenced by various characteristics, including its surface chemistry, pore structure, and particle size. Micropore volume and oxygen content are key properties affecting the equilibrium adsorption capacity of activated carbon (Pendleton et al, 1997, Considine et al, 2001Nowack et al, 2004;Yu et al, 2007;Tennant and Mazyck, 2007). Besides equilibrium capacity, adsorption kinetics is another important aspect of adsorptive removal, and smaller adsorbent particles have faster adsorption kinetics (e.g., Najm et al, 1990).…”

Influence of the Surface and Structural Characteristics of Activated Carbons on Adsorptive Removal of Halo-Olefinic Impurities from 1,1,1,3,3-Pentafluoropropane

“…A broad band at 1300-1000 cm −1 is assigned to C\O stretching in acid, alcohols, phenols, prone, ethers and eaters [20]. The presence of a relatively strong band around 1560 cm −1 can be attributed to the conjugated systems such as diketone, keto-ester and keto-enol structures, carboxylic groups and quinone structure [7,21,22]. This band also appears in all the samples.…”

A rapid kinetic dye test to predict the adsorption of 2-methylisoborneol onto granular activated carbons and to identify the influence of pore volume distributions

“…The presence of a peak for bituminous carbons at~15 Å may indicate a need for smaller micropores as well. Yu et al (2007) found a strong correlation (R 2 ¼ 0.95) for three bituminous carbons for the removal of MIB at pore widths <20 Å . Quinlivan et al (2005) identified a ratio of 1.5Â the critical diameter of an adsorbate (in this case~11.2 Å for MIB as calculated from Table 2) as necessary for adsorption.…”

“…Mesopores provide transport for smaller molecules (MIB) as well as storage for larger molecules such as NOM (Hsieh et al, 2000;Newcombe et al, 2002). Several authors have discussed the effects of surface chemistry and pore volume distributions on the sorption of MIB and similar trace compounds (Karanfil et al, 1999;Redding et al, 2009;Snyder et al, 2007;Tennant et al, 2007;Mackenzie et al, 2005;Yu et al, 2007).…”

“…Several research teams have attempted to predict MIB adsorption in the presence of NOM (Graham et al, 2000;Nowack et al, 2004;Rangel-Mendez et al, 2005;Yu et al, 2007;Summers et al, 2013). Also, several teams have compared pore volume distributions to dye adsorption (Krupa et al, 1996;Kasaoka et al, 1989).…”