Equilibrium adsorption of chlorophenols on granular activated carbon

Abstract

The adsorption of chlorinated phenols from aqueous solution on granular activated carbon was studied in batch reactors. Singlecomponent equilibrium adsorption data for the eight compounds in two concentration ranges at pH 7.0 and 30°C were fit well by both the Langmuir and the Freundlich equations. The adsorptive capacities at pH 7.0 increase from pentachlorophenol to trichlorophenols and are fairly constant from trichlorophenols to monochlorophenols. Equilibrium measurements were also conducted for 2,4,5-trichlorophenol. 2,4-dichlorophenol, and 4-chlorophenol over a wide pH range. A surface complexation model has been proposed to describe the effect of pH on adsorption equilibria of chlorophenols on activated carbon. Activated carbon surface functional sites are divided into acidic and basic groups with which molecular and ionized forms of chlorophenols interact, respectively, and form two neutral complexes. The simulations of the model are in excellent agreement with the experimental data. Waler Environ. Res., 67, 892 (1995).

Adsorption and desorption of pentachlorophenol on cells ofMycobacterium chlorophenolicum PCP-1

“…So far, PCP adsorption has been studied mainly with adsorbents such as powdered activated carbon (Lin et Biomass Preparation al., 1991;Siahpush et al, 1992), granular activated carbon (Nelson and Yang, 1995), and polyurethane foam Mycobacterium chlorophenolicum PCP-1 (DSM 43826) (Hu et al, 1994). The main purposes of these studies (Hä ggblom et al, 1994), was grown on a modified minwere to investigate the use of adsorbents and coimmobieral salt medium (Wittmann et al, 1994) del and Pfennig (1977), and 20 g/L glucose as the sole (1989) studied the adsorption and desorption (termed carbon and energy source.…”

Effects of solution pH on adsorption of chlorophenols by cross‐linked polyvinyl pyrrolidone (PVP XL) polymers

“…Many studies were conducted to test the adsorption of chlorophenols on surfaces such as GAC [10,24,25], montmorillonite [6], alumina pillared clays [3], and surfactant modified clays [6,24,26] in the last 20 years. Different adsorption isotherms were used to fit the adsorption data to account for the adsorption mechanism.…”

“…In an equilibrium adsorption study, it was found that protonated species of PCP followed a linear adsorption isotherm, indicating a partitioning mechanism on hexadecyltrimethylammonium (HDTMA)-clays, whereas deprotonated species followed a Langmuir adsorption isotherm [6]. In contrast, adsorption of 2,4-DCP, 2,4,5-TCP, and 2,3,4,6-TeCP and PCP adsorption on GAC followed Langmuir isotherm [25]. A lower adsorption capacity of TeCP and PCP by GAC was found compared with DCP and TCP.…”

“…A lower adsorption capacity of TeCP and PCP by GAC was found compared with DCP and TCP. For 2,4,5-TCP adsorption on GAC, an increase in solution pH from 4.15 to 10.25 decreased the Langmuir adsorption capacity from 2.7 to 1.6 mmol g 21 [25]. If the linear portion was used to calculate the K d , the values were 200, 100, and 70 L kg 21 for TCP adsorption on GAC at pH 4.15, 8.17, and 9.30, respectively.…”

Effect of adsorbate structure on adsorption from solutions

“…For adsorbate and solvent the adsorption phenomenon depends on the differences between their chemical properties, structure and interactions (mutual and with solid surface). The adsorption of various series of different organic adsorbates was analyzed to find some correlations between the sorption experimental data and the properties of adsorbate and adsorbent [4,[10][11][12][13][14][15][16][17][18][19]. Many of benzene derivatives possess acidic or basic functional groups.…”