Effects of ultrasound on adsorption–desorption of p-chlorophenol on granular activated carbon

Abstract

The aim of this work is the evaluation of the effects of ultrasound on p-chlorophenol adsorption-desorption on granular activated carbon. Adsorption equilibrium experiments and batch kinetics studies were carried out in the presence and the absence of ultrasound at 21 kHz. Results indicate that the adsorption of p-chlorophenol determined in the presence of ultrasound is lower than the adsorption observed in the absence of ultrasound. Desorption of p-chlorophenol from activated carbon with and without the application of ultrasound was studied. The desorption rates were favoured by increased ultrasound intensity. This rise is more noticeable as temperature increases. The addition of ethanol or NaOH to the system causes an enhancement of the amount of p-chlorophenol desorbed, especially in the presence of ultrasound. A synergetic enhancement of the desorption rate was observed when ultrasonic irradiation was coupled with ethanol chemical regeneration.

Remediation of Salt- and Petroleum Hydrocarbon- Contaminated Soils using Ultrasound and Soil Washing.

“…Page 30 Similar results were observed in many other studies (Breitbach et al, 2002;Hamdaoui et al, 2003;. In the study of , adsorption isotherm was used to study the adsorption ability of phenol on active carbon and the results showed that ultrasound enhanced the initial adsorption rate but reduced the adsorption capacity which might be due to the decrease of surface area and pore volume of carbons.…”

“…In addition, although many previous studies have reported the effect of ultrasound on TPH desorption (Breitbach et al, 2002;Hamdaoui et al, 2003;, most of the sorbates were selected as specific organic contaminants for mechanism investigations, and few studies were conducted to examine the desorption behavior of petroleum hydrocarbons fractions from different soils under the impact of ultrasound.…”

“…Adsorption and desorption data are most commonly represented by adsorption and desorption isotherms, which is a plot of the amount of adsorbate retained by a solid as a function of the concentration (liquid) or pressure (gas) of that adsorbate in the equilibrium gas or solution at certain temperature (McBride, 1994 (Breitbach and Bathen, 2001;Hamdaoui et al, 2003; model is usually observed only at a situation of low range of adsorption (McBride, 1994).…”

Intensification of textile effluent chemical oxygen demand reduction by innovative hybrid methods

“…The intra-particle diffusion coefficient (K w ) can be determined using the following equations [41]:…”

“…The results show that the incorporation of US enhanced the intraparticle diffusion by nearly 12 times. This may be attributed to the induced turbulence and additional convective mass transfer inside the pores caused by the micro jets with high velocity produced by US [41]. In addition, the cavitation also produced acoustic microstreaming or formation of tiny eddies that enhance the mass transfer at the liquid-solid interface nearby the sorbent surface and also within the pores.…”