Thermodynamics and Kinetics Studies of Pentachlorophenol Adsorption from Aqueous Solutions by Multi-Walled Carbon Nanotubes

Abstract

The adsorption of pentachlorophenol (PCP) from aqueous solutions using pristine multi-walled carbon nanotubes (MWCNTs) was studied kinetically and thermodynamically. The results showed that MWCNTs are good adsorbents for the elimination of PCP from aqueous solutions in a very short time compared with activated charcoal. The kinetics study showed that the adsorption of PCP is mainly due to the diffusion of PCP from the aqueous phase to the solid phase beside intra-particle diffusion. This intraparticle diffusion was more significant for activated charcoal compared with MWCNTs. The equilibrium adsorption of PCP at different temperatures was studied, and the adsorption isotherms were well described using different adsorption models. Thermodynamics study showed that the adsorption process was product-favored (enhanced) as the temperature decreased.

Removal of chlorophenol from aqueous solutions by multi-walled carbon nanotubes: Kinetic and thermodynamic studies

“…The adsorption decreases randomness at the solid/solution interface with some structural changes in the adsorbate and adsorbent, and an affinity of the MWCNTs toward chlorophenols. The values of the thermodynamic parameters estimated in this study agreed well with a previous published study [37], which focus on the adsorption of pentachlorophenol (PCP) by pristine MWCNTs. The G • for the DCP was less negative (−2.19 kJ mol −1 at 298 K) compared with PCP in the previous study [37] (−33.7 kJ mol −1 at 298 K), while the H • for the DCP was more negative (−38.3 kJ mol −1 ) compared with PCP in (−23.7 kJ mol −1 ), whereas, the S • for the DCP was negative (−121.1 J mol −1 K at 298 K) compared with PCP which was found to be positive (33.5 J mol −1 K at 298 K).…”

Nickel(II) biosorption by Rhodotorula glutinis

“…Several two-parameter (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich) [6,16,20], three-parameter (Sips, Toth, RedlichPeterson and Radke-Prausnitz) [20][21][22], and four-parameter (Fritz-Schluender) [23] sorption isotherm models were used to fit the experimental equilibrium data obtained at different initial Ni(II) concentrations.…”

Microscale scavenging of pentachlorophenol in water using amine and tripolyphosphate-grafted SBA-15 silica: Batch and modeling studies

“…PCP persists in the environment for a long and is well known for its toxicity to biota (Abdel Salam and Burk, 2009;EPA, 1980). Before 1984, it was one of the most widely used biocides, and this has led to its prevalence in the environment.…”

“…Detectable PCP levels have been found in most people living in industrialized societies, probably as a result of food chain exposure to PCP in the environment (Eisler, 1989;Fisher, 1991). PCP is sparingly soluble in water but the removal of this toxic compound from aqueous systems represents a problem especially at low concentrations (Abdel Salam and Burk, 2009); hence, there is need to develop efficient removal methods.…”