The increase of Emerging Contaminants - ECs (which include pharmaceutically active compounds, personal care products, artificial sweeteners and endocrine disrupting chemicals) in wastewaters and the concern about the unknown long-term effects of their accumulation in the environment brought researchers to a growing awareness about the need to improve existing technologies and to develop new strategies for the removal of this new class of pollutants from wastewater [1].

Ibuprofen [2-(4-Isobutylphenyl) propionic acid] is a nonsteroidal anti-inflammatory drug (NSAID) that is primarily used as a painkiller and antipyretic. Due to its widespread use, it is one of the most prevalent ECs found in the environment, with detected levels in wastewater treatment plants influents which go from the tens to the hundreds µg/L [2].

Over the years, adsorption was proved to be efficient methods for wastewater treatment due to their high efficiency and low costs, also thanks to the employment of solid materials which can be easily separated and reused [3]: for this reason, this technology is promising for the removal of ECs from waters. In this work, the kinetics of adsorption of commercial activated carbon towards ibuprofen was investigated and described using adsorption dynamic intraparticle model (ADIM) developed by Russo et al. [4]. Although the adsorption capacity of activated carbon was widely studied in the literature, the corresponding kinetics models are limited.  By fitting the kinetic data obtained from a series of adsorption tests conducted in a thermostated, stirred glass-jacketed reactor, it was possible to obtain important parameters like the surface diffusivity, D_S, and the fluid-solid mass-transfer coefficient, k_m.

In particular, the mass balances have been developed by taking into account for both the external and internal mass transfer diffusion limitations, solving the dynamic partial differen-tial equations (PDEs) system along the radius of the sorbent particles, considering both the fluid andsolid phases that constitute the sorbent particle. From a numerical point of view, the solution of thistype of problem is very challenging because it involves the simultaneous solution of many PDEs, ODEs and AEs. The equilibrium isotherm model was predicted using Fruendlich model.

With the validated model, the influence of some operating parameters on the adsorption behavior was studied, namely, solution bulk density, solution initial concentration, stirring rate and temperature effect. For simplicity, only the data collected to investigate the stirring rate and temperature dependency are reported in Figure 1. As revealed, from 500rpm on, no fluid-solid mass transfer limitation occurs, and by increasing the temperature a corresponding increase of both the adsorption rate and the ibuprofen uptake is observed.

Conference Title

26th International Congress of Chemical and Process Engineering

Conference Country

Czechia

Conference Date

Aug. 21, 2022 - Aug. 25, 2022

Conference Sponsor

https://2022.chisa.cz/welcome/

Additional Info

Conference Website