Single and multi-component adsorption of psychiatric pharmaceuticals onto alternative and commercial carbons

Vânia Calisto,Guilaine Jaria,Carla Patrícia Silva,Catarina I.A Ferreira,Marta Otero,Valdemar I Esteves

doi:10.1016/j.jenvman.2017.01.029

Vânia Calisto, Guilaine Jaria + Show 4 more

Open Access

https://doi.org/10.1016/j.jenvman.2017.01.029

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Abstract

This work describes the adsorptive removal of three widely consumed psychiatric pharmaceuticals (carbamazepine, paroxetine and oxazepam) from ultrapure water. Two different adsorbents were used: a commercial activated carbon and a non-activated waste-based carbon (PS800-150-HCl), produced by pyrolysis of primary paper mill sludge. These adsorbents were used in single, binary and ternary batch experiments in order to determine the adsorption kinetics and equilibrium isotherms of the considered pharmaceuticals. For the three drugs and both carbons, the equilibrium was quickly attained (with maximum equilibrium times of 15 and 120 min for the waste-based and the commercial carbons, respectively) even in binary and ternary systems. Single component equilibrium data were adequately described by the Langmuir model, with the commercial carbon registering higher maximum adsorption capacities (between 272 ± 10 and 493 ± 12 μmol g−1) than PS800-150-HCl (between 64 ± 2 and 74 ± 1 μmol g−1). Multi-component equilibrium data were also best fitted by the single component Langmuir isotherm, followed by the Langmuir competitive model. Overall, competitive effects did not largely affect the performance of both adsorbents. Binary and ternary systems maintained fast kinetics, the individual maximum adsorption capacities were not lower than half of the single component systems and both carbons presented improved total adsorption capacities for multi-component solutions.

Highlights

The global occurrence of pharmaceuticals in the environment is a reasonably welldocumented reality
One should note that PS800-150-HCl was not physically or chemically activated, having been produced by the pyrolysis of paper mill sludge only followed by an acid washing step
The simplicity of single-component isotherm models, in comparison with multi-component ones, is undoubtedly a sound advantage in the application of those models in multi-solute systems. This manuscript describes the adsorption of three pharmaceuticals (CBZ, PAR and OXZ) onto a non-activated waste-based carbon (PS800-150-HCl) and an activated commercial carbon (PBFG4) either in single or in multi-solute solutions

Summary

Introduction

The global occurrence of pharmaceuticals in the environment is a reasonably welldocumented reality. The most commonly applied adsorbents, activated carbons, are in general expensive and have with high regeneration costs These drawbacks have motivated the search for alternative adsorbents, including materials produced from agricultural and industrial wastes (Bhatnagar and Sillanpää, 2010; Calisto et al, 2015; Fernandez et al, 2015; Ferreira et al., 2015; Ioannidou and Zabaniotou, 2007; Mohan et al, 2014). Multicomponent adsorption data are essential for the design of treatment systems (Noroozi and Sorial, 2013) and, the scarcity of such data was the main motivation for the work here presented This manuscript describes the single, binary and ternary adsorptive removal of three widely consumed psychiatric pharmaceuticals (carbamazepine, oxazepam and paroxetine) from ultrapure water, by a commercial activated carbon and an alternative waste-based carbon produced by pyrolysis of primary paper mill sludge with the aim of evaluating and comparing the performance of the studied carbons under competitive effects

Experimental section

Results and Discussion

Conclusions