Journal of Advanced Chemical Engineering

Adsorption of oxytetracyclin on modified bentonites

2^nd International Conference on Advances in Chemical Engineering and Technology

November 16-17, 2017 | Paris, France

Faroudja Mohellebi, Fairouz Kies, Abir Azara and Kamel Rebai

Ecole Nationale Polytechnique, Algerie

Posters & Accepted Abstracts: J Adv Chem Eng

Abstract:

Environmental pollution as a consequence of technological evolvement has become one of the most crucial problems of the century. Pharmaceutical pollutants (PPs) are a group of emerging anthropogenic hazard contaminants that contain different groups of human and veterinary medicinal compounds that are used widely all over the globe. PPs exist in the environment at a very low concentration but, generally due to their bio-accumulation, they pose a potential long-term risk for aquatic and terrestrial organisms.. Among the pharmaceuticals pollutants, the antibiotics deserve special attention because they are used in very large quantities and are biologically active molecules that can interact with specific biological targets leading to emergence of the phenomenon of microorganismâ??s resistance towards the potential pathogens such as bacteria. The adsorption process under laboratory conditions showed promising results in oxytetracyclin wastewater treatment in comparison with the traditional methods to treat pharmaceuticals discharge. Adsorbents that are commercially available, e.g., commercially activated carbon, are very effective but expensive. Therefore, research is currently focused on adsorbents that remove pharmaceuticals pollutants from wastewater at a low cost. An adsorbent can be considered low cost if it requires little processing is abundant in nature, or is a byproduct or waste material from another industry. Therefore, the natural adsorbents have gained much attention for the adsorption of various pollutants from an aqueous medium. Bentonite clay may be an alternative adsorbent because of their abundance in most continents of the world and its low cost. Bentonite is mainly composed of montmorillonite, consists of layers of two tetrahedral silica sheets sandwiching one octahedral alumina sheet. Adsorption of oxytetracyclin on grinded bentonite (particle size of 100 μm) was studied in batch reactor. This study investigated the influence of various parameters on the oxytetracyclin removal efficiency. These include bentonite types (untreated bentonite, Na-bentonite and H-bentonite), contact time, and effects of temperature. Results show that equilibrium was reached after 30 minutes of contact for the different bentonites. The results clearly depict that the Na-bentonite exhibited the best absorption under the conditions: Na-bentonite dosage of 4g/L, pH 6, reaction temperature of 19±1°C. It was found that the removal efficiencies of oxytetracyclin are of 70% and 80 % for antibiotic concentrations of 20 and 50 ppm, respectively. The adsorption isotherm data were well fitted well with Langmuir better than Freundlich models. Oxytetracyclin adsorption onto Na-bentonite was well represented by the pseudo second-order kinetic model. Thermodynamic parameters such as free energy change (Î?G°), enthalpy change (Î?H°) and entropy change (Î?S°) have been calculated on the basis of Langmuir constants. The negative values of Î?G° were indicative of the spontaneity of the adsorption process. The negative values of Î?H° revealed the exothermic nature of the adsorption process. The negative values of â??S were due to the decrease in the degree of freedom resulting from the immobilization of pollutant molecules on the Na-bentonite surface.

Biography :

Faroudja  Mohellebi has her expertise in adsorption and sustainable development. She has always worked in the field of environmental protection and waste management. She has built  several models after years of experience in research, evaluation, teaching and administration both in superior education institutions. Since the beginning of his career, Pr F. Mohellebi has been involved in multidisciplinary research on clays. In addition to their fundamental character, their research work almost always had an applied purpose. Its theme is centered on the physical-chemistry of lamellar materials (Clays, natural clay minerals) with the study * Surface properties and porosity, * Structural and textural modifications by thermal, chemical and / or physical means Currently, Prof. F. MOHELLEBI works on waste management by using them as a low cost adsorbent for emerging pollutants.