Removal of tetracycline from polluted water by chitosan-olive pomace adsorbing films.

This paper focuses on the removal of tetracycline frompollutedwater by chitosan-olive pomace adsorbing films. More specifically, both rawolive solidwastes (olive pomace) and the olive solid wastes/chitosan compositewere compared and used for this purpose. Adsorption capacities values of 16 mg × g−1 and 1.6 mg × g−1 were obtained for the two adsorbents respectively. However, chitosan/olive pomace is proposed as suitable for environmental applications avoiding the dispersion of the pomace blocked inside the chitosan film. To detail the adsorption process, the effect of several experimental parameters such as the pH values, ionic strength, amount of adsorbent and pollutant and temperature valueswas investigated. The results showed that the adsorption process improved increasing the pH values, with amaximumat pH 8, and itwas negatively affected by the presence of salts that retarded the adsorption. Indeed, the desorption of tetracyclinewas obtained in aMgCl2 2Msolution. So, a low-cost and cleaner approach, fundamental for the pollutant recovery and for an adsorbent safe reuse, for several cycles of adsorption/desorption, transforming a waste in resource is presented. The kinetics, isotherms models of adsorption and the thermodynamic parameters (ΔG°, ΔH° and ΔS°) were also evaluated observing that the physisorption of the pollutant occurred with and an endothermic character (ΔH° N 0) with ΔG° b 0 and ΔS° N 0. The use of Advanced Oxidation Processes was proposed as possible alternative to the tetracycline recovery, obtaining its degradation after the desorption. With the present paper, the alternative reuse of olive pomace is reported avoiding its disposal in the environment claiming its potential in the removal/recover of emerging contaminants from water.