Separate and simultaneous removal of doxycycline and oxytetracycline antibiotics by electro-generated adsorbents (EGAs)

Abstract

In this paper, two Electro-Generated Adsorbents (EGAs) are presented as adsorbents of two antibiotics doxycycline hyclate (DCH) and oxytetracycline (OTC). The investigated adsorbents called EGANaCl and EGA NaNO3 were prepared by electrolysis in NaCl and NaNO3 electrolytes, respectively, using aluminum electrodes. The physical analyses showed that they were a mixture of AlO(OH) and three Al(OH)3 with bayerite as the main aluminum hydroxide. XRD, XPS and TGA studies ascertained the influence of NaCl and NaNO3 electrolytes towards the formation of bayerite and boehmite respectively in the alumina and, the possible EGA – antibiotic sorption through C 1 s peaks in the antibiotic laden EGAs. In view of industrial effluents and contaminated water bodies with a mixture of antibiotic compounds, the adsorption of OTC and DCH was studied from the three DCH – OTC mixtures (1:1, 1:0.5 and 0.5:1) despite from the respective aqueous solutions using batch methods. The compliance of three kinetic and five isotherm models was checked and discussed with respect to the sorption of antibiotic molecules.