Evaluation of the ciprofloxacin adsorption capacity of common industrial minerals and application to tap water treatment

Many technologies exist to treat medication residues however their implementation in different types of treatment processes for wastewater and water intended for human consumption is balanced against their cost-effectiveness and faces technical difficulties. The contribution of a set of natural industrial minerals commonly used in filtration to the elimination of ciprofloxacin was evaluated. This amphoteric antibiotic is also widely found in hospital effluents. The best adsorption rates found in a non-competitive environment were obtained for MONADOR montmorillonite. This natural, inert, readily available mineral is known for its high crystallinity. its high cation exchange capacity (CEC) and its very high specific surface area. By taking into account the size and volume of the ciprofloxacin molecule, the principal component analysis clearly shows that the CEC is a determining factor in the elimination of this molecule and that the microporosity of activated carbon is not involved in this process. Adsorption in tap water, the innovative element of this study, shows that MONADOR <20 mu m bentonite shows a mean CIP adsorption rate of 184 +/- 6 mg/g, and can therefore compete with activated carbon. This work constitutes the first stage in the qualification of low-cost industrial minerals for environmental protection in its broadest sense. (C) 2019 Elsevier B.V. All rights reserved.