A hybrid Electro-Driven adsorption and degradation system for antibiotics and dyes based on composite tablets composed of deep eutectic solvent-functionalized nanomaterials

Abstract

In this study, a unique hybrid system was designed and developed for the continuous electro-driven adsorption and degradation of typical antibiotics together with dyes, which were based on immobilized deep eutectic solvent of thymol-benzyl alcohol on zeolitic imidazolate framework-8 (ZIF-8) and multi-walled carbon nanotubes (MWCNTs). After prepared with simple and mild method, the composite tablets were comprehensively characterized by various ways. Due to their large specific surface area and high thermal stability, the maximum adsorption efficiencies of sulfa pyrimidine (SDZ), ciprofloxacin (CIP), methylene blue (MB), malachite green (MG) and crystal violet (CV) were 90.52%, 85.18%, 94.89%, 94.61% and 96.18%, respectively. The adsorption efficiency of chlortetracycline (CTC) was only 9.66% due to the existence of competitive adsorption at the same condition. In addition, the high adsorption efficiency was validated by the real water samples. Multiple interactions including electrostatic interaction, π-π, H-bonding in the adsorption process were all revealed by the kinetics and isotherms studies, spectral analysis and molecular simulation. At last, the composite tablets were easily recycled after elution process, meanwhile the adsorbed antibiotics and dyes were almost completely degraded during the subsequent electrochemical oxidation process. It was expected to provide valuable insights to the combination of the new applied form of green solvents and electro-driven integrated technology as well as synergistic effects deriving from advantages of different functional materials for multi-task process.