Facile fabrication of shapeable three-component hydrogen-bonded covalent-organic aerogel as permeable reactive barrier material for efficient in-situ fluoroquinolone contaminated groundwater remediation

Fluoroquinolones (FQs) antibiotics found in groundwater pose hazardous impacts to organisms and humans. Moreover, permeable reactive barrier (PRB) is reckoned as an effective in-situ remediation technique for FQ-contaminated groundwater, in which PRB materials with high adsorption capacity and moldability are severely desired. Herein, a shapeable three-component hydrogen-bonded covalent-organic aerogel with sulfonic acid (SLEL-3) was fabricated based on a multiple-component method. The appraisal of SLEL-3 for the capture of levofloxacin (LVF) and ciprofloxacin (CIP) was evaluated systematically through kinetics and isotherms, which exhibited satisfactory adsorption performance in the following aspects: amended adsorption capacity, acceptable removal depth and resistance to ions and acidity/alkalinity. The proposed adsorption mechanisms involved a combination of pore filling effect, electrostatic effect, hydrogen bonding, π-π/n-π electron-donor–acceptor (π-π/n-π EDA), Lewis acid-base and hydrophobic/hydrophilic interaction. More importantly, in view of self-shaping ability, adaptability to harsh conditions, high swellability as well as felicitous hydraulic conductivity, novel PRB systems integrating SLEL-3 into 1-D column and 2-D tank in lab-scale study were developed for the capture of LVF, achieving impressive removal efficiencies of 86% and 92.65% over a 72-h period, respectively. Thus, this study provides a new notion of contriving a shapeable, eco-friendly and practicable covalent-organic polymer for potentially efficient in-situ remediation of FQ contaminated groundwater with a large area.