A Crosslinked Ionic Organic Framework for Efficient Iodine and Iodide Remediation in Water

Area of Science:

• Materials Science
• Environmental Chemistry
• Water Treatment

Background:

• Iodine is crucial for water disinfection but residual iodine and iodide pose health risks.
• Current methods struggle to remove low iodine/iodide concentrations (≈5 ppm) effectively.
• Limited research exists on iodine/iodide remediation across wide temperature ranges (up to 90°C).

Purpose of the Study:

• To develop an efficient adsorbent for removing iodine and iodide species from water.
• To investigate the performance of the adsorbent across a broad temperature range.
• To address the challenge of low-concentration iodine/iodide removal in water treatment.

Main Methods:

• Synthesized a single-crystalline ionic hydrogen-bonded crosslinked organic framework (H_COF-7) using nitrate dimer-directed synthesis.
• Utilized halogen bonding and anion exchange mechanisms for iodine/iodide removal.
• Conducted packed column breakthrough experiments at temperatures ranging from 23°C to 90°C.

Main Results:

• H_COF-7 demonstrated efficient removal of iodine and iodide species, reducing concentrations to 0.22 ppm at room temperature.
• Achieved high breakthrough volumes (≥18.3 L g^-1) in packed columns across the tested temperature range.
• The adsorbent maintained high performance under practical water treatment conditions.

Conclusions:

• H_COF-7 is a highly effective adsorbent for removing iodine and iodide from water.
• The material shows promise for water treatment applications, particularly in challenging temperature conditions.
• This work presents a significant advancement in addressing residual iodine contamination in water.