Double macrocyclic cationic crosslinked network enabling ultrafast and efficient aqueous Cr(Ⅵ) remediation

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.
• Efficient remediation of Cr(VI) from industrial wastewater is crucial for water purification.

Purpose of the Study:

• To develop a novel material for the efficient and ultrafast removal of Cr(VI).
• To investigate the adsorption mechanisms and potential applications of the developed material in wastewater treatment and reuse.

Main Methods:

• Construction of a dual-macrocyclic cationic cross-linked network (P1) via quaternization-driven nucleophilic substitution.
• Characterization of P1's structure and properties, including its adsorption performance for Cr(VI).
• Evaluation of P1's efficiency across a wide pH range and in the presence of coexisting anions.
• Mechanistic studies to elucidate the Cr(VI) removal process.

Main Results:

• P1 demonstrated ultrafast Cr(VI) adsorption, reaching equilibrium within 4 minutes.
• Achieved a high Cr(VI) adsorption capacity of 265.96 mg g⁻¹.
• Effective Cr(VI) removal was observed over a broad pH range (3-11) with resistance to interfering anions.
• Treated wastewater showed reduced toxicity, allowing for potential agricultural reuse.

Conclusions:

• The rationally constructed dual-macrocyclic cationic network (P1) is highly effective for Cr(VI) remediation.
• P1's unique structure and functional groups facilitate synergistic adsorption and partial reduction mechanisms.
• The material shows promise for industrial wastewater treatment and sustainable water management.