Antibiotics removal using a chitosan-based polyelectrolyte in conjunction with ultrafiltration membranes

Area of Science:

• Environmental Science
• Water Treatment Technology
• Polymer Chemistry

Background:

• Antibiotic pollution poses a global threat to aquatic ecosystems and human health.
• Conventional water treatment methods struggle to remove diverse pharmaceutical contaminants effectively.

Purpose of the Study:

• To investigate the efficacy of alkylated chitosan polyelectrolyte (ChA-PE) combined with ultrafiltration for removing amoxicillin (AMX), tetracycline (TET), and ciprofloxacin (CIP).
• To optimize removal conditions and assess the binding characteristics and capacity of ChA-PE for these antibiotics.

Main Methods:

• Utilized ultrafiltration membranes integrated with ChA-PE for antibiotic removal.
• Investigated various experimental parameters including pH, ionic strength, polymer ratio, and antibiotic concentration.
• Determined maximum retention capacity and irreversibly bound antibiotic interaction values.

Main Results:

• Achieved up to 80% antibiotic retention at pH 11.0 across different polymer/antibiotic ratios.
• Demonstrated stronger irreversible binding of ChA-PE to amoxicillin (0.74) and tetracycline (0.92) compared to ciprofloxacin (0.51) at pH 11.
• Reported high maximum retention capacities: 185.6 mg g⁻¹ (CIP), 420.2 mg g⁻¹ (AMX), and 632.8 mg g⁻¹ (TET), with high association efficiencies (73.54%–93.83%).

Conclusions:

• ChA-PE shows significant potential as an effective adsorbent for removing common antibiotics from aqueous systems.
• The ChA-PE/ultrafiltration system offers a promising solution for mitigating antibiotic contamination in water.
• The study highlights the tunable interaction of ChA-PE with different antibiotic structures, paving the way for targeted pollutant removal.