Radiation-synthesized PVP-CMC/CNT biodegradable hydrogels for efficient dye removal

Area of Science:

• Materials Science
• Environmental Science
• Polymer Chemistry

Background:

• Methyl orange (MO) is a toxic, persistent pollutant requiring effective wastewater treatment.
• Biodegradable hydrogels offer a sustainable approach to remove refractory organic pollutants.

Purpose of the Study:

• To synthesize and characterize biodegradable polyvinylpyrrolidone-carboxymethyl cellulose (PVP-CMC) hydrogel and its carbon nanotube (CNT) nanocomposite.
• To evaluate the adsorption performance of these hydrogels for methyl orange removal from aqueous solutions.

Main Methods:

• Hydrogels were synthesized via gamma irradiation copolymerization of PVP and CMC, with CNTs incorporated into the polymer matrix.
• Biodegradation rates were assessed by soil weight loss over 16 weeks.
• Adsorption studies were conducted to determine removal efficiency, adsorption capacity, and kinetics.

Main Results:

• The PVP-CMC hydrogel and PVP-CMC/CNT nanocomposite hydrogel exhibited biodegradation rates of 87% and 54.8%, respectively.
• The nanocomposite hydrogel demonstrated enhanced thermal stability and a higher surface area (5.653 m²/g).
• The PVP-CMC/CNT nanocomposite achieved a maximum adsorption capacity of 216 mg/g for MO at pH 4, with a removal efficiency of 94.7%.

Conclusions:

• The synthesized PVP-CMC and PVP-CMC/CNT hydrogels are effective and sustainable materials for methyl orange removal.
• The incorporation of CNTs enhances the hydrogel's properties, leading to superior adsorption performance.
• These findings highlight the potential of these hydrogels for advanced water purification applications.