Synthesis of clay-based superabsorbent composite and its sorption capability

Area of Science:

• Materials Science
• Environmental Science
• Polymer Chemistry

Background:

• Superabsorbent composites (SACs) are crucial for water management and pollutant removal.
• Bentonite, a natural clay, offers a cost-effective and abundant substrate for composite materials.
• Developing efficient adsorbents for heavy metal ions is critical for environmental protection.

Purpose of the Study:

• To synthesize a novel superabsorbent composite using bentonite and acrylic acid.
• To characterize the synthesized composite and evaluate its water absorbency.
• To investigate the heavy metal ion adsorption capacity of the composite for environmental remediation.

Main Methods:

• Copolymerization of partially neutralized acrylic acid (AA) on bentonite micropowder.
• Crosslinking with N,N'-methylenebisacrylamide and initiation with ammonium persulfate.
• Characterization using FTIR, TGA, SEM, and water retention tests; adsorption studies using Langmuir and Freundlich models.

Main Results:

• The synthesized superabsorbent composite (SAC) demonstrated water absorbency of 352 g H(2)Og(-1) in distilled water and 110 g H(2)Og(-1) in 0.2% NaCl.
• Maximum adsorption capacities (Q(m)) for heavy metal ions were: Pb(II) (1666.67 mg g(-1)), Cd(II) (416.67 mg g(-1)), Cu(II) (222.22 mg g(-1)), and Ni(II) (270.27 mg g(-1)).
• Adsorption data fitted well with Langmuir and Freundlich models, indicating effective heavy metal ion removal.

Conclusions:

• The bentonite-based superabsorbent composite exhibits excellent water retention properties.
• The composite demonstrates high efficiency in removing various heavy metal ions from aqueous solutions.
• This novel SAC shows significant potential for application in wastewater treatment and environmental remediation.