Removal of dyes using multifunctional copolymer comprising, starch-citric, cinnamic, and acrylic acids as an...

Area of Science:

• Materials Science
• Environmental Chemistry
• Polymer Science

Background:

• Wastewater contamination by organic dyes poses significant environmental challenges.
• Developing efficient and sustainable adsorbents is crucial for dye removal.
• Starch-based biopolymers offer a renewable and abundant resource for adsorbent synthesis.

Purpose of the Study:

• To synthesize and characterize a novel starch-based adsorbent for organic contaminant removal.
• To investigate the adsorption performance of the synthesized copolymer towards cationic dyes.
• To evaluate the mechanism, kinetics, and isotherm models governing the adsorption process.

Main Methods:

• Graft copolymerization and cross-linking of citric acid-modified starch with cinnamic and acrylic acids to form the CASCA copolymer.
• Characterization using XRD, TGA, SEM-EDX, FT-IR, and BET techniques.
• Adsorption experiments for methylene blue and crystal violet under varying conditions (pH, contact time, concentration).

Main Results:

• The CASCA copolymer exhibited a porous, heterogeneous, and thermally stable structure.
• Maximum adsorption capacities reached 564.67 mg/g for methylene blue and 440.22 mg/g for crystal violet.
• Adsorption followed pseudo-second-order kinetics and was best described by the Sips isotherm model.

Conclusions:

• The synthesized CASCA copolymer is a highly effective adsorbent for cationic dye removal from wastewater.
• The adsorbent demonstrates excellent durability and recyclability over multiple adsorption-desorption cycles.
• Starch-derived biopolymers present a promising route for developing sustainable water treatment solutions.