Enhanced Reactive Brilliant Blue Removal Using Chitosan-Biochar Hydrogel Beads

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Biochar adsorbents face challenges with weak affinity and difficult separation.
• Wastewater treatment requires efficient methods for dye removal.

Purpose of the Study:

• To develop chitosan-biochar hydrogel beads (CBHBs) for effective removal of reactive brilliant blue (RBB KN-R) dye.
• To investigate the adsorption behavior and mechanism of RBB KN-R onto CBHBs.

Main Methods:

• Adsorption experiments were conducted to study the behavior and mechanism of RBB KN-R removal by CBHBs.
• Kinetic and isotherm models (pseudo-second-order, intraparticle diffusion) were applied.
• Factors influencing adsorption, such as pH, temperature, and coexisting substances, were analyzed.

Main Results:

• CBHBs demonstrated pH-dependent adsorption, with optimal removal at pH 2.
• The maximum adsorption capacity (q_m) reached 140.74 mg/g at 298.15 K, with adsorption increasing at higher temperatures.
• Adsorption involved a complex mechanism including π-π interactions, electrostatic attraction, hydrophobic interaction, and hydrogen bonding.
• Coexisting substances and high ionic strength reduced adsorption capacity.
• CBHBs maintained over 95% adsorption capacity after three cycles.

Conclusions:

• CBHBs are a promising, durable, and cost-effective adsorbent for reactive brilliant blue dye removal.
• The study highlights the potential of CBHBs for efficient wastewater treatment.