High-value zeolitic material from bagasse fly ash: utilization for dye elimination

Area of Science:

• Environmental Chemistry
• Materials Science
• Waste Management

Background:

• Sugar industry waste, bagasse fly ash (BFA), presents disposal challenges.
• Reactive dyes like turquoise blue (TB) and brilliant magenta (BM) are common industrial pollutants.
• Alkaline hydrothermal treatment can modify waste materials for enhanced functionality.

Purpose of the Study:

• To synthesize zeolitic fly ash (ZFA) from BFA.
• To investigate the adsorption performance of BFA and ZFA for TB and BM dyes.
• To determine optimal adsorption conditions and understand the adsorption mechanism.

Main Methods:

• Bagasse fly ash (BFA) was treated hydrothermally with alkali to produce zeolitic fly ash (ZFA).
• Batch adsorption experiments were conducted using BFA and ZFA to remove TB and BM dyes.
• Adsorption parameters including concentration, time, adsorbent dose, pH, and temperature were optimized.
• Langmuir isotherm and pseudo-second-order kinetic models were applied to analyze adsorption data.

Main Results:

• ZFA exhibited improved morphology and enhanced adsorption capacity compared to BFA.
• Optimal dye removal was achieved at specific conditions: 200-300 mg/L dye concentration, 60 min agitation, 5-10 g/L adsorbent dose, pH 2-4, and 298 K.
• Maximum adsorption capacities for ZFA were 21.74 mg/g for TB and 100.00 mg/g for BM.
• Adsorption kinetics followed a pseudo-second-order model, suggesting chemisorption.

Conclusions:

• Alkaline hydrothermal treatment effectively converted BFA into ZFA with superior dye adsorption properties.
• ZFA is a promising adsorbent for removing reactive dyes from wastewater.
• The adsorption process is primarily governed by chemisorption, indicating strong interactions between dyes and the adsorbent.