Sustainable Conversion of Pulp Industry Sludge into Activated Biochar for High-Performance Methylene Blue Removal

Area of Science:

• Materials Science
• Environmental Engineering
• Chemical Engineering

Background:

• Pulp and paper industry sludge presents a significant waste stream.
• Valorization of sludge into activated biochar (A-BC) offers environmental and economic benefits.
• A-BC can be utilized for wastewater treatment, particularly for dye removal.

Purpose of the Study:

• To produce activated biochar (A-BC) from pulp and paper industry biological sludge.
• To investigate the effect of pyrolysis temperature on A-BC properties and performance.
• To evaluate the A-BC's efficacy in removing methylene blue (MB) dye from aqueous solutions.

Main Methods:

• Sludge treatment with phosphoric acid (H3PO4) followed by pyrolysis at temperatures ranging from 400 to 550 °C.
• Characterization of A-BC using proximate analysis, FTIR, XRD, Raman spectroscopy, and BET surface area analysis.
• Adsorption studies using methylene blue (MB) with Langmuir and pseudo-second-order kinetic models.

Main Results:

• A-BC produced at 450 °C (A-BC2) showed enhanced porosity and surface area.
• A-BC2 exhibited a maximum adsorption capacity of 390.73 mg g-1 for MB.
• Adsorption followed Langmuir isotherm and pseudo-second-order kinetics, indicating chemisorption.

Conclusions:

• Activated biochar derived from paper industry sludge is a sustainable material for dye removal.
• Optimized pyrolysis temperature (450 °C) maximizes A-BC's adsorption efficiency.
• This valorization aligns with circular economy principles for waste management and water treatment.