Catechol-Modified Alkali Lignin for Cr (VI) Removal from Synthetic Wastewater

Area of Science:

• Environmental Chemistry
• Materials Science
• Biotechnology

Background:

• Chromium (VI) ions are highly toxic, necessitating their removal from industrial wastewater.
• Alkali lignin, a byproduct of paper pulping, is an abundant and underutilized biomass resource.

Purpose of the Study:

• To develop a novel adsorbent material for the efficient removal and reduction of hazardous chromium (VI) ions.
• To explore the utilization of alkali lignin as a functional material in environmental remediation.

Main Methods:

• Catechol-modified alkali lignin (CAL) was synthesized using catechol, acetone, and alkali lignin.
• Characterization of CAL using SEM, TGA, FTIR, and XPS.
• Investigation of adsorption behavior and kinetics, including Langmuir isotherm and pseudo-second-order models.

Main Results:

• CAL demonstrated a high adsorption capacity for chromium (VI) (498.4 mg/g).
• CAL achieved simultaneous adsorption and reduction of chromium (VI) to chromium (III) (54.6%).
• The adsorption mechanism is influenced by the functional groups present in CAL.

Conclusions:

• Catechol-modified alkali lignin offers an efficient and integrated approach for chromium (VI) removal and detoxification.
• This method presents a sustainable pathway for valorizing alkali lignin and addressing chromium contamination.
• The developed adsorbent surpasses the performance of single-function lignin-based materials.