Adsorption of hexavalent chromium from aqueous solution by modified corn stalk: a fixed-bed column study

Area of Science:

• Environmental Chemistry
• Adsorption Science
• Water Treatment Technologies

Background:

• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks due to its toxicity and carcinogenicity.
• Effective and sustainable methods for Cr(VI) removal from industrial wastewater are crucial.

Purpose of the Study:

• To investigate the efficacy of modified corn stalk (MCS) as an adsorbent for Cr(VI) removal in a continuous fixed-bed column.
• To evaluate the influence of operational parameters on Cr(VI) adsorption performance.
• To model the breakthrough curves using established kinetic models for process design.

Main Methods:

• Continuous fixed-bed column experiments were conducted using MCS as the adsorbent.
• Key parameters studied included bed depth, flow rate, influent Cr(VI) concentration, and solution pH.
• Adsorption data were analyzed using Adams-Bohart, Thomas, and Yoon-Nelson models.

Main Results:

• Exhaustion time increased with greater bed depth and decreased flow rate and influent Cr(VI) concentration.
• The Thomas and Yoon-Nelson models demonstrated good agreement with the experimental breakthrough curve data.
• Modified corn stalk exhibited excellent adsorption capacity for Cr(VI) removal.

Conclusions:

• Modified corn stalk is a highly effective adsorbent for removing Cr(VI) from aqueous solutions in a fixed-bed column system.
• The study provides valuable parameters for designing fixed-bed adsorption systems for Cr(VI) remediation.
• MCS presents a promising, sustainable adsorbent for industrial wastewater treatment.