Removal of hexavalent chromium by biosorption process in rotating packed bed

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.
• Biosorption offers a promising method for removing toxic heavy metals from wastewater.
• Tamarindus indica fruit shell is an underutilized biomass with potential for pollutant removal.

Purpose of the Study:

• To investigate the efficacy of crude tamarind fruit shell as a biosorbent for Cr(VI) removal.
• To evaluate the performance of a rotating packed bed contactor for continuous Cr(VI) remediation.
• To understand the mass transfer mechanisms and kinetics governing Cr(VI) removal.

Main Methods:

• Biosorption experiments were conducted using crude tamarind fruit shell in a rotating packed bed contactor.
• The concentration of Cr(VI) and Cr(III) in the aqueous phase was monitored over time.
• A mathematical model was developed to describe the Cr(VI) removal process, considering mass transfer resistances and reaction kinetics.

Main Results:

• Crude tamarind fruit shell demonstrated effective removal of Cr(VI) from aqueous solutions.
• The primary removal mechanism involved the reduction of Cr(VI) to Cr(III) within the biosorbent.
• Mass transfer resistance, pH, and packing depth significantly influenced the depletion rate of Cr(VI).
• The rotating packed bed enhanced mass transfer rates compared to conventional fixed bed systems.

Conclusions:

• Crude tamarind fruit shell is a viable and sustainable biosorbent for hexavalent chromium removal.
• Rotating packed bed technology offers an efficient approach to intensify mass transfer for wastewater treatment.
• The developed mathematical model adequately represents the biosorption process, aiding in system design and optimization.