Chromate reduction by Arthrobacter CR47 in biofilm packed bed reactors

Area of Science:

• Environmental Microbiology
• Bioremediation
• Wastewater Treatment

Background:

• Hexavalent chromium (Cr(VI)) is a toxic heavy metal pollutant.
• Effective bioremediation strategies are needed for Cr(VI) removal from industrial wastewater.
• Arthrobacter sp. is a soil bacterium with potential for metal reduction.

Purpose of the Study:

• To evaluate the Cr(VI) reduction efficiency of bacterial strain Cr47 (Arthrobacter sp.).
• To compare Cr(VI) removal rates in batch and recirculating packed bed biofilm reactors.
• To assess the performance of Arthrobacter sp. biofilms using laboratory and industrial model solutions.

Main Methods:

• Isolation and identification of bacterial strain Cr47 using 16s rDNA sequencing.
• Monitoring Cr(VI) reduction in batch and recirculating packed bed biofilm reactors.
• Using laboratory solutions (K2Cr2O7) and industrial model solutions (chrome plating wastewater) with glucose or sucrose enrichment.

Main Results:

• Arthrobacter sp. strain Cr47 was identified from soil.
• Batch reduction followed an exponential decay model with a kinetic parameter of 0.071 mg(L h)(-1) Cr(VI).
• Recirculating reactors achieved Cr(VI) removal rates of 0.79 mg(L h)(-1) (lab solutions) and 0.49 mg(L h)(-1) (industrial solutions).

Conclusions:

• Arthrobacter sp. packed bed biofilm reactors demonstrate significant Cr(VI) reduction capabilities.
• The performance is comparable to established aerobic and anaerobic fixed-film bioreactors.
• This study highlights the potential of Arthrobacter sp. for Cr(VI) bioremediation.