Comparative Analysis of Bioremediation and Phytoremediation in Mitigation of Heavy Metals.

The study explored the use of bacterial and phytoremediation methods to address cobalt and nickel contamination. Bacterial species such as Escherichia coli and Staphylococcus aureus were cultivated in media contaminated with varying concentrations of cobalt and nickel, and their growth curves were analysed through colorimetry. The results showed that both species were effective in reducing the concentrations of cobalt and nickel, with E. coli exhibiting slightly better efficiency. A relationship between the growth phases of the bacteria and their metal uptake rates was noted, underscoring the potential of these microorganisms in bioremediation efforts. However, the ability of E. coli and S. aureus to remediate cobalt was found to be limited, indicating that their effectiveness may not be significant in environments with high levels of cobalt contamination. The potential for phytoremediation was evaluated using Eichhornia crassipes (water hyacinth) and Pistia stratiotes (water lettuce). E. crassipes, which was grown in nickel-contaminated water for 20 days, showed a significant reduction in nickel concentrations, as measured by Atomic Absorption Spectroscopy (AAS). Likewise, P. stratiotes exhibited impressive capabilities in cobalt remediation, achieving a notable decrease in cobalt levels. The high efficiency of P. stratiotes was linked to its rapid growth, substantial biomass, and extensive root system, which provided a large surface area for metal absorption. These results are consistent with previous research that emphasized the effectiveness of aquatic plants like P. stratiotes in absorbing heavy metals, highlighting their potential for cobalt phytoremediation. The comparative analysis indicated that bacterial remediation is a quick and effective method for metal reduction, while phytoremediation offers a sustainable and environmentally friendly alternative, along with the benefit of biomass production. This study supports an integrated approach that combines microbial and phytoremediation techniques to tackle heavy metal pollution effectively. Additionally, the findings may enhance understanding of the stress physiology in plants subjected to heavy metal exposure.