Abstract

Problem addressed: Bangladesh's shipbreaking and recycling industry (SBRI), particularly in Sitakunda, has led to significant environmental degradation due to releasing hazardous heavy metals into soil and seawater. Pollutants such as Arsenic (As), Lead (Pb), Cadmium (Cd), Cobalt (Co), Chromium (Cr), Copper (Cu), Nickel (Ni), and Mercury (Hg) have detrimental effects on marine ecosystems and public health. Bioremediation has recently evolved as a cost-effective and eco-friendly approach for heavy metal removal. This work models the efficiency of bioremediation-based formulas for heavy metal reduction.

Experimental approach: Seawater samples were collected from the Sitakundu, Chittagong, shipbreaking yard to assess heavy metal contamination concentration using ICP-MS. Eight toxic heavy metals were identified, and four plant-derived formulations were developed to remove heavy metals. The effectiveness of these formulations in reducing heavy metal concentrations was evaluated through statistical analysis. ANOVA and TUKEY Test, performed in GraphPad Prism v10, confirmed a significant reduction (P < 0.0001).

Main results and findings: Formula 4 demonstrated the highest removal efficiency, reducing heavy metals in seawater by 85–93%. While Formulas 1-3 also displayed significant adsorption capabilities, their efficiency was comparatively lower. Mercury (Hg) and Cobalt (Co) exhibited the most pronounced reduction. Across all tested heavy metals, the highest removal occurred within 36 hours.

Conclusion: False daisy (Eclipta alba), Aloe vera (Aloe barbadensis), and water hyacinth (Eichhornia crassipes) were identified as the most effective plant species for bioremediation. The developed formulas demonstrate high efficiency, ease of application, and environmental safety, making them viable for large-scale implementation.

This work is licensed under a Creative Commons Attribution 4.0 License.