Marine macrophytes as effective lead biosorbents.

Area of Science:

• Environmental Science
• Marine Biology
• Bioremediation

Background:

• Lead contamination in aquatic environments poses significant risks.
• Seagrasses and marine macrophytes are potential biosorbents for heavy metal removal.
• Understanding biosorption mechanisms is crucial for developing effective remediation strategies.

Purpose of the Study:

• To investigate the biosorption performance of various marine macrophytes for lead removal.
• To determine the effect of pH on lead biosorption by Cymodocea nodosa.
• To evaluate the influence of seaweed structure and phyla on lead sorption capacity.

Main Methods:

• Biosorption experiments were conducted using different species of seagrass and marine algae.
• The effect of pH on lead biosorption equilibrium was studied for Cymodocea nodosa.
• Equilibrium data were analyzed using competitive equilibrium models.
• Lead uptake was quantified for seaweeds from Chlorophyta, Heterokontophyta, and Rhodophyta phyla at a constant pH.

Main Results:

• Cymodocea nodosa exhibited maximum lead biosorption of approximately 140 mg/g at pH 3.3 to 5.
• Brown algae (Heterokontophyta) demonstrated the highest lead sorption potential, with maximum uptake of 220 mg/g (C. compressa) and 140 mg/g (S. lomentaria).
• Green algae (Chlorophyta) showed lead uptake between 40-90 mg/g, while red algae (Rhodophyta) had lower uptake (10-40 mg/g).

Conclusions:

• Seagrasses and marine macrophytes are effective biosorbents for lead removal from aqueous solutions.
• Brown algae exhibit superior lead sorption capabilities compared to green and red algae.
• pH plays a critical role in optimizing lead biosorption by marine macrophytes.