Biochar from Alternanthera philoxeroides could remove Pb(II) efficiently

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Eutrophic lake restoration often involves managing invasive hydrophytes like Alternanthera philoxeroides (AP).
• Heavy metal contamination in water bodies poses significant ecological and health risks.
• Development of cost-effective adsorbents is crucial for efficient water treatment.

Purpose of the Study:

• To synthesize a novel bio-adsorbent from AP for heavy metal removal.
• To evaluate the adsorption performance of the synthesized AP biochar (APB) for lead (Pb(II)).
• To elucidate the adsorption mechanism and assess the environmental significance of APB.

Main Methods:

• Pyrolysis of Alternanthera philoxeroides (AP) under oxygen-limited conditions at 600 °C to produce AP biochar (APB).
• Batch adsorption experiments to determine the adsorption capacity and equilibrium time for Pb(II).
• Comparison of APB performance with commercially active carbon (AC).
• Analysis of adsorption mechanisms, including functional group interactions and ion exchange.

Main Results:

• APB demonstrated a high maximum adsorption capacity for Pb(II) of 257.12 mg/g, 5.3 times higher than AC.
• Adsorption equilibrium was reached rapidly within 2.5 hours.
• Initial solution pH had a minimal effect on Pb(II) adsorption by APB.
• Adsorption mechanism involves precipitation, complexation with functional groups/carbonates, and ion replacement.

Conclusions:

• Alternanthera philoxeroides-derived biochar (APB) is a highly effective and low-cost adsorbent for Pb(II) removal.
• APB offers a promising solution for treating heavy metal-contaminated water, contributing to ecological restoration.
• The study highlights the environmental significance of utilizing aquatic biomass for sustainable water remediation.