Nanomaterial-functionalized biochar hybrids for enhanced Pb²⁺ removal: surface engineering and interfacial mechanisms

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Lead (Pb) contamination in wastewater poses significant risks to human health and ecosystems.
• Industrialization increases waste generation, exacerbating environmental degradation.
• Waste-derived biochar (W-BC) presents a sustainable method for waste management and pollutant removal.

Purpose of the Study:

• To review recent advancements in using W-BC for lead ion (Pb²⁺) adsorption from wastewater.
• To analyze the mechanisms of W-BC functionalization with nanomaterials (NMs) for enhanced adsorption.
• To discuss strategies, parameters, and regeneration techniques for effective lead removal using W-BC.

Main Methods:

• Literature review of W-BC functionalization with various nanomaterials (metal, metal-oxides, carbon, polymer).
• Analysis of adsorption mechanisms including electrostatic interactions, π-π interactions, hydrogen bonding, surface complexation, and redox processes.
• Exploration of experimental parameters (contact time, adsorbent dosage, pH) and regeneration approaches.

Main Results:

• Nanomaterial functionalization significantly enhances W-BC's surface area and Pb²⁺ adsorption capacity.
• Various interaction mechanisms contribute to improved lead ion removal efficiency.
• Optimized experimental conditions and effective regeneration strategies are crucial for practical applications.

Conclusions:

• W-BC, especially when functionalized with NMs, is a highly effective and cost-efficient adsorbent for lead removal from wastewater.
• This approach supports sustainable development goals (SDGs) and promotes a circular economy by converting waste into valuable remediation materials.
• Further research into regeneration and large-scale application is vital for real-world implementation.