Selective copper recovery from ammoniacal waste streams using a systematic biosorption process.

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Industrial effluents from electroplating and metal extraction often contain copper (Cu) and ammonia (NH3).
• Selective recovery of Cu from complex streams containing carbonate (CO3^2-) and zinc (Zn) is crucial for economic viability and environmental protection.

Purpose of the Study:

• To assess sustainable biosorbents for selective Cu recovery from NH3-bearing effluents.
• To identify a cost-effective and environmentally friendly alternative to synthetic adsorbents.

Main Methods:

• Screened 23 biosorbents for Cu adsorption capacity and selectivity in ammoniacal solutions.
• Optimized adsorption conditions (pH, contact time) for promising candidates.
• Evaluated performance in a real complex bioleachate containing Cu, NH3, Zn, and CO3^2-.

Main Results:

• Pinecone demonstrated high Cu removal efficiency (up to 68%) across a wide pH range (5-12).
• Pinecone exhibited a high maximum adsorption capacity (1.07 mmol g^-1) and Cu/Zn selectivity (3.97).
• Effective Cu removal (69.4%) was achieved in a real industrial bioleachate without pre-treatment.

Conclusions:

• Pinecone is a highly effective, selective, and sustainable biosorbent for Cu recovery from complex industrial streams.
• Integrating bioleaching and biosorption offers a closed-loop, sustainable approach to Cu extraction and recovery.
• This method reduces environmental impact and addresses elemental sustainability using abundant, natural resources.