Valorization of Golden Mussel Shells for Sustainable Phosphorus Recovery in Wastewater Treatment

The golden mussel (Limnoperna fortunei) poses environmental and infrastructural challenges due to its ability to attach to various substrates and form dense colonies. These colonies are difficult to remove and threaten hydroelectric power stations, water treatment plants and fishing activities. However, the high calcium carbonate content of golden mussel shells (GMSs) presents an opportunity for phosphorus (P) recovery from wastewater, addressing both waste management and resource scarcity. This study evaluated the effectiveness of GS for P recovery from synthetic and real wastewater. Batch experiments were conducted to assess P recovery capacity under varying adsorbent dosages, pH levels, contact times and isotherm conditions (Langmuir, Freundlich and Temkin). Also, the chemical and physical analyses of GMSs were performed to elucidate the mechanisms of P recovery. The Freundlich isotherm model best describes the process, while the Langmuir model suggests a maximum recovery potential of approximately 59.9 mg P g−1 of GMS, demonstrating a P recovery efficiency of up to 60.7% at a P concentration of 40–50 g L−1 and a contact time of 3 h. Due to the predominance of negative charges, it was concluded that the precipitation was the major mechanism for P recovery by GS. This study highlights the potential of GMSs as a sustainable and low-cost material for phosphorus recovery in wastewater treatment, offering a promising solution for both waste valorization and environmental management contributing to a circular economy.