Gong, et al (2024) Adsorption of phosphorus in wastewater by lanthanum-modified magnetic sewage sludge biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More. Desalination and Water Treatment. https://doi.org/10.1016/j.dwt.2024.100603

In the recent study published in Desalination and Water Treatment, researchers developed an efficient biochar for phosphorus removal from wastewater. The biochar, modified with lanthanum and magnetic properties, was synthesized using a one-pot hydrothermal process and vacuum freeze-drying (VFD) pretreated sewage sludge. This modification increased the biochar’s surface area and pore volume, enhancing its ability to adsorb phosphorus. The VFD-treated biochar demonstrated a BET-specific surface area of 7.111 m²/g and a maximum adsorption capacity of 97 mg/g at 25°C. The adsorption performance remained stable even in the presence of high concentrations of other anions.

The adsorption mechanism of the lanthanum-modified biochar involved both physisorption and chemisorption processes. Key mechanisms included surface precipitation, intraparticle diffusion, hydrogen bonding, ligand exchange, and electrostatic attraction. This study provides valuable insights into optimizing synthetic designs for phosphate multifunctional composites and presents a novel approach for sludge phosphorus recovery.

Given the critical need for phosphorus recycling due to its role in eutrophication and its status as a non-renewable resource, the study highlights the potential of using modified sewage sludge biochar as a sustainable and cost-effective solution. The research also addresses current limitations in sludge management, particularly in China, where improper disposal of sewage sludge leads to significant environmental pollution. This innovative approach to phosphorus recovery could lead to more efficient and environmentally friendly wastewater treatment methods.