From Algae to Advanced Adsorbents: Sustainable Activated Carbon for Pharmaceutical Removal

The increasing occurrence of pharmaceutical compounds in aquatic environments has become a major environmental concern due to their persistence, continuous release, and potential adverse effects on ecosystems and human health. In this context, the development of sustainable adsorbents from renewable biomass represents a promising strategy for water treatment while supporting circular economy principles. This study explores the synthesis of activated carbon derived from algal biomass and evaluates its potential for the removal of pharmaceutical contaminants from aqueous media.

Activated carbon was synthesized from algal biomass through pyrolysis under an inert atmosphere followed by chemical activation using a metallic halide. The resulting material was characterized in terms of surface chemistry and textural properties. Adsorption experiments were performed using antipyrine solutions in the concentration range of 10-100 mg L⁻¹ under orbital agitation to evaluate adsorption kinetics and adsorption capacity.

Chemical activation of algal biomass generated a mesoporous activated carbon with enhanced surface functionality, demonstrating the potential of algal waste as a low-cost and sustainable precursor for advanced pharmaceutical adsorbents. These characteristics favored the generation of active adsorption sites and enhanced mass transfer and adsorbate diffusion within the porous network. Adsorption experiments revealed a rapid uptake, with equilibrium achieved within 45 min. The material exhibited adsorption capacities close to 70 mg g⁻¹, demonstrating its effectiveness for contaminant removal from water.

The results demonstrate that algal biomass can be successfully valorized into high-performance activated carbon for water treatment applications. The combination of developed porosity, favorable surface chemistry, and fast adsorption kinetics highlights the potential of this material for the efficient removal of pharmaceutical contaminants. Furthermore, the proposed approach contributes to biomass valorization and resource recovery, supporting the transition toward more sustainable and circular water treatment technologies.