Unveiling the potential of olive oil production residues as adsorbent materials for water treatment: A literature review

Olive oil is a nutritionally and economically valuable product whose global production has steadily increased, alongside the generation of large volumes of solid and liquid waste. Olive oil mill wastewater and solid residues such as olive pomace and olive stones have become major environmental concerns due to their high pollutant load. At the same time, these byproducts offer an opportunity: their valorization as low-cost, sustainable adsorbents for water treatment. Addressing this dual environmental challenge, this review provides a comprehensive and systematized synthesis of the current state of research on the use of olive oil production residues for water decontamination via adsorption. Specifically, the study maps the types of byproducts used, their target pollutants, removal efficiencies, and adsorption capacities. Unlike previous reviews, this work emphasizes studies that apply raw or minimally processed residues, as well as experiments conducted with real wastewater or under environmentally relevant conditions. The data are presented in a structured and comparative format, highlighting promising results and underexplored combinations. By identifying trends, gaps, and practical applications, this review contributes to advancing the development of circular economy-based, eco-friendly solutions for water pollution control and provides a valuable resource for future research and implementation.