A tremendous quantity of pistachio waste is produced worldwide annually, offering both environmental challenges and opportunities. This agricultural by-product can be repurposed in various forms, including sieved pistachio shells, pistachio-derived biochar, or in combination with other materials for diverse environmental applications. Notably, pistachio waste can be converted into materials with a high surface area and porous structure, primarily used as adsorbents for removing various pollutants such as dyes, pharmaceutical agents, heavy metals, and greenhouse gases. The adsorption process involves utilizing pistachio waste in different forms such as powder, biochar, or activated carbon, and in conjunction with nanomaterials like TiO