Egg waste, one of the most important nutrients for humans, is divided into two groups: egg shells and membranes. These biomass wastes, which are directly disposed of in landfills, have high potential for secondary environmental pollution. In particular, the presence of microorganisms on their surface can affect environmental conditions and environmental health. Residual liquids on the shells can increase foul odors and the growth of flies and insects. Egg shells and membranes, which are active waste components, need to be converted into value-added products in line with the UN Sustainable Development Goals (such as SDG-6 and SDG-12). Therefore, such biomass wastes should be recycled, reused, or converted into products. Egg waste, with its high biosorbent potential, has gained popularity among scientists worldwide for removing various contaminants that cause water pollution (such as dyes, heavy metals, pesticides, drug residues, endocrine disruptors, etc.). Egg waste is particularly valuable due to its easy availability, low cost, biodegradability, and environmental friendliness. In this context, egg shells and membranes were subjected to separate processes. This review article examines the stages (breaking, grinding, sieving, separation, washing, etc.) of egg waste before it begins its journey as a biosorbent, with detailed evaluations of the applied techniques, physicochemical properties, and mechanisms.