Sustainable estrogen removal through adsorption onto carbon-derived materials prepared from biomass wastes: a review

The presence of estrogenic compounds in aqueous environments has raised significant environmental and public health concerns due to their endocrine-disrupting effects. These compounds, both natural (estrone: E1, 17β-estradiol: E2, and estriol: E3) and synthetic (17α-ethinylestradiol: EE2), are frequently detected in wastewater and surface waters, where conventional treatment processes often fail to remove them successfully. Adsorption has been regarded as a promising, low-cost solution for removing these compounds, especially when coupled with activated carbon made from agro-industrial waste. This is considered an environmentally friendly solution, as it reuses waste materials and adds value to them. This review presents a comprehensive analysis of 28 studies published from 2011 to 2026 on the use of activated carbon for the removal of estrogens. It discusses the properties of estrogens, their environmental impact, and the health risks of long-term exposure. It also explains the physicochemical mechanisms behind estrogen adsorption and highlights the main adsorption and kinetic models used, with a reflective discussion on the results. Although results are promising, most studies only performed their assays under ideal matrices or monocomponent systems. Future research should include multicomponent systems, simulated wastewater matrices, and initial estrogen concentrations closer to those found in nature. Challenges remain in improving adsorbent efficiency, regeneration, and overall sustainability.