Biomass as eco-friendly adsorbents for the removal of emerging pollutants from wastewater: A review

Rapid industrialization and urbanization have led to significant contamination in wastewater, posing severe risks to human health and environmental sustainability. Unfortunately, many underdeveloped countries still cannot afford contemporary water treatment methods. Furthermore, one of the main causes of concern is the rising environmental toxicity resulting from exposure to solid wastes. This review comprehensively examines the sources, toxicological effects, and conventional and emerging methods for removing heavy metals, antibiotics, and pesticides from wastewater. Therefore, with prominence on adsorbents that are cheap and practical in the context of the underdeveloped world, the present state-of-the-art review is focused on the elimination of antibiotics, heavy metals, and pesticides from wastewater. Renewable biomass-based adsorbents, including agricultural residues (e.g., rice husk, peanut shells), microbial biomass (e.g., bacteria, fungi), and microalgal biomass, offer cost-effective and eco-friendly alternatives. These bioadsorbents leverage functional groups like hydroxyl and carboxyl for efficient pollutant removal. The review highlights their adsorption capacities, optimal conditions, and challenges, such as leaching and interference from co-existing ions. In a nutshell, the present article includes the developments in the utilization of bioadsorbents by advocating for further research into sustainable modifications and pilot-scale applications to address water pollution, particularly in developing nations.