<p>Radio-contaminant and biomass waste remain a threat to the ecosystem, especially, the water bodies, the lifeline of the ecosystem. This paper reviewed radio-contaminant adsorption from aqueous environments using biomass waste-derived biochar (BWDBC). This review aims to analyze the extensive body of literature on the topic, pinpoint important pragmatic findings on research domains, figure out problematic issues and knowledge gaps that could provide a basis for future research endeavors, and project future research hotspots. The maximum reported adsorption capacity for radio-contaminant was 1527.02&#xa0;mg/g for uranium using wheat straw BWDBC. Chelation/complexation, pore diffusion, ion exchange, precipitation, van der Waals forces, π-π interactions, and electrostatic interactions through oxygenated, and oxime functional groups are the main mechanisms of radio-contaminant adsorption. The majority of radio-contaminant adsorption was best described by the pseudo-second-order kinetic, Langmuir isotherm, and Thomas model (for column adsorption). Most exhausted BWDBC can be eluted/regenerated mostly with acid/base and reused up to 3–6 times with an adsorption performance of &gt; 75% in most cases while upholding their original structural integrity. In authentic radio-wastewater and competitive adsorption scenarios, the existence of other ions typically reduced the sorption of radio-contaminants. Glancing forward, research on innovative hybrid techniques, neural network modeling, density functional theory simulations, and techno-economic analysis should be considered. This study advances not just the remediation of water pollution but also responsible consumption, sustainable waste management systems, and circular economy.</p> Graphical Abstract <p></p>