In this study, waste shrimp shell and phosphorous-containing wastewater were used to synthesize calciumdecorated biochar modified with phosphorus (Ca -BC -P) and utilized to remove uranium from aqueous solutions. The results from static adsorption experiment demonstrated that Ca -BC -P exhibited good U(VI) adsorption performance in acidic environments, with a maximum theoretical adsorption capacity of 1074.29 mg g -1 . The adsorption behavior perfectly fit Langmuir isotherm and the pseudo -second -order kinetic models, which revealed the nature of monolayer chemical adsorption by Ca -BC -P. Th...