Uranium Absorption Onto Biochars

Heavy metal and radionuclide contamination waste (such as that from runoff from former uranium mines) seriously threatens clean water sources in several regions, including the Four Corners area of the Southwest. This study evaluated the potential of biochar derived from waste biomass as a low-cost absorbent to remove uranium from contaminated water. Biochars from the pecan, cattle, and hemp industries were tested in batch adsorption studies focusing on the effects of initial uranium concentration, solution pH, and contact time. Hemp residue-derived biochar has significantly higher absorption than those derived from the pecan wood and cattle manure. Studies conducted been at a concentration of 1ppm, with a pH of 3-4, for time intervals as long as 72 hours. In future work, batch testing will be conducted at different concentration and pH ranges; In addition, the uranium loaded biochars will be combusted to analyze radionuclide fractionation between gas/vapor and ash, providing insights into the potential for radioactive waste volume reduction without regeneration of the absorbents