A procedure was developed for preparing an effective sorbent based on lignin phosphorylated in the presence of urea. The phosphorus content was 16.6 wt %. The total exchange capacity was 0.86 mmol g−1 for Cu2+ ions and 0.23 mmol g−1 for UO 22+ ions. The effect of urea on the lignin phosphorylation was examined by IR spectroscopy.