Lignite, thermally-modified and Ca/Mg-modified lignite for phosphate remediation.

Aqueous phosphate uptake is needed to reduce global eutrophication. Negatively charged adsorbent surfaces usually give poor phosphate sorption. Chemically- and thermally-modified lignite (CTL) was prepared by impregnating low-cost lignite (RL) with Ca and Mg cations, basified with KOH (pH ̴ 13.