Two new materials for adsorption of metal ions from aqueous media have been developed. The organic functional groups amine (-NH2) and sulfonate (-SO3H) were successfully attached to a commercially available fine-grained activated carbon (AC) via electrophilic aromatic substitutions. The surface properties of the materials were investigated using FTIR spectroscopy, XPS, BET surface area analysis, gravimetric methods, and elemental analysis. The NH2-AC and SO3H-AC each had a functional group density of 3 mmol/g. Batch metal ion adsorption experiments were conducted to determine metal binding properties of the adsorbent materials. Based on the distribution coefficients (K-d) of metal ions tested, the unmodified AC and sulfonated-AC both had an affinity for metal ions in decreasing order of Nd>Luapproximate toLa>Ph>Cu>Niapproximate toCd>Mnapproximate toCa, while the amine-AC had an affinity for metal ions in the order of Cumuch greater thanNdapproximate toLuapproximate toLa>Pb>Ni>Cd>Mnapproximate toCa. With maximum K-d values of 130,000 for amine-AC and 25,000 for sulfonated-AC, compared to a K-d of 2,000 for unmodified AC, the modified activated carbons have a strong potential for use in removing heavy metal ions and lanthanide ions from aqueous wastes.