The adsorption capacity of lignin for lead can be controlled by varying the chain length of alkyl, attaching the amine to the lignin surface from C2 (ethyl) to C18 (octadecyl). Altering the chain length had a strong effect on the contribution of amine groups in the adsorption of lead ions by lignin. The adsorption capacity increased 105.0% as the chain length increased to butyl (C4); however, further chain lengths, up to C18, provided no additional benefit, and in some cases even hindered the adsorption capacity of lignin. A short-chain alkyl (C4) group enhanced the beneficial amine contributions for metal ion adsorption, which resulted from the efficient inductive effectiveness of the alkyl groups.