Two unconventional raw materials, the seeds from Spondias purpurea L. (red mombin) and Inga edulis (ice cream bean), were characterized and used as precursors to produce good-quality zinc chloride-activated carbons for potential use in water treatment applications. The red mombin seed was significantly more porous than the ice cream bean seed, while the activated carbons prepared from red mombin seed and ice cream bean seeds showed both a very well-established microporous-mesoporous structure. Equilibrium as well as kinetic adsorption experiments were conducted with methylene blue, methyl orange, and As(V). It was revealed that both seeds are unconventional, renewable, cheap, and suitable agro-precursors for production of activated carbons with potential application in wastewater treatment.