Modified activated carbon from bamboo was used as a low-cost potential adsorbent to remove cadmium, copper and lead in single, bimetal and trimetal aqueous solutions. Using the initial concentration of 40 ppm, the analysis was conducted to determine the effect of pH (2.5, 3.0, and 5.5), contact time (60, 90, 120 min) and adsorbent dosage (20, 40, 60 mg/50 mL of solution). Results showed that for single metal aqueous solution, the % adsorption for Cu, Cd, and Pb were 89.0%, 87.4%, and 99.5% respectively. For bimetal aqueous solution the % adsorption of CuCd, CuPb, CdCu, CdPb, PbCu,and PbCd were 90.6%, 98.9%, 55.1%, 80.7%, 99.6%, and 96.05%, respectively. While for trimetal aqueous solutions, % adsorption of Cu, Cd, and Pb were 87.4%, 73.0%, and 98.4%, respectively. The % removal uptake followed the order Pb > Cu> Cd gave insights into competition effects among the three solutes during the adsorption process. Using Box–Behnken Design, the effect pH of the aqueous solution is an important controlling parameter in which the % adsorption increased as the pH level is increased while other parameters were insignificant.