The adsorption treatment of wastewater by activated carbon is one of the most successful methods. Biomass wastes present a great potential for adsorbent materials because of their availability and carbonaceous nature. Eucalyptus wood strips were used as a precursor to prepare activated carbon by chemical activation with KOH as an adsorbent for adsorption of methylene blue dye. Activated carbon was prepared by the mass ratio of KOH to biochar of 1:2, activation time of 90 min, and an activation temperature of 500 oC. Adsorption followed by chemical reduction of Ag+ on the surface of Activated Carbon has been used to prepare the Ag nanoparticle-loaded activated carbon composite. The prepared silver nanoparticles-loaded activated carbon was characterized by X-ray diffraction, Fourier transforms infrared spectroscopy, and Scanning electron microscopy. Its adsorptive methylene blue dye removal and antimicrobial activity were studied. In addition, the performance of the activated carbon was characterized by Brunauer–Emmett–Teller equation, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Thermo gravimetric analysis, and point of zero charges. The activated carbon's surface area, pore volume, and pore diameter were 547.127 m2 /g, 0.1377 cm3 /g, and 1.6624 nm, respectively. Batch adsorption experiments were conducted to evaluate the effects of pH, the initial concentration of methylene blue, contact time, and dose of activated carbon upon removal of methylene blue from the aqueous solution. The results indicated that a high adsorption capacity (95.5 mg/g) was achieved by using 20 mg activated carbon and 40 ppm methylene blue aqueous solution at a contact time of 180 min, and a removal efficiency of (95.46%) was obtained. The adsorption isotherm and kinetic data best fit the Langmuir model and the pseudo-second-order model with a high correlation coefficient (R2 ) of 0.9989 and 0.9995respectively. The antibacterial property of AgNPs-AC was tested using the disc diffusion technique.