ABSTRACT The purpose of this research was to synthesise the chitosan-polyacrylamide composite (CH-PAA) and follow up with an investigation of its capacity to adsorb anionic Sirius yellow K-CF dye, under different environmental conditions. In order to increase the uptake value of the synthesised CH-PAA, the surface chemistry of this adsorbent was modified by bringing it into contact with ZnO nanoparticles (CH-PAA-ZnO). The characterisation tests using XRD, FT-IR, TEM, and FE-SEM analyses demonstrated the successful loading of ZnO onto the CH-PAA surface without causing damage to the chemical composition of the original materials. Excellent removal efficiency of the Sirius yellow K-CF dye (≈ 100%) by CH-PAA-ZnO was performed under the conditions cited namely, pH of 2, dye concentration of20 mg/L, adsorbent dosage of 0.05 g/L, temperature of 40°C, and contact time of 90 minutes. It was evident that the ZnO nanoparticles strongly facilitate the removal process, in which 42% enhancement of dye removal efficiency was recorded, after the CH-PAA was modified with these nanoparticles. The values of the thermodynamic parameters determined at different concentrations of Sirius yellow K-CF dye (negative Δ G o values; and positive Δ H o and Δ S o values) indicated that the dye adsorption process onto the CH-PAA-ZnO was favourable, spontaneous, and endothermic. Based on the R2 values (> 0.99) of the linear fitting determined, the experimental data pertinent to the isotherm and kinetic studies are represented by the Langmuir isotherm and pseudo-second-order kinetic formulas, respectively. Also, the isotherm study revealed that 1 g of CH-PAA-ZnO was capable of capturing 149.79 mg of the dye molecules in 1 L aqueous solution. On comparison with the other adsorbent used for the same purpose, the CH-PAA-ZnO can be an efficacious adsorbent and a good alternative to treat wastewater containing Sirius yellow K-CF dye, in an acidic medium.