Abstract The efficiency of zinc hydroxide nanoparticle loaded on activated carbon (Zn(OH)2-NP-AC) in the removal of sunset yellow from aqueous solutions using ultrasonic-assisted adsorption method was investigated. This nanomaterial was characterized using different techniques such as SEM, XRD and UV–vis spectrophotometer. A central composite design (CCD) was used for the optimization of significant factors using response surface methodology (RSM). Under the best conditions (5.2min of sonication time, pH3, 0.023g of adsorbent and 30mgL−1 of SY), Langmuir model was fitting the experimental equilibrium data well. The small amount of proposed adsorbent (0.023g) is applicable for the successful removal of SY (>97%) in short time (5min) with high adsorption capacity (83–114mgg−1).
