Simultaneous ultrasound-assisted removal of sunset yellow and erythrosine by ZnS:Ni nanoparticles loaded on activated carbon: Optimization by central composite design

• We demonstrate a methodology for simultaneous dyes removal from aqueous solution.
• Application of ultrasound accelerates mass transfer and decreases the removal time.
• Small amount of proposed adsorbent is enough for removal of high content of dyes.
• An experimental design methodology was used to optimize the parameters.

The present study focused on the simultaneous ultrasound-assisted removal of sunset yellow and erythrosine dyes from aqueous solutions using ZnS:Ni nanoparticles loaded on activated carbon (ZnS:Ni-NP-AC) as an adsorbent. ZnS:Ni nanoparticles were synthesized and characterized using different techniques such as FESEM, XRD and TEM. The effects of various parameters such as sonication time, pH, initial dye concentrations and adsorbent dose on the percentage of dye removal were investigated. Parameters were optimized by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF). A good agreement between experimental and predicted values was observed. The ultrasound-assisted adsorbent (0.04 g) was capable of high percentage removal (98.7% and 99.6%) of sunset yellow and erythrosine in short time (3.8 min).