No abstract

The simultaneous and competitive ultrasound‐assisted removal of naphthol green B (NG‐B) and phenol red (PH‐R) dye from aqueous solutions were rapidly performed onto copper‐doped zinc sulfide nanoparticles loaded on pistachio‐nut shell activated carbon (Zn‐S: Cu‐NPs‐PAC). Novel adsorbent was recognized by FT‐IR, EDX, SEM and particle size distribution techniques. First, the effect of pH on the removal efficiency was optimized by one‐at‐a‐time procedure and subsequently dependency of dyes removal in their binary situation to variables such as sonication time, initial dyes concentrations and adsorbent dosage was fully investigated and optimized by central composite design (CCD) under response surface methodology (RSM) as well as by regarding desirability function (DF). The good agreement between experimental and predicted values supports suitability of the present model for well definition adsorption state. The ultrasound strongly enhanced mass transfer and performance, while 0.035 g of adsorbent is sufficient and capable to remove high percentage (>99.0%) of dyes in the rapid time (6 min). The experimental equilibrium data represented by Langmuir at mild conditions for successful removal of high adsorption capacity in binary system (196 mg g−1 for PH‐R, 76 mg g−1 for NG‐ B). Kinetics evaluation of experiments at various time intervals reveals applicability of pseudo‐second‐ order models for description of adsorption processes.