Statistical optimization of removal of Cr(VI) by Pistacia Atlantica-based activated carbon nano-structures using experimental design

Pistacia Atlantica, an inexpensive and plentiful natural resource in Kermanshah province, was used to produce nanostructures of activated carbon (AC). The structural properties of AC nanostructure were characterized utilizing Fourier transform infrared (FTIR), Barret-Joyner-Halenda (BJH), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Chromium (Cr(VI)) is an extremely toxic and carcinogenic substance so its water pollution has become more and more serious. Its wastewater treatment is still a big problem because more than 96% of it is stockpiled on land, leading to environmental pollution and threatening human health [1,2]. This study used Pistacia Atlantica-based activated carbon nanostructures to remove Cr(VI) from aqueous solution and effective factors on the removal mechanism have been analyzed. In this work, a rapid/assisted adsorption method followed by ultraviolet-visible spectroscopy (UV/Vis) detection has been used for efficient short-time removal of Cr(VI). A combination of central composite design (CCD) and response surface methodology (RSM) has been applied to model and optimize the influencing variables on the Cr(VI) adsorption by produced AC nanostructure. More specifically, the effects of imperative variables such as adsorbent mass, Cr(VI) concentration, temperature, and stirring time have been investigated. The results show that the Langmuir and pseudo-second-order kinetic models fitted well to the adsorption experimental data [3,4]. Compared with the recently reported techniques for removing Cr(VI), the proposed technique has several advantages such as low cost, the abundance of raw materials, ease of production, fast adsorption kinetics, and high adsorption capacity.