Optimization of efficient removal of lead ions with piperazine-modified magnetic graphene oxide (PIP@MGO) nanocomposite using RSM

Disposal of industrial effluents and wastewaters is one of the most important challenges in the industrial world today. Among the various toxic metal ions, lead is a highly toxic pollutants that is released into the natural environment due to industrial activities. Acumination of Pb(II) ions inside the human body lead to various health consequences, therefore, in order to environmental clean-up, it is absolutely essential to design appropriate technologies for the completely elimination or reduce to an acceptable the level of Pb۲+ ions. In the various treatment technologies, adsorption as a non-hazardous method is currently preferred for the heavy metal removal due to its many benefits. Graphene oxide (GO) as a single-layered۲two-dimensional nanomaterial has aroused great interest between analytical chemists due to large surface area, high mobility and good conductivity. The dispersibility of GO nanosheets is very high and their separation from the solution medium is very difficult. To solve this problem and facilitate the separation after adsorption process, it is possible to create magnetic properties in graphene by making magnetic graphene nanocomposites.In this research, the piperazine functionalized magnetic graphene oxide (PIP@MGO) nanocomposite was synthesized and used for the removal of Pb۲+ ions. The physicochemical properties of adsorbent was characterized by XRD, FESEM, EDS, TGA, VSM and FT-IR analysis. In this method, the batch removal process were designed by response surface methodology (RSM) based on a central composite design (CCD) model. The results indicated that the highest efficiency was obtained from the quadratic model under optimum conditions of prominent parameters (pH = ۶.۰, adsorbent dosage = ۷۰ mg, initial concentration of lead = ۱۰ mg L-۱, and contact time = ۳۰ min). Adsorption data showed that lead uptake followed the Freundlich isotherm model equation and pseudo-second order kinetic model. The maximum adsorption capacity was found to be ۵۵۴.۴ mg/g.

کلیدواژه ها:

Removal of Pb (II) ، Nanocomposite ، Response surface method ، Isotherms ، Water treatment