Modeling and optimization of dye removal using “green” clay supported iron nano-particles

•Green synthesis of iron-nano-particles.•Simple process of synthesis without any hazard possibility.•Optimization of dye removal by using Response Surface Methodology.•Dye toxicity removal.•Higher dye removal efficiency in short retention time.

This study addresses a process to produce green synthesized clay-supported nano-iron particles (CnIPs). Green tea was used to synthesize nano-particles supported on bentonite clay. Synthesized CnIPs were used for color removal of Malachite Green (MG) dye. The removal process was optimized using a Response Surface Methodology (RSM). The significance of this process over the conventional techniques of producing CnIPs was to avoid the use of hazardous chemical compounds used in their synthesis. Phyto-toxicity results on Vigna radiata by using the treated and the untreated dye solution demonstrated the decrease of in toxicity after treatment with CnIPs. Regeneration of CNIPs was also performed for evaluating the reuse potential of the CNIPs in repeated cycles.