In situ green synthesis of copper(ii) oxide (CuO) and maleic anhydride grafted polypropylene (PP-MAH) for highly efficient nanocatalysis in tannery wastewater treatment

Abstract

The discharge of substantial volumes of wastewater laden with toxic contaminants from tannery factories poses severe environmental challenges. This study delves into the synthesis of a CuO–PP-MAH nanocomposite and explores its efficacy in reducing the BOD/COD levels in tannery wastewater. Addressing this issue necessitates the development of nanoparticles incorporated within polymeric nanocomposites, utilizing eco-friendly resources and minimizing the use of hazardous precursors. In this context, a novel in situ melt mixing and extrusion technique has been introduced for the synthesis of CuO–PP-MAH, wherein copper oxide (CuO) nanoparticles are immobilized onto maleic anhydride grafted polypropylene (PP-MAH). Scanning and transmission electron microscopy revealed well-dispersed copper oxide nanoparticles on the polymeric support, exhibiting diameters ranging from 20 to 60 nm due to maleic anhydride functionalization. Fourier transform infrared spectroscopy confirmed the complexation of copper moieties with maleic anhydride grafted onto the polymeric chains. This method yielded a stable, high surface area, highly efficient, and regenerative catalytic nanocomposite. The potential of this nanocomposite as a green catalyst was assessed for COD/BOD reduction in industrial tannery wastewater, demonstrating remarkable catalytic activity in diminishing COD/BOD. Notably, the process did not involve any toxic solvents and adhered to the principles of green chemistry. Furthermore, this approach is scalable for industrial applications, indicating its practical viability.