Biosynthesis of Copper Nanoparticles and its Application in Vulindlela Wastewater Treatment Plant and Removal of Toxic Dye

Chemical flocculants are known to pose environmental risks due to their toxicity, prompting interest in biodegradable and eco-friendly bioflocculants as alternatives. Despite their environmental benefits, the industrial adorption of bioflocculants is hindered by their lower efficiency and high production costs. Nanotechnology offers promising solutions for removing contaminant and pathogenic bacteria from potable water. The bioflocculant Kytococcus sedentarius was utilized to produce copper nanoparticles (CuNPs). Biosynthesized nanoparticles were characterized using UV-Vis spectroscope (UV-Vis), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and thermogravimetric analysis (TGA). CuNPs exhibited a wide pH stability with pH 7 having a highest flocculating activity of 98% with a low dosage size of 0.2 mg/mL. Cytotoxicity test results revealed that the nanoparticles are non-toxic at low concentrations up to 75 µL. Moreover, the synthesized nanoparticles have antimicrobial activity when tested. The biosynthesized CuNPs removed dyes effectively with the removal efficiency of ± 90% on all treated dyes. The CuNPs had a high biological oxygen demand (BOD), chemical oxygen demand (COD) removal efficiencies of 93% and 97%, respectively. Thus, the as-synthesized CuNPs have a potential to be applied in wastewater treatment to replace synthetic flocculants.