Biogenic nanoparticle based adsorption for chromium contaminated wastewater treatment

Abstract

The discharge of chromium-contaminated wastewater from industries such as ferrochrome plants and leather manufacturing poses a significant environmental challenge due to the toxic and carcinogenic properties of Chromium [Cr(VI)]. Nanoparticles have emerged as one of the most effective solutions for wastewater treatment due to their high surface area, enhanced reactivity, and ability to target specific contaminants. In recent years, their eco-friendly synthesis, scalability, and efficiency in removing heavy metals and other pollutants have made them vital in addressing environmental challenges, particularly in industrial wastewater management. Their unique properties make them indispensable in modern wastewater treatment technologies. This study explores the application of biogenically synthesized titanium dioxide (TiO₂) for removal of Cr(VI) from synthetic wastewater. Lemon grass leaf extracts has been used as potential precursor in synthesis of TiO₂ nanoparticles from readily available micro size particles of TiO₂ powder. The process was further enhanced by ultrasonic assistance, which promoted the formation of uniformly dispersed nanoparticles with high surface area, improving their adsorption. Experimental techniques, such as X-ray Diffraction, have been utilized to confirm the biogenic synthesis of TiO₂ nanoparticles, demonstrating a size reduction from 10 μm to 35.79 nm. The nanoparticles demonstrated excellent Cr(VI) removal efficiency, achieving 84.55% reduction under optimal conditions. Among the various adsorption isotherm models, the Freundlich model proved to be the best fit, with an R² value exceeding 0.997. This method not only leverages sustainable synthesis processes but also offers potential scalability for industrial applications in waste water treatment.