Green Synthesis of Copper Nanoparticles Using Industrial Wastewater from a Textile Factory

Thesis Abstract

The increasing environmental concerns associated with traditional chemical synthesis of metal nanoparticles necessitate the development of sustainable and eco-friendly approaches, particularly in industries such as textiles, which generate large volumes of wastewater containing complex chemical effluents. This study investigates the green synthesis of copper nanoparticles (CuNPs) utilizing industrial wastewater from a textile manufacturing plant as both a reducing and stabilizing agent. The primary aim is to optimize the synthesis process for environmentally benign production of CuNPs with high purity and stability, and to evaluate their potential applications. The specific objectives include characterizing the physicochemical properties of wastewater, establishing optimal synthesis conditions (pH, temperature, and nanoparticle concentration), and assessing the antimicrobial efficacy and catalytic activity of the synthesized CuNPs. A mixed-methods research design was adopted, combining qualitative assessments of wastewater composition with quantitative experimentation on nanoparticle synthesis. The population comprised wastewater samples from the textile factory’s effluent streams, with a sample size of 30 representative samples collected over a six-month period. Chemical characterization was performed using inductively coupled plasma mass spectrometry (ICP-MS), Fourier transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy to identify key reducing agents and functional groups involved in nanoparticle formation. The synthesis process involved varying parameters such as pH (4-10), temperature (25-80°C), and copper precursor concentration (0.1-2 mM), with the resulting CuNPs characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Antimicrobial activity was evaluated against Escherichia coli and Staphylococcus aureus using disc diffusion methods, while catalytic efficacy was assessed through the reduction of methylene blue dye, monitored spectrophotometrically. Data analysis involved regression analysis to determine optimal synthesis conditions and ANOVA to evaluate the significance of parameter effects on nanoparticle size and stability. The antimicrobial and catalytic data were analyzed using t-tests and kinetic models, respectively. The anticipated results include identification of specific organic compounds in wastewater responsible for reduction and stabilization, synthesis of CuNPs with controlled size distribution (average diameter of 10-20 nm), and confirmation of their efficacy as antimicrobial agents and catalysts. It is expected that the wastewater's organic components will serve as effective bioreductants, enabling the synthesis process to be conducted under ambient conditions without hazardous chemicals. This research aims to contribute to the existing body of knowledge by demonstrating a feasible circular economy approach, whereby industrial effluents are repurposed for green nanomaterial synthesis, thus integrating waste management with nanotechnology. The novel aspect lies in utilizing real industrial wastewater as both a reducing and stabilizing agent, reducing dependency on chemical reagents and minimizing environmental impact. It also provides insights into the specific chemical interactions involved, guided by the theory of green chemistry and the principles of sustainable development. The findings are expected to inform industry practices, promoting environmentally sustainable nanoparticle production and potential scale-up in textile factories and other related sectors. The study concludes that industrial wastewater can serve as an innovative, cost-effective, and eco-friendly source for synthesizing copper nanoparticles with significant antimicrobial and catalytic properties. Recommendations include implementing wastewater-based nanoparticle synthesis at an industrial level, developing standardized protocols for wastewater pre-treatment to optimize nanoparticle quality, and exploring further applications in biomedicine and environmental remediation. Future research directions should investigate the long-term stability of such nanoparticles in real-world applications and assess their potential environmental impacts during disposal or reuse. This work underscores the importance of integrating environmental sustainability with cutting-edge nanotechnology to address pressing ecological challenges.