Degradation of Organic Pollutants Using Green Catalysts: Sustainable Approaches and Emerging Trends

The organic contaminants' presence in water systems: including synthetic dyes, pesticides, pharmaceuticals, and phenolic compounds, is detrimental to the environment as well as public health. These pollutants may disrupt aquatic ecosystems, bioaccumulation, and antimicrobial resistance which means they persist, contaminate, and pollute drinking water sources. Due to limited treatment methods, other available conventional alternatives: chemical oxidation, adsorption, or even biological degradation along with high energy expenses, non-effective alternatives, and added hazard, pollution, inefficiency, or risk all fall short. In this sense, attending to organic pollutant degradation has drawn interest for using green catalysis as an innovative sustainable alternative to foster eco-friendly processes unlike cradle-to-grave methods. Illustration of green catalysis includes enzyme-based systems, metal-organic frameworks (MOFs), biosynthesized nanomaterials, and bio char supported materials which all provide mild conditions with low toxicity and a high level of biodegradability. The scope of the research focuses on the applications of pollutant degradation using various green catalysts along with their synthesis and characterization. Characterization was done with Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR), and for some catalysts, X-ray Diffraction (XRD) was also used. Different parameters of pH, temperature, light intensity, and energy were used to determine degradation efficiency while evaluating the kinetics of degradation using pseudo first-order rate equations. The analytical techniques of UV-Vis spectroscopy, High Performance Liquid Chromatography (HPLC), and Total Organic Carbon (TOC) analysis were utilized to evaluate the degree of mineralization. Results indicate that green catalysts optimize the parameters for over 90% degradation efficiency, and demonstrate enhanced reusability and reduced environmental impact. Some mechanistic studies indicated that radical production and adsorption were the most significant contributors to the degradation process. These findings highlight the potential of green catalysis in water treatment processes. This study supports international environmental policies by presenting innovative low-cost green approaches to reduce organic contamination and help preserve clean water resources.