Nanotechnology in Wastewater Treatment: Evolution and Environmental Impact

Abstract

Access to clean and safe water is a major global challenge due to population growth, industrialization, and increasing environmental pollution. Conventional filtration, sedimentation, and biological treatments have been widely used to improve water quality. However, these methods are often ineffective in removing emerging contaminants such as pharmaceuticals, heavy metals, and microplastics. Nanotechnology has recently gained attention as an advanced approach for improving water purification. Carbon-based nano-adsorbents, semiconductor photocatalysts (TiO2, ZnO), and nanofiltration (NF) architectures are examples of nanotechnology-enabled technologies that enhance the removal of pollutants through processes like adsorption, photocatalysis, and membrane filtration. These materials possess unique properties such as high surface area and strong adsorption capacity. Although nanotechnology offers many advantages for wastewater treatment, concerns remain regarding the environmental impact and potential toxicity of nanomaterials. The studies indicating technical effectiveness must be balanced against acute and sublethal ecotoxicological risks. Therefore, further research is required to ensure their safe and sustainable application in water treatment systems. In order to create a sustainable path for water process engineering, this review bridges the gap between remedial performance and environmental safety.