Research Projects

Water scarcity across urban and agricultural regions is resulting in utilization of treated wastewater for aquifer recharge and also ensuring long-term groundwater sustainability. While this practice is widely adopted for its efficiency, it also introduces emerging contaminants such as engineered nanoparticles (ENPs) and toxic metals into the subsurface environment. Materials like zinc oxide (ZnO) and copper oxide (CuO) nanoparticles, commonly found in cosmetics, textiles, and agrochemicals, often escape complete removal during conventional wastewater treatment. Engineered nanoparticles (ENPs), particularly ZnO and CuO, not only pose intrinsic ecological and human health risks but also act as carriers or facilitators for the vertical migration of toxic heavy metals such as arsenic (As) and lead (Pb). These metals, often adsorbed onto nanoparticle surfaces or released due to dissolution processes, may exhibit enhanced mobility in the unsaturated zone and potentially reach groundwater with greater efficiency than in their ionic form alone. Their subsequent release into recharge basins raises concerns about their mobility, persistence, and potential ecological and human health risks, especially as they infiltrate deep into soil and aquifer systems. This study aims to address these knowledge gaps by investigating the vertical transport and fate of ENPs and toxic metals in natural recharge settings, using advanced field-based methods and risk profiling tools. Key aspects such as mobility through the vadose zone, retention in porous media, transformation under varying geochemical conditions, and their potential to impact groundwater quality will be studied. The project will investigate both particulate forms and dissolved ion release resulting from ENP dissolution, addressing the dual risks posed by nanoparticles themselves and their ionic derivatives (e.g., Cu²⁺, Zn²⁺).