Wastewater treatment plants often produce byproducts that are difficult to manage, environmentally harmful, and costly. Current systems struggle to fully utilise the waste they generate. Hiya Shah, a BTech student from Ahmedabad University’s Class of 2027, aims to address these challenges by simplifying and optimising treatment processes through a detailed analysis of hydrodynamics and mass transfer within the system. Her approach involves redesigning the traditionally complex geometry of wastewater treatment systems to make them more efficient and sustainable.
Prior researches highlight that oxygen bubbles can play a critical role in chemical reactions to remove impurities, such as pharmaceutical contaminants like ibuprofen, through advanced oxidation processes. However, in conventional systems, the complex geometry of contactors with electrodes results in uneven mixing and inefficient oxygen usage. Hiya’s study demonstrates that optimising mixing can significantly reduce oxygen loss during aeration and improve the removal of impurities, paving the way for reusable water.
Under the guidance of Professors Arijit Ganguli and Ramya Srinivasan from Ahmedabad University’s School of Engineering and Applied Science, Hiya explored the use of jet loop contactors instead of stirred contactors. These systems, free of rotating or movable parts, are more reliable, cost-effective, and environmentally friendly.
Her research employed a simplified experimental setup using a beaker with an inlet at one end to observe mixing patterns. Initial experiments involved a single-phase water system with a 0.1 cm inlet diameter, aiming to transition to a two-phase system with oxygen bubbles to further enhance water quality. The experiments analysed flow rates to understand the shift from laminar (steady) to turbulent (chaotic) flow, studying diffusion patterns, velocity vectors, and mixing efficiency. The results revealed asymmetric mixing patterns influenced by flow rates and the compartmental design, which housed electrodes covering three-fourths of the beaker. These findings were validated using ANSYS software, ensuring accuracy and minimising errors.
Additionally, the study explored optimising pore size for efficient oxygen bubble ejection and proposed recycling bubbles to improve sustainability. Hiya presented her work, "Hydrodynamics and Mixing in an Advanced Oxidation Process: Single-Phase CFD Simulations and Experimental Measurements," at the Global Research Conference on Renewable Energy and Sustainable Development in Germany, hosted by the Foster Research Group.
Speaking about her research, Hiya said, “The ultimate goal is to achieve efficient oxygen bubble generation and integration into the system. Creating a perforator for experimental bubble generation is challenging, so the next step involves two-phase simulations with water and oxygen bubbles. This builds on our initial experiments using dye to observe flow patterns. While simulating two-phase systems is complex, as my professors have advised, we aim to overcome this hurdle before moving to experimental testing. This research has the potential to revolutionise wastewater treatment by making it more efficient, sustainable, and environmentally friendly.”