Research Projects

Nearly 1.2 billion people suffer due to inadequate access to water, and about 2.7 billion people face scarcity of pure water. Therefore, the prime objective should be water harvesting and recycling wastewater to save our present and future generations. For wastewater treatment, numerous conventional methods are available (e.g., chlorine, ozone, UV light, mixing oxidation technology, membrane filtration, etc.). However, these techniques have several drawbacks. These chemicals in water treatment can affect the environment, oxidation is an expensive method for water disinfection, and in the case of UV treatment, energy efficiency is low and does not provide residual activity. Cavitation is considered one of the newer ways to treat water. Hydrodynamic cavitation (HC) and acoustic cavitation (AC) are used for water treatment applications. HC has emerged as one of the potential technologies for wastewater treatment as it is not only environmentally friendly but also has the advantage of scalability. Further, this technique has the potential to remove a wide range of pollutants like pharmaceuticals (clofibric acid, ibuprofen, etc.), toxic cyanobacteria (Microcystis aeruginosa), green microalgae (Chlorella vulgaris), bacteria (Legionella pneumophila), and viruses (Rotavirus) from wastewater. In most cases, HC is superior to AC, as it consumes less energy. The most widely used cavitation-generating devices are venturi, orifice, nozzles, valve, and rotor-stator combinations. The parameters used to identify the effectiveness of cavitation generation are cavity volume, cavitation intensity, energy consumption, and bubble lifetime. In these cavitation-generating devices, geometrical parameters play an important role. Most of the research determined the efficacy by considering a few operating parameters, whereas the effect of these parameters and their interactions should be paid more attention to. This is a research gap (details discussed in other technical data) which is going to be addressed in the present work. Most HC reactors require multi-pass through the reactor to get the desired water quality; it is challenging to implement in real-life applications. Some researchers proposed a hybrid system to overcome such issues by combining two techniques. Among them, HC and the chemical oxidation method gained popularity, showing a good synergetic effect. But the most desirable location and process of addition of chemicals can be found if a good knowledge of the flow physics of cavitation is understood. Based on the literature survey, extensive research is necessary for the direction of hydrodynamic cavitation for wastewater treatment to make the technique more effective for both industrial and domestic applications. In the present work, an optimised design of an HC reactor will be determined and experimentally characterised and contrasted with a commercial HC reactor. Then the efficacy will be tested for industrial wastewater and in the presence of HC-AOP.