The effect of applied waveform on plasma discharge in micrometre-sized bubbles for plasma-water treatment

With the increasing number of applications of plasma-treated water, understanding the different methods of its generation becomes important for adapting to specific uses.<br/><br/>Plasma can be applied on the water surface, as a direct discharge in the water or formed in gas bubbles dispersed in the water bulk.<br/><br/>The process of plasma water treatment involves the generation of charged species, which are then dissolved in water, enhancing the conductivity of the plasma-treated water as a whole.<br/><br/>Discharges created in bubbles increase the interaction area between plasma and water, which can lead to better mass transfer of species created in plasma treatment. As bubbles can move freely in water, pulse waveforms are used to ensure the capacitive character of the discharge.<br/><br/>With treatment time the water conductivity increases, and the plasma discharge changes its character. Both plasma's influence on water and water's influence on plasma play significant roles in generating and sustaining plasma in these complex systems, affecting the species created in water; this is why researching how they intertwine is of high importance for both applications and fundamental understanding of discharge processes in plasma bubbles.