Investigating the Influence of the Pulsed Corona Discharge Over Hypersaline Water

Desalination plant and saltwork production currently produce large quantities of by-product, in the form of bitterns, which is generally regarded as waste. Up to now methods to discard this waste are unsustainable and restricted by high capital costs and non-universal application. Cold atmospheric plasma over liquids has led to various established industrial implementations, as well as promising applications, including chemical analysis, nanomaterials synthesis and plasma medicine. In this study interaction plasma – hypersaline water using cathodic or anodic polarization was investigated. Pulses of 2.3 kV, repeated at a frequency of 1 kHz, were applied to produce a pulsed corona discharge (PCD) over hypersaline water (HSW) surface. It was observed that in cathode polarization, considerable number of metallic cations can be extracted from the solution in the form of precipitate salts, while in anodic configuration, despite having a higher spectral intensity for Na (589.5 nm), it was less efficient in the salt precipitation. The findings of this study suggest that changing polarization also changes the mechanism of plasma interaction, indicating to be an interesting technique to explore selective saline water chemical extraction.

Keywords:
Desalination; plasma in liquid; crystallization; hypersaline solutions; separation