Water desalination using atmospheric pressure plasma combined with thermal treatment

Abstract

Abstract Herein, a novel method is presented for enhancing the thermal desalination process of saline water and seawater using atmospheric pressure plasma (APP). The effect of APP treatment combined with thermal heating (APP-TH) on the energy consumption, conductivity, and pH of seawater and saline water is investigated. Utilizing scanning electron microscopy and X-ray diffractometry, the evolution of the morphology, structure, and chemical composition of precipitated crystals is characterized. The APP-TH method reduces the energy consumption for desalination by 40.5% for saline water and by 52.82% for seawater when compared to the TH-only method. The pH value remains approximately unchanged, decreasing slightly for the saline water from 7.1 for untreated saline water to 7.05 after APP-TH treatment. However, after APP-TH treatment, the pH value of the seawater increased slightly, from 7 to 7.8. The total dissolved salts decreased after APP-TH treatment, lowering the conductivity of the saline water from 65,000 µS/cm to 160 µS/cm and the conductivity of the seawater from 58,200 µS/cm to 243 µS/cm. Moreover, the size of precipitated crystals from saline water is 31.47 nm after APP-TH treatment, compared to 55.59 nm after TH-only treatment. They also dropped from 41 nm to 39.5 nm for seawater. Compared with traditional approaches, this research proposes an optimistic solution to address global potable water scarcity issues.

Keywords

• Atmospheric pressure plasma (APP)
• Thermal desalination
• Saline water
• Conductivity
• pH