Plasma-Assisted Advanced Oxidation Process and Novel Materials for Water and Wastewater Treatment

Abstract

The rapid growth in world population brings with it the need for improvement in the current technology for water purification, in order to provide adequate potable water to everyone. The plasma-based advanced oxidation process (AOP) is one of the most widely studied and best developed processes owing to its environmental compatibility, simple structure, efficiencies and ease of operation. In this study, a plasma-based AOP was stably generated using contact non-equilibrium low-temperature plasma and plasma synthesized composite nanomaterials (TiO2/Ag NPs) for water and wastewater purification. The degradation efficiency of the pollutants was determined by UV–Vis absorption spectroscopy. It was found that, due to the simultaneous production of highly reactive species, plasmas can efficiently eliminate pollutants that are difficult to remove using conventional methods. Aqueous solutions of various pollutants were treated by a low-pressure discharge. Experimental results indicated that CNP was effective for degradation azo dye pollutants (methylene blue (MB) and methyl orange MO) and antibiotics (ofloxacin (OFX) and ciprofloxacin (CFX)): МВ and МО were degraded by 98.5% and 97.0%, respectively after 3 min of plasma treatment; OFX and CFX were degraded by ~95.0% and 80.0%, respectively AOP by CNP indicated. The photodegradation of methylene blue catalyzed by plasma synthesized TiO2/Ag was studied under UV irradiation. The degradation (~91%) was obtained with 2.4 g/L TiO2/Ag within 90 min irradiation.