Reactor design in plasma-liquid systems for wastewater treatment

Low-temperature plasmas (LTPs) represent a promising yet often controversial technology for water treatment that offer unique capabilities for degrading persistent contaminants. Despite demonstrated success at both bench and pilot scales, LTP-based treatment faces skepticism due to perceptions of high energy consumption and limited scalability compared to other advanced oxidation processes.

This opinion piece advocates for a strategic reorientation in plasma research, urging the scientific community to prioritize the study of relevant contaminants and realistic water matrices while applying chemical engineering principles to systematically describe these systems and develop universal laws guiding plasma reactor design for water treatment. Modular reactor arrangements, pre-concentration strategies, real-world testing, and a clear understanding of how contaminant type (surfactant vs. non-surfactant) influences reactor design are essential for advancing LTP technology beyond proof-of-concept studies. To achieve commercial viability, research must transition from trial-and-error approaches to systematic investigations integrating plasma physics, chemistry, and engineering.