Making Waves: Terminology and metrics for electrosorption of trace organic compounds

Electro-enhanced adsorption and desorption (electrosorption) is emerging as a versatile route to remove and concentrate trace organic contaminants, including PFAS and pharmaceuticals, by coupling conductive adsorbents with electrical control. Many systems borrow process concepts from capacitive deionization (CDI), yet at environmentally relevant influent levels, they operate in a low-loading regime where affinity, competition, and transport dominate rather than charge-storage-limited salt/ion uptake. The electrical step also enables controlled release (electrodesorption) for regeneration, recovery, and enrichment, supporting capture-concentrate operation. This Making Waves article proposes a mechanism-consistent vocabulary and a compact reporting framework that links treatment goals to key metrics: affinity- and process-relevant descriptors (adsorption coefficient, selectivity, breakthrough/retardation, recovery, and enrichment) when electrosorption of trace organic compounds is the goal. Clear terminology and reporting will improve comparability across studies and accelerate rational design of electrosorption technologies tailored to trace organic pollutants.