Standard reporting of Electrical Energy per Order (EEO) for UV/H2O2 reactors (IUPAC Technical Report)

The concept of Electrical Energy per Order (E-EO) was introduced in 2001 as a figure of merit for evaluating the energy requirements of ultraviolet-based advanced oxidation processes (UV AOPs) used for the degradation of various organic contaminants. The EEO parameter represents the energy input into the reactor that can achieve an order of magnitude decrease in the concentration of a target contaminant in a unit volume. Since the introduction of this parameter, it has become increasingly popular among UV AOP researchers and practitioners. However, the E-EO is often reported without important details that affect the parameter, making its interpretation difficult. The E-EO depends on a variety of factors (e.g. the concentration and identity of the target contaminant and the amount of hydrogen peroxide added). Therefore, the E-EO parameter needs to be reported in the literature with several other experimental details affecting the reactor performance and in a way that proper comparisons can be made between reactors across studies or manufacturers. This paper discusses the proper application of the E-EO parameter for bench-,pilot-,and full-scale studies. Sucralose (artificial sweetener, C12H19Cl3O8) is proposed as a standard substance for reactor comparison.