In this study, we report the development of the electro-Fenton (EF) process at a semi-pilot scale plant using an open undivided electrochemical reactor design. To do so, a series of three-dimensional (3D) cathodes constituted of packed and fixed bed of glassy carbon pellets and dimensionally stable anodes (DSA) are employed. To highlight the treatment efficiency of the EF process, bisphenol A (BPA), that is known to be a persistent molecule, is used as model molecule. First, the applied current intensity was studied and optimized in order to determine the limiting current of O2 reduction under hydrodynamics conditions of 0.6 m3.h-1. Then, the effect of cathode’s number on the removal efficiency of BPA versus time of electro-Fenton treatment was investigated. Many parameters were carried out using the EF reactor i.e., the effect of the initial pollutant concentration as well as the effect of the treatment flow rate. The obtained results demonstrate that the degradation efficiency of BPA increases with the cathode’s number increases and the pollution charge the decreases. Only few seconds of treatment by EF process were needed to eliminate BPA for the dilute solutions (≤ 10 mg.L-1). The biodegradability of the treated solution and its mineralization were also investigated by refereeing to the measurements of COD, TOC and BOD5. Finally, the scale-up strategy of the reactor design to an industrial pilot plant is discussed.