Scaled-up electrochemical reactor with a fixed bed three-dimensional cathode for electro-Fenton process: Application to the treatment of bisphenol A

Ayman Chmayssem (1) , Samir Taha (2) , Didier Hauchard (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 Centre AZM pour la recherche en Biotechnologie et ses applications

The authors report on the development of an open undivided electrochem. reactor with a compact fixed bed of glassy C pellets as three-dimensional cathode for the application of electro-Fenton process. Bisphenol A (BPA) was chosen as model mol. to improve its efficiency to the treatment of persistent pollutants. The study of the BPA removal efficiency in function of the applied current intensity was studied to det. the limiting current of O2 redn. (optimal conditions of H2O2 prodn. at flow rate of 0.36 m3 h-1) which was 0.8 A (0.5 A/100 g of glassy C pellets). Many parameters were carried out using this electro-Fenton reactor degrdn. kinetics, influence of anodic reactions on DSA, effect of initial pollutant concn. In the optimal current condition, the global prodn. rate of H2O2 and ·OH was studied. The yield of electro-Fenton reaction (conversion of H2O2 to ·OH) was very high (> 90%). The abs. rate of BPA degrdn. was detd. as 4.3 × 109 M-1 s-1. COD, TOC and BOD5 measurements indicated that only few minutes of treatment by electro-Fenton process were needed to eliminate BPA for dil. solns. (10 and 25 mg L-1). In this case, the biodegradability of the treated solns. occurred rapidly. For higher concn. levels, an efficient removal of BPA appeared for treatment time >1 h and >90 min were necessary to obtain the biodegradability of BPA solns. In optimum conditions, the scale-up of the electrochem. reactor applied to electro-Fenton process was suggested and depended on the concn. level of the pollutant. The operating parameters of the scaled-up reactor might be deduced from the new section of each fixed bed exposed to the flow, from values of liq. flow velocity and from the corresponding limiting c.d. obtained with the reactor at lab. scale. The compact fixed bed cathode in an open undivided electrochem. reactor appears as an appropriate soln. as pre-treatment electro-Fenton process followed by the biol. treatment of persistent pollutant.

Mots clés: Electro-Fenton process; Fixed-bed cathode; Water treatment; Bisphenol A; advanced oxidation process

Domaines: Chimie; Génie chimique

Ayman Chmayssem, Samir Taha, Didier Hauchard. Scaled-up electrochemical reactor with a fixed bed three-dimensional cathode for electro-Fenton process: Application to the treatment of bisphenol A. Electrochimica Acta, 2017, 225, pp.435-442. ⟨10.1016/j.electacta.2016.12.183⟩. ⟨hal-01475803⟩