Electro-technologies for the removal of 2,4,6-trichloroanisole from naturally contaminated cork discs: reactor design and proof of concept

Abstract

The electrochemical (EC) process for the removal of 2,4,6-trichloroanisole (TCA) from cork discs was investigated for the first time. For process development, six different EC reactors (based on a 3-compartment set-up) and four process variables were tested. Independently of the reactor design used, the application of a low level direct current for 8 h (10 mA, 0.16 mA/cm2) had a positive effect on TCA removal. The best option is to place the cork discs in a middle compartment separated from the cathode compartment by the use of a passive membrane, and from the anode compartment by a cation exchange membrane. In this reactor design, the TCA levels in 78% of the cork discs decreased to values below limit of detection (0.49 ng/L; TCA initial concentration between 0.5 and 2 ng/L). By immersing the discs’ in a saline solution for 24 h prior current application, the TCA removal was improved by 10–15%. When the 34 cork discs contaminated with 2.5 times-fold more TCA were subjected to EC after 24 h immersion in the saline solution, the percentage of discs in which TCA concentration was below 0.49 ng/L decreased to 41%. Still, and considering that TCA perception threshold in wines starts at 1.5 ng/L, 85% of the cork discs exposed to EC reatment presented TCA levels below the threshold. Results showed that the here developed EC system could be a viable method for the removal of TCA from cork discs.