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Groundwater Treatment using a Solid Polymer Electrolyte Cell with Mesh Electrodes

MetadataDetails
Publication Date2019-02-04
JournalChemElectroChem
AuthorsRoger Oriol, Davide Clematis, Enric Brillas, José Luis Cortina, Marco Panizza
InstitutionsUniversitat PolitĂšcnica de Catalunya, Universitat de Barcelona
Citations18

Abstract This article reports the high performance of a solid polymer electrolyte cell, equipped with a NafionÂź N117 membrane packed between a Nb/boron‐doped diamond (Nb/BDD) mesh anode and a Ti/RuO 2 mesh cathode, to degrade the insecticide imidacloprid spiked at 1.2-59.2 mg L −1 into low conductivity groundwater by electrochemical oxidation. The natural water matrix was first softened using valorized industrial waste in the form of zeolite as reactive sorbent. Total removal of the insecticide, always obeying pseudo‐first‐order kinetics, and maximum mineralization degrees of 70 %-87 % were achieved, with energy consumption of 26.4±1.6 kWh m −3 . Active chlorine in the bulk and . OH at the BDD surface were the main oxidants. Comparative studies using simulated water with analogous anions content revealed that the natural organic matter interfered in the groundwater treatment. Trials carried out in ultrapure water showed the primary conversion of the initial N and Cl atoms of imidacloprid to NO 3 − and Cl − ions, being the latter anion eventually transformed into ClO 3 − and ClO 4 − ions. 6‐Chloro‐nicotinonitrile, 6‐chloro‐pyridine‐3‐carbaldehyde, and tartaric acid were identified as oxidation products.