Use of carbon felt cathodes for the electrochemical reclamation of urban treated wastewaters

Abstract

This work focuses on the application of electrolysis with carbon felt cathodes for the reclamation of actual effluents from municipal wastewater treatment facilities (WWTFs) in combination with different anode materials (dimensionally stable anodes-DSA, conductive diamond anodes-CDA and iron-Fe). First of all, the efficiency of electrodisinfection with CDA and DSA was assessed, finding that total elimination of Escherichia coli (E. coli) can be attained at applied electric charges below 0.03 Ah dm-3 , and that the disinfection process is more efficient when using CDA. Furthermore, it was observed that the formation of hydrogen peroxide on carbon felt cathodes limits the concurrence of disinfection by-products (chlorates, perchlorates and organic chlorinated by-products), an interesting result that broadens the potential of CDA for the regeneration of urban wastewater. Results with Fe anodes show that it is possible to attain the complete removal of microorganisms with comparable efficiency to that of CDA (due to the contribution of Fenton's reaction) and that it was possible to totally remove the turbidity of the effluent when working at current densities from 12.50 A m-2. Finally, it was found that Fe is the most efficient anode material (lowest power consumption) at low current densities and CDA is the most appropriate one at current densities higher than 5 A m-2. According to these results, the pairs anode-cathode CDA-carbon felt and Fe-carbon felt behave as the most promising electrode materials to be applied in wastewater reclamation processes.

pH dependent kinetic insights of electrocatalytic arsenite oxidation reactions at Pt surface

“…In particular, the existence of extremely high As(III) concentrations in Bangla delta (Bangladesh and West Bengal, India) ground waters could be due to the reductive dissolution of hydrous ferric oxide by iron-reducing bacteria [5]. Previously, sufficient attention has been paid in elimination of arsenic from water [6][7][8]. At the same time, various techniques have been developed for the detection of As(III) and among them, the following techniques deserve to mention (i) ion chromatographic detection of arsenite and arsenate (ii) inductively coupled plasma mass spectrometry for the quantitative estimation of arsenic compounds, and (iii) electrochemical sensing followed by oxidation of As(III) into As(V).…”

“…It subsists in the nature using four different oxidation states +V (arsenate), +III (arsenite), 0 (arsenic), and −III (arsine) [1]. Concerning toxicity, inorganic arsenic (arsenite) is one of the most notorious carcinogens over the glove [1][2][3][4][5][6][7][8][9][10]. The extreme water solubility of arsenite ions is responsible for its widespread presence in the underground water.…”

Electrocatalytic Reduction-oxidation of Chlorinated Phenols using a Nanostructured Pd-Fe Modified Graphene Catalyst

“…A good number of carbon-based materials have been investigated as potential catalyst supports, such as carbon fiber paper [26], carbon felt [27], glassy carbon substrate [28], carbon nanotubes [29], and granular graphite [30]. However, the materials should be inexpensive and have good electrical conductivity.…”

Conductive diamond electrochemical oxidation of caffeine-intensified biologically treated urban wastewater

“…According to the literature (Crump et al, 1998;Cotillas et al, 2015), hydrogen peroxide may act as an oxidant or reactant, depending on the composition of the reaction medium. Thus, H 2 O 2 can react with hypochlorite to form chloride (Eq.…”