Jailson Vieira de Melo

Bio: Jailson Vieira de Melo is an academic researcher from Federal University of Rio Grande do Norte. The author has contributed to research in topics: Electrolysis & Thin film. The author has an hindex of 4, co-authored 5 publications receiving 439 citations.

Decontamination of real textile industrial effluent by strong oxidant species electrogenerated on diamond electrode: Viability and disadvantages of this electrochemical technology

Abstract: In a previous work [1] , the treatment of dye solutions containing Remazol Red BR (RRB) and Novacron Blue C-D (NB) by anodic oxidation using boron doped diamond anode (BDD) demonstrated that the electrochemical treatment is an efficient alternative for removing color and chemical oxygen demand (COD) and this technology can be used for depuration of real effluents. More recently, these assumptions have been confirmed by oxidizing electrochemically a real textile effluent using BDD anode [2] . Then, as a further development of the research carried out in these previous studies [1] , [2] , in the present work, it has been considered appropriate to extend the investigation to the anodic oxidation, using BDD anode, of a specific real effluent discharged by Brazilian textile industry, adding Na2SO4 or NaCl salts in order to verify the applicability of this treatment producing in situ strong oxidant species (peroxodisulfates or active chlorine, respectively). In this study, we also attempt to discuss critical evidence about the viability of peroxodisulfates or active chlorine. Results obtained in this research clearly demonstrated that the effect of the electrogenerated strong oxidant species, peroxodisulfates or active chlorine, depends on electrocatalytic mechanism followed on BDD surface, improving the color and COD removal. However, there is a limit of NaCl for treating real effluents avoiding the formation of organochloride compounds; and it is a subject of critical importance, from the environmental point of view, to apply this alternative treatment.

Use of a Dual Arrangement of Flow Cells for Electrochemical Decontamination of Aqueous Solutions Containing Synthetic Dyes

Abstract: The present study was motivated by innovative reports published by De Battisti and co-workers (Martinez-Huitle et al., Electrochim Acta 50:949, 2004; Martinez-Huitle et al., J Appl Electrochem 35:1087, 2005) in 2004, on the electrochemical oxidation of chloroanilic and oxalic acids using electrolytic flow cell with parallel plate electrodes. These studies were few of the pioneering studies employing different design and configuration of electrochemical flow cells. Therefore, in this work, the applicability of single flow cell and dual flow cell (serial mode of SFC) systems was investigated for removing organic pollutants. Galvanostatic electrolyses were performed using the two electrochemical systems for degrading synthetic dye effluents (Remazol Red RB and Novacron Yellow), employing as electrocatalytic materials: Ti/Pt and Ti/Pt–SbSn. The electrochemical treatment of dye solutions led to complete discoloration and partial organic matter removal at different operating conditions (current density and flow cell configuration). The influence of these parameters was examined, in order to compare the use of single flow cell or dual flow cell, based on the energy consumption and costs. From the results obtained using dual flow cell configuration; higher color and organic matter removals were achieved in short times of electrolysis, confirming that this treatment process can be a suitable pre-treatment alternative for depuration of textile effluents decreasing the energy consumed when a single flow cell is employed.

Lab-made 3D-printed accessories for spectroscopy and spectroelectrochemistry: a proof of concept to investigate dynamic interfacial and surface phenomena

Abstract: 3D printing is presented as an auspicious additive manufacturing technique for diverse interesting applications coupling electrochemistry and spectroscopy techniques, proposing as utilities: a general-purpose module for specular spectroscopy and spectroelectrochemical (SEC) cells for in situ UV-VIS and Raman measures capable of acting in flux or a stationary regime. As a proof of concept, UV-VIS absorption and middle-infrared spectra of an azo dye thin film were collected with the specular module showing characteristic bands according to the literature data. SEC investigations related to the Prussian Blue (PB) film growth on the platinum electrode surface were also investigated. By applying appropriate potentials, the PB film growth was accompanied by a proportional increase in the absorption signal at 700 nm in the UV-VIS region. This signal was related to the intervalence charge transfer from the Fe(II)-C to Fe(III)-N. Moreover, the Raman SEC experiment presented scattering intensity at 2092 and 2156 cm-1, related to the (CN) mode associated with the Fe(II) and Fe(III) cations, which was observed during the thin film growth. In addition, the conversion to the Berlin Green (BG) and Prussian White (PB) forms was monitored while applying the suitable potential and in situ spectroscopic observations of structural changes during the redox processes were also detected as described in the literature. Thus, it is possible to state that the accessories successfully validated in situ spectroelectrochemical dynamic investigations unlocking many other applications in this research field.

Single and Coupled Electrochemical Processes and Reactors for the Abatement of Organic Water Pollutants: A Critical Review.

Abstract: Traditional physicochemical and biological techniques, as well as advanced oxidation processes (AOPs), are often inadequate, ineffective, or expensive for industrial water reclamation. Within this context, the electrochemical technologies have found a niche where they can become dominant in the near future, especially for the abatement of biorefractory substances. In this critical review, some of the most promising electrochemical tools for the treatment of wastewater contaminated by organic pollutants are discussed in detail with the following goals: (1) to present the fundamental aspects of the selected processes; (2) to discuss the effect of both the main operating parameters and the reactor design on their performance; (3) to critically evaluate their advantages and disadvantages; and (4) to forecast the prospect of their utilization on an applicable scale by identifying the key points to be further investigated. The review is focused on the direct electrochemical oxidation, the indirect electrochemical oxidation mediated by electrogenerated active chlorine, and the coupling between anodic and cathodic processes. The last part of the review is devoted to the critical assessment of the reactors that can be used to put these technologies into practice.