Proof of Concept for the Organic Electrorefinery Technology with Actual Effluents.

This work describes results of a first proof of the concept of electrorefinery with a real waste obtained from a cashew nut factory, and it shows the effect of the current densities of both the anodic oxidation and electrochemically assisted separation processes on the performance of the system. Results obtained demonstrate that electrorefinery is a promising option to minimize the carbon fingerprint, worth studying for increasing the sustainability of the environmental remediation of wastes, because valuable species can be obtained from the destruction of pollutants and recovered within the same integrated process. They also point out that there is still a long way to reach an optimum solution for this technology, but it is worth the effort to be made.

Combination of electro-oxidation and biological processes for lindane landfill leachate treatment: simultaneous degradation of contaminants and biological reduction of electro-generated chloride-derived by-products.

Real lindane landfill leachate (HCH-LL) is characterised by high chlorinated organic compounds concentrations (primarily hexachlorocyclohexane (HCH) isomers and degradation products generated during more than 40 years of ageing), posing environmental and human health risks. In this work, the co-treatment of real HCH-LL (pre-treated via electro-oxidation (EO)) and urban wastewater using an activated sludge process operated in an anoxic/oxic sequencing batch (A/O-SBR) mode was investigated. EO tests were conducted employing either a boron-doped diamond (BDD) anode or a dimensionally stable anode (DSA), resulting in effective HCH isomers removal (>93 % after 20 Ah/L).

Sustainable integrated process for cogeneration of oxidants for VOCs removal.

This study upgrades the sustainability of environmental electrochemical technologies with a novel approach consisting of the in-situ cogeneration and use of two important oxidants, hydrogen peroxide (HO) and Caro's acid (HSO), manufactured with the same innovative cell. This reactor was equipped with a gas diffusion electrode (GDE) to generate cathodically HO, from oxygen reduction reaction, a boron doped diamond (BDD) electrode to obtain HSO, via anodic oxidation of dilute sulfuric acid, and a proton exchange membrane to separate the anodic and the cathodic compartment, preventing the scavenging effect of the interaction of oxidants. A special design of the inlet helps this cell to reach simultaneous efficiencies as high as 99% for HO formation and 19.

Advanced oxidation and a metrological strategy based on CLC-MS for the removal of pharmaceuticals from pore & surface water.

In this work, it is studied the photolysis, electrolysis, and photo-electrolysis of a mixture of pharmaceutics (sulfadiazine, naproxen, diclofenac, ketoprofen and ibuprofen) contained in two very different types of real water matrices (obtained from surface and porewater reservoirs), trying to clarify the role of the matrix on the degradation of the pollutants. To do this, a new metrological approach was also developed for screening of pharmaceuticals in waters by capillary liquid chromatography mass spectrometry (CLC-MS). This allows the detection at concentrations lower than 10 ng mL.

Electrochemical Production of Hydrogen Peroxide in Perchloric Acid Supporting Electrolytes for the Synthesis of Chlorine Dioxide.

This work focuses on the electrochemical production of hydrogen peroxide in supporting electrolytes containing perchlorate ions for being used as a reagent in the reduction of chlorates to produce chlorine dioxide, as a first step in the manufacture of portable ClO production devices. This study evaluates the effect of the current density, pressure, and temperature on the production of hydrogen peroxide, and concentrations over 400 mg L are reached. The average rate for the formation of hydrogen peroxide is 9.

Electrospray Deposition of Catalyst Layers with Ultralow Pt Loading for Cost-Effective H Production by SO Electrolysis.

The hybrid sulfur (HyS) thermochemical cycle has been considered as a promising approach for the massive production of clean hydrogen without CO emissions. The key to advance this technology and to enhance the cycle efficiency is to improve the electrocatalytic oxidation of SO, which is the pivotal reaction within this process. Hence, this paper investigates, for the first time, the effect of electrospray and air gun deposition techniques and the influence of very low Pt loadings (<0.

Assessing the viability of electro-absorption and photoelectro-absorption for the treatment of gaseous perchloroethylene.

This work focuses on the development of electro-absorption and photoelectro-absorption technologies to treat gases produced by a synthetic waste containing the highly volatile perchloroethylene (PCE). To do this, a packed absorption column coupled with a UV lamp and an undivided electrooxidation cell was used. Firstly, it was confirmed that the absorption in a packed column is a viable method to achieve retention of PCE into an absorbent-electrolyte liquid.

Electrochemically assisted dewatering for the removal of oxyfluorfen from a coagulation/flocculation sludge.

This work focuses on the evaluation of the electrochemical dewatering of sludge obtained in the coagulation of wastes polluted with oxyfluorfen. To do this, sludge samples were treated, aiming not only to reduce the sludge volume, but also to facilitate the degradation of oxyfluorfen contained in the cake via electrolysis with a boron-doped diamond anode. Results show that water can be effectively recovered through three sequential stages.

Selection of anodic material for the combined electrochemical-biological treatment of lindane polluted soil washing effluents.

This paper focuses on the removal of lindane from soil washing effluents (SWEs) using combined electrochemical -biological processes. In particular, it has been evaluated the influence of the anodic material used in the electrolysis of the SWE on the biodegradability and toxicity of the effluents. Four anode materials were tested: Boron Doped Diamond (BDD), Carbon Felt (CF), and Mixed Metal Oxides Anodes with iridium and ruthenium (MMO-Ir and MMO-Ru).

Biological treatment of wastewater polluted with an oxyfluorfen-based commercial herbicide.

Fluoxil-24 is a commercial herbicide based on oxyfluorfen (a hazardous non-soluble organochlorinated compound) and additional compounds used as solvents. The aim of this work is to study the biotreatability of this commercial herbicide in water through batch experiments performed at different temperatures (15, 20, 25 and 30 °C) and initial concentrations (85, 150, 300 and 500 mg L of oxyfluorfen). Activated sludge from an oil refinery wastewater treatment plant was acclimated and used for biodegradation experiments.

Improving the catalytic effect of peroxodisulfate and peroxodiphosphate electrochemically generated at diamond electrode by activation with light irradiation.

Boron doped diamond (BDD) anode has been used to oxidatively remove Rhodamine B (RhB), as persistent organic pollutant, from synthetic wastewater by electrolysis, photoelectrolysis and chemical oxidation containing sulfate and phosphate as supporting electrolytes. RhB is effectively oxidized by electrolysis and by chemical oxidation with the oxidants separately produced by electrolyzing sulfate or phosphate solutions (peroxodisulfate and peroxodiphosphate, respectively). The results showed that light irradiation improved the electrolysis of RhB due to the activation of oxidants under irradiation at high current densities.

Driving force behind electrochemical performance of microbial fuel cells fed with different substrates.

The performance of miniaturized microbial fuel cells operating with five different substrates (acetate, lactate, glucose and octanoate) were studied with the aim to identify the reason for its different performance. In all cases, the COD removal rate was about 650 mg COD L d. However, the bio-electrochemical performance of the MFC was very different, showing the MFC fed with acetate the best performance: 20 A m as maximum current density, 2 W m of maximum power density, 0.

Improving biodegradability of soil washing effluents using anodic oxidation.

In this work, a combination of electrochemical and biological technologies is proposed to remove clopyralid from Soil Washing Effluents (SWE). Firstly, soil washing was carried out to extract clopyralid from soil. After that, four different anodes-Ir-MMO, Ru-MMO, pSi-BDD and Carbon Felt (CF)-were evaluated in order to increase the biodegradability of the SWE.

Influence of sludge age on the performance of MFC treating winery wastewater.

The objective of this paper was to determine the influence of sludge age on microbial fuel cell (MFC) performance for generating electricity and removing organic matter from winery wastewater. Six Solid Retention Times (SRT) were used: 1.2, 1.

Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil.

Combined soil washing and CDEO for the removal of atrazine from soils.

In this work, it is studied the removal of atrazine from spiked soils by soil washing using surfactant fluids, followed by the treatment of the resulting washing waste by electrolysis with boron doped diamond (BDD) anode. Results confirm that combination of both technologies is efficient for the removal and total mineralization of atrazine. Ratio surfactant/soil is a key parameter for the removal of atrazine from soil and influences significantly in the characteristic of the wastewater produced, affecting not only to the total organic load but also to the mean size of micelles.

Break-up of oil-in-water emulsions by electrochemical techniques.

Electrochemically-assisted technologies can be successfully applied to the treatment of oil-in-water (O/W) emulsions. In this work, it is studied the influence of the main parameters (electrical charge passed, pH, electrolyte, oil content and operation mode) in the efficiency of these processes, when aluminium electrodes are used. The pH was found to be the most significant parameter, and good removal efficiencies were only obtained for pHs in the range 5-9.