Electrochemical Processes and Apparatuses for the Abatement of Acid Orange 7 in Water

We have studied the electrochemical treatment of aqu eous solutions contaminated by Acid Orange 7 (AO7) by electro-Fenton process (EF). The main object ive was to evaluate how the electrochemical route affects the performances of the d egradation process. EF process was carried out in a number of very different reactors: conventional bench scale electrochem ical cell, microfluidic electrochemical reactor, microbial fuel cell and stack for reverse electrodialysis processes. The utilisation of micro devices allowed to work without the addition of a supporting elec trolyte and improved the performances of EF. Microbial fuel cell did not need the supply of electric energy bu t our device requir…

Utilization of Reverse Electrodialysis Processes for the Abatement of Pollutants in Water

The simultaneous generation of electric energy and th e treatment of waters contaminated by Cr(VI) was carried out by reverse electrodialysis processes using salinity gradients. The effect on the process of the nature of the cathode was investigated.

Effect of the air pressure on electro-Fenton process

Electro-Fenton process is considered a very promising tool for the treatment of waste waters contaminated by organic pollutants refractant or toxic for microorganisms used in biological processes [1-6]. In these processes H2O2 is continuously supplied to an acidic aqueous solution contained in an electrolytic cell from the two-electron reduction of oxygen gas, directly injected as pure gas or bubbled air. Due to the poor solubility of O2 in aqueous solutions, two dimensional cheap graphite or carbon felt electrodes give quite slow generation of H2O2, thus resulting in a slow abatement of organics. In this context, we report here a series of studies [7-9] on the effect of air pressure on the…

Electrochemical conversion of carbon dioxide to formic acid at Sn and BDD cathodes

Electrochemical reduction of CO2 to useful compounds in the aqueous electrolyte has been actively investigated as alternative technologies to contribute to curbing the rising levels of CO2 in the atmosphere. Many researchers have focused on the CO2 reduction to formic acid, which is considered one of the main target-products owing to its usefulness for agriculture, chemical and pharmaceutical industry, and it is expected to be a good hydrogen storage medium for an upcoming H2-energy-based society [1,2]. In the last few years, an increasing attention was devoted to the utilization of tin electrode for its low cost, low toxicity as well as the high selectivity towards the synthesis of formic …

Electrochemical conversion of carbon dioxide in pressurized electrochemical cells

To limit the negative effect of carbon dioxide as a greenhouse gas, an interesting approach is the utilization of Carbon Capture and Conversion (CCC) methodology, which is focused on the use of CO2 waste as a feedstock to produce added-value products by using the excess electric energy from renewable source [1]. In this framework, an increasing attention has been devoted to the electrochemical conversion of carbon dioxide to formic acid in water [2-3] or CO [1]. Since the main hurdle of the CO2 reduction from aqueous solution is the low CO2 solubility in water, in this work, the utilization of pressurized electrochemical cells is evaluated. The effect of various operating parameters, includ…

How far are we from the valorization of waste-CO2 to formic acid via electrochemical routes for the applicative scale?

To date, the decarbonization of the world economy and storage and production of energy from alternative C-based sources is considered a relevant topic. The electrochemical conversion of CO2 has been widely investigated since the 1870s as a promising strategy to convert waste-CO2 into value-added chemicals [1,2]. Recently, it was highlighted that, among the several emerging technologies for CO2 conversion to value-added products on an applicative scale, electrochemical technologies are the closest to commercialization due to the numerous start-ups and established companies being invested in this area (e.g., Opus-12, Dioxide Material, and Carbon Recycling International) [3]. These technologie…

Electrochemical remediation of kaolin-soil contaminated by phenol: effect of several operative parameters

Electrochemical remediation technology is considered an appealing strategy for the remediation of fine- grained soils, characterized by a low hydraulic conductivity and large specific surface area, contaminated with inorganic, organic, and mixed pollutants. In both Electrokinetic (EK) and Electrochemical Geo-Oxidation (ECGO) technologies, an electric field is imposed on the contaminated soil to remove the pollutants by the combined mechanisms of electroosmosis, electromigration, and/or electrophoresis. Moreover, ECGO uses low voltage and both direct and alternating amperage (DC/AC) applied in a proprietary series to induce reduction-oxidation reactions on soil surfaces at the micro-scale. A…

Semi-Continuous Lab-scale Plant for Hydrothermal or Organosolv Treatment of Lignocellulosic Biomass

Lignocellulosic biomass is increasingly being considered as a potential alternative source for both fuels and goods production. In order to better address the starting material to higher conversion and selectivity in the desired products, the possibility to selectively control the dissolution of the three main constituents of the matrix (hemicellulose, cellulose and lignin) should be pursued. As the three biopolymers are intimately connected one another, a suitable pretreatment step could help the effectiveness of the whole process, by producing cleavage of the biomacromolecules interconnecting bonds and by starting their depolymerization . In this frame, we developed a semi-continuous lab-…

A continuous reaction system for hydrothermal liquefaction of microalgae

REDUCTION OF CARBON DIOXIDE TO FORMIC ACID IN VARIOUS KINDS OF ELECTROCHEMICAL DEVICES.

The reduction of carbon dioxide is considered a relevant topic for both the synthesis of chemicals and/or fuels and the decrease of global warming. Indeed, the utilization of CO2 as a feedstock for producing chemicals may contribute to alleviate global climate changes caused by the increasing CO2 emissions and provide new opportunities for catalytic and industrial development. In the last years, an increasing attention has been devoted to the electrochemical conversion of carbon dioxide to formic acid or formate in water. Thus, formic acid has a broad market and wide application range in dyeing, textile and leather industries, in rubber production, as an intermediate in the chemical and pha…

Study of energetic properties of different tree organs in six Olea europaea L. cultivars

AbstractPruning is an important horticultural practice for the management of olive orchards (Olea europaea L.) that generates a considerable amount of residues every year. Olive orchards are increasingly expanding beyond the Mediterranean Basin to new growing Countries (Australia, California, Argentina, Chile and Uruguay) and this will certainly lead to larger availability of pruning material. Currently, the interest in use of olive tree pruning residues for energy purposes is increasing but unfortunately, the information on the differences among organs of the tree, in terms of calorific value and ash content, is scarce. Another unknown aspect is the effect of cultivar vigour on dry matter …

Hydrothermal liquefaction of municipal sludge in sub- and super- critical water

Hydrothermal liquefaction of municipal sludge was conducted to investigate the effects of sub- and supercritical water and of the fluid dynamic regime on the quality of the products. Preliminary experimental runs were performed at two different temperatures (350°C and 400°C) changing reaction time in order to work at fixed kinetic severity of the process. An improvement of the C content in the solid residues and of the ratio H/C of the biocrude was obtained when a stirred reactor was used both in sub- and supercritical water. A hydrocarbon fraction was separated from biocrude whose maximum yield of 25% w/w was achieved in supercritical conditions. Results showed that the cumulative energy r…