Hydrogen generation by electrolysis of seawater

The sea waves-generated power and its utilization in situ for the hydrogen generation by seawater electrolysis is a very interesting way. The seawater electrolysis is technically feasible and is a perspective procedure for an environmentally-clean commercial production of hydrogen and associate products The aim of this work is to examine the variation of the tension and energy consumption at electrolysis of natural seawater (Black Sea – Constanta, Romania) comparative with electrolysis of a solution of 15% NaOH, in the same condition

Seawater electrolysis for hydrogen production

A perspective procedure for an environmentally-clean commercial production of hydrogen by seawater as an „in situ” utilisation of marine wave generated power is the seawater electrolysis. In this paper original studies in seawater, using the methods of steady-state polarisation curves and the impedance spectroscopy were made on Ni

The cathodic evolution of hydrogen on nickel in artificial seawater

The hydrogen evolution reaction (HER) on Ni electrode in artificial seawater was investigated by steady-state polarisation curves and electrochemical impedance spectroscopy methods at the room temperature and at high temperatures (30–60oC). The electrochemical kinetics parameters of the HER – Tafel slope, charge transfer coefficient and exchange current density – were evaluated in accordance with the potential scan direction and temperature. The Tafel slopes are significantly higher than 120 mV/decade and they increase with the increasing of the solution temperature. The charge transfer coefficient is lower than 0.5 and it decreases with temperature. The exchange current density has a magnitude order of 10-5 A·cm-2 and its value is increasing with increasing solution temperature. The activation energy of the HER has a moderate value, that slowly decreases with the cathodic polarisation increase. The HER is controlled by the charge transfer step and by the mass transfer of the intermediate reaction product Hads on the electrode surface

Stakeholders' perspectives on the operationalisation of the ecosystem service concept : Results from 27 case studies

The ecosystem service (ES) concept is becoming mainstream in policy and planning, but operational influence on practice is seldom reported. Here, we report the practitioners' perspectives on the practical implementation of the ES concept in 27 case studies. A standardised anonymous survey (n = 246), was used, focusing on the science-practice interaction process, perceived impact and expected use of the case study assessments. Operationalisation of the concept was shown to achieve a gradual change in practices: 13% of the case studies reported a change in action (e.g. management or policy change), and a further 40% anticipated that a change would result from the work. To a large extent the impact was attributed to a well conducted science-practice interaction process (>70%). The main reported advantages of the concept included: increased concept awareness and communication; enhanced participation and collaboration; production of comprehensive science-based knowledge; and production of spatially referenced knowledge for input to planning (91% indicated they had acquired new knowledge). The limitations were mostly case-specific and centred on methodology, data, and challenges with result implementation. The survey highlighted the crucial role of communication, participation and collaboration across different stakeholders, to implement the ES concept and enhance the democratisation of nature and landscape planning. (C) 2017 Published by Elsevier B.V.Peer reviewe

Main Trends and Research Directions in Hydrogen Generation Using Low Temperature Electrolysis: A Systematic Literature Review

Hydrogen (H2) is the most abundant element in the universe and it is also a neutral energy carrier, meaning the environmental effects of using it are strictly related to the effects of creating the means of producing of that amount of Hydrogen. So far, the H2 generation by water electrolysis research field did not manage to break the efficiency barrier in order to consider H2 production as a technology that sustains financially its self-development. However, given the complexity of this technology and the overall environmental impacts, an up-to-date research and development status review is critical. Thus, this study aims to identify the main trends, achievements and research directions of the H2 generation using pure and alkaline water electrolysis, providing a review of the state of the art in the specific literature. Methods: In order to deliver this, a Systematic Literature Review was carried out, using PRISMA methodology, highlighting the research trends and results in peer review publish articles over more than two years (2020–2022). Findings: This review identifies niches and actual status of the H2 generation by water and alkaline water electrolysis and points out, in numbers, the boundaries of the 2020–2022 timeline research

Chlorate Electrochemical Removal from Aqueous Media Basedon a Possible Autocatalytic Mechanism

International audienceThe electrochemical chlorate reduction at the Pt electrode in 0.5 M H2SO 4 deaerated solutions has beenstudied using potentiostatic steady-state voltammetry. The kinetics parameters (Tafel slope, charge transfercoefficient, current density, and reaction order) were evaluated in function of chlorate concentration (1x10-4 – 0.2 M KClO). The process of chlorate reduction is a complex one that implies two charge transfer 3controlled steps with formation of free radicals and an extent potential region controlled by the concentrationpolarization. The current density dependence of chlorate concentration tends to an exponential growth atconcentration ≥ 0.1 M KClO3 and becomes exponential in the conditions of the Cl−3/Cl− catalyst systempresence. In the second charge transfer, a surface reaction between free radical ·Cl- 2and platinum electrodewith formation of complex anions PtCL 42- and PtCL 62- is responsible for the rapid increase of the reactionrate

A Derivative Spectrometric Method for Hydroquinone Determination in the Presence of Kojic Acid, Glycolic Acid, and Ascorbic Acid

A new, simple, and sensitive spectrometric method was developed for hydroquinone (HQ) determination in the presence of other depigmenting agents (kojic acid (KA), glycolic acid (GA), and ascorbic acid (AA)), commonly introduced in skin lightening products. The method is based on the oxidation of the depigmenting agents by potassium dichromate in sulfuric acid medium and subsequent measurement of the amplitude of the first-order derivative absorption spectrum at 268 nm. By applying the zero-crossing method, at this wavelength, the oxidation products of KA, AA, and GA do not interfere in the indirect determination of HQ. Beer’s law was obeyed in the range of 0.22–22 μg·mL−1 HQ, with a detection limit of 0.07 μg·mL−1. The developed method was applied with good results for the first time to the rapid determination of HQ in binary, ternary, and quaternary mixtures, thus proving that it could represent an effective tool for various skin lightening products analyses

Electrochemical strategies for gallic acid detection: Potential for application in clinical, food or environmental analyses

International audiencePolyphenols are important to human health thus making it interesting and necessary to identify and assess methods for their detection. Gallic acid (GA) is a well-known antioxidant compound, found in tea leaves, various fruits, fruit seeds and in fruit-derived foods and beverages. In this study, to electrochemically detect this compound and assess the potential for GA detection, different analytical conditions at pH values of 5.8, 7 and 8 were tried. Two types of device were used for GA detection: (1) Lazar ORP-146C reduction-oxidation microsensors, coupled with a Jenco device, for estimation of antioxidant capacities of different electroactive media, and (2) screen-printed carbon sensors coupled with a mobile PalmSens device using differential pulse voltammetry (qualitative and quantitative GA determination). These proposed methods were validated by analysing some real samples: wine, green tea, apple juice and serum fortified with GA. Detection was evaluated in terms of specific calibration curves, with low limit of detection (LOD) and limit of quantification (LOQ), low response time, and high sensitivities. The analytical characteristics obtained recommend these methods to be tested on more other types of real samples. Our proposed methods, used in the established conditions of pH, may have further application in other clinical, food or environmental samples analyses in which the results of total antioxidants contents are usually expressed in GA equivalents

Thermal option for energy recovery from two organic substrates: grape and residual sunflower seeds

The aim of this paper is to find out the opportunities of spent grape marc and sunflower oil cake utilization in Romania as a potential source of renewable energy. Different scenarios such as centralized and decentralized power plants are analyzed, underlining the advantage and disadvantage of each solution. In particular this work focuses on electricity production and thermal energy recovery. These types of materials best suit the energy recovery solution, because of their high distribution on the Romanian territory, but also the elemental analysis revealed the composition of these wastes being similar to that of wood, which best fits the combustion process. On the basis of mass and energetic balance, the most appropriate solution will be chosen, but also considering the environmental issue