O-doped Graphitic Granular Biochar Enables Pollutants Removal via Simultaneous HO Generation and Activation in Neutral Fe-free Electro-Fenton Process.

HO generation by 2-electron oxygen electroreduction reaction (2eORR) has attracted great attention as an alternative to the industry-dominant anthraquinone process. Electro-Fenton (EF) process, which relies on the HO electrogeneration, is regarded as an important environmental application of HO generation by 2eORR. However, its application is hindered by the relatively expensive electrode materials.

Efficient HO electrogeneration at graphite felt modified via electrode polarity reversal: Utilization for organic pollutants degradation.

Electrochemical synthesis of HO offers a great potential for water treatment. However, a significant challenge is the development of efficient cathode materials for the process. Herein, we implement a practical electrochemical cathode modification to support efficient HO electrogeneration via the reduction of dissolved anodic O.

"Self-cleaning" electrochemical regeneration of dye-loaded activated carbon.

A low maintenance, "self-cleaning" electrochemical approach is evaluated for regeneration of dye-loaded granular activated carbon (GAC). To do so, batch experiments were conducted using a low-cost granular activated carbon/stainless steel mesh (GACSS) composite cathode and a stable Ti/mixed metal oxides (Ti/MMO) anode without the addition of oxidants or iron catalysts. The GACSS cathode supports simultaneous HO electrogeneration via the supplied O from Ti/MMO anode and the subsequent HO activation for ·OH generation, thus enabling the cracking of dye molecules adsorbed on GAC and regenerating the GAC's sorption capacity.

The Role of Dietary Phytoestrogens and the Nuclear Receptor PPARγ in Adipogenesis: An in Vitro Study.

Background: Phytoestrogens, naturally occurring plant chemicals, have long been thought to confer beneficial effects on human cardiovascular and metabolic health. However, recent epidemiological studies, have yielded conflicting outcomes, in which phytoestrogen consumption was both positively and negatively correlated with adiposity. Interestingly, several dietary phytoestrogens are known to stimulate or inhibit the activity of the peroxisome proliferator-activated receptor gamma (PPARγ), a key physiological regulator of adipogenesis.

Activated carbon as effective cathode material in iron-free Electro-Fenton process: Integrated HO electrogeneration, activation, and pollutants adsorption.

Major challenges for effective implementation of the Electro-Fenton (EF) water treatment process are that conventional efficient cathodes are relatively expensive, and HO activation by Fe may cause secondary pollution. Herein, we propose a low-cost activated carbon/stainless steel mesh (ACSS) composite cathode, where the SS mesh distributes the current and the AC simultaneously supports HO electrogeneration, HO activation, and organic compounds (OCs) adsorption. The oxygen-containing groups on the AC function as oxygen reduction reaction (ORR) sites for HO electrogeneration; while the porous configuration supply sufficient reactive surface area for ORR.

Degradation of 4-Chlorophenol in Aqueous Solution by Sono-Electro-Fenton Process.

Electro-Fenton (EF) and ultrasound radiation (US) have been of interest for the removal of chlorinated compounds from water. This study evaluates the effects of different parameters on sono-electro-Fenton (SEF) for degradation of 4-chlorophenol (4-CP) in an aqueous solution. This study uses pulsing US waves along with Pd-catalyzed EF to degrade contaminants in water while maintaining temperature.

Assessment of groundwater quality and remediation in karst aquifers: A review.

Karst aquifers, capable of storing and transmitting large amount of water, are the main source of drinking water in many regions worldwide. Their excessive permeability leads to an enhanced vulnerability to retain and spread the contamination accordingly. From sustainability perspective, the environmental, economic and social impacts of karst contamination on water resources management are gaining more attention.

"Floating" cathode for efficient HO electrogeneration applied to degradation of ibuprofen as a model pollutant.

The performance of the Electro-Fenton (EF) process for contaminant degradation depends on the rate of HO production at the cathode via 2-electron dissolved O reduction. However, the low solubility of O (≈1×10 mol dm) limits HO production. Herein, a novel and practical strategy that enables the synergistic utilization of O from the bulk electrolyte and ambient air for efficient HO production is proposed.

Electrolytic control of hydrogen peroxide release from calcium peroxide in aqueous solution.

The in situ generation of hydrogen peroxide (HO) for water treatment is more practical than the use of liquid HO, which is costly to store and transport. Calcium peroxide (CaO), a solid carrier of HO, can release HO on dissolution in water. However, the constant HO release rate of CaO has been a bottleneck constraining its wider application.

Immobilized palladium-catalyzed electro-Fenton's degradation of chlorobenzene in groundwater.

This study investigates the effect of palladium (Pd) form on the electrochemical degradation of chlorobenzene in groundwater by palladium-catalyzed electro-Fenton (EF) reaction. In batch and flow-through column reactors, EF was initiated via in-situ electrochemical formation of hydrogen peroxide (HO) supported by Pd on alumina powder or by palladized polyacrylic acid (PAA) in a polyvinylidene fluoride (PVDF) membrane (Pd-PVDF/PAA). In a mixed batch reactor containing 10 mg L Fe, 2 g L of catalyst in powder form (1% Pd, 20 mg L of Pd) and an initial pH of 3, chlorobenzene was degraded under 120 mA current following a first-order decay rate showing 96% removal within 60 min.

Transient reactive transport model for physico-chemical transformation by electrochemical reactive barriers.

A comprehensive model that integrates coupled effects of chemical, physical, and electrochemical processes, is necessary for design, analysis, and implementation of the electro-remediation of groundwater under flow conditions. A coupled system of equations to solve for transport and multiple reactions in an electrochemical reactor is numerically intensive due to highly stiff nature of reaction model formulation. In this study, the focus is to develop an efficient model for reactions associated with the transport and physico-chemical transformation in an electrochemical reactor.

Rates of HO Electrogeneration by Reduction of Anodic O at RVC Foam Cathodes in Batch and Flow-through Cells.

The Electro-Fenton process for in-situ HO electrogeneration is impacted by low O utilization efficiency (<0.1%) and the need of acid for pH adjustment. An electrochemical flow-through cell can develop localized acidic conditions, coupled with simultaneous formation and utilization of O to enhance HO formation.

Electrochemically-induced reduction of nitrate in aqueous solution.

In this study, we evaluated the removal of nitrate from synthetic groundwater by a cathode followed by an anode electrode sequence in the electrochemical flow-through reactor. We also tested the feasibility of the used electrode sequence to minimize the production of ammonia during the nitrate reduction. The performance of monometallic Fe, Cu, Ni and carbon foam cathodes was tested under different current intensities, flow rates/regimes and the presence of Pd and Ag catalyst coating.

LABORATORY TESTING OF THE POTENTIAL FOR THE INFLUENCE OF SUSPENDED SEDIMENTS ON THE ELECTROCHEMICAL REMEDIATION OF KARST GROUNDWATER.

Due to the complicated nature of karst aquifers, many groundwater treatment technologies are difficult to implement successfully. A particular challenge arises because sediments are ubiquitous and mobile in karst systems and may either facilitate contaminant transport or act as long-term substrates for storage via sorption. However, electrochemical remediation is a promising technology to be optimized for karst aquifers due to easy manipulation and control of groundwater chemistry as well as low cost, ability for in situ application, and performance under alternative power sources.

BULK CHEMISTRY OF KARST SEDIMENT DEPOSITS.

Sediments are ubiquitous in karst systems and play a critical role in the fate and transport of contaminants. Sorbed contaminants may be stored on immobile sediments or rapidly dispersed on mobile sediments. Sediments may also influence remediation by either enhancing or interfering with the process.

Electrochemical dechlorination of trichloroethylene in the presence of natural organic matter, metal ions and nitrates in a simulated karst media.

A small-scale flow-through limestone column was used to evaluate the effect of common coexisting organic and inorganic compounds on the electrochemical dechlorination of trichloroethylene (TCE) in karst media. Iron anode was used to produce ferrous ions and promote reducing conditions in the column. The reduction of TCE under 90 mA current, 1 mL min flow rate, and 1 mg L initial TCE concentration, was inhibited in the presence of humic acids due to competition for direct electron transfer and/or reaction with atomic hydrogen produced at the cathode surface by water electrolysis.

Review-Physicochemical hydrodynamics of gas bubbles in two phase electrochemical systems.

Electrochemical systems suffer from poor management of evolving gas bubbles. Improved understanding of bubbles behavior helps to reduce overpotential, save energy and enhance the mass transfer during chemical reactions. This work investigates and reviews the gas bubbles hydrodynamics, behavior, and management in electrochemical cells.

Large volume leukapheresis is efficient and safe even in small children up to 15 kg body weight.

Background: The collection of peripheral blood stem cells, although now a routine procedure, is still a challenge in low body weight children because of specific technical and clinical issues. For paediatric patients it is crucial to obtain an adequate number of CD34+ cells with the minimum number of procedures: this can be done using large volume leukapheresis (LVL).

Materials And Methods: We analysed the efficacy and safety of 54 autologous LVL performed in 50 children (33 [66%] males and 17 [34%] females), median age 2 years (range, 1-5) and median body weight 12 kg (range, 6-15).

Electrochemical degradation of trichloroethylene in aqueous solution by bipolar graphite electrodes.

In this study, we tested the use of the bipolar electrodes to enhance electrochemical degradation of trichloroethylene (TCE) in an undivided, flow-through electrochemical reactor. The bipolar electrode forms when an electrically conductive material polarizes between feeder electrodes that are connected to a direct current source and, therefore, creates an additional anode/cathode pair in the system. We hypothesize that bipolar electrodes will generate additional oxidation/reduction zones to enhance TCE degradation.

The influence of cathode material on electrochemical degradation of trichloroethylene in aqueous solution.

In this study, different cathode materials were evaluated for electrochemical degradation of aqueous phase trichloroethylene (TCE). A cathode followed by an anode electrode sequence was used to support reduction of TCE at the cathode via hydrodechlorination (HDC). The performance of iron (Fe), copper (Cu), nickel (Ni), aluminum (Al) and carbon (C) foam cathodes was evaluated.

Influence of humic substances on electrochemical degradation of trichloroethylene in limestone aquifers.

In this study we investigate the influence of humic substances (HS) on electrochemical transformation of trichloroethylene (TCE) in groundwater from limestone aquifers. A laboratory flow-through column with an electrochemical reactor that consists of a palladized iron foam cathode followed by a MMO anode was used to induce TCE electro-reduction in groundwater. Up to 82.

Electrochemical transformation of thichloroethylene in groundwater by Ni-containing cathodes.

In this study, we evaluate the use of different stainless steel (SS) materials as cost-effective cathode materials for electrochemical transformation of trichloroethylene (TCE) in contaminated groundwater. Ni, which is present in certain SS, has low hydrogen overpotential that promotes fast formation of atomic hydrogen and, therefore, its content can enhance hydrodechlorination (HDC). We a flow-through electrochemical reactor with a SS cathode followed by an anode.