Electrochemical Deammonification of Synthetic Swine Wastewater

The ammonia electrolysis process, which presents as only products nitrogen and hydrogen fuel, was evaluated for the deammonification of wastewater. The effects of cell voltage, pH, and flow rate were analyzed for single pass ammonia electro-oxidation of synthetic swine wastewater. A surface response analysis was performed to obtain quadratic models that predict the NH₃ conversion and hydrogen (H₂) production where pH was identified as the variable with the most statistic significance to explain changes in ammonia conversion with hydrogen production. NH₃ conversions above 80% and specific energy consumption under 3 kW·h kg^–1 of NH_3, without considering the energy that can be obtained from the H₂ produced, show that the ammonia electrolysis technology has promising potential for the deammonification of wastewater with less energy consumption than the conventional nitrification/denitrification process

Dermatological Journals Indexed in MEDLINE/PubMed

<p>Dermatological Journals Indexed in MEDLINE/PubMed</p

Optimization of the Electrochemical Extraction and Recovery of Metals from Electronic Waste Using Response Surface Methodology

The rapid growth of electronic waste can be viewed as both an environmental threat and an attractive source of minerals that can reduce the mining of natural resources. In this work, response surface methodology was used to optimize an electrochemical process for the extraction and recovery of base metals from electronic waste using a mild oxidant (Fe³⁺). Through this process, the effective extraction of base metals can be achieved, enriching the concentration of precious metals and significantly reducing environmental impacts and operating costs associated with waste generation and chemical consumption. The optimization was performed using a bench-scale system specifically designed for this process. Operating parameters such as flow rate, applied current density, and iron concentration were optimized to reduce the specific energy consumption of the electrochemical recovery process to 1.94 kWh per kilogram of metal recovered

Anion Exchange Membrane Electrolyzers as Alternative for Upgrading of Biomass-Derived Molecules

Upgrading of biomass-derived platform molecules to fuels or chemicals provides a unique alternative for the substitution of fossil sources with renewables. Electrochemical reduction (ECR) is one of the upgrading technologies, alternative to catalytic reduction, which only requires electricity as the energy input and can be powered by carbon free energy sources. Moreover, ECR does not require external addition of hydrogen, as this can be generated <i>in situ</i>. In this work, an anion exchange membrane (AEM) membrane electrode assembly (MEA) has been tested for the efficient reduction of biomass-derived molecules and compared with a cation exchange membrane (CEM) MEA. The cathode electrocatalyst has been modified with the addition of hydrophobicity and anion exchange ionomers and incorporated onto an anion exchange membrane. Electrochemical experiments were performed with a metal free electrocatalyst in the presence and absence of surrogate compounds. The results showed that changes in the catalyst formulation can increase the overpotential for the competing hydrogen evolution reaction (HER), while significantly enhancing the reduction of the organic molecules. Bulk electrolysis experiments demonstrated higher efficiencies for furfural ECR in AEM-MEA vs CEM-MEA, reaching conversions up to 94% at 50 mA cm^–2 and in the absence of a supporting electrolyte. Moreover, AEM-MEA was able to facilitate water management during the reduction process and contribute to the separation of small carboxylic acids

Facile Room-Temperature Electrodeposition of Rare Earth Metals in a Fluorine-Free Task-Specific Electrolyte

Electrochemical deposition of rare earth metals at room temperature has attracted increasing interest due to its advantage in energy efficiency over traditional hydrometallurgical and pyrometallurgical processes. Recent progress has been made with fluorinated electrolyte systems; however, the formation of an electrode-passivating fluoride layer by electrolyte decomposition is often overlooked. Such a passivation layer causes significant and rapid decay of the deposition current and significantly hinders practical application. To address this issue, we demonstrate a fluorine (F)-free task-specific electrolyte utilizing the borohydride anion for the efficient electrodeposition of rare earth metals. By eliminating the passivation effect, the deposition process exhibits a stable current and accumulates a thick neodymium deposit on the electrode. Raman spectroscopy of the electrolyte reveals a synergetic effect between rare earth borohydride and lithium borohydride which promotes the dissociation of both borohydride salts, resulting in significantly increased ionic conductivity and electrochemical performance. Cyclic voltammetry and in-depth X-ray photoelectron spectroscopy of the deposits suggest that the electrodeposition of rare earth metals could undergo a Li-mediated reduction process. Quantitative analysis of the deposits reveals that the overall concentration of the rare earth elements reaches 75% which contains 40–48% metallic phase

Low-Temperature Electrochemical Upgrading of Bio-oils Using Polymer Electrolyte Membranes

While bio-oil-derived fuels hold much promise as a replacement for petroleum, transformation of the highly oxygenated mixture has proven challenging. In particular, bio-oils are reactive and difficult to upgrade through catalytic pyrolysis. To reach a stabilized product capable of deep deoxygenation at elevated pressure and temperature, conversion or separation of reactive groups is required. This paper describes an electrochemical process for stabilization and upgrading of bio-oils prior to hydrotreating at high pressure and temperature. This electrolytic process uses a three-compartment cell designed to hydrogenate reactive carbonyl components while separating small acid molecules, such as acetic and formic acids, which act as catalysts for condensation reactions and consume hydrogen gas to produce low-value gases in hydrotreating. To avoid conductivity issues, electrodes are appended to anion- and cation-exchange membranes. The cell was tested using a mixed acetic acid and formic acid surrogate fed to the cathode compartment, where the decrease in the concentration followed the applied charge to the cell. Experiments performed using pine pyrolysis oil demonstrated a significant reduction in the total acid number (TAN), an increase in pH from 2.6 to over 4, and a modest reduction of the carbonyl concentration. Analysis showed the reduction in TAN was primarily due to removal of carboxylic compounds. Experiments observed a decrease in the reactive carbonyl (aldehydes and ketones) concentration that followed applied charge. The results with the newly devised reactor show promise for the electrochemical route for upgrading bio-oils, but significant improvements in TAN removal and carbonyl conversion are needed. Given the distributed nature of biomass, an electrochemical process paired with pyrolysis could be used to densify and stabilize an oil product near the source. The densified liquid could then be shipped to centralized refineries for final upgrading to fuel and/or chemical products

Exploring Genomic, Geographic and Virulence Interactions among Epidemic and Non-Epidemic St. Louis Encephalitis Virus (Flavivirus) Strains

<div><p><i>St</i>. <i>Louis encephalitis virus</i> (SLEV) is a re-emerging arbovirus in South America. In 2005, an encephalitis outbreak caused by SLEV was reported in Argentina. The reason for the outbreak remains unknown, but may have been related to virological factors, changes in vectors populations, avian amplifying hosts, and/or environmental conditions. The main goal of this study was to characterize the complete genome of epidemic and non-epidemic SLEV strains from Argentina. Seventeen amino acid changes were detected; ten were non-conservative and located in proteins E, NS1, NS3 and NS5. Phylogenetic analysis showed two major clades based on geography: the North America and northern Central America (NAnCA) clade and the South America and southern Central America (SAsCA) clade. Interestingly, the presence of SAsCA genotype V SLEV strains in the NAnCA clade was reported in California, Florida and Texas, overlapping with known bird migration flyways. This work represents the first step in understanding the molecular mechanisms underlying virulence and biological variation among SLEV strains.</p></div

Correspondence analysis exploring the distribution of 200 non-conservative mutations in 14 SLEV strains through biological features.

<p>Axes CA1 and CA2 account for 84.8% of the total variation observed. HP: high pathogenicity, LP: low pathogenicity, HV: high viremia, LV: low viremia. Source of isolation: Mqt: mosquitoes, Mml: mammals, Brd: birds. Colored dots represent each mutation analyzed distributed by protein.</p

Phylogenetic analyses performed using the SLEV sequences listed in Table 1. (A): Maximum Likelihood analysis. (B): Bayesian inference analysis. (C) Geographic distribution of analyzed St. Louis encephalitis virus strains and migratory bird flyway.

<p>West Nile virus (Acc. Number: DQ211652), Murray Valley Encephalitis virus (Acc. Number: AF161266) and Japanese Encephalitis virus (Acc. Number: M18370.1) were used as outgroups. Abbreviations for the different geographic origin of strains were used as follow: USA (United States); MEX (Mexico); GTM (Guatemala); ARG (Argentina); BRA (Brazil); PERU (Peru); TRN (Trinidad); PAN (Panamá).</p

Spearman’s correlation indices and confidence intervals obtained comparing source of isolation (Mml: mammals, Brd: birds, Mqt: mosquito) and biological behavior (viremia in birds and pathogenicity in mice)in 14 SLEV strains.

<p>Gradient scale colors indicate strength of correlation (positive or negative). *: statistically significant differences.</p